阅读说明：本技术 可转换式肾输尿管导管 (Convertible nephroureteral catheter ) 是由 哈利·R·斯茂赛 蒂姆·H·威廉姆斯 于 2014-11-03 设计创作，主要内容包括：本申请涉及可转换式肾输尿管导管。本发明提供了一种肾输尿管导管,其包括可拆卸部分以使得当移除所述可拆卸部分时,所述导管转换成内支架。所述导管包括具有两个固位特征、一个可拆卸部分和一个内管的管。所述内管能够可移除地插入至所述管和所述可拆卸部分中,并且丝线延伸穿过所述内管的腔的至少一部分并且穿过所述管以保持零件附接。可以移除所述丝线以从所述管移除所述内管并继而移除所述可拆卸部分。当将所述可拆卸部分附接至所述管时,所述导管是肾输尿管导管。当从所述管移除所述可拆卸部分时,所述导管变为支架。(The present application relates to convertible nephroureteral catheters. A nephroureteral catheter is provided that includes a detachable portion such that when the detachable portion is removed, the catheter converts into an internal stent. The catheter includes a tube having two retention features, a detachable portion, and an inner tube. The inner tube is removably insertable into the tube and the detachable portion, and a wire extends through at least a portion of a lumen of the inner tube and through the tube to keep parts attached. The wire may be removed to remove the inner tube from the tube and then the detachable portion. When the detachable portion is attached to the tube, the catheter is a nephroureteral catheter. When the detachable portion is removed from the tube, the catheter becomes a stent.)

1. A catheter that converts into a stent, the catheter comprising:

a tube, wherein the tube comprises a lumen, a proximal end, a distal end, a first retention feature near the distal end, and a second retention feature near the proximal end;

a detachable portion, wherein the detachable portion is removably coupled to the tube and comprises a lumen in fluid communication with the lumen of the tube when coupled;

a wire extending through at least a portion of the detachable portion and at least a portion of the tube, wherein the wire is detachably coupled to the proximal end of the tube, a distal end of the wire terminating in the proximal end of the tube, wherein the wire is configured to selectively couple the detachable portion to the tube;

wherein the detachable portion is removable from the tube once the wire is removed from the tube.

2. The catheter of claim 1, wherein the wire includes a portion that extends through and over the cylindrical wall of the proximal end of the tube and the cylindrical wall of the distal end of the detachable portion to selectively couple the tube and the detachable portion.

3. The catheter of claim 1, wherein a first portion of the wire extends substantially parallel to the lumen of the detachable portion, a second portion of the wire extends across the detachable portion and the tube, a third portion of the wire extends over an outer surface of the tube, and a fourth portion of the wire extends back into the lumen of the tube.

4. The catheter of claim 1, wherein when a pulling force is applied to the wire, the wire is displaced from the proximal end of the tube, causing the tube and the detachable portion to separate.

5. The catheter of claim 4, wherein the wire is coupled to a locking mechanism disposed adjacent a proximal end of the detachable portion and configured to displace the wire.

6. The catheter of claim 4, wherein the catheter transforms into the stent upon separation of the tube and the detachable portion.

7. The catheter of claim 1, wherein the proximal end of the tube is configured to abut a distal end of the detachable portion when the tube and the detachable portion are coupled.

8. The catheter of claim 1, wherein a distal end of the detachable portion is insertable into the proximal end of the tube.

9. The catheter of claim 8, wherein an outer diameter of a distal end of the detachable portion is less than an inner diameter of the proximal end of the tube.

10. The catheter of claim 1, wherein the first retention feature and the second retention feature comprise pigtail portions.

11. The catheter of claim 10, wherein the tube further comprises a plurality of drainage apertures extending through a wall of the tube and disposed adjacent the first retention feature and the second retention feature.

12. The catheter of claim 1, wherein the detachable portion is a portion of the catheter that extends from a body cavity or hole to an external location of a patient when the catheter is placed within the body cavity or hole.

13. The catheter of claim 1, wherein the tube is the stent retained within and configured to drain fluid from a body lumen or hole.

Technical Field

The present invention generally relates to catheters. More particularly, the present invention relates to nephroureteral catheters.

Background

Many patients suffer from stenosis or obstruction in the ureters of the unilateral or bilateral kidneys. The ureter is the muscular tube connecting the kidney to the bladder. When urine is produced by the kidneys, it drains into the central collection system of the kidneys and then travels through the ureters into the bladder. Patients may suffer from ureteral stenosis or obstruction due to kidney stones, cancer, infection, trauma, and past medical devices. In rare cases, some children are born with unilateral or bilateral ureteral obstruction. If left untreated, the obstruction will eventually lead to renal failure.

Regardless of the cause, treatment of an obstructed ureter is to relieve the obstruction. Occlusion removal is performed by inserting a long tube to connect the collection system of the kidney to the bladder. The tube is called a stent and is placed through the ureter.

Stent insertion is typically performed by one of two methods. The stent may be inserted through the urinary tract. In this way, a scope is advanced through the urethra into the bladder. A wire is then inserted into the ureter in a retrograde fashion, and the scope is used to thread the wire. When the wire reaches the collecting system of the kidney, a plastic stent is inserted through the wire. The stent is a straight plastic tube with a pigtail-shaped crimp on each end. Once in place, the wire is removed and the speculum is withdrawn from the bladder. One pigtail crimp of the scaffold resides in the collecting system of the kidney, while the other pigtail crimp resides in the bladder. The straight portion of the stent penetrates the ureter. This is done using direct visualization with a scope and also with perspective guidance. The stent is typically left for a period of about three months, at which time the stent is then replaced with a new stent by the urologist using similar techniques.

A second method for insertion is to percutaneously insert the stent. The process is typically carried out in stages. The right or left flank of the patient is prepared under sterile conditions, depending on which kidney is to be accessed (sometimes both kidneys are accessed to treat bilateral obstruction). Intravenous sedation was used. A small gauge needle is used to pierce the collection system of the kidney and inject contrast media, allowing full visualization of the entire collection system. The central portion is initially pierced with a small needle and then a larger needle is used to pierce a smaller but safer area of the collection system. A guidewire is threaded into the collection system of the kidney, and a pigtail drain or nephrostomy catheter is placed, sutured to the back, and hung to a bag for extracorporeal drainage. Once the blood has been cleared from the urine, the patient is returned to the angiography table, allowed to lie prone and the wire is inserted through the catheter into the kidney. The catheter is then removed. The wire is passed through the ureter into the bladder (across the stenosis) and the nephroureteral catheter is placed.

Nephroureteral catheters are long plastic tubes that pass from outside the patient's body to the collecting system of the kidney, through the ureter and into the bladder. The catheter allows drainage of urine into the bladder and out of the body into the bag. The catheter is typically left in the patient for 7 to 10 days, at which time the patient is returned to the angiography table and a wire is passed through the tube into the bladder. A see-through guide is used to remove the tube and place the stent. This is the same type of stent that is placed by a urologist working through the bladder. This can be a complicated and difficult procedure.

Disclosure of Invention

According to the present invention, a nephroureteral catheter is provided, which comprises a detachable section such that, when the detachable section is removed, the catheter is converted into a stent.

The catheter includes a tube having a circular cross-section, a first end, a second end, a first retention feature proximate the first end, and a second retention feature proximate the second end. The catheter further comprises: a detachable portion, wherein the detachable portion is in fluid communication with the tube at the second end and is removably attachable to the tube; an inner tube comprising at least one lumen, wherein the inner tube is removably insertable into the tube and the detachable portion; and a wire extending through at least a portion of one of the at least one lumen of the inner tube. A portion of the wire is attached to the tube.

The convertible nephroureteral catheter eliminates the steps of removing the nephroureteral catheter and placing a new stent into the patient. The convertible nephroureteral catheter saves time due to the elimination of steps. The physician need not take steps such as sterile preparation to place a new catheter in the patient, rather, the physician need only unbolt the hub of the convertible nephroureteral catheter to remove the outer portion of the catheter. Money is also saved because one required conduit is reduced. In addition, other supplies required for placement of typical internal catheters, such as wires, sheaths, and other equipment, will be omitted. The patient will only receive minimal (if any) radiation from the fluoroscopy.

The convertible nephroureteral catheter will also cause less patient discomfort due to minimal manipulation resulting from fewer steps required. With prior stenting procedures, local and intravenous sedation (IV station) and care monitoring are required.

For procedures to remove the removable portion of the convertible nephroureteral catheter, the patient will not need sedation. A new procedure for transforming the convertible nephroureteral catheter may be performed bedside.

The convertible nephroureteral catheter allows for a catheterization procedure as a single step procedure rather than a multi-step procedure. The ability to percutaneously insert a catheter with a single step may provide advantages over urinary tract insertion, as they will now all require only a single step for insertion, whereas the use of the convertible nephroureteral catheter will not require general anesthesia as required for urinary tract insertion.

The present application provides the following:

1) a catheter, comprising:

a tube comprising a cylindrical wall, a first end, a second end, a first retention feature proximate the first end, and a second retention feature proximate the second end;

a detachable portion, wherein the detachable portion is in fluid communication with the tube at the second end and is removably attachable to the tube;

an inner tube comprising at least one lumen, wherein the inner tube is removably insertable into the tube and the detachable portion; and

a wire extending through at least a portion of a lumen of the at least one lumen of the inner tube;

wherein a portion of the wire is attached to the tube.

2) The catheter of claim 1), wherein the inner tube and the detachable portion are removable upon removal of the wire, thereby transforming the catheter into a stent.

3) The catheter of claim 1), wherein the first retention feature and the second retention feature comprise a first crimp and a second crimp, respectively.

4) The catheter of claim 2), further comprising a plurality of holes extending through an outer surface of the tube.

5) The catheter of claim 1), further comprising a locking mechanism at a first end of the detachable portion, wherein the locking mechanism is configured to open and close, and wherein when closed, the locking mechanism prevents access to an interior of the detachable portion.

6) The catheter of claim 1), wherein the inner tube comprises two lumens.

7) The catheter of claim 1), wherein the wire is a flat wire comprising a raised portion, and wherein the raised portion is secured to an inner wall of the tube.

8) A nephroureteral catheter converted into a stent, comprising:

a tube, wherein the tube comprises a lumen, a first end, a second end, a first retention feature proximate the first end, and a second retention feature proximate the second end;

a detachable portion, wherein the detachable portion is insertable into the tube and comprises a lumen in fluid communication with the lumen of the tube when inserted;

a wire extending through the detachable portion and at least a portion of the tube;

wherein the detachable portion is removable from the tube once the wire is removed from the tube.

9) The nephroureteral catheter of claim 8), wherein the detachable portion is a portion of the tube extending from the center of the patient's kidney to the back.

10) The nephroureteral catheter of claim 8), wherein a first portion of the wire extends substantially parallel to the lumen, a second portion of the wire extends through the detachable portion and the tube, a third portion of the wire extends over the outer surface of the tube, and a fourth portion of the wire extends back through the tube into the detachable portion.

11) The nephroureteral catheter of claim 8), wherein the tube comprises a plurality of holes each extending through the tube.

12) The nephroureteral catheter of claim 8), further comprising a locking mechanism at the first end and located outside the patient when the catheter is placed inside the patient.

13) A method for converting a catheter into a stent, comprising:

providing a catheter having a tube and a detachable portion, the tube including a first end, a second end, a first retention feature proximate the first end, and a second retention feature proximate the second end, wherein the detachable portion is in fluid communication with the tube at the second end and is removably attachable to the tube; and

removing the detachable portion from the catheter to convert the catheter into a stent.

14) The method of claim 13), further comprising:

providing an inner tube extending through the tube and at least a portion of the detachable portion and comprising at least one lumen;

extending a wire through at least a portion of the at least one lumen of the inner tube; and

attaching a portion of the wire to the tube;

wherein removing the detachable portion comprises removing the wire and the inner tube from the tube.

15) The method of claim 13), further comprising:

providing a locking mechanism at a first end of the detachable portion, wherein the locking mechanism is configured to open and close; and

closing the locking mechanism to prevent access to the interior of the detachable portion.

16) The method of claim 13), further comprising:

the catheter is positioned within a patient by creating an incision at a surgical site of the patient and inserting the catheter through the incision.

17) The method of 16), wherein the surgical site is a urethra of the patient for accessing one or more of the bladder, ureter, and kidney via the side abdomen.

18) The method of claim 16), further comprising:

attaching the catheter to a conduit external to the patient.

19) The method of 16), wherein removing the detachable portion comprises removing the detachable portion from the patient.

20) The method of 13), wherein the method is for providing or monitoring treatment for a disease of the kidney or bladder.

21) A method for converting a medical device from a catheter to a stent, comprising:

providing a medical device in a first form as a catheter, wherein the catheter comprises a proximal portion that extends outside the patient when inserted into the patient; and

transitioning the medical device from the first form to a second form by detaching the proximal portion from a patient and removing the proximal portion;

wherein in the second form the medical device comprises a stent.

Drawings

Various embodiments are described herein with reference to the following drawings. For reasons of clarity, certain aspects of the drawings are depicted in a simplified manner. Not all alternatives and alternatives are shown in the drawings, and the invention is therefore not limited in scope to the contents of the drawings. In the drawings:

fig. 1 depicts a nephroureteral catheter according to an example embodiment;

fig. 2 depicts a detachable portion of the nephroureteral catheter of fig. 1, according to an example embodiment;

fig. 3 depicts a detachable portion of the nephroureteral catheter of fig. 1, according to an example embodiment;

fig. 4a depicts a detailed view of a removable attachment system according to an example embodiment;

FIG. 4b depicts a detailed view of a removable attachment system according to an example embodiment;

fig. 5 a-5 b depict detailed views of a removable attachment system according to an example embodiment;

FIG. 6 depicts a detailed view of a removable attachment system according to an example embodiment;

FIG. 7 depicts a detailed view of a removable attachment system according to an example embodiment; and

fig. 8 depicts the stent remaining after the detachable portion has been removed, according to an example embodiment.

Detailed Description

Fig. 1 depicts a catheter 100 according to an example embodiment. The catheter 100 is provided for use as a nephroureteral catheter and is configured for placement within a patient.

The catheter 100 allows drainage of urine into the bladder and out of the body into the bag. The catheter 100 includes a tube 110, the tube 110 having a circular cross-section 120, a detachable portion 130, a locking mechanism 140, an inner tube 150, a first pigtail curl 160, a second pigtail curl 170, and indicia 190. The catheter 100 also includes a first end 112, a second end 114, and a plurality of holes 116. When the detachable portion 130 is attached to the catheter, the catheter 100 is a nephroureteral catheter. When the detachable portion 130 is removed from the catheter, the catheter becomes the stent 200, as shown in fig. 8.

The tube 110 may be flexible. The tube 110 has a hollow interior or cavity to allow fluid to flow through the tube. A plurality of apertures 116 extend through the tube 110 so that fluid can flow into or out of the tube 110 through the apertures. The tube 110 is of sufficient length so that it extends from outside the patient's body into the kidney, through the ureter and into the bladder.

The first pigtail crimp 160 and the second pigtail crimp 170 function to retain or hold the tube 110 in place in the patient. The first pigtail curl 160 is positioned near the first end 122 and the second pigtail curl 170 is positioned near the second end 114 such that the first pigtail curl 160 is within the collecting system of the kidney and the second pigtail curl 170 is within the bladder. Each crimp serves as a retention feature and ensures that tube 110 does not move out of the ureter because each crimp is too large to pass through the ureter. The second pigtail coil 170 enters the ureter in a straight position, but once it has left the ureter, the material of the tube 110 at the section of the second pigtail coil is bent for a given space.

The first pigtail curl 170 is such that: after the tube also enters the kidney in a straight position, the first pigtail crimp 170 is bent into the crimped position shown in fig. 1 and once in place may also be bent into the crimped position. However, to assist in bending the first pigtail curl into place, the cord 180 may be pulled through one of the plurality of holes 116, as shown in fig. 2, and manually pulled on both ends 182, 184 until the first pigtail curl is set in place. Thereafter, the cord 180 may be manually removed by pulling on one of the ends 182, 184. The cord 180 may be a suture. Alternatively, the cord 180 may be several other materials.

The locking mechanism 140 may be several locking mechanisms currently used in the art. The locking mechanism locks the detachable portion 130 of the tube 110 and can be manually opened and removed to access any of the detachable portion 130, the inner tube 150, or the tube 110.

The detachable portion 130 may be made of the same material as the tube 110. The removable portion 130 may be flush with the tube 110 at 190. The detachable portion 130 includes a hollow section within which the inner tube 150 can slide. As shown in fig. 2, the inner tube may extend through a portion of the tube 110. The inner tube 150 includes a hollow interior to allow fluid to flow through the interior of the inner tube 150. Fluid is exchanged between the tube 110 and the inner tube 150 through the hollow interior of the inner tube 150. The tube 110 also includes at least a portion of a hollow section within which the tube portion 150 is slidable. In some example embodiments, the detachable portion 130 and the hollow portion of the tube 110 may be sized such that when the inner tube portion 150 is positioned inside the detachable portion 130 and the hollow portion of the tube 110, a frictional seal exists between the outer surface of the tube portion 150 and the walls of the hollow portion. However, the tube portion 150 can be attached to the tube 110 in some other manner. For example, in an alternative embodiment, the inner tube 150 may include threads on its outer surface that correspond to threads along the wall of the hollow interior of the tube 110, and thus in order to remove the inner tube 150 from the tube 110, the inner tube 150 must be unscrewed from the tube 110. In another alternative embodiment, the detachable portion 130 may comprise a smaller circumference than the tube 110 such that the detachable portion 130 may also fit within a hollow portion of the tube 110, e.g., 2mm or 3mm into the tube 110. Thus, when the inner tube 150 is in place within the tube 110 and the detachable portion 130, the inner tube 150 is pushed outward on the detachable portion 130, which in turn presses on the tube 110, resulting in a tighter fit. In this embodiment, the detachable portion 130 may still be manually removed from the tube 110 after the inner tube 150 is removed from the tube 110.

The detachable portion 130 may be manufactured as part of the catheter 100. When attached to the catheter 100 and in place within the patient, the detachable portion 130 extends from the center of the kidney to an exit port on the patient's back, terminating eventually with a locking mechanism 140 located outside the patient's body.

In another example embodiment, the inner tube portion 250 and the wire 255 may extend through the detachable portion 230 and the tube 210, as shown in fig. 3. In this embodiment, the inner tube portion 250 includes a hollow interior or lumen 252 to allow fluid flow therethrough. Thus, fluid is exchanged between the tube 210 and the inner tube portion 250 through the hollow interior of the inner tube portion 250. The tube 210 also includes at least a portion of a hollow section within which the tube portion 250 can slide.

The detachable portion 230 may be manufactured as part of the catheter 200. When attached to the catheter 200 and in place within the patient, the detachable portion 230 extends from the center of the kidney to the exit port on the patient's back, and finally terminates with a locking mechanism 240 located outside the patient's body.

Fig. 4a shows a detailed view of the catheter 200 of fig. 3. A wire 255 is shown extending through the lumen 252 of the inner tube 250. In some example embodiments, the wire 255 may extend from the locking mechanism 240 through the entire length of the lumen 252 of the inner tube 250 in the distal direction. However, in other example embodiments, the wire 255 may only extend partially through the lumen 252 of the inner tube 250. Wire 255 may include a portion 256 that extends through and over the exterior of tube 210 in the region where tube 210 overlaps inner tube 250, thereby securing tube 210 and inner tube 250. Portion 256 may include a first angled section 257 extending from within the cavity 252 of the inner tube 250 through the wall of the tube 210 and the outer surface 202 of the tube 210, a generally flat section 258 extending over the outer surface 202 of the tube 210, and a second angled section 259 extending from the generally flat section 258 back through the wall of the tube 210 into the cavity 252 of the inner tube 250.

As will be described in further detail below, the wire 255 may be secured to the locking mechanism 240 and then removed at the locking mechanism 240 to disconnect the distal section of the inner tube 250 from the tube 210, thereby making the catheter 200 a stent. For example, the locking mechanism may include a luer lock. Other locking mechanisms are also contemplated. Such a locking mechanism may be secured via any of several engagement or fastening methods.

The wire 255 may comprise a material, such as a metal composite, having sufficient tensile strength to hold the inner tube 250 and the tube 210 together. Example metal composites that may be used are, for example, stainless steel, Elgiloy, nickel-cobalt alloys (e.g., MP35N), or nickel-titanium alloys (e.g., nitinol).

To connect the detachable portion 230 to the tube 210, a wire 255 may be fed through the inner tube 250, which may contain one or more lumens.

In an alternative embodiment shown in fig. 4b, instead of the wire 255 running through the wall of the tube 210 and extending beyond the exterior 202 of the tube 210 to secure the inner tube 250 within the tube 210, the wire 255 may instead run on a separate wire segment 254 that is perpendicular to the wire 255 and within the lumen of the tube 210. The individual wire segments 254 may be fused into the wall of the tube 210 while providing a small area for passage of the wire 255 and a large area for passage of the inner tube 252. The wire 255 may continue its path over the individual wire segments 254, remaining entirely within the lumen of the tube 210, and completing the second angled section 259 to return into the lumen 252 of the inner tube 250.

Fig. 5 a-5 b show detailed top and side views of the wire 350 within the tube 310 according to an example embodiment. The tube 310 may take the same form as the tube 110 or the tube 210 described with reference to fig. 1-4 b, or may be similar in form thereto. The detachable portion 330 and the inner tube 350 are also shown in the figures and may take the same form as the detachable portion 130 or detachable portion 230 and the inner tube 150 or 250 described with reference to fig. 1-4 b, or may be similar in form thereto. In the embodiment shown in fig. 5 a-5 b, a wire 355 comprising a metal band may be used to removably attach the detachable portion 330 to the tube 310. The engagement portion 356 of the wire 355 is shown engaged into the inner wall 305 of the catheter 300. The engaging portion 356 may include bumps, hills, or other distinct surfaces that extend above the surface of the remaining wire 355.

Fig. 6 shows a detailed cross-sectional side view of the wire 450 within the catheter 400 according to an example embodiment. The catheter 400 may take the same form as the catheter 100 or the catheter 200 described with reference to fig. 1-4 b, or may be similar in form thereto. The detachable portion 430 is also shown in the figures and may take the same form as the detachable portion 130 or detachable portion 230 described with reference to fig. 1-4 b.

The inner tube 450 may include two lumens, a first lumen 451 and a second lumen 452. The first cavity 451 may include a wall to separate the first cavity 451 from the second cavity 452. A wire 455, which may take the form of a wire 255 or a wire 355, may extend through the first lumen 451 and thus be isolated within the lumen 451 so as not to interfere with the second lumen 452. The second lumen 452 may function as a wire guide or stent straightening lumen. The dual lumen feature of the inner tube 450 allows the use of an isolated access passage (second lumen 452) for equipment fixtures such as wire guides or stent straighteners without the risk of obstructing the wire 455 located within the lumen 451. The first lumen 451 provides a protective guard against dislodgement of the wire 455 during implantation of the catheter in the patient and during corresponding replacement of the catheter tool during the interventional procedure. Fluid may be exchanged between catheter 400 and inner tube 450 via first lumen 451 and second lumen 452.

Fig. 7 shows a detailed cross-sectional side view of an example detachable portion 530 of a catheter 500 according to an example embodiment. The catheter 500 may take the same form as the catheter 100 or the catheter 200 described with reference to fig. 1-4 b, or may be similar in form thereto. The catheter 500 may comprise a tube 510, which tube 510 may take the same form as the tube 110 or the tube 210 described with reference to fig. 1-4 b, or may be similar in form thereto.

The detachable portion 530 may include a first tube portion 532, a second tube portion 534, and a transition 536 from the first tube portion 532 to the second tube portion 534. The transition 536 may take the form of a step and may include an approximately 90 degree transition. The lumen 533 may extend through the first and second tube portions 532, 534 as shown, and may include the same diameter in both portions. The transition 536 may mate with or abut the tip 505 of the catheter 500. The second tube portion 534 includes a smaller diameter than the first tube portion 532 and is sized and shaped to fit within the lumen of the catheter 500. This design for the detachable portion 530 makes additional inner tubes (such as the inner tube 150 and the inner tube 250, for example) unnecessary.

Fig. 8 shows a perspective view of the stand 200 remaining after the detachable portion has been removed. The stent 200 comprises the same tube 110 as the catheter 100 with the first pigtail crimp 160 and the second pigtail crimp 170 intact within the patient's body. The detachable portion 130, the inner tube 150, and the locking mechanism 140 have been removed. The new tip 210 is located at the mark 190.

In operation, the right or left abdomen of a patient is prepared under sterile conditions depending on which kidney is to be accessed. Intravenous sedation was used. A small gauge needle is used to pierce the collection system of the kidney and inject contrast media, allowing full visualization of the entire collection system. The central portion is initially pierced with a small needle and then a larger needle is used to pierce a smaller but safer area of the collection system. A guidewire is threaded into the collection system of the kidney, and a pigtail drain or nephrostomy catheter is placed, sutured to the back, and hung to a bag for extracorporeal drainage.

Once the blood has been cleared from the urine, the patient is replaced and a wire is inserted through the catheter into the kidney, and the catheter is removed. The wire is threaded through the ureter into the bladder (across the stenosis) and the catheter 100 is placed. The pigtails are crimped 160, 170 to their proper positions. The catheter is typically left in the patient for 7 to 10 days, at which time the patient is replaced.

At this point, if the physician desires to exchange catheter 100 for stent 200, the physician will unlock locking mechanism 140 and will remove the locking mechanism to access inner tube 150. The physician would then manually push the inner tube 150 through the hollow portion of the tube 110 toward the first end 112 until the inner tube 150 has been pushed past the marker 190 and is no longer within the hollow portion of the tube 110.

In another example embodiment, where a wire is used, such as the wire described with reference to fig. 3-7, the physician will first release a locking mechanism that maintains a connection with the wire (such as wire 255, 355, 455, or 555). For example, the wire may be released using a method such as unscrewing a cap. In such example embodiments, the unscrewed cap (which has been attached to the wire at the proximal luer hub) disengages the wire from the catheter (e.g., catheters 310 and 400) by pulling the cap away from the hub and fully withdrawing the wire from the inner tube (e.g., inner tubes 250, 350, 450). Once the wire has been removed, the detachable portions (e.g., detachable portions 330 and 530) and inner tube can now be fully retracted from the patient's body, thereby converting the catheter into a stent (e.g., stent 200).

Once the inner tube 150 has been removed from the tube 110, the detachable portion 130 is no longer attached to the tube 110, and both the detachable portion 130 and the inner tube 150 can be removed from the patient's body. Once the detachable portion 130 and inner tube 150 are removed, the catheter 100 becomes a stent 200, as shown in fig. 3. This is the same type of stent that is typically placed by a urologist working through the bladder. The stent 200 now includes a new tip 210 at the marker 190.

One example of when a convertible nephroureteral catheter may be used is when a patient has a ureteral obstruction and has hydronephrosis (dilation of the collection system of the kidney) and hydrouretery (dilation of the ureter). The patient has a device inserted into the collection system through the lateral abdomen and into the bladder through the ureter. The device will remain open for extracorporeal drainage until infection or bleeding is cleared from the urine. When the urine has been cleared, the exterior portion of the convertible nephroureteral catheter 100 will be removed, thereby converting the catheter into an internal stent. From this point on, the stent will drain urine directly from the kidney to the bladder. The stent will remain in place until it is ready to be removed or replaced.

Another use example is where a patient has recently experienced kidney stones and the ureters are temporarily inflamed and blocked. The convertible nephroureteral catheter was inserted in the same manner as described above. However, in this case, the catheter is temporarily in place until inflammation improves; once this is confirmed, the entire catheter is removed by pulling it out of the flank with a contrast injection under fluoroscopy. In this case, the detachable portion is not detached. However, it is also possible to leave the catheter in place as a stent and remove the detachable portion, depending on the clinical needs.

Yet another example of use is where a patient has a leak from the ureter due to trauma, instrument use, stone removal, cancer, or another cause, and a diversion of urine flow both in vivo and ex vivo is necessary. In this case, the convertible nephroureteral catheter 100 is placed inside the patient and allows for extracorporeal drainage of urine. This allows for a longer diversion of the in vivo urine flow when the leakage is improved and the catheter is converted to a stent by removing the detachable portion 130. The stent 500 will be removed at a later time after the leak is resolved.

It should therefore be appreciated that certain changes can be made in the above constructions without departing from the spirit and scope of the invention. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.