阅读说明：本技术 用于治疗水肿的装置和方法 (Devices and methods for treating edema ) 是由 Y·尼灿 R·基廷 S·马尔默 O·英巴 E·布雷迪 G·麦卡弗里 R·威利斯顿 于 2020-02-26 设计创作，主要内容包括：本披露涉及使用带有囊袋的叶轮来治疗水肿的装置和方法,该囊袋可以安装在叶轮壳体上。本发明提供了使用留置插管来治疗水肿的装置和方法,该留置插管带有叶轮以降低淋巴管的出口处的压力、以及在该叶轮上的囊袋以引导和限制血液流动。该囊袋限制从颈静脉的回流并且将该流引导到叶轮笼中。通过将该流汇集到该叶轮笼中,可以增大沿着血管向下的流量,由此获得影响淋巴出口的侧向压力降低。由于淋巴出口压力降低,淋巴系统中的流体引流至该出口并进入循环系统中。(The present disclosure relates to devices and methods for treating edema using an impeller with a bladder that may be mounted on the impeller housing. The present invention provides devices and methods for treating edema using an indwelling cannula with an impeller to reduce pressure at the outlet of the lymphatic vessel, and a bladder on the impeller to direct and restrict blood flow. The bladder restricts backflow from the jugular vein and directs the flow into the impeller cage. By converging the flow into the impeller cage, the flow down the blood vessel can be increased, thereby obtaining a lateral pressure reduction affecting the lymphatic outlet. As the lymphatic outlet pressure decreases, fluid in the lymphatic system drains to the outlet and into the circulatory system.)

1. An apparatus, comprising:

a cannula comprising a proximal portion and a distal portion;

an impeller housing attached to the distal portion of the cannula, wherein an impeller is disposed in the impeller housing; and

an expandable member aligned on an outside of the impeller housing.

2. The apparatus of claim 1, wherein an outer surface of the expandable member is physically coupled to an outer surface of the impeller housing.

3. The apparatus of claim 2, wherein the outer surface of the expandable member is physically coupled directly to the outer surface of the impeller housing without any membrane, sheath, or device between the outer surface of the expandable member and the outer surface of the impeller housing.

4. The apparatus of claim 1, wherein the expandable member surrounds the impeller housing.

5. The device of claim 1, wherein the expandable member is a balloon.

6. The apparatus of claim 5, wherein the bladder is inflatable, and further wherein the bladder surrounds the impeller housing.

7. The apparatus of claim 1, wherein the impeller housing comprises metal and a portion of the expandable member is secured to a surface of the metal by an adhesive.

8. The device of claim 7, wherein at least a portion of the surface of the metal is impregnated with a polymer to promote adhesion to the adhesive.

9. The apparatus of claim 1, further comprising:

a motor housing connected to a proximal portion of the cannula;

a motor disposed within the motor housing;

a drive cable extending from the motor to the impeller through the cannula; and

an inflation lumen extending along the cannula to the expandable member.

10. A method of treating edema using the device of claim 1, the method comprising: inserting a distal portion of the cannula into a patient's innominate vein; operating the impeller; and inflating the inflatable member to thereby reduce pressure at the lymphatic vessel.

11. An apparatus, comprising:

a cannula having a proximal portion and a distal portion, the distal portion sized for insertion into a lumen of a patient and including a pump; and

an expandable member connected to the pump, wherein, when expanded, the expandable member comprises a torus shape, wherein a proximal surface of the torus shape directs fluid into the impeller housing.

12. The apparatus of claim 11, wherein the inner radius of the torus shape is substantially the same as the radius of the proximal end of the impeller housing.

13. The apparatus of claim 11, wherein the inflatable member comprises an inflatable bladder mounted on the pump.

14. The apparatus of claim 13, wherein the pump comprises an impeller housing having an impeller therein, wherein the bladder is mounted around at least a portion of a proximal end of the impeller housing.

15. The apparatus of claim 14, wherein the impeller housing comprises a distal portion and a proximal portion, wherein an outer diameter of the proximal portion is less than an outer diameter of the distal portion, wherein the expandable member is disposed about the proximal portion of the impeller housing when unexpanded.

16. The device of claim 15, wherein the impeller comprises one or more blades on a shaft, wherein a radius measurement taken from an axis of the impeller to an outer edge of the blade decreases from a distal portion to a proximal portion of the impeller.

17. The device of claim 16, wherein an outer edge of each vane includes a turn defining a decreasing radius located near a transition between the distal and proximal portions of the impeller housing.

18. The device of claim 15, wherein a distal portion of the impeller housing includes one or more outlets, and wherein the impeller shaft flares outwardly near a distal end of the impeller such that when the impeller rotates, the impeller pumps blood through the impeller housing and out the one or more outlets.

19. The apparatus of claim 11, wherein the pump comprises an impeller disposed within an impeller housing, and the inflatable member comprises an inflatable bladder connected to an outer surface of the impeller housing.

20. The device of claim 19, wherein the balloon defines an annulus when inflated.

Technical Field

The present disclosure relates to devices and methods for treating edema.

Background

Congestive heart failure occurs when the heart fails to pump enough blood to maintain blood flow to meet the body's needs. People with heart failure may experience shortness of breath, fatigue, and swollen limbs. Heart failure is a common and potentially fatal disease. In 2015, it affected about 4000 million people worldwide and about 2% of adults overall. Up to 10% of people over 65 years are predisposed to heart failure.

In heart failure, the pressure in the ventricles and atria rises excessively. As a result, the heart shoots blood harder, resulting in elevated blood pressure, which may lead to edema in the interstitial chambers of the body. Edema refers to an abnormal accumulation of fluid in body tissues that results when elevated blood pressure prevents lymphatic fluid from draining from the interstitium. Over time, the additional work of the heart can weaken and remodel the heart, further reducing the ability of the heart to function properly. Fluid accumulation leads to dyspnea and Acute Decompensated Heart Failure (ADHF) hospitalization. These conditions can lead to serious health consequences, including death.

Disclosure of Invention

The present invention provides devices and methods for treating edema using an indwelling cannula having an impeller to reduce pressure at the outlet of the lymphatic vessel, and a bladder on the impeller to direct and restrict blood flow. The bladder restricts backflow from the jugular vein and directs the flow into the impeller cage. By converging the flow into the impeller cage, the flow down the blood vessel can be increased, thereby obtaining a lateral pressure reduction affecting the lymphatic outlet. As the lymphatic outlet pressure decreases, fluid in the lymphatic system drains to the outlet and into the circulatory system. These effects can be optimized by: the bladder is disposed on or around the impeller cage (and in some embodiments, the bladder may be directly connected to the impeller cage), surrounds the cage, and forms an annulus that funnels the fluid flow into the impeller cage. The shape of the bladder in the deployed state directs and promotes blood flow into the inlet of the impeller. The ability of the device to reduce pressure at the lymph outlet is optimized by using an impeller on the cannula in conjunction with a bladder.

The geometry of the combined impeller cage and toroidal bladder uses flow dynamics to drain the lymphatic system. The impeller cage in combination with the bladder creates a local constriction (or obstruction) in the flow cross-sectional area through the vessel (e.g., innominate vein). This flow constriction creates a venturi effect, in which the fluid pressure is reduced, suitable for the outlet of the lymphatic vessels. As the pressure at the lymphatic outlet drops, lymphatic fluid drains from the lymphatic system to the circulatory system. Thus, the devices and methods of the present disclosure use a bladder mounted to an impeller to drain lymph using the laws of hydrodynamics. The devices and methods of the present invention can be used to alleviate edema symptoms because operating the impeller (with the bladder attached to the impeller cage) in the innominate vein near the lymph outlet effectively reduces the pressure at the lymph outlet and drains lymph fluid. Accordingly, the present invention provides methods and devices for treating edema and congestive heart failure using a bladder mounted to an impeller cage.

In certain aspects, the present disclosure provides a device for treating edema. The device includes: a cannula having a proximal portion and a distal portion; an impeller housing attached to the distal portion of the cannula, wherein an impeller is disposed in the impeller housing; and an inflatable member (e.g., bladder) aligned on an outside of the impeller housing. The outer surface of the expandable member may be physically coupled to the outer surface of the impeller housing. Preferably, the outer surface of the expandable member is physically coupled directly to the outer surface of the impeller housing, i.e. without any membrane, sheath or device between the outer surface of the expandable member and the outer surface of the impeller housing. The expandable member may surround the impeller housing.

Where the expandable member is a bladder, the bladder may be inflatable and may surround the impeller housing. In some embodiments, the impeller housing comprises metal, and a portion of the expandable member is secured to a surface of the metal by an adhesive. At least a portion of the surface of the metal is impregnated with a polymer to promote adhesion to the adhesive. Embodiments of the device may include a motor housing connected to the proximal portion of the cannula, wherein a motor is disposed within the motor housing. A drive cable may extend from the motor to the impeller through the cannula, with an inflation lumen extending along the cannula to the expandable member. Related embodiments provide methods of using the device to treat edema. The method comprises the following steps: inserting the distal portion of the cannula into a patient's innominate vein; operating the impeller; and inflating the inflatable member to thereby reduce pressure at the lymphatic vessel.

Aspects of the present invention provide an edema treatment apparatus that includes a cannula having a proximal portion and a distal portion sized for insertion into a lumen of a patient and including a pump and an expandable member connected to the pump. When inflated, the expandable member comprises a toroidal shape, wherein a proximal surface of the toroidal shape directs fluid into the pump. Preferably, the inner radius of the annular shape is substantially the same as the radius of the proximal end of the pump. The inflatable member may comprise an inflatable bladder mounted on the pump. In some embodiments, the pump includes an impeller housing having an impeller therein, wherein the bladder is mounted around at least a portion of a proximal end of the impeller housing. In some embodiments, the impeller housing comprises a distal portion and a proximal portion, wherein an outer diameter of the proximal portion is less than an outer diameter of the distal portion such that the expandable member is disposed about the proximal portion of the impeller housing when unexpanded. The impeller may have one or more blades on the shaft, wherein the radius measured from the axis of the impeller to the outer edge of the blade decreases from the distal to proximal portion of the impeller. The outer edge of each vane may include a turn defining a decreasing radius located near a transition between the distal and proximal portions of the impeller housing. In a preferred embodiment, the distal portion of the impeller housing has an outlet and the impeller shaft flares outwardly near the distal end of the impeller such that when the impeller is rotated, the impeller pumps blood through the impeller housing and out the one or more outlets.

The pump may include an impeller disposed within the impeller housing, and the inflatable member may include an inflatable bladder connected to an outer surface of the impeller housing. In some embodiments, the bladder defines an annulus when inflated. When the bladder is inflated, the surface of the annulus may attach to the surface of the impeller housing. Preferably, the distal portion of the cannula may pass through a 12Fr introducer sheath when the expandable member is unexpanded.

Aspects of the present disclosure provide an apparatus and associated method for compensating for pressure changes resulting from pump induced flow using a flow restrictor. In one aspect, the invention provides a method for treating edema. The method includes operating the pump to increase flow through the innominate vein of the patient, and deploying a flow restrictor upstream of the pump after the operating step to restrict flow from the jugular vein to the innominate vein to balance pressure downstream of the pump. The method may include operating the pump and then limiting the increased flow through the innominate vein once the flow affects the pressure in the jugular vein. The method may further include sensing an increase in pressure in the jugular vein caused by the increased flow with a pressure sensor and restricting the flow in response to sensing the increased pressure in the jugular vein. The restriction to flow may be adjusted based on the sensed pressure. Preferably, the method includes placing the device containing the pump within the vasculature of the patient prior to the operating step. The device includes a cannula sized for at least partial implantation within the vasculature, and the pump includes an impeller assembly disposed at a distal portion of the cannula. In some embodiments, the proximal portion of the cannula is connected to a motor housing, and the device includes a pressure sensor and an expandable flow restrictor attached to the cannula proximal to the pump. Preferably, the flow restrictor comprises an inflatable bladder, and restricting flow comprises inflating the flow restrictor. Sensing may be performed using a computer system communicatively connected to the pressure sensor. Inflation of the flow restrictor may be adjusted periodically or continuously in response to the sensed pressure.

Other aspects of the invention provide a method for treating edema. The method includes operating the pump to increase flow through the patient's innominate vein, sensing a change in pressure in the patient's jugular vein resulting from the increased flow, and adjusting the flow restrictor to restrict flow from the jugular vein to the innominate vein based on the sensed pressure. The method may further comprise inserting a cannula into the innominate vein, wherein the cannula includes a pump, a pressure sensor, and a flow restrictor. Preferably, the flow restrictor comprises an inflatable bladder, and adjusting the flow restrictor comprises at least partially inflating the bladder. Sensing may be performed using a pressure sensor. The method may include periodically or continuously adjusting inflation of the flow restrictor in accordance with the sensed pressure. Preferably, the method comprises adjusting the inflation to balance the pressure downstream of the pump. Optionally, the pump comprises an impeller assembly arranged at the distal portion of the cannula. The proximal portion of the cannula may be connected to a motor housing having a motor therein operatively coupled to the impeller assembly. In some embodiments, the cannula is coupled to a computer system operable to read pressure or control inflation.

Aspects of the invention provide a wash-free system, device and method for treating edema. For example, these aspects provide a wash-free device comprising: a cannula having a proximal portion and a distal portion; an impeller connected to the distal portion of the cannula; a motor connected to a proximal portion of the cannula; a drive cable extending from the motor to the impeller through the cannula; and an impermeable sleeve on the drive cable extending through the cannula. The sleeve features a distal seal at the impeller and a proximal seal at the motor such that fluid outside the sleeve is prevented from entering the sleeve and contacting the drive cable. The sleeve and at least the distal seal exclude fluid from the drive cable. Either seal (or both) may include one or more O-rings. The device may include a first lumen and a second lumen extending through the cannula, wherein the first lumen and the second lumen have first and second proximal ends, respectively, accessible from outside the motor housing. Preferably, the first and second lumens are symmetrically arranged about the drive cable to balance the device. The cannula preferably does not include a cleaning system or cleaning fluid. In some embodiments, the impeller is located in an impeller housing, and the device further has at least one expandable member connected to the distal portion of the cannula. The expandable member may be connected to the impeller housing, and the device may further include a second expandable member disposed along the cannula. Preferably, the first expandable member comprises an annulus pocket directly connected to a surface of the impeller housing. The device may also include at least one pressure sensor disposed along the cannula proximal to the impeller.

In some embodiments, the proximal seal includes a fitting between the impermeable sleeve and a portion of the impeller such that the fitting excludes fluid and allows the impeller and drive cable to rotate within the device.

Related aspects provide a method of using a no-clean apparatus. The wash-free device may be used in a method for treating edema. The method comprises the following steps: the method includes inserting a distal portion of a cannula into a patient's innominate vein and driving an impeller connected to the distal portion of the cannula with a motor at a proximal portion of the cannula. The motor is connected to the impeller by a drive cable extending through the cannula. Driving the impeller reduces the pressure at the lymphatic vessels. The impermeable sleeve extends over the drive cable through the cannula such that bodily fluids outside the impermeable sleeve are prevented from entering the impermeable sleeve and contacting the drive cable. The method may further comprise: a flow restrictor disposed along a distal portion of the cannula is inflated to restrict flow from the jugular vein to the innominate vein, wherein inflation uses an inflation lumen extending through the cannula outside the impermeable sleeve. The reduced pressure at the lymphatic vessels promotes drainage from the lymphatic system to the circulatory system.

Preferably, the impermeable sleeve has a proximal seal at the housing of the motor and a distal seal at the impeller. The proximal seal prevents blood and bodily fluids from escaping from the patient through the motor housing or the proximal portion of the cannula. The distal seal may include a fitting between the impermeable sleeve and a portion of the impeller, wherein the fitting excludes fluid and allows the impeller and drive cable to rotate within the device. The impermeable sleeve may be made of a polymer, such as polytetrafluoroethylene.

The method may include inflating at least one balloon disposed along the cannula with an inflation lumen having a proximal end accessible from outside the motor housing while the distal portion of the cannula is inserted in the innominate vein. Blood and body fluids are preferably excluded from the drive cable without the use of a wash fluid or wash system.

Other aspects of the present disclosure relate to methods and devices that use and deliver anticoagulants to facilitate efficient operation of the device to treat edema. For example, aspects of the present disclosure provide a device that includes an intravascular pump having a built-in delivery mechanism for anticoagulant (i.e., moving parts for delivering anticoagulant to the pump). Accordingly, the present invention provides an edema treatment apparatus, the apparatus comprising: inserting a tube; an impeller assembly mounted at a distal portion of the cannula; and a drug lumen extending through the cannula and terminating substantially at the inlet of the impeller assembly such that drug released from the drug lumen flows through the inlet and the impeller assembly. Preferably, the cannula and impeller assembly is sized for insertion through the jugular vein of a patient. The device may further comprise a reservoir in fluid communication with the drug lumen. The impeller assembly may include an impeller housing, wherein the impeller is rotatably disposed in the impeller housing. The device may include a motor connected to the proximal end of the cannula and operatively connected to the impeller via a drive cable extending through the cannula. Preferably, the port is located at the impeller housing, proximal to the impeller.

In some embodiments, the cannula includes a tube through which the drive cable extends, wherein a cap is attached around a terminal portion of the tube. The impeller housing is mounted to the cover by a plurality of posts to define an inlet to the impeller housing. The cap seals the terminal end of the flexible tube to the shaft of the impeller, and the port may be located in the cap. The impeller housing may have one or more outlets around a distal portion of the impeller such that operation of the impeller within the vessel drives blood into the impeller assembly via the inlet and out of the impeller assembly via the outlet.

The device may include an anticoagulant (e.g., tirofiban, heparin, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin, or fondaparinux) in the reservoir. When the device is inserted into a patient's blood vessel and the impeller is operated, anticoagulant is released from the port in the impeller cage and the released anticoagulant mixes with the blood and washes the rotating impeller.

A related aspect of the invention provides a method for treating edema. The method comprises the following steps: operating the pump to increase flow through the patient's innominate vein; and releasing anticoagulant at or near the inlet of the pump. The pump may include an impeller in a cage at a distal portion of the cannula, and the anticoagulant may be released from a port in or near a proximal portion of the cage. Optionally, the proximal end of the cannula terminates at a housing containing a motor, wherein the motor is operatively coupled to the impeller by a drive cable extending through the cannula. The cannula may include a drug lumen extending therethrough and terminating at the port. The method may comprise the steps of: providing an anticoagulant in a reservoir in fluid communication with the drug lumen; inserting a cannula into the vasculature of a patient to position an impeller in a innominate vein; operating the motor to drive the impeller; and flushing the impeller with anticoagulant by releasing anticoagulant from the port. Preferably, the pump is operated to reduce the pressure at the lymphatic vessel, thereby draining lymph fluid from the patient's lymphatic system.

In certain embodiments, the pump includes an impeller on a distal portion of the cannula, and the anticoagulant is released from a port at a proximal portion of the impeller.

By releasing the anticoagulant, clotting or thrombosis is prevented from interfering with the operation of the impeller. Optionally, the method may include restricting flow from the jugular vein to the innominate vein, thereby facilitating flow from the subclavian vein to the innominate vein.

The present invention provides devices and methods useful for treating edema by an indwelling cannula placed in a patient's blood vessel and used to pump blood to cause a reduction in pressure at the outlet of the lymphatic vessel. The cannula pumps blood through the impeller, but is clean-free because the cannula does not include a system for cleaning or flushing the cannula components with a cleaning fluid. The wash-free cannula avoids blood-related mechanical complications such as clotting or thrombosis through an impermeable sleeve or shroud that protects the moving parts of the impeller drive system. For example, the drive cable to the impeller may be protected by an impermeable sleeve, the distal end of which is closed by a distal seal near the impeller and may also be closed at the proximal end (e.g., outside the patient) by a proximal seal (e.g., by an O-ring fitted to the motor housing and/or a cannula handle for guiding the impeller into position and driving the impeller). The impermeable sleeve or shield and appropriate seals exclude blood and bodily fluids from entering the operable components of the cannula system. Thus, the impermeable sleeve or shield and any associated seals provide a wash-free system to maintain smooth and reliable operation of the cannula by excluding blood or bodily fluids from the operable parts of the cannula.

Edema may be treated by accessing a blood vessel, such as the jugular vein, and guiding a cannula through the blood vessel. The cannula is guided to position the impeller near the lymphatic outlet. For example, the impeller may be positioned in a innominate vein. The significant length of the cannula and the impeller can be positioned to be located within the blood vessel and thus can be surrounded by and operate within the blood. To avoid problems caused by blood clotting within or hemolysis caused by moving parts of the impeller, the cannula includes a sealing sleeve or shield to exclude blood from the impeller and associated moving parts. The cannula may further include a proximal seal at the outer motor housing to prevent backflow of blood out of the patient. The sealing sleeve or shield is much simpler in operation and maintenance than complex washing systems that use washing fluid delivered by the washing lumen to prevent blood from interfering with the operation of the device. Also, the wash-free systems with the devices and methods of the present invention do not affect blood chemistry or osmolarity by not using wash fluids, as they do not release external fluids into the blood stream. Accordingly, the present invention provides the following apparatus and method: a sealing sleeve or shield is used on an intravascular cannula with a blood pump or impeller to reduce pressure at the outlet of the lymphatic vessel while also preventing adverse effects such as clotting or hemolysis. Since the devices and methods of the present invention reduce the pressure at the lymphatic outlet, they facilitate drainage of lymphatic fluid from the lymphatic system. Thus, the devices and methods of the present invention may be used to treat edema or congestive heart failure.

The present invention provides devices and methods for treating edema using an indwelling cannula to place an impeller in a patient's blood vessel near the outlet of the lymphatic vessel. The impeller is operated to cause a local drop in blood pressure, thereby facilitating drainage of lymph fluid from the lymphatic system. The cannula is also used to release an anticoagulant (e.g., heparin) to flush and lubricate the impeller. Specifically, the anticoagulant inhibits the occurrence of blood coagulation, hemolysis, or thrombosis, and inhibits interference with smooth operation of the impeller. A drug lumen extending along the cannula to a release port located just upstream or proximal of the impeller may be used to release the anticoagulant. The suspension or solution of anticoagulant can flow down the lumen and be released, thereby flushing the moving parts of the impeller (e.g., the impeller blades, the drive cable, and the bearing surfaces between the impeller and the surrounding impeller housing). Anticoagulants prevent blood from clotting at these sites and surfaces, thereby avoiding the adverse effects of thrombosis or hemolysis.

By releasing anticoagulant into the impeller, the device of the present invention operates smoothly and reliably within the patient's blood vessel. The device of the present invention facilitates drainage of lymph fluid from the lymphatic system to the circulatory system by using an impeller to drive blood flow and relieve pressure at the lymph outlet. Preferably, the impeller is provided by a cannula that releases an anticoagulant, such as heparin, at or near the entrance to the impeller cage. The devices and methods of the present invention are useful for treating edema and congestive heart failure due to drainage of lymphatic fluid. These devices avoid the adverse effects of blood clotting or other effects because they use anticoagulants to maintain smooth and reliable operation of the impeller. Thus, the devices and methods of the present invention may be used to treat edema and congestive heart failure.

The present invention provides devices and methods for treating edema using an intravascular pump to pump blood through the circulatory system in a manner that releases pressure from the lymphatic system at the outlet into the circulatory system. The apparatus and method of the present invention further uses a flow restrictor in the circulation system upstream of the pump to balance the pressure changes caused by the pump and compensate for the downstream flow. The device may be provided as an indwelling intravascular cannula having a mechanical pump (such as an impeller) and a selectively deployable flow restrictor (e.g., an inflatable balloon). Congestive heart failure or edema is treated by inserting a cannula and operating the pump in the circulatory system (e.g., in the innominate vein) just downstream of the lymphatic outlet. Pumping blood out of the lymphatic outlet tends to reduce the pressure at the outlet. The method of the present invention further uses a flow restrictor for flow compensation to restrict upstream flow and thus amplify or maintain the pressure drop at the lymph outlet.

Access may be provided through the jugular vein and the cannula may be guided into position (e.g., under radiographic imaging) to position the pump directly downstream of the lymphatic outlet. The proximal end of the cannula may house a motor connected to the impeller by a drive cable. Once the impeller is positioned in the innominate vein, the motor is operated to drive the impeller to pump blood toward the heart and away from the lymph outlet, thereby reducing pressure at the lymph outlet. Without the method and apparatus of the present invention, blood reflux or blood flow through the jugular vein may simply increase to restore hydrostatic equilibrium. To compensate for this effect, the cannula includes a selectively deployable flow restrictor, such as a balloon inflatable via an inflation lumen extending along the cannula. When the capsular bag expands, it inhibits reflux through the jugular vein, thereby maintaining a local pressure reduction at the lymphatic outlet. Due to the low pressure at the lymphatic outlet, the lymph flows out of interstitial spaces within the body tissue, thereby relieving the pressure there, and thereby relieving edema and preventing congestive heart failure.

Thus, the devices and methods of the present invention use intravascular pumps and flow restrictors, respectively, to reduce lymphatic pressure and compensate for increased circulation. These approaches effectively drain lymph fluid from the lymphatic system and thus alleviate edema. Thus, the devices and methods of the present invention may be used to prevent congestive heart failure.

The present invention provides an impeller assembly structured to facilitate flow without recirculation. When the impeller is in operation, the structural features of the impeller assembly guide the flow and act as guide vanes that guide the fluid smoothly through the impeller. Due to the vane-like features of the structure that makes up the impeller assembly, the fluid flow through the impeller assembly is directed along a smooth and continuous flow line so that the overall flow pattern is free of eddies or recirculation. The impeller assembly may be connected to a distal portion of an intravascular treatment cannula and may be used to treat edema.

By directing the cannula to the jugular vein of a patient suffering from edema and operating the impeller near the lymphatic vessels, the device promotes and increases blood flow along the jugular vein, which reduces pressure at the output of the lymphatic vessels according to bernoulli's principle. As the pressure at the output end of the lymphatic vessel is reduced, lymph is drained from the lymphatic system and enters the circulatory system, thereby alleviating the adverse reactions and symptoms of edema.

Further, the impeller assembly may include a specialized combination of structures to facilitate flow therethrough. For example, the impeller assembly may have an inflatable bladder disposed thereon. The inflation lumen extends down the cannula and through a rigid stub extending from the cannula to the impeller housing. Several of these rigid stubs collectively support the housing relative to the cannula. One or any number of these rigid stubs may each have an inflation lumen therethrough. The inner cavity need not be concentrically disposed within the stub and is eccentric in the preferred embodiment because the stub-relative to the inner cavity-supports excess material entering the interior space of the impeller housing. The excess material extending inwardly from each stub acts as a flow guide to direct the flow into a smooth pattern without turbulence or recirculation. Since the main advantage of the intravascular impeller is that it can effectively pump blood therethrough, efficient operation without recirculation or turbulence provides an optimized treatment tool for alleviating edema effects and symptoms.

In certain aspects, the present invention provides a device for treating edema. The device includes a cannula having a proximal portion and a distal portion. An impeller assembly is coupled to the distal portion. The impeller assembly has an impeller operatively disposed therein. The proximal portion of the impeller assembly is configured to facilitate flow into the inlet of the impeller assembly without recirculation. When the impeller is operated within a blood vessel, blood flows through the housing of the impeller assembly without recirculation.

The impeller assembly may include a cap fixed to the distal portion and one or more stubs extending from the cap to the housing. The housing may have a diameter greater than a diameter of the cap such that the proximal base of the housing, the cap, and the one or more struts define an inlet. In some embodiments, the post includes an inflation lumen extending therethrough to inflate a bladder mounted on the impeller assembly. Preferably, the stub is substantially parallel to the axis of the impeller and projects radially inwardly from at least a portion of the inner surface of the impeller housing. Such stubs may define guide vanes within the impeller assembly that direct fluid flow when the impeller is in operation to thereby prevent recirculation or vortex flow. The stub may include a fluid lumen extending therethrough, wherein the fluid lumen is non-concentric with at least a portion of the body of the stub due to the material of the stub forming the guide vane within the impeller assembly. The apparatus may have a number, for example three, of stubs, wherein each stub of the number of stubs defines a guide vane within the impeller assembly that guides fluid flow when the impeller is in operation to thereby prevent recirculation or vortex flow. The device may optionally include a drug lumen extending through the cannula and terminating substantially within the proximal portion of the impeller assembly such that drug released from the drug lumen flows through the inlet and the impeller assembly.

In certain embodiments, the cannula includes a tube having a drive cable extending therethrough, wherein a cap is connected around a terminal portion of the tube, wherein the impeller housing is mounted to the cap by a plurality of posts that define guide vanes to promote laminar fluid flow through the impeller assembly. The impeller housing may have one or more outlets around a distal portion of the impeller such that operation of the impeller within the vessel drives blood into the impeller assembly via the inlet and out of the impeller assembly via the outlet such that the blood exhibits smooth, laminar flow without recirculation or vortex flow.

Aspects of the invention provide a method for treating edema. The method includes inserting a distal portion of a cannula into a patient's innominate vein. The cannula includes a impeller assembly on the distal portion. An impeller disposed within the impeller assembly is driven to reduce pressure at the lymphatic vessel. The proximal portion of the impeller assembly is configured to facilitate flow into the inlet of the impeller assembly without recirculation.

The cannula may include a cap secured to the distal portion, and one or more stubs extending from the cap to support the housing of the impeller assembly. The housing may have a diameter greater than a diameter of the cap, and the proximal base of the housing, the cap, and the one or more stubs may define the inlet. The stubs may extend substantially parallel to the axis of the impeller and project radially inwardly from at least a portion of the inner surface of the impeller housing. These stubs may define guide vanes within the impeller assembly that direct fluid flow when the impeller is in operation to thereby prevent recirculation or vortex flow. One or more of the stubs may include a fluid cavity that is non-concentric with at least a portion of the body of the stub due to the material of the stub forming the guide vane within the impeller assembly.

The method can comprise the following steps: the flow restrictor is inflated by delivering an inflation fluid to an inflatable flow restrictor mounted on the impeller assembly via an inflation lumen extending through the cannula. The impeller housing may include one or more outlets around a distal portion of the impeller such that operation of the impeller within the vessel drives blood into the impeller assembly via the inlet and out of the impeller assembly via the outlet such that the blood exhibits smooth, laminar flow without recirculation or vortex flow.

Drawings

Figure 1 shows a device for treating edema.

Figure 2 provides a detailed view of the impeller assembly.

Fig. 3 shows the expandable member in a deployed state.

Figure 4 shows the motor housing connected to the cannula.

Figure 5 illustrates the steps of a method of using the device to treat edema.

Fig. 6 is a detailed view of the impeller assembly with the expandable member in a deployed state.

Fig. 7 illustrates a method for treating edema using a flow restrictor to equalize pressure and compensate for downstream flow.

Fig. 8 shows a flow restrictor and a pressure sensor for the balancing and compensation method.

Fig. 9 shows a device inserted into the vasculature of a patient.

Fig. 10 illustrates a related method of treating edema using a flow restrictor for balance/compensation.

FIG. 11 is a detailed view of features that provide a clean-free system.

Fig. 12 illustrates a method of treating edema using a wash-free device.

Fig. 13 illustrates a portion of an intravascular device for treating edema that releases anticoagulant at an intravascular pump.

Fig. 14 is a cross-sectional view through the impeller assembly.

FIG. 15 shows the results of the computer flow model.

Fig. 16 is a partial cross-sectional view of an impeller assembly.

Fig. 17 is a side view of the impeller assembly.

Fig. 18 illustrates an exemplary inlet region of the impeller assembly.

Fig. 19 shows an inlet region with an internal inflation lumen.

FIG. 20 is a detailed view of the proximal portal.

Fig. 21 shows a side view of an impeller assembly with a rectangular proximal inlet.

Fig. 22 shows an impeller assembly with an arcuate proximal stub.

Fig. 23 shows a side view of a proximal portion of the impeller assembly.

Figure 24 shows an impeller assembly.

Figure 25 shows an elongate impeller assembly.

Fig. 26 shows a cross-sectional view of the impeller assembly.

Figure 27 is a cross-sectional view of the impeller assembly within a vein.

Fig. 28A-28F illustrate the attachment and folding of the expandable member.

Fig. 29 shows an impeller assembly with an expandable member having an elongated surface to interface with a vessel wall.

Figure 30 shows an impeller assembly having a two-piece expandable member.

Figure 31 is a partial cross-sectional view of the distal portion of the cannula.

Fig. 32 is a partial cross-section of a self-expanding impeller assembly.

Figure 33 shows a partial cross section of the impeller assembly.

Figure 34 shows the inlet of the impeller assembly.

Fig. 35 is an exemplary cannula system.

Fig. 36 shows a cannula with an expandable member slidably mounted along the shaft of the cannula.

Fig. 37 shows a fluid passage across the expandable member that allows a controlled amount of blood flow.

Figure 38 shows a cannula with an alternative bypass channel.

Fig. 39 illustrates a patient interface with a sheath in certain circumstances.

Fig. 40 shows a patient interface in some cases holding a sheath by an adhesive film.

Fig. 41 shows a flow control sheath.

Figure 42 shows a proximal portion of the cannula system.

Fig. 43 illustrates a locking mechanism for securing the cannula shaft to the hub of the sheath during therapy.

FIG. 44 shows the locking mechanism engaged with the cannula shaft.

FIG. 45 shows a schematic view of a push lock mechanism.

Fig. 46 shows an alternative locking mechanism.

FIG. 47 is a partial cross-sectional view of a jugular vein showing a flow control sheath inserted therein.

Figure 48 shows an indwelling cannula system.

Fig. 49 is a section taken along line a-a of fig. 48.

Figure 50 is an indwelling cannula.

Fig. 51 is an enlarged view of the dotted circle B of fig. 50 according to an embodiment of the present invention.

Fig. 52 is an enlarged view of the dotted circle B of fig. 50 according to another embodiment of the present invention.

Fig. 53 is an enlarged view of the dashed circle B of fig. 50, in accordance with various embodiments of the present invention.

Figure 54 shows distal flushing of the indwelling cannula.

Figure 55 illustrates distal flushing of an indwelling cannula according to various embodiments.

Figure 56 shows an indwelling cannula with a cleaning system.

FIG. 57 illustrates a cross-section of the central lumen taken along line A-A of FIG. 56, in accordance with one embodiment of the present invention.

FIG. 58 illustrates a cross-section of the central lumen taken along line A-A of FIG. 56, in accordance with various embodiments of the present invention.

FIG. 59 shows a cross-section of the central lumen taken along line A-A of FIG. 56, in accordance with another embodiment of the present invention.

Fig. 60 shows an optimized guide surface for a cage inlet.

FIG. 61 shows a sub-optimal guide surface.

Fig. 62 shows a cage inlet.

FIG. 63 shows a sub-optimal inlet configuration.

Detailed Description

The present disclosure relates to devices and methods for treating edema or congestive heart failure. The devices of the present disclosure include a cannula sized for insertion through the jugular vein, wherein the cannula uses or includes a number of different features, each of which is described herein, either individually or in combination. Embodiments of the device include therapeutic devices in which a flow restrictor, such as a bladder, is mounted to a cage or housing of an intravascular pump or impeller. In some of those embodiments, the shape of the balloon in the deployed state directs and promotes blood flow to the inlet of the impeller. In certain embodiments, the devices of the present disclosure include an impeller having a proximal diameter that is smaller than a distal diameter to compensate in size for positioning the capsular bag on the impeller cage. Aspects of the present invention relate to a wash-free system or wash-free intravascular treatment cannula that does not use a wash fluid to protect the impeller from thrombosis or clotting. In certain embodiments, the devices and methods of the present disclosure utilize anticoagulant (such as heparin) release at the inlet of the impeller cage. Other embodiments of the present disclosure relate to devices and methods that use a flow restrictor such as a bladder to equalize pressure and compensate for downstream flow when operating an impeller to drain a lymphatic vessel. Features and embodiments of the present disclosure include an edema treatment device including a symmetrical arrangement of lumens about a drive shaft to balance the drive shaft. In some embodiments, those lumens have proximal terminations outside the motor housing and extend down to the distal portion of the cannula. The devices of the present disclosure may include atraumatic tips with threads therein to allow for smooth material transitions. Embodiments of the present disclosure may include a guide wire extending through the impeller cage. These embodiments are described and illustrated in greater detail herein, and may be present in any suitable combination in the devices of the present disclosure.

Fig. 1 shows a device 101 for treating edema. Device 101 includes a cannula 105 including a proximal portion 109 and a distal portion 115. An impeller housing 203 is attached to the distal portion 115 of the cannula 105, wherein an impeller is disposed in the impeller housing. The expandable member 301 may be aligned on the outside of the impeller housing 203. The expandable member 301 is depicted in a collapsed configuration and thus appears as merely a smooth continuation of the impeller housing 203.

The apparatus 101 may include a flow restrictor 801 and at least one pressure sensor 805. In the depicted embodiment, the flow restrictor 801 is proximal to the expandable member 301. Preferably, the flow restrictor 801 and the expandable member 301 are each independently selectively deployable to restrict, impede, direct, or direct fluid flow around the relevant portion of the device 101. In a preferred embodiment, the flow restrictor 801 and the expandable member 301 are each in fluid communication with a dedicated inflation lumen extending along the length of the cannula 105.

One feature of device 101 is an impeller 205, which is preferably disposed within an impeller assembly 201 that provides an impeller housing 203 and other mechanical features, such as ports and openings that may be used to pump blood and fluids into a patient's blood vessel.

Fig. 2 gives a detailed view of the impeller assembly 201. The impeller assembly 201 comprises an impeller housing 203 in which an impeller 205 is rotatably arranged. The expandable member 301 is aligned on the outside of the impeller housing 203. The expandable member is shown in phantom in fig. 2 (the phantom lines being used to aid in viewing other features of the device 101). The dashed lines indicate the position and placement of the expandable member 301 in its collapsed or undeployed state. An impeller housing 203 is attached to the distal portion 115 of the cannula 105, wherein an impeller is disposed in the impeller housing. The expandable member 301 is aligned on the outside of the impeller housing 203. The expandable member is shown in phantom in fig. 2 (the phantom lines being used to aid in viewing other features of the device 101). The dashed lines indicate the position and placement of the expandable member 301 in its collapsed or undeployed state.

As shown, impeller 205 has blades 206 on a shaft 207. The radius measured from the axis of the impeller 205 to the outer edge of the blades 206 decreases from the distal to proximal portion of the impeller. This can be seen as follows: the outer edge of each vane 206 includes a turn 209 defining a decreasing radius near the transition between the distal and proximal portions of the impeller housing 203.

When the distal portion 115 of the device 101 is inserted into the vasculature of a patient and the motor in the motor housing 401 is operated, the impeller 205 rotates and forces fluid (i.e., blood) through the impeller housing 203. To this end, the proximal end of the impeller housing 203 includes one or more inlets 255, while the distal portion of the impeller housing 203 includes one or more outlets 227. Impeller shaft 207 flares outwardly near the distal end of impeller 205 such that when impeller 205 rotates, the impeller pumps blood through impeller housing 203 and out the one or more outlets 227.

Fig. 14 is a cross-sectional view through impeller assembly 201 on distal portion 115 of device 101. The impeller assembly 201 comprises an impeller housing 203 in which an impeller 205 is rotatably arranged.

The impeller assembly 201 is connected to the distal portion 115 of the cannula. The impeller assembly has an impeller 205 operatively disposed within the assembly. The cross-sectional view of the impeller assembly 201 shows that the proximal portion of the impeller assembly is configured to facilitate flow into the inlet of the impeller assembly without recirculation.

When the impeller 205 is operated within a blood vessel, blood flows through the housing 203 of the impeller assembly 201 without recirculation.

As shown in this cross-sectional view, in the depicted embodiment, the impeller assembly 201 includes a cap 249 fixed to the distal portion 115 and one or more stubs 1405 extending from the cap 249 to the casing 203. Any one or more of the stubs 1405 may include a cavity 415. The diameter of the housing 203 is larger than the diameter of the cap 249. It can be seen that structurally, the proximal base of the housing 203, the cap 249, and the one or more stubs 105 define one or more inlets to the impeller housing 201.

In the depicted embodiment, the stub 1405 has an inflation lumen 415 extending therethrough to inflate a bladder mounted on the impeller assembly. The stub 1405 is substantially parallel to the axis of the impeller 205 and projects radially inward from at least a portion of the inner surface of the impeller housing 203. When so structured, each stub 1405 defines a vane within the impeller assembly 201 that directs fluid flow when the impeller 205 is in operation, thereby preventing recirculation or vortex flow.

As shown, the stub 1405 has a fluid lumen 415 extending therethrough. Because the material of the stub 1405 forms a guide vane within the impeller assembly 201, the fluid lumen 415 is not concentric with at least a portion of the body of the stub 1405. Referring to, for example, fig. 3, it can be seen that the apparatus 101 may include a plurality (e.g., at least three) of stubs. Together, these stubs define guide vanes within the impeller assembly that guide fluid flow when the impeller is in operation, thereby preventing recirculation or vortex flow.

The impeller housing 201 includes one or more outlets 258 around a distal portion of the impeller 205. The operation of impeller 205 within the vessel forces blood into impeller assembly 201 via inlet 255 and out of impeller assembly 201 via outlet 258 such that the blood exhibits a smooth, laminar flow without recirculation or turbulence.

Fig. 15 shows how blood flows through the impeller assembly 201 via the inlet 255 and out of the impeller assembly 201 via the outlet 258 such that the blood exhibits a smooth, laminar flow without recirculation or turbulence. The image depicts the results of the computer flow model. The flow model shows that the flow through the impeller assembly with the inventive structure is smooth and no recirculation occurs.

Since the model test results demonstrate a smooth and efficient flow, the device of the present invention pumps blood more efficiently than other devices without the structure shown herein.

Computer model test results show that the flow is smooth and there is no turbulence or recirculation within the flow.

The device of the present invention is useful in treating edematous patients because it is more efficient than other devices and pumps blood without turbulence or recirculation. Thus, by using the devices of the present disclosure, a clinician can perform methods for treating edema. The method includes inserting the distal portion 115 of the cannula into the patient's innominate vein. The cannula has an impeller assembly 201 on the distal portion 115. The method comprises the following steps: the impeller 205 disposed within the impeller assembly 201 is driven to thereby reduce the pressure at the lymphatic vessels. The proximal portion of impeller assembly 201 is configured to facilitate flow into the inlet of the impeller assembly without recirculation, as clearly shown in the depicted computer flow model. The cannula may have any of the other features disclosed herein (e.g., a cap secured to the distal portion by one or more stubs of a housing extending from the cap to support the impeller assembly, wherein the diameter of the housing is greater than the diameter of the cap, and wherein the proximal base of the housing, the cap, and the one or more stubs define an inlet).

As shown by the image of the results of the computer flow model, these stubs define guide vanes within the impeller assembly that guide the fluid flow as the impeller operates, thereby preventing recirculation or vortex flow. Streamlines that appear clearly in the computer flow model avoid any loops that may occur when recirculation or turbulence occurs in the flow. Since the flow through the impeller assembly 201 is free of recirculation or vortex flow, the image from this computer flow model shows only streamlines without loops, circles, spirals, etc.

The impeller housing includes one or more outlets around a distal portion of the impeller. When the impeller is operated within a blood vessel, the impeller forces blood into the impeller assembly via the inlet and out of the impeller assembly via the outlet such that the blood exhibits a smooth, laminar flow without recirculation or turbulence.

The apparatus and methods of the present disclosure may include other features.

The device 101 of the present disclosure may further include a drug lumen 251 extending through the cannula 105 and terminating substantially at the inlet 255 of the impeller assembly 201. In some embodiments, the impeller assembly 201 further includes an atraumatic tip 231 with a threaded fitting 237 therein to allow for a smooth transition of material properties between the rigid impeller cage 203 (e.g., metal) and the softer material of the atraumatic tip 239. The tip 239 preferably comprises a suitable pliable material, such as a polymer. The material may comprise, for example, a polyether block amide such as those sold under the trademark PEBAX by Achima (King of Prussia, Pa.). Although polyether block amides are mentioned in detail, the polymer may include any number of other polymers, such as Polytetrafluoroethylene (PTFE), Fluorinated Ethylene Propylene (FEP), polyurethane, polypropylene (PP), polyvinyl chloride (PVC), polyetheresters, polyesters, polyamides, elastomeric polyamides, block polyamides/ethers, silicones, polyethylenes, Marlex high density polyethylene, linear low density polyethylene, Polyetheretherketone (PEEK), Polyimides (PI), or Polyetherimides (PEI). The threaded fitting 237 may include a threaded stud (e.g., made of metal or plastic such as polycarbonate) that is threadably fitted to both the impeller housing 203 and the atraumatic tip 231. By including a long post (e.g., a length greater than its own maximum diameter, preferably at least about 2 or 3 times longer) for fitting 237, tip 231 can be deformed but prevented from exhibiting or exhibiting any kinks or discontinuities. Additionally, as shown, tip 231 may include a guidewire lumen 239.

The expandable member 301 on the impeller assembly 201 is depicted in a collapsed configuration with dashed lines. The impeller assembly 201 operates as a pump and includes an impeller 205 disposed within an impeller housing 203. In a preferred embodiment, the inflatable member 301 comprises an inflatable bladder connected to the outer surface of the impeller housing 203.

Fig. 3 shows the expandable member 301 in a deployed state. In the depicted embodiment, the expandable member 301 is provided as a bladder. As shown, the bladder defines an annulus when inflated. The outer surface of the expandable member 301 is physically coupled to the outer surface of the impeller housing 203 (e.g., the bladder may be adhered to the housing 203 by an adhesive).

Preferably, the outer surface of the expandable member 301 is physically coupled directly to the outer surface of the impeller housing 203 without any membrane, sheath or device 101 between the outer surface of the expandable member 301 and the outer surface of the impeller housing 203. The expandable member 301 may partially or completely encircle the impeller housing 203. The inflatable member 301 may be provided as an inflatable bladder surrounding the impeller housing 203.

The device of the present disclosure may include features to aid in adhering the bladder to the impeller housing 203. For example, the impeller housing may comprise a metal (e.g., stainless steel, aluminum, titanium, nitinol, etc.), and a portion of the expandable member 301 may be secured to a surface of the metal by an adhesive. To promote adhesion, at least a portion of the surface of the metal may be impregnated with a polymer. In some embodiments, the metal surface is impregnated with polyurethane to a depth of at least 3 μm, at least at an outer proximal portion of the impeller cage 203.

The device 101 is configured for placement in a bodily vessel through the use of an expandable member 301 mounted to the impeller cage 203. The impeller housing may comprise an axis that is positioned substantially parallel to the axis of the blood vessel. Preferably, the expandable member 301 is impermeable to flow across the expandable member. The expandable member 301 is configured to abut a vessel wall in use and in so doing direct fluid flow to the inlet of the impeller housing 203.

In use, the expandable member 301 anchors or holds the impeller assembly 201 in a fixed position relative to the axis of the blood vessel. In this anchored state, the expandable member 301 conforms to the vessel wall at the attachment region, and the attachment region comprises a generally cylindrical section of the vessel wall. The central axis of the expandable member and the central axis of the impeller housing are preferably substantially identical.

The inflatable member is configured to allow the axis of the impeller housing to articulate relative to the axis of the bladder in use. The articulation of the impeller relative to the bladder preferably includes two degrees of freedom.

In some embodiments, the expandable member 301 comprises a bladder, and the membrane of the bladder comprises an omega-shaped cross-section.

The impeller housing 203 may comprise a tubular member, and a wall of the tubular member may comprise a hole extending through the wall of the tubular member to at least partially define an inflation port of the bladder. Preferably, the inflation port is connected to an inflation system outside the patient via a cannula. Such a connection may include a shaped metal tube or conduit that couples to and forms a seal with (i.e., "sealingly couples with") the inflation port. In certain embodiments, coupling the expandable member to the impeller housing includes at least one circumferential seal around an outer diameter of the housing. More preferably, the expandable member is coupled to the impeller housing including a first circumferential seal around an outer diameter of the housing and a second circumferential seal around the outer diameter, wherein the second circumferential seal is axially spaced from the first circumferential seal. In some embodiments, the circumferential seal has an axial length, and a portion of the seal surrounds an inflation port extending across the impeller housing and a wall of the expandable member. The impeller housing may include an inflation port located between the first and second circumferential seals.

Referring back to fig. 2 and 3, preferably the pouch has a collapsed state (fig. 2) for delivery and removal, and an expanded state (fig. 3). In some embodiments, in the collapsed state, at least a portion of the bladder material may slide relative to the axis of the impeller housing (i.e., may slide axially relative to the impeller housing). For example, at least a portion of the capsular bag material may be configured to slide proximally during delivery and distally during withdrawal. It may be provided that the bladder comprises an annulus shape with first and second necks coupled to the impeller housing. Preferably, the distance between the first and second neck portions is less than the circumference of the torus shaped bladder.

The coupling between the expandable member 301 and the impeller housing 203 may include an interface layer. For example, the interface layer may include an interpenetrating layer. In certain embodiments, the impeller housing includes a slit, and the interpenetrating layer causes the material of the membrane to interpenetrate into the slit of the impeller housing. The interpenetrating layer may include an adhesive layer, which may include an acrylate material.

In some embodiments, expandable member 301 is configured to exert a radially outward force on the vessel wall. The apparatus may be configured such that said applying said radially outward force substantially secures at least a portion of the impeller housing 203 to a central axis of the blood vessel. The impeller housing includes an internal cavity extending from a proximal section of the impeller housing to a distal section or outlet of the housing, the internal cavity configured to receive the impeller 205. The impeller housing includes a first diameter adjacent the proximal section and a second diameter adjacent the distal section. In certain embodiments, the diameter of the inner cavity of the impeller housing varies between the proximal section and the distal section. Similarly, the radial dimension of the impeller blades 206 may vary between the proximal and distal sections. The varying diameter of the impeller housing lumen diameter may define a taper, a step, a plurality of steps, a plurality of tapered segments, a dog bone shape, a parabolic shape, or a combination thereof. The impeller blades are configured to fluidly engage an inner cavity of the impeller housing. Preferably, the impeller blades 206 are configured to be spaced apart from the interior cavity of the impeller housing. The impeller assembly 201 has at least one inlet opening and at least one outlet opening. The at least one inlet opening and the at least one outlet opening may be separated by a distance of between 1 and 40 mm. Preferably, the at least one inlet opening and the at least one outlet opening are spaced approximately 5 millimeters apart, and the proximal end of the impeller 205 may be positioned approximately 0.5 millimeters from the distal edge of the inlet. This configuration is preferred because it helps to minimize recirculation at the transition from the inlet to the impeller 205. In some embodiments discussed herein, such as in fig. 25, the distance between the inlet and the outlet may be extended to about 25-30 millimeters. This configuration provides better laminar flow into the impeller 205. In other embodiments, the at least one inlet opening and the at least one outlet opening may be spaced approximately 3 millimeters apart, such that the impeller 205 is closer to or just within the inlet. The at least one inlet opening includes a proximal end and a distal end. A proximal portion of the annulus extends proximally from a distal end of the proximal inlet opening to define an access funnel leading to the inlet opening. The distal portion 115 of the cannula 101 is configured to be inserted into a blood vessel of a patient, and the proximal portion 109 of the cannula is configured to extend outside the patient.

The proximal portion 109 of the cannula 101 may terminate at the motor housing 401.

Fig. 4 shows the motor housing 401 connected to the proximal portion 109 of the cannula 105. The motor 405 is disposed within the motor housing 401. A drive cable 411 extends from the motor 405 to the impeller through the cannula 105. In a preferred embodiment, inflation lumen 415 extends along cannula 105 to expandable member 301. The drive cable 411 preferably extends through a sleeve, such as the impermeable sleeve 121, within the cannula 101. In a wash-free embodiment, the impermeable sleeve 121 may include a seal at one or both ends to exclude fluid from the drive cable 411. The impermeable sleeve 121 meets the motor housing 401 at the proximal seal 433.

In certain embodiments, the motor 405 comprises a rotor operable to rotate at high speed, and the cannula 101 comprises a drive cable 411 to transmit the rotational speed through the cannula 101 to the impeller 205. The drive cable 411 may be capable of transmitting rotational speeds greater than 5,000rpms (e.g., >10,000rpm, >15,000rpm, or >20,000rpm) to the impeller 205. Most preferably, the cannula is configured for athermal operation while transmitting a high rotational speed to the impeller.

The impermeable sleeve 121 may comprise a material such as Polytetrafluoroethylene (PTFE). For example, the impermeable sleeve 121 may be provided by a thick walled PTFE tubing. The thick walled PTFE tubing may have a wall thickness greater than 75 microns, preferably >100 microns, >125 microns, or greater than 150 microns. Optionally, the drive shaft has a cross-sectional moment of inertia of a certain value. The drive cable 411 may comprise a cylindrical superelastic member over at least a portion of the length of the drive shaft. The gap between the drive shafts may be less than a few microns. In some embodiments, the impermeable sleeve 121 comprises a hydrophobic material. The impermeable sleeve 121 may comprise a material having a Hildebrand solubility parameter (delta) of less than 16MPa (0.5). The impermeable sleeve 121 may comprise a material having a Hildebrand solubility parameter of less than 14MPa (0.5). For example, the delta for nylon is about 15.7MPa ^ 0.5; the delta of Polytetrafluoroethylene (PTFE) is about 6.2MPa 0.5. The impermeable sleeve 121 may comprise a PTFE material and the drive cable 411 may comprise a nitinol rod, and the gap between the rod and the sleeve may be less than a few microns. Preferably, the concentricity of the rod is greater than 95%. The drive cable may have a first diameter and a second diameter, wherein the first diameter is slightly larger than the second diameter. The impermeable sleeve may comprise a polymeric material having a dynamic coefficient of friction of less than 0.08 or less than 0.07, 0.06 or 0.05.

The devices of the present disclosure may be used to treat edema or congestive heart failure. By using the device of the present disclosure, the pump can be operated to facilitate flow in the innominate vein, thereby lowering the pressure at the output of the lymphatic vessel, which drains lymphatic fluid from the lymphatic system. To compensate for pressure variations in the circulation system that may result from operating the pump, the present disclosure provides a method for compensating for pressure variations.

Fig. 5 shows the steps of a method 501 of treating edema using the device 101. The method 501 comprises the following steps: inserting 510 the distal portion 115 of the cannula 105 into the patient's innominate vein 939; operating 515 the impeller; and inflating 517 the expandable member 301 to thereby reduce pressure at the lymphatic vessel 907.

Method 501 may include using a device 101 including a cannula 105 having a proximal portion 109 and a distal portion 115, the distal portion 115 sized for insertion into a body lumen of a patient. The device 101 includes a pump (e.g., an impeller assembly 201) and an expandable member 301 connected to the pump. When inflated, the expandable member 301 comprises a torus shape, wherein a proximal surface of the torus shape directs fluid into the impeller housing 203. Preferably, the inner radius of the torus shape is substantially the same as the radius of the proximal end of the impeller housing 203. In some embodiments, the expandable member 301 comprises an inflatable bladder mounted on the pump. The pump includes an impeller housing 203 having an impeller therein, wherein the bladder fits around at least a portion of the proximal end of the impeller housing 203. The impeller housing 203 may include a distal portion and a proximal portion, wherein an outer diameter of the proximal portion is less than an outer diameter of the distal portion. The expandable member 301 is disposed about a proximal portion of the impeller housing 203 when unexpanded. When the bladder is inflated, the surface of the annulus is attached to the surface of the impeller housing 203. When the expandable member 301 is unexpanded, the distal portion 115 of the cannula 105 may be passed through a 12Fr introducer sheath.

Fig. 6 is a detailed view of the impeller assembly 201 with the expandable member 301 in a deployed state. Impeller 205 is located substantially within and/or directly downstream of the deployed flow restrictor. The inflation lumen 415 extends through the distal portion 115 of the cannula and terminates at a port 601 into the expandable member 301. Visual inspection of the surface of the expandable member 301 on the proximal side and the inner surface of the impeller housing 203 shows that these surfaces form a smooth continuous surface that funnels fluid through the impeller housing 203 under the thrust of the impeller. This drives blood through the blood vessel and regulates the fluid pressure in the vicinity. When operating essentially in innominate veins, the pressure at the outlet of the lymphatic vessels is reduced, which promotes drainage of lymphatic fluid and relief of edema.

Fig. 7 illustrates a method 701 for treating edema. The method 701 comprises the following steps: the pump is operated 710 to increase flow through the patient's innominate vein 939, and a flow restrictor is deployed 717 upstream of the pump after the operating step to thereby restrict flow from the jugular vein to the innominate vein 939 to balance 729 the pressure downstream of the pump. The method 701 may include operating the pump and then limiting the flow once the increased flow through the innominate vein 939 affects the pressure in the jugular vein.

The method 701 preferably includes sensing 715 a pressure increase in the jugular vein caused by the increased flow with the pressure sensor 805 and restricting the flow in response to sensing the increased pressure in the jugular vein.

Fig. 8 shows a flow restrictor 801 and a pressure sensor 805. In fact, as shown in fig. 8, device 101 includes pressure sensors 805 at locations along cannula 105 proximal and distal to flow restrictor 801. In the depicted embodiment, the pressure sensors 805 include a pressure sensing lumen that extends along the cannula 105 and terminates at a thin-cut sensing orifice along the side of the cannula 105. The sensing lumen extends proximally along the cannula to the motor housing 401, wherein the sensing lumen preferably exits from the housing 401 and is in fluid contact with a mechanical pressure sensor device, such as a piezoelectric pressure sensor. The interior of the pressure sensing lumen preferably establishes at least a substantial hydrostatic equilibrium from the thin-sided sensing orifice along the side of cannula 105 to the mechanical pressure sensor device, such that readings from the sensing device(s) provide information of the pressure in the area surrounding flow restrictor 801. Thus, information provided by the pressure sensor 805 may be fed back into the method 701 and used as information to control the deployment 717 of the flow restrictor 801. The method 701 preferably includes inserting 705 a device 101 including a pump into the vasculature of a patient prior to the step of operating 710.

Fig. 9 shows the device 101 inserted 705 into the vasculature of a patient. The device 101 includes a cannula 105 sized for partial implantation within the vasculature, and the pump includes an impeller assembly 201 disposed at a distal portion 115 of the cannula 105. The distal portion 115 is passed through the jugular vein and inserted down the innominate vein 939. Preferably, proximal portion 109 of cannula 105 is connected to motor housing 401 and device 101, and one or more pressure sensors 805 and deployable flow restrictors 801 are attached to cannula 105 proximal to the pump.

Once the impeller assembly is at least partially within the innominate vein 939, the impeller 205 spins to pump blood through the impeller housing 203. This causes a reduction in pressure around the outlet of lymphatic vessel 907. The pressure reduction causes lymphatic fluid to drain from lymphatic vessels 907 into the circulatory system. Drainage of lymph fluid relieves edema or reduces congestive heart failure. The method 701 further includes deploying 717 a flow restrictor 801 upstream of the impeller assembly 201 to thereby restrict flow from the jugular vein to the innominate vein 939 to equalize 729 pressure downstream of the impeller assembly 201. The method 701 may further include sensing 715 pressure and adjusting 735 the restriction to flow based on the pressure sensed 715 via the one or more pressure sensors 805.

In some embodiments, the flow restrictor 801 comprises an inflatable bladder, and restricting 717 flow comprises inflating the flow restrictor. Optionally, sensing 715 is performed using a computer system communicatively connected to pressure sensor(s) 805. The method 701 may include periodically or continuously adjusting 735 inflation of the flow restrictor as a function of the sensed pressure.

Fig. 10 illustrates a related method 1001 for treating edema. The method 1001 includes inserting a pump into 1005 a innominate vein and operating 1010 the pump to increase flow through a patient innominate vein 939. Pressure changes in the patient's jugular vein caused by the increased flow are sensed 1015, and a restrictor 801 is adjusted 1029 based on the sensed pressure to restrict flow from the jugular vein to the innominate vein 939. Preferably, method 1001 includes inserting a cannula 105 into 1005 innominate vein 939. Cannula 105 includes a pump, pressure sensor 805, and flow restrictor 801. The occluder may comprise an inflatable bladder, and adjusting 1029 the occluder may comprise at least partially inflating and/or deflating the bladder. Sensing 1015 may be performed using pressure sensor 805. The method 1001 preferably includes periodically or continuously adjusting inflation of the flow restrictor in accordance with the sensed pressure. The method 1001 may include adjusting 1029 inflation to balance pressure downstream of the pump. In a preferred embodiment, the pump includes an impeller assembly 201 disposed at the distal portion 115 of the cannula 105. The proximal portion 109 of the cannula 105 is connected to a motor housing 401 having a motor 405 therein operatively coupled to the impeller assembly. In certain embodiments, cannula 105 is coupled to a computer system operable to read pressure or control inflation.

Aspects and embodiments of the present disclosure relate to a wash-free system that may be understood to refer to or include methods and devices for treating edema that do not use a washing system or washing fluid.

FIG. 11 is a detailed view of features that provide a clean-free system. The no-clean system may be provided by an apparatus 101 comprising: a cannula 105 having a proximal portion 109 and a distal portion 115; an impeller 205 connected to the distal portion 115 of the cannula 105; a motor 405 connected to the proximal portion 109 of the cannula 105; a drive cable 411 extending from the motor 405 to the impeller 205 through the cannula 105; and an impermeable sleeve 121 extending over the drive cable 411 through the cannula 105.

The sleeve 121 has a distal seal 435 at the impeller. Referring back to fig. 4, the sleeve 121 may have a proximal seal 433 at the motor 405. Due to the sleeve 121 and at least the distal seal 435, bodily fluids outside the impermeable sleeve 121 are prevented from entering the impermeable sleeve 121 and contacting the drive cable 411. The sleeve 121 and at least the distal seal 435 exclude fluid from the drive cable 411.

Referring back to fig. 4, the proximal seal 433 (see fig. 4) may include one or more O-rings. Similarly, the distal seal 435 between the sleeve 121 and the drive cable 411 may be provided by an O-ring or collar or a press-fit or extended friction-fit tube. Any suitable seal may be included to prevent blood or bodily fluids from entering the sleeve and contacting the drive cable 121. The drive cable 121 may be provided from any suitable material, including, for example, nitinol or braided steel cable. Contact with blood may present a risk of hemolysis or coagulation, which may interfere with the ability of the drive cable 411 to rotate freely (e.g., at >5,000rpm) within the sleeve 121 and cannula 105. The sleeve excludes blood and thus eliminates concerns about coagulation or hemolysis, allowing the drive cable 411 and impeller 205 to operate freely without obstruction.

Embodiments of device 101 may include multiple lumens. For example, the device 101 may include first and second inflation lumens 415 (or a single inflation lumen 415). The device may include a drug lumen 251 extending through the cannula 105. In a preferred embodiment, the device 101 includes at least a first inflation lumen 415 and a second inflation lumen 415, both of which extend through the cannula 105. The first and second inflation lumens 415, 415 have respective first and second proximal ends 416 (see fig. 1) accessible from outside the motor housing 401. Preferably, the first lumen and the second lumen are symmetrically arranged about the drive cable 411 to balance the device 101. As shown, cannula 105 does not include a purging system or purging fluid.

Referring back to fig. 1 and 3, the device 101 may include an impeller 205 located in an impeller housing 203. Device 101 includes at least a first expandable member 301 connected to distal portion 115 of cannula 105. The first expandable member 301 may be connected to the impeller housing 203, wherein the device 101 further comprises a second expandable member 801 disposed along the cannula 105. The first expandable member 301 may use an annulus pocket that is directly connected to the surface of the impeller housing 203. Device 101 may further include at least one pressure sensor 805 disposed along cannula 105 proximal to the impeller. In a no-clean embodiment, distal seal 435 may be provided using a fitting 1107 between impermeable sleeve 121 and a portion of impeller 205, where fitting 1107 excludes fluid and allows impeller 205 and drive cable 411 to rotate within device 101. The depicted device 101 may be used to treat edema, and may feature a wash-free device. The wash-free device may be used in a method for treating edema.

Fig. 12 illustrates a method 1201 for treating edema using a wash-free device. The method 1201 comprises: the distal portion 115 of the cannula 105 is inserted 1205 into a patient's innominate vein 939, and the impeller 205 connected to the distal portion 115 of the cannula 105 is driven 1210 by the motor 405 at the proximal portion 109 of the cannula 105. Motor 405 is connected to impeller 205 by a drive cable 411 that extends through cannula 105 to thereby reduce pressure at lymphatic vessel 907 at 1217. The impermeable sleeve 121 extends over the drive cable 411 through the cannula 105 such that bodily fluids outside the impermeable sleeve are prevented from entering the impermeable sleeve and contacting the drive cable. The impermeable sleeve 121 and at least the distal seal 435 exclude fluid from entering the impermeable sleeve 121 and contacting the drive cable 411 by the exclusion of 1215.

The method 1201 may include inflating 1229 a flow restrictor disposed along the distal portion 115 of the cannula 105 to restrict flow from the jugular vein to the innominate vein 939. Inflation 1229 may be performed using an inflation lumen 415 extending through cannula 105 out of impermeable sleeve 121. In some embodiments, a repelling void between the drive cable 411 and the impermeable sleeve 121 is used to exclude 1215 blood and bodily fluids from the drive cable 411. For example, the exclusion gap may include a hydrophobic material (PTFE) on one side of the gap, a smooth metal shaft 411 on the other side, and a gap size that prevents the inflow of blood components. For example, a void size of about 0.5 μm will prevent the influx of red blood cells, white blood cells, and platelets. It can be seen that a void size of 0.1 μm excludes 1215 all blood and body fluids. The drive cable 411 may not be concentric with the sleeve 121, so preferably the gap size is the largest gap between the two.

The reduced pressure at lymphatic vessels 907 promotes drainage from the lymphatic system into the circulatory system. Preferably, the impermeable sleeve 121 includes a proximal seal 433 at the housing of the motor 405 and a distal seal 435 at the impeller 205. The proximal seal 433 prevents blood and bodily fluids from escaping from the patient through the motor housing 401 or the proximal portion 109 of the cannula 105. In some embodiments, the distal seal 435 comprises a fitting between the impermeable sleeve and a portion of the impeller, wherein the fitting excludes fluid and allows the impeller and drive cable to rotate within the device 101.

The method 1201 may include inflating at least one balloon 301, 801 disposed along the cannula 105 through an inflation lumen 415 having a proximal end accessible from outside the motor housing 401 while inserting the distal portion 115 of the cannula 105 into the innominate vein 939. In various embodiments, the proximal seal 433 utilizes an O-ring; the impermeable sleeve 121 comprises PTFE; drive cable 411 comprises a metal, such as nitinol; one or both of the bladder 301 and the flow restrictor 801 may comprise polyvinyl chloride, cross-linked polyethylene, polyethylene terephthalate (PET), or nylon; or any combination of these materials. With method 1201, blood and body fluids are removed 1215 from drive cable 411 without the use of a washing fluid or washing system.

Other features and benefits are provided by or are within the scope of the present disclosure.

The methods and devices of the present disclosure avoid the problems of thrombosis or hemolysis that may otherwise interfere with the function of mechanical systems or create surface irregularities that lead to other complications. For example, mechanical systems may be most medically beneficial when avoiding blood clotting or other coagulation related phenomena. Thus, the provided embodiments of the devices and methods of the present disclosure inhibit clotting, thrombosis, hemolysis, or other problems that may occur when treating edema.

Certain embodiments provide a device that operates with the benefit of an anticoagulant. The device may include a pump (e.g., an impeller assembly) that is flushed with a solution or suspension containing an anticoagulant, such as heparin. Where a pump or impeller assembly is provided via the cannula, the cannula may include a lumen, reservoir, port, or other such feature to release the coagulant at or near the pump.

Fig. 13 illustrates a portion of an intravascular device 101 for releasing anticoagulant at an intravascular pump for treatment of edema. The device 101 includes a cannula 105, an impeller assembly 201 mounted at a distal portion 115 of the cannula 105, and a drug lumen 251 extending through the cannula 105 and terminating substantially at an inlet 255 of the impeller assembly 201. When device 101 is in use (e.g., when impeller 205 is operated within a patient's blood vessel), drug released from drug lumen 251 flows through inlet 255 and impeller assembly 201. Preferably, the cannula 105 and impeller assembly are sized for insertion through the jugular vein of a patient. The device 101 may include a reservoir in fluid communication with the drug lumen 251. The reservoir may be, for example, a solution bag (also known as an "IV bag") on a stent near the treatment gurney and in fluid communication with the drug lumen 251 (e.g., via a luer lock).

In certain embodiments of the anticoagulant delivery device 101, the impeller assembly 201 has an impeller housing 203 in which an impeller 205 is rotatably disposed. Device 101 preferably includes a motor 405 connected to the proximal end of cannula 105 and operatively connected to impeller 205 via a drive cable 411 extending through cannula 105. Drug lumen 241 preferably extends through cannula 105 (e.g., outside of sleeve 121 surrounding drive cable 411) and may terminate at port 252 such that anticoagulant released therefrom flushes impeller 205 or impeller assembly 201. Preferably, the port 252 is located at the impeller housing 203, proximal to the impeller.

To define the inlet 255, the cannula 105 can include a tube having a drive cable extending therethrough, wherein the cap 249 is connected around a terminal portion of the tube, wherein the impeller housing 203 is mounted to the cap by a plurality of stubs to define the inlet 255 to the impeller housing 203. In some embodiments, a cap 249 seals the terminal end of the flexible tube to the shaft of the impeller, and the port 252 may be located in the cap 249. Preferably, the impeller housing 203 includes one or more outlets 258 around the distal portion 115 of the impeller such that operation of the impeller 205 within the vessel forces blood into the impeller assembly 201 via the inlet 255 and out of the impeller assembly via the outlets 258.

Device 101 may contain an anticoagulant in the reservoir. When device 101 is inserted into a patient's blood vessel and impeller 205 is operated, anticoagulant is released from port 252 in impeller cage 201 and the released anticoagulant mixes with the blood and flushes rotating impeller 205. Any suitable anticoagulant may be used. For example, the anticoagulant may include one or any combination of the following: heparin, tirofiban, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin and fondaparinux. Due to the anticoagulant, the device 101 can be used to treat edema to drain lymphatic or blood vessels using an impeller.

Using such devices, aspects of the invention provide a method for treating edema. The method comprises the following steps: operating the pump to increase flow through the patient's innominate vein 939; and releasing anticoagulant at or near the inlet of the pump. The pump may include an impeller 205 in the cage 203 at the distal portion 115 of the cannula 105, and the anticoagulant is released from a port 252 in or near the proximal portion of the cage. Preferably, the proximal end of the cannula 105 terminates at a housing containing the motor 405, and the motor 405 is operatively coupled to the impeller by a drive cable extending through the cannula 105. In this method, the cannula 105 includes a drug lumen extending therethrough and terminating at the port. The method may include providing an anticoagulant in a reservoir in fluid communication with the drug lumen; inserting the cannula 105 into the vasculature of the patient to position the impeller in the innominate vein 939; operating the motor 405 to drive the impeller; and flushing the impeller with anticoagulant by releasing anticoagulant from the port. Preferably, the method includes operating the pump to reduce the pressure at lymphatic vessel 907, thereby draining lymph fluid from the patient's lymphatic system. The pump may include an impeller on the distal portion 115 of the cannula 105. The method may include: releasing anticoagulant from a port at the proximal portion 109 of the impeller; preventing coagulation or thrombosis from interfering with the operation of the impeller by releasing anticoagulant; or both. The anticoagulant may include heparin, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin, or fondaparinux. By using the flow restrictors 801, 301, the method may include restricting flow from the jugular vein to the innominate vein 939, thereby facilitating flow from the subclavian vein to the innominate vein 939.

Fig. 16 is a partial cross-sectional view of the impeller assembly 1601. The impeller assembly 1601 comprises an impeller housing 1603 in which an impeller 1605 is rotatably arranged. An expandable member 1607 is attached to the outside of the impeller housing 1603. The expandable member 1607 is depicted in an expanded state.

The impeller assembly 1601 may be designed to facilitate blood flow through the impeller housing 1603. To facilitate blood flow, the impeller housing 1603 can include a proximal inlet 1655. Preferably, the impeller housing 1603 includes at least four proximal inlets 1655. Proximal inlet 1655 may be generally rectangular and may include rounded corners. The impeller assembly 1601 may also include a distal outlet 1658. For example, the impeller assembly 1601 may include four to five distal outlets 1658. Preferably, the proximal inlet 1655 and distal outlet 1658 comprise substantially rounded features, such as rounded corners. The rounded feature is preferred because it provides a smooth contact surface for blood to flow through the impeller housing 1603. This can reduce the chance of damage to particles (e.g., blood cells) in the blood that occurs when the blood strikes a sharp surface.

In a preferred embodiment, the expandable member 1607 is attached to an outer surface of the impeller housing 1603. The expandable member 1607 may include a shape that promotes blood flow into the impeller housing 1603 when the expandable member 1607 is in an expanded state. In some embodiments, the expandable member 1607 forms a D-ring around the circumference of the impeller housing 1603. In a preferred embodiment, the expandable member 1607 forms an omega-shaped ring around the circumference of the impeller housing 1603. In other embodiments, the expandable member 1603 forms a substantially circular ring around the impeller housing 1603.

In the expanded state, the proximal face 1613 of the expandable member 1607 may be substantially aligned with the distal portion 1615 of the proximal inlet 1655. The distal face 1617 of the expandable member 1607 may be substantially aligned with the proximal extent 1619 of the distal outlet 1658.

In a preferred embodiment, the expandable member 1607 comprises an elastomeric film, such as a polyurethane film. The expandable member 1607 may be a balloon. The pouch may comprise a low hardness material, for example <80 shore D hardness or <70 shore D hardness or less than 60 shore D hardness or a hardness between 60 shore a and 60 shore D hardness.

The expandable member 1607 may include a fluid-tight space, i.e., an inflation space 1623, that is radially expandable relative to the impeller housing 1603. The impeller assembly 1601 may include an inflation tube 1627 connecting an inflation space 1623 to a lumen of the cannula 1602. The inflation tube 1627 may extend between the cannula 1602 and the inflation space 1623, e.g., parallel to the proximal stub 1633. The inflation tube 1627 may extend outside of the proximal stub 1633 (as shown). Alternatively, the inflation tube 1627 may extend inside the proximal stub 1633. Inflation tube 1627 may be coupled to inflation space 1623 by extending through the wall of expandable member 1607. Alternatively, the inflation tube 1627 may be connected with the inflation space 1623 by extending through the interface between the expandable member 1607 and the impeller housing 1603 or by extending through the wall of the impeller housing 1603. The fluid-tight space 1623 may include an inflation port for inflating the expandable member 1607.

Inflation tube 1627 may include an outer surface and an inner lumen. Inflation tube 1627 preferably sealingly penetrates into inflation space 1623. Penetration of inflation tube 1627 into inflation space 1623 may include sealing of the penetration area. The sealing may include a melting or bonding operation.

Fig. 17 is a side view of the impeller assembly 1701. An inflatable member 1707, such as a bladder, is attached to the outer surface of the impeller housing 1703. The expandable member 1707 may be generally toroidal in shape. The expandable member 1707 is depicted with light lines to show the structure below the expandable member 1707. A proximal face 1713 of the expandable member 1707 extends over the distal access area 1715. In this configuration, the proximal face 1713 of the expandable member 1707 provides a funnel to funnel blood flow to the inlet of the impeller housing 1703, thereby promoting blood flow through the device.

The impeller assembly 1701 is sized for insertion into a innominate vein. The expandable member 1707 is sized such that in the deployed state, the expandable member 1707 opposes a wall of the innominate vein to impede, direct, or guide blood flow into the impeller housing 1703. In some embodiments, the inner diameter of the expandable member 1707 is substantially equal to the outer diameter of the impeller housing 1703. The inner diameter of the expandable member 1707 may extend over a portion of the proximal portal. This arrangement helps to funnel blood to the impeller assembly 1701 without the distal edge of the inlet interfering with blood flow. In some embodiments, the proximal inlet is generally D-shaped with rounded features to prevent the blood cells from being sheared.

The expandable member 1707 may include a bonding region comprising a generally cylindrical section where the expandable member 1707 is bonded to the impeller assembly 1701. In some embodiments, the inlet region may include a conical member 1737 coaxial with the impeller. The tapered element 1737 may be proximal to the impeller and may be configured to minimize the flow recirculation zone.

Fig. 18 illustrates an exemplary inlet area 1855 of the impeller assembly 1801. The inlet region 1855 includes a tapered element 1837 having flow directing features that project radially outward from a surface of the tapered element 1837. These flow directing features may be aligned with the proximal stub. The drive element 1839 may extend through the tapered element 1837 and connect with an impeller disposed inside the impeller assembly 1601. In the illustrated embodiment, the inflation lumen 1827 is external to the impeller assembly 1801.

Fig. 19 shows an inlet region 1955 with an internal inflation lumen. The inflation lumen is inside the impeller housing 1903. The inflation lumen may be connected to and extend through the tapered element 1937. The inflation lumen may, for example, extend through a wall of the impeller housing 1903. Alternatively, the inflation lumen may be positioned inside the impeller housing 1903.

Fig. 20 is a detailed view of the proximal inlet 2055. The proximal access 2055 is defined by a proximal stub 2033. These proximal stubs 2033 extend parallel to each other, connecting the proximal portion 2041 of the impeller housing 2003 to the distal portion 2043 of the impeller housing 2003. The proximal stub 2033 is designed such that when the cannula is operated within a patient, the proximal stub 2033 can separate and direct blood flow to the impeller housing 2003 without causing a recirculation flow pattern. The proximal stub 2033 may include a proximal rim 2045 and a distal rim 2047. The proximal stub 2033 and rims 2045, 2047 may, for example, define a generally rectangular inlet area 2055. In some embodiments, the generally rectangular inlet region 2055 comprises a curved rectangular inlet. The curved rectangular inlet may have a chamfer, for example, around at least a portion of the edges 2045, 2047 of the inlet 2055. The chamfer may provide a gradual transition area for blood flow into impeller housing 2003.

In some embodiments, the proximal stub 2033 comprises a substantially constant width along the length of the proximal stub 2033. In other embodiments, the width of the proximal stub 2033 can vary, for example, the width of the proximal stub 2033 is greater at the proximal end than at the distal end, or vice versa. The proximal stub 2033 may include a first wall thickness and a second wall thickness, wherein the first wall thickness is greater than the second wall thickness. In some embodiments, the proximal stub 2033 can comprise a wedge-shaped wall thickness.

Preferably, the impeller housing 2003 is generally cylindrical in shape to facilitate passage through innominate veins. The impeller housing 2003 may include a plurality of internal diameters for manipulating blood flow through the impeller housing 2003 and such that blood flow experiences minimal disturbances, such as recirculation or turbulence, within or near the impeller assembly 2001. For example, the impeller housing 2003 may include a first inner diameter D1 and at least a second inner diameter D2, wherein the first inner diameter is larger than the at least a second diameter. In some embodiments, the impeller housing 2003 may include a stepped portion defined by a change in inner diameter. In some embodiments, impeller housing 2003 may include a wedge-shaped diameter, for example, defined by an inner diameter that tapers or decreases along the length of impeller housing 2003 toward one end.

Fig. 21 shows a side view of the impeller assembly 2101 with a rectangular proximal inlet 2155. This configuration can reduce blood recirculation at the proximal region of the impeller assembly 2101 by providing a larger inlet area at the distal most region of the inlet 2147.

Fig. 22 shows an impeller assembly 2201 having an arcuate proximal stub 2233. The arcuate proximal stub 2233 extends longitudinally and radially. In some embodiments, the curved proximal stub 2233 comprises a tubular member. These tubular members may be welded to the impeller assembly 2201 to connect the proximal portion 2241 of the impeller housing 2203 to the distal portion 2243 of the impeller housing 2203. The arcuate proximal stub 2233 may be connected to a proximal portion 2241 of the impeller housing 2203 that is integral with the cannula shaft. The curved proximal stub 2233 can comprise a unitary structure. The overall structure may include a 3D printed structure.

The impeller assembly 2201 may be mounted distally to a cannula shaft (not shown) that includes a plurality of lumens, and at least one of the lumens is sealingly connected to an expandable member 2207 attached to an outer surface of the impeller housing 2203.

Fig. 23 shows a side view of a proximal portion of impeller assembly 2301. The proximal portion of the impeller assembly 2301 includes a proximal hub 2383, a proximal inlet 2355, and a body section 2385. The proximal hub 2383 may be configured to promote a smooth flow pattern as fluid (e.g., blood) is directed into the proximal inlet 2355. The hub 2383 can include an axial cross-section with a generally circular outer geometry to facilitate movement within the vein. The hub 2383 may include a wedge geometry. For example, the cross-sectional diameter of the hub 2383 can decrease along the length of the hub 2383 from the first end to the second end. The hub 2383 can have a wedge-shaped outer geometry that can include a proximal diameter, an intermediate diameter, and a distal diameter, wherein the intermediate diameter is greater than the proximal diameter or the distal diameter, and transitions between the proximal diameter, the intermediate diameter, and the distal diameter are substantially smooth. The curve between the proximal diameter, the intermediate diameter and the distal diameter may be free of inflection points.

Fig. 24 shows an impeller assembly 2401. The impeller assembly 2401 includes an impeller housing 2403 in which an impeller 2405 is rotatably disposed. An expandable member 2407, depicted in phantom, is attached to an outer surface of the impeller housing 2403, the expandable member 2407 being shown in an expanded state.

The impeller assembly 2401 is designed to facilitate the flow of blood through the impeller housing 2403. Impeller assembly 2401 may include rounded corners 2435 below the proximal end of proximal stub 2433 to provide mechanical support and prevent recirculation of blood in these areas when the cannula is positioned intravenously. In some embodiments, the proximal stub 2433 tapers toward its distal end.

Fig. 25 shows an elongated impeller assembly 2501. Elongate impeller assembly 2501 includes an expandable member 2507 spaced apart from proximal inlet region 2555. Expandable member 2507 can be, for example, approximately 1-25cm from proximal entry region 2555. Preferably, the expandable member is at least 1cm from the proximal entry region 2555.

Fig. 26 shows a cross-sectional view of the impeller assembly 2601. The impeller assembly 2601 includes an impeller housing 2603, with an impeller 2605 rotatably disposed therein. The impeller assembly 2601 includes a distal portion 2645. The distal portion 2645 may include a generally disc-shaped tip 2647. The distal portion 2645 can have an at least partially planar surface. The disc-shaped tip 2647 can be spaced apart from a proximal surface of the distal portion 2645.

The impeller 2605 may include a substantially fixed axial position relative to the impeller housing 2603. The distal portion 2645 may include a substantially fixed axial position relative to the impeller housing 2603. The fixed axial position of the impeller 2605 and the distal portion 2645 may define a distal void 2651 between the distal portion 2645 and the impeller 2605. Gap 2651 is preferably greater than 5 um. Gap 2651 may be greater than 10um or 20 um. The voids 2651 may preferably be less than 150um, 120um or 100 um. Ideally, gap 2651 is between 25um and 50 um.

Fig. 27 is a cross-sectional view of the impeller assembly 2601 within a vein 2756. The impeller assembly 2701 includes an impeller housing 2703 with an impeller 2705 within the impeller housing. The impeller housing 2703 has an expandable member 2707 attached to an outer surface of the impeller housing 2703.

The impeller 2705 includes at least one blade 2753. The blade 2753 includes a proximal end and a distal end. The core diameter of the impeller 2705 includes a proximal end and a distal end. The core diameter proximal end is the proximal end of the blades 2753. The core diameter distal end and the blade distal end terminate substantially in the same axial region. The core diameter is smallest at the proximal end of the impeller 2705 and largest near the distal end of the core diameter. The core diameter may include a curved wedge surface.

The proximal end of the impeller 2705 core diameter may be spaced from the distal end of the ferrule 2761. The proximal end of the impeller 2705 core diameter and the distal end of the ferrule 2761 include a controlled proximal clearance. The voids 2751 are preferably greater than 5 um. The voids 2751 can be greater than 10um or 20 um. The voids 2751 may preferably be less than 150um, 120um, or 100 um. Ideally, the gap 2751 is between 25um and 50 um.

The impeller 2705 may include an inner diameter that extends through at least a portion of the length of the impeller 2705 and is coaxial with the impeller 2705. The impeller 2705 may comprise a bearing arrangement distal to the distal surface. The bearing surface may comprise a ball bearing arrangement, such as a ceramic bearing arrangement or a PTFE or PEEK bearing surface arrangement.

Fig. 28A-28F illustrate the attachment and folding of the expandable member 2807. In particular, these figures detail the attachment of the expandable member 2807 to the outer surface of the impeller housing 2803, as well as the folding of the expandable member 2807 as it is inflated or as the cannula is delivered or withdrawn.

Fig. 28A is a partial cross-sectional view of the impeller assembly 2801. A cross-sectional portion delineated by dashed lines and labeled B illustrates a portion of the expandable member 2807 and is enlarged in fig. 28B. The expandable member 2807 includes at least one coupling 2863 to attach the expandable member 2807 with the impeller housing 2803. The coupling 2863 may create a sealed annular space in the expandable member 2807.

The coupling 2863 may include a laser weld joint, a solvent weld joint, an adhesive weld joint, a hot air or heated surface weld joint, or any other similar type of attachment. The coupling 2863 may include a prepared outer surface of the impeller housing 2803 to which the expandable member 2807 is attached. For example, the impeller housing 2803 may be prepared such that the impeller housing 2803 includes at least one of: a primer surface, a chemically activated surface, a plasma activated surface, a mechanically abraded surface, a laser ablated surface, an etched surface, or a textured surface. The prepared outer surface of the impeller housing 2803 may include a surface roughness, a patterned surface, or a high energy surface.

Referring to fig. 28B, the expandable member 2807 may include at least one neck 2867, and the neck 2867 may be sized to couple with the impeller housing 2803. The expandable member 2807 may include a joint distal end 2831 and a joint proximal end 2832. The shape of the distal end 2831 may be configured to change as the expandable member is inflated/deflated (compare fig. 28B, 28D, and 28E) or as the cannula is moved within the vein. In particular, the joint distal end 2831 may include a distal neck section joined to the impeller housing 2803, and a distal transition section 2845 integral with the neck 2867 but not attached to the impeller housing 2803. As the expandable member 2807 is inflated, the distal transition segments 2867 may fold inward. The joint proximal end may include a neck 2832 joined to the impeller housing 2803, and a proximal transition section integral with the neck but not joined to the impeller housing. The expandable member 2807 may be configured to be substantially rigid in the expanded configuration. The expandable member 2807 may be configured to be compliant in the expanded configuration. The expandable member 2807 may be made of a polyurethane or pebax or nylon material. The expandable member 2807 may be made of polytetrafluoroethylene.

Fig. 28C is a partial cross-sectional view of the impeller assembly 2801, with the expandable member 2807 partially inflated. This portion of the expandable member 2807 (labeled D) is shown in enlarged partial cross-section in fig. 28D. Notably, the shape of the distal neck changes as the expandable member 2807 is inflated (compare fig. 28D where the expandable member is partially inflated with fig. 28B where the expandable member is fully inflated).

Fig. 28E is a partial cross-sectional view of an impeller assembly 2801 with a moderately inflated expandable member 2807. The portion of the expandable member 2807 shown in partial cross-section is enlarged in fig. 28F (labeled F). In particular, the expandable member 2807 is more inflated than the expandable member 2807 shown in fig. 28D. Upon inflation of the expandable member 2807, the distal transition sections 2845 may fold outward to eliminate potential recirculation zones at the interface between the bladder and the housing 2803.

Fig. 29 shows an impeller assembly 2901 having an expandable member 2907 with an elongate surface 2974 to interface with a vessel wall. The elongated surface 2974 increases the interaction between the blood vessel and the impeller assembly 2901 to limit movement of the impeller assembly within the blood vessel. Inflatable member 2907 may include a compliant material. The compliant material may be polyurethane or silicone. The compliant material may stretch 100% to 800%, creating an elongated surface 2974. In other embodiments, inflatable member 2907 may include a non-compliant material that is inflatable to a particular size or range of sizes, even when internal pressure is increased.

Fig. 30 shows an impeller assembly 3001 having a two-piece expandable member 3007. The two-piece expandable member 3007 includes a first portion 3065 comprising a compliant material and a second portion 3066 comprising a non-compliant material. The first 3065 and second 3066 portions may be attached to each other and to the impeller housing 3003 to define an inflated annular space. Preferably, the first portion 3065 of the expandable member 3007 includes the portion of the expandable member 3007 that interacts with the vessel wall during operation of the cannula.

Fig. 31 is a partial cross-sectional view of the distal portion of the cannula 3101. The distal portion of the cannula 3101 is attached to the impeller housing 3103 with the expandable member 3107 mounted to the outer surface row of the impeller housing 3103. The impeller housing 3103 is connected to the distal portion of the cannula 3101 by a plurality of proximal stubs 3133. The proximal stub 3133 preferably comprises a flexible material, such as latex, silicone, or teflon, in order to be easier to guide within the patient's vein. The proximal stub 3133 may be configured to conform to anatomical curvature. The drive shaft 3139 connecting the motor to the impeller disposed within the impeller housing 3103 may include a flexible drive cable.

Fig. 32 is a partial cross-section of the self-expanding impeller assembly 3201. The impeller assembly 3201 includes an impeller housing 3203 in which an impeller 3205 is disposed. The expandable body 3207 is attached to a surface of the impeller housing 3203 between the proximal inlet 3255 and the distal outlet 3258.

In the expanded configuration, expandable body 3207 is configured opposite a vein wall over a longitudinal section of the vein. The longitudinal attachment section extends proximally to a proximal inlet 3255. The longitudinal attachment section extends distally to the distal inlet 3258. Expandable body 3207 is configured to provide a proximal funnel extending from an area of attachment to a vessel wall to a distal end of inlet port 3255. The proximal inducer funnel is configured to promote a converging flow pattern at the entrance to the proximal inlet 3255. Expandable body 3207 may be configured to provide a distal flow-directing funnel extending from a proximal region of outlet 3258 to a region of attachment to a vessel wall to a distal end of outlet 3258. The distal diversion funnel may be configured to promote a divergent flow pattern distally exiting from the outlet 3258. The divergent flow mode may be configured to gradually decelerate the fluid distal the outlet and maintain a large proportion of the pressure gain generated by the impeller 3205 by reducing recirculation or negative velocity flow modes.

Expandable body 3207 may include a nitinol, non-compliant, or porous membrane. A longitudinal section of expandable body 3207 may include a compliant material. Preferably, the funnel of the expandable body 3207 comprises a relatively low compliance material (or semi-compliant material or non-compliant material).

The cannula 3200 may include a plurality of pull wires 3279 attached to the expandable body 3207 and configured to facilitate collapse of the expandable body 3207 in preparation for removal of the cannula 3200 from the body.

Fig. 33 shows a partial cross-section of the impeller assembly 3301. The impeller assembly 3301 includes proximal stubs 3333 that attach the proximal portion 3341 of the impeller housing 3301 to the distal portion 3343 of the impeller housing 3301. The at least one proximal stub 3333 includes an inflation lumen, i.e., an integrated inflation channel, that extends through the proximal stub 3333 to inside the expandable member 3307 attached to the outer surface of the impeller assembly 3301. The inflation lumen provides a structure for inflating the expandable member 3307. The inflation lumen preferably terminates within the inlet to minimize disruption to flow within the housing. This is facilitated by the more proximally located expandable member 3307.

Fig. 34 shows the inlet 3433 of the impeller assembly 3401. The inlet 3433 is configured to facilitate fluid flow into the assembly 3401. This configuration includes a proximal hub 3480 having at least one runner 3481. Runner 3481 extends from a proximal region of proximal hub 3480 and terminates at inlet 3433. Runner 3481 extends between first stub 3433 and second stub 3434. Flow channel 3481 can be configured to regulate the flow of blood upstream of the inlet. For example, flow channel 3481 can taper inwardly along the length of flow channel 3481 toward entrance 3433.

Fig. 35 is an exemplary cannula system 3500. In particular, fig. 35 illustrates a cannula 3500 in accordance with aspects of the present invention, showing the interaction between the impeller assembly 3501 of the cannula 3500 and the vessel wall 3556. The cannula 3500 includes an impeller assembly 3501, a cannula shaft 3581, a proximal expandable member 3508, a hub 3583, and a motor (not shown).

The impeller assembly 3501 is sized for placement within a blood vessel, with the shaft 3581 extending from the impeller assembly 3501 to a location outside of the patient's body. Shaft 3581 may include a multi-lumen shaft. The first proximal expandable member 3508 is attached to the shaft 3581 and may be configured to restrict blood flow to the impeller assembly 3501.

The motor may be connected to an impeller housed within the impeller assembly 3501 and may be configured to drive the impeller at high RPM. The impeller assembly 3501 may include a distal expandable member 3507 mounted onto an outer surface of the impeller housing 3503 and encasing the impeller housing 3503, e.g., similar to an expandable ring. Distal expandable member 3503 may be configured to adhere to a vessel wall 3556 during operation of the cannula.

The proximal expandable member 3508 may be mounted on the cannula shaft 3581 proximal of the impeller assembly 3501. The proximal expandable member 3508 may be spaced apart from the impeller assembly 3501. For example, the proximal expandable member 3508 may be a distance of 1-10cm upstream of the impeller assembly 3501, preferably about no more than about 5 cm.

The proximal expandable member 3508 can be sized to be placed (inflated) between the vascular access site and the outflow port of the thoracic catheter 3585. The expandable members 3507, 3508 are preferably configured to atraumatically contact the vessel wall.

In some embodiments, the proximal expandable member 3508 may be configured to reduce the amount of blood flowing in the blood vessel by obstructing blood flow. Proximal expandable member 3508 may be configured to adjust the amount of blood flowing in a blood vessel by obstructing, restricting, guiding, or directing blood flow. For example, the proximal expandable member 3508 may include an aperture to facilitate fluid flow through the expandable member 3508 when the expandable member 3508 is in the expanded state. For example, the aperture can substantially comprise one of an annular ring or a crescent shape, wherein the lumen passes through the body of expandable member 3508. The holes may include valleys or depressions in the outer surface of the expandable member 3508. The aperture may include a channel below the expandable member 3508. The expandable member 3508 may include a shape that defines the aperture. For example, expandable member 3508 can be at least partially shaped as a sphere, a cone, a cylinder, and the aperture can comprise an annular ring or a crescent. The shape of the expandable member 3508 may include, for example, a double D shape, and the aperture may be defined by a surface between two joined shapes. The expandable member 3508 may include a helical shape that wraps around the cannula shaft 3581, and the bore may include a passage defined by the space between adjacent helices.

The proximal expandable member 3581 can include a compliant material, and the compliant material can include a compliant pressure relationship. Inflatable member 3581 may be manufactured such that the compliant pressure relationship is repeatable. Expandable member 3581 can include a calcined member. Expandable member 3581 may be configured to achieve a precise diameter at a given pressure. The expandable member 3581 may be configured to have minimal hysteresis when inflated, deflated, and re-inflated.

The hub 3583 can be configured to facilitate inflation of the distal expandable member 3507 and can be configured to at least partially inflate the proximal expandable member 3508. For example, hub 3583 may include a passageway to one or more lumens extending through cannula shaft 3581 and connected to proximal expandable member 3508 and/or distal expandable member 3507. The expandable members may be inflated by injecting fluid into the lumen from hub 3583. Hub 3583 may be configured to inflate proximal expandable member 3508 into attachment with a innominate blood vessel.

The device may include a connector cable 3585 configured to connect the cannula to a console (not shown) that may include a computer having hardware, software, and a user interface. The console may be configured for operating the device.

Fig. 36 shows a cannula 3600 with an expandable member 3608 slidably mounted along a shaft 3681 of the cannula 3600. The cannula 3600 includes a first cannula shaft 3681 and a second cannula shaft 3682. The cannula 3600 includes an impeller assembly 3601 attached to a distal end of the first cannula shaft 3681. A proximal expandable member 3608 is mounted near the distal end of the second cannula shaft 3682.

The first cannula shaft 3681 may include a multi-lumen tubing, wherein the first lumen is configured to facilitate inflation of the distal expandable member 3607, while the second lumen is configured to transmit mechanical or electrical energy to facilitate operation and control of an impeller disposed within the impeller assembly 3601.

The second cannula shaft 3682 can include a multi-lumen tubing, wherein the first lumen is configured to enclose the first cannula shaft 3681 and the second lumen is configured to inflate the proximal expandable member 3608. The first cannula shaft 3681 and the second cannula shaft 3682 may be configured to facilitate relative axial movement (indicated by the arrows) between the distal expandable member 3607 and the proximal expandable member 3608. The relative axial movement may be limited distally. The relative axial movement may be limited proximally. The cannula 3600 may include first and second stops, and axial movement of the second shaft 3682 may be limited by the first and second stops. The first and second stops may be mounted on the first shaft 3681, external to the patient (inside or around the hub). The axial movement may comprise a fine movement. The fine movement may comprise, for example, a screw thread or a ratchet mechanism.

Relative axial movement between the distal expandable member 3607 and the proximal expandable member 3608 may provide better anatomical placement, i.e., placing the distal expandable member 3607 accurately in the innominate vein and then placing the proximal expandable member 3608 accurately between the vessel wall access site and the chest catheter.

The first shaft 3681 and the second shaft 3682 may extend outside of the patient's body. During use, the second shaft 3682 can be coupled and decoupled from the first shaft. In the collapsed state, the cannula may be sized for advancement through the lumen of the valve and sheath. The second shaft 3682 may include a distal section and a proximal section. The distal section may comprise a tubular member and an inflation lumen, wherein the proximal expandable member is sealingly welded (glued) to the distal section so as to create an inflation space in the expandable member 3607 in fluid communication with the inflation lumen.

The proximal section of the second shaft may include an inflation lumen, and members configured to transmit axial pushing and pulling forces to the distal section of the second shaft 3682. The proximal section of the second shaft may be concentric or eccentric to the first shaft. The inflation lumen of the proximal section may be integral with the wall of the proximal section of the second shaft.

Fig. 37 shows a fluid passage across the expandable member 3708 that allows a controlled amount of blood flow. The proximal expandable member 3708 can be configured to oppose a vessel wall. The proximal expandable member 3708 can include a flow channel 3706, the flow channel 3706 defining a lumen through the body of the expandable member 3708. Flow is indicated by black arrows. Flow channel 3706 can include a collapsed state and an expanded configuration. The flow channel 3706 can be configured to expand when the expandable member 3708 is inflated. The expandable member 3708 can include at least one inner membrane that can be configured to support the body flow channel 3706 when in an expanded state. The proximal expandable member 3708 can be configured to allow 100ml or more of fluid per minute to pass through the expandable member 3708.

Figure 38 shows an insertion tube 3800 having an alternative bypass channel 3806. The second shaft 3882 includes a tubular member having a distal end and a proximal end, and a lumen 3883 extending through the distal and proximal ends. The lumen 3883 may be sized to provide a fluid flow path in the distal section below the inflated expandable member 3808. The second shaft 3882 may include an access port 3885 at a proximal end of the distal section of the second shaft 3882, which may be configured to facilitate blood flow into the fluid flow path.

Fig. 39 shows a patient interface 3900 with a sheath 3904 in this situation. The proximal expandable member, the flow entry port, and the pressure sensor may be on the sheath. The cannula system may include a cannula including an impeller assembly at the distal end of the elongate shaft and a flow control sheath 3904 including a flow restrictor, a fluid channel, and a pressure sensor.

The system may be configured to be percutaneously inserted into a vein of patient 3908. Inserting the cannula includes inserting percutaneously into the neck region. The flow control sheath 3904 may be configured to be placed to provide an access platform for other components of the system. The flow control sheath 3904 can include a flow restrictor adjacent the tip. The occluder may include an expanded state and a collapsed state. In the collapsed state, the occluder may be configured to fully collapse onto the shaft of the sheath. In the collapsed state, the OD of the flow restrictor may be substantially the same as the axis of the sheath. In the collapsed configuration, the flow restrictor may be located in an annular recess in the diameter of the shaft of the flow control sheath. In the expanded configuration, the flow restrictor may be configured to at least partially restrict fluid flow through the jugular vein. The flow restrictor may be configured to control flow through the jugular vein. The flow restrictor may be configured to prevent inadvertent displacement of the flow control sheath during surgery.

The flow control sheath may include a pressure sensor that may be configured to measure pressure in the vein upstream of the flow restrictor. The sheath may include a lumen in a sheath wall, and the pressure sensor may be positioned in the lumen. The pressure sensing lumen may include a port that may be configured to establish a hydrostatic connection between blood in the vein and the pressure sensor. The pressure sensor and the pressure sensing lumen may be sized to prevent blood flow into the pressure sensing lumen.

Fig. 40 shows a patient interface 4000 holding a sheath 4004 by an adhesive film 4010 in this case. The adhesive member 4010 helps maintain a sterile area around the access site and secures the hub 4080 of the sheath 4004 to the skin. This reduces irritation to the patient from movement of the hub 4080 by accidental forces. The membrane 4010 can be shaped to allow the addition of a second or third layer to connect the sheath 4004 or all of the various system elements of the cannula together or to the skin.

Fig. 41 shows a flow control sheath 4150. A number of different features of the flow control sheath 4150 are shown according to some preferred embodiments. In particular, the flow control sheath 4150 may include a flow restrictor 4151 (shown in an inflated state), a sheath tip 4152, a port 4153, a pressure sensor 4154, a sheath shaft 4155, and a hub 4159, the hub 4159 including a pressure sensor lead 4156, an inflation side port 4157, and a flush and inject side port 4158. At least one suture hole may be added to the hub 4159 to facilitate fixation to the patient.

Fig. 42 shows a proximal portion of a cannula system 4200. A cannula 4269 (similar to the cannula described in fig. 40) is disposed in the cannula sheath 4280. The cannula 4269 includes a shaft 4270, a proximal expandable member 4271 (depicted in an expanded state), and a cannula pressure sensor 4273. The sheath 4280 comprises a sheath tip 4272, a sheath pressure sensor 4274, a sheath shaft 4275, a pressure sensor lead 4276, an inflation side port 4277, and a hub 4278.

Fig. 43 illustrates a locking mechanism 4300 used to secure a cannula shaft 4392 to a hub 4391 of a sheath 4390 during therapy. The locking mechanism 4300 includes an arm 4396, wherein a cannula shaft grip 4395 is attached to the distal end of the arm 4396. When engaged, the cannula shaft grip 4395 attaches to the cannula shaft 4392 to prevent movement. The locking mechanism 4300 is advantageous because it prevents the distal expandable member of the cannula system described above from shifting during therapy. The locking mechanism 4300 is configured to lock the cannula shaft 4392 to the sheath 4390 during at least a portion of a procedure.

The locking mechanism 4300 may be configured to be easily engaged and disengaged. The locking mechanism may be configured to prevent relative movement between the cannula distal pouch and the access sheath 4390. The locking mechanism 4300 may include a clamp 4395 on the locking mechanism 4300; the clamp on the mechanism 4300 may be configured to clamp onto the cannula shaft 4392 from one side of the shaft 4392. The lock mechanism 4300 may be pre-mounted on the quill shaft 4392 so that when securing is desired, the lock mechanism 4300 may slide into place.

The locking mechanism may be integral with the sheath. The locking mechanism may optionally be attached to the sheath. Preferably, the locking mechanism may be a Tuohy Borst type locking mechanism.

FIG. 44 shows the lock mechanism 4300 engaged with the cannula shaft.

Fig. 45 shows a schematic view of a push lock mechanism 4500.

Fig. 46 shows an alternative locking mechanism 4600. The locking mechanism 4600 includes an arm 4696 attached to the hub 4691 of the sheath 4690. The arm 4696 includes a cannula shaft grip 4695 attached to the distal end of the arm 4696. When engaged, the cannula shaft grip 4695 attaches to the cannula shaft 4692 to prevent movement. Additional embodiments of the locking system may include a C-shaped shaft that may be secured to the cannula shaft proximal to the sheath. The shaft will be configured such that an interference lock is created between the cannula shaft OD and the sheath ID when the shaft is slid into the sheath hub.

Fig. 47 is a partial cross-sectional view of the jugular vein 4752 showing the flow sheath 4750 inserted therein. The flow restrictor 4751 of the sheath 4750 is shown in a deployed state with the flow restrictor 4751 opposite the wall of the jugular vein 4752. In a preferred position, the shaft 4755 of the sheath 4750 terminates adjacent to the intersection of the subclavian vein 4753 and the thoracic catheter 4756. The hub 4759 is external to the jugular vein 4752.

Figure 48 illustrates an indwelling cannula system 4800 according to aspects of the present invention. Indwelling cannula system 4800 includes a cannula shaft 4851 with an impeller assembly 4861 mounted to the distal portion of the cannula shaft. Cannula shaft 4851 includes a proximal expandable member 4850 attached to the outer surface of cannula shaft 4851. Proximal expandable member 4850 includes a flow channel 4854 that allows fluid to bypass proximal expandable member 4850 at a controlled rate.

FIG. 49 is a section taken along line A-A of FIG. 48 showing the lumen of the cannula shaft 4851. These lumens are internal to extend through the cannula shaft 4851. A proximal expandable member lumen 4901 for delivering fluid (i.e., gas or liquid) for inflating the proximal expandable member 4850 is shown. A separate distal expandable member lumen 4902 is provided to deliver fluid to inflate expandable member 4862. The separate lumens allow the proximal and distal expandable members 4850, 4862 to be manipulated independently of each other during treatment. A pressure sensor lumen 4966 is provided for one or more pressure sensors disposed on the cannula system 4800 to send and receive electrical signals. One or more reinforcement lumens 4930 may be provided to reinforce the cannula 4800 so that the cannula 4800 may be more easily guided through the body.

Figure 50 shows an indwelling cannula 5000. The cannula 5000 includes mechanical components (e.g., an impeller 5005 and/or a drive shaft 5007) as well as a cleaning system. The cleaning system functions to exclude biological fluids and materials from the cannula 5000 and mechanical components operating within the cannula 5000. In this manner, bodily fluids are prevented from entering the crevices of the cannula 5000, thereby ensuring smooth and efficient operation of the mechanical parts within the cannula 5000 (e.g., the impeller 5005 and the drive shaft 5007) while also preventing patient fluid from flowing to the proximal portion of the cannula 5000 outside the patient where bodily fluids may leak from the cannula. The cleaning system will further prevent air from passing through the same channel into the vein.

The cannula 5000 may be used to reduce pressure in the venous system region. The cannula 5000 includes an impeller assembly 5009 mounted at the distal end of the cannula 5000. The impeller assembly 5009 includes an expandable member 5013, a cage 5015 having an inlet area 5017 and an outlet area 5019, and an impeller therein. The impeller 5005 can rotate within the cage 5015 at high RPM. The impeller 5005 can further include a distal surface, a proximal surface, and an impeller blade surface. The distal surface, proximal surface, and impeller blade surface are configured to rotate within the cage in close proximity to, but not in contact with, the adjacent surface.

The impeller assembly 5009 can further include a ferrule 5023. The ferrule 5023 can include a distal surface 5025 and a proximal surface 5027. The impeller 5005 rotates in the gap of the distal surface of the ferrule 5023.

The gap between the ferrule distal surface 5025 and the impeller 5005 comprises a proximal void 5029, and the proximal void 5029 is configured to remain stationary during operation. The proximal void 5029 is configured to define a transition between the static cuff and the rotating impeller 5005. The proximal void 5029 is configured to allow blood to flow through the proximal void 5029 without flow disruption, flow recirculation, or turbulence. The proximal void 5029 can be in fluid communication with a cannula lumen that is in fluid communication with a fluid reservoir outside of the patient. The proximal void 5029 can be configured to prevent blood flow into the proximal void 5029.

In a preferred embodiment, the proximal void 5029 comprises a resistive fluid pressure configured to prevent blood from entering the proximal void. For example, the resistive fluid may be a wash fluid delivered from a fluid reservoir outside the patient. The cleaning fluid may be used to clean or flush the proximal void 5029, thereby removing debris; such as described in commonly owned U.S. patent application 62/629,914, which is incorporated herein by reference. The resistive fluid pressure may comprise hydrostatic pressure, which may comprise fluid pressure pulses. The fluid pressure comprises a solution, which may comprise saline, glucose or heparin solution.

The viscosity of the cleaning solution can be adjusted to effectively clean small voids and pores. The solution may also be immiscible with blood to prevent blood from contacting the clear surface. For example, the solution may be a hydrophobic solution. In some embodiments, the proximal void 5029 can comprise a seal, such as a spring-loaded seal.

The gap between the distal-most surface of the impeller 5005 and the tip 5031 comprising the bearing housing 5033 can comprise the distal void 5041, and the distal void 5041 can be configured to remain stationary during operation. The distal void 5041 may be configured to define a transition between the rotary impeller 5005 and the static tip 5031. The distal void 5041 may be configured to allow blood to flow through the distal void without flow disruption, recirculation, or turbulence.

In a preferred embodiment, the distal void 5041 is in fluid communication with a cannula lumen that is in fluid communication with a fluid reservoir external to the patient. The distal void 5041 may be configured to prevent blood flow into the distal void, for example, by providing purging from a fluid reservoir as described above. The distal void 5041 may include a resistive fluid pressure configured to prevent blood from entering the distal void. The resistive fluid pressure comprises a hydrostatic pressure. The fluid resistance pressure comprises fluid pressure pulses. The fluid pressure comprises a solution, such as saline, glucose or heparin solution. The viscosity of the cleaning solution can be adjusted to effectively clean small voids and pores. The solution may also be immiscible with blood to prevent blood from contacting the clear surface. The solution may be a hydrophobic solution. The distal void 5041 may include a seal, such as a spring-loaded seal.

Fig. 51 is an enlarged view of the dotted circle B of fig. 50 according to an embodiment of the present invention. In this embodiment, fluid is delivered from a wash channel 5101 extending along the central lumen of the device. The purge passage may be external to the PTFE liner surrounding the central lumen of the cannula.

Fig. 52 is an enlarged view of the dotted circle B of fig. 50 according to another embodiment of the present invention. In this embodiment, the cleansing fluid is delivered from a reservoir outside the patient via a cleansing channel 5201 that travels through the lumen for inflating the expandable member 5013. Purge channel 5201 is external to the PTFE liner of the drive cable.

Fig. 53 is an enlarged view of the dashed circle B of fig. 50, in accordance with various embodiments of the present invention. In this embodiment, the cleaning fluid is delivered from the cleaning channel 5301, which cleaning channel 5301 extends through the PTFE liner surrounding the drive lumen.

Figure 54 illustrates distal flushing of the indwelling cannula 5400. The flush fluid (i.e., cleaning fluid) is delivered through the inner lumen 5403 of the expandable member 5407. The flushing fluid travels through the inner cavity 5403 and the distal bearing housing 5411, thereby preventing blood from flooding the bearings of the cannula. The cleansing fluid flows into the distal void 5431, thereby irrigating and preventing blood from filling the distal void 5431. The cleaning fluid travels down the second lumen 5437 to the proximal void 5439 and flushes blood from the proximal void 5439.

Figure 55 illustrates distal flushing of indwelling cannula 5500 according to various embodiments. In this embodiment, the cleansing fluid is delivered via a cleansing lumen 5505 that is separate and distinct from the lumen used to inflate the expandable member 5507. The purging liquid travels through the purge lumen 5505 and into the distal bearing housing 5511, thereby preventing blood from flooding into the cannula's bearings. The clearing fluid flows into distal void 5531, thereby flushing and preventing blood from filling distal void 5531. The cleaning fluid then travels down second lumen 5537 to proximal void 5539 to flush blood from proximal void 5539.

Figure 56 shows an indwelling cannula 5600 with a cleaning system. Cannula 5600 includes a central lumen 5603 optimized for delivery of cleaning fluids and maintaining concentricity of the cannula 5600 components. The internal structure of central lumen 5306 can have various configurations, some of which are detailed below in a cross-section taken along line a-a through cuff 5606.

Fig. 57 illustrates a cross-section of the central lumen 5603 taken along line a-a of fig. 56, according to one embodiment of the present invention. In this embodiment, the purge channel 5709 is external to a drive shaft 5711 that connects the motor to the impeller of the device. A profiled extrusion 5713 is located between the purge channel and the drive shaft 5711. The profiled extrusion 5713 includes a plurality of projections 5715, for example, at least two projections 5715, and preferably three projections 5715, the projections 5715 extending outwardly from a central hub 5717 surrounding the drive shaft 5711. Profiled extrusions 5713 optimize the cleaning cross-sectional area and also help maintain assembly concentricity.

Fig. 58 illustrates a cross-section of the central lumen 5603 taken along line a-a of fig. 56, in accordance with various embodiments of the present invention. In this embodiment, the purge passage 5809 is associated with a drive shaft 5711 that connects the motor to the impeller of the device. Purge channel 5809 is defined by profiled extrusion 5813. The profiled extrusion 5813 includes a plurality of extensions 5815, such as at least two extensions 5815, and preferably three extensions 5815, which extensions 5815 extend inwardly from an outer hub 5817 surrounding the drive shaft 5711. Profiled extrusion 5813 defines and optimizes the cleaning cross-sectional area and maintains assembly concentricity.

Fig. 59 illustrates a cross-section of the central lumen 5603 taken along line a-a of fig. 56, according to another embodiment of the present invention. In this embodiment, the central lumen 5603 houses a coil drive shaft 5905 that connects the motor to the device impeller. The cleaning channel 5909 encircles the coil drive shaft 5905. The purge passage 5909 is defined by an outer hub 5911 surrounding the coil drive shaft 5905.

Fig. 60 shows an optimized guide surface 6001 of a cage inlet 6003. Referring to fig. 27, the optimized guide surface 6001 includes a portion of a cuff 6007 that tapers toward the impeller 6011 in coordination with the outer boundary surface 6015. The optimized guide surface 6001 maintains axial momentum and prevents recirculation of fluid 6017 into the cage assembly 6021. In particular, the optimized guide surface 6001 tapers in a manner that creates flow field convergence and minimizes fluid divergence in the inlet region 6003. The optimized guide surface 6001 may include a curved wedge-shaped cross-section. The optimized guide surface 6001 may be configured to reduce the cross-sectional area flatly along the length of the inlet 6003. For example, the variation in cross-sectional area of the optimized guide surface 6001 along the length of the inlet 6003 may be less than or equal to about 1mm². The optimized guide surface 6001 may include a curved taper. The optimized guide surface 6001 may include a cylindrical cross-section. The optimized guide surface 6001 may include a generally conical cross-section.

In some embodiments, the outer boundary surface 6015 tapers over at least a portion of the inlet region 6003. Referring to fig. 17, the outer boundary surface 6015 may comprise the proximal surface of the expandable member. Alternatively, the outer boundary surface 6015 may comprise the inner surface of the cage.

Figure 61 shows a suboptimal guide surface 6105. The suboptimal guide surface 6105 can cause a flow disturbance 6107 of the fluid flowing into the inlet region 6111. In particular, the sub-optimal guide surface 6105 includes a steeper profile than the optimized guide surface 6017 of fig. 60. The steeper profile results in a change in axial momentum and divergent flow of blood fluid into the inlet region 6111. These flow disturbances 6107 are prevented by the optimized guide surface 6017.

Fig. 62 shows a cage entrance 6201. The following optimal configuration is shown: wherein the fluid flow 6207 is aligned with the inlet 6201 along the optimized guide surface 6017. The flow 6207 is primarily in the X direction with no rotational component promoting a smooth flow entry 6201.

Fig. 63 shows a sub-optimal inlet configuration 6301. The sub-optimal configuration includes a steep guide surface 6105 that causes recirculation and impedes flow in the inlet. The rotational component of velocity dominates and carries the flow below the inlet stub 6215. This phenomenon creates an interrupted flow 6217 in the inlet 6301 and reduces the effectiveness of the inlet 6301 to direct flow to the impeller.

Is incorporated by reference

Throughout this disclosure, other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been referenced and cited. All of these documents are hereby incorporated by reference in their entirety for all purposes.

Equivalents of

Various modifications of the invention, in addition to those shown and described herein, as well as many other embodiments thereof, will be apparent to those skilled in the art from the entire contents of this document, including the references to the scientific and patent documents cited herein. The subject matter herein contains important information, exemplification and guidance which can be applied to the practice of this invention in its various embodiments and equivalents thereof. The scope of the present invention is not intended to be limited to any one of the exemplary embodiments shown or described herein. Rather, any one or more features of any exemplary embodiment shown or described may be combined with any other embodiment as long as the combination does not render the invention inoperable.