TECHNICAL FIELD

The disclosure of the present patent application relates to pyelo-ureteral catheters, and particularly to a pyelo-ureteral stent for percutaneous intraoperative insertion in a patient. BACKGROUND ART

A ureter is a tubular passageway in a body that conveys urine from a kidney to a bladder. Urine is transported through the ureter under the influence of hydrostatic pressure assisted by contractions of muscles located within the walls of the ureter. A urological condition that some patients experience is congenital uretero-pelvic junction (UPJ) obstruction. This obstruction or blockage occurs where the ureter attaches to the kidney. As a result, the flow of urine through the ureter decreases and fluid pressure inside the kidney increases.

Patients suffering from a UPJ obstruction must undergo pyeloplasty, a surgical reconstruction of the renal pelvis. The original ureter is surgically incised below the level of the obstruction (anastomosis line) and the abnormal section is removed. Then, the ureter is repositioned and attached to healthy renal pelvic tissue.

Pyelo-ureteral stents are designed to extend through the ureter to facilitate drainage from a kidney to the ureter during the pyeloplasty procedure area and usually for seven to ten days after the procedure. The stents generally include small diameter tubing of a biocompatible material. The pyelo-ureteral stent with an exteriorized end post-pyeloplasty can be used to aid in transfer of urine from the patient's kidney and ureter out of the patient, where post-operative edema or obstructions or other conditions may inhibit normal flow through the surgical anastomosis. Ideally, the stent should allow for flow of urine without migrating out of or further into the kidney, or out of or further into the bladder. Ureteral stents are positioned in the ureter by various procedures including, antegrade (percutaneous) placement, retrograde (cystoscopic) placement through the urethra, as well as by open ureterotomy or surgical placement in the ureter under direct visual placement.

With many conventional stents, a physician must select what size stent to use based only on approximations of the patient's physiology. Other disadvantages of traditional stents generally relate to high infection rates, vulnerability to dislodgement, incompatibility with laparoscopic or robotic pyeloplasty methods, a requirement of anesthesia for removal, unreliability of postoperative contrast studies in the presence of the stent, difficulty in connecting with urine collection bags and syringes, and causing discomfort and bladder spasms.

Further, when a conventional pyelo-ureteral stent is used, it is generally necessary to insert a separate tube (e.g., Penrose drain) into the patient' s body (below the stent) to serve as a drain for directing blood and/or urine from the perinephric space outside the body. The tube is covered with gauze to collect drainage flowing therefrom. Use of such a tube is often problematic, as it requires a separate incision into the body and additional stitches. Also, such drainage tubes frequently slip out of the body. Further, as only gauze is used to receive the drainage from such tubes, it is difficult to determine exact amounts of bleeding and/or urine leakage post-surgery.

Thus, a ureteral stent solving the aforementioned problems are desired.

DISCLOSURE OF INVENTION

The pyelo-ureteral stent includes a hollow, flexible primary tube and a hollow, flexible secondary tube extending along a portion of an outer wall of the primary tube. The primary tube is a generally elongated tube including an open proximal end, a closed distal or ureteric end, a renal coil or coiled renal drainage portion between the proximal and distal ends, a perforated internal collection portion proximate the distal end, and a primary lumen extending between the proximal end and the distal end. An inflatable balloon valve extends through a wall of the primary tube, between the internal collection portion and the renal coil. An air tube having opposed open ends extends along the outer wall of the primary tube. The air tube is connected to the inflatable balloon valve at one end and to a one-way external valve and an inflatable balloon at an opposing end. The secondary tube has a closed distal end, an open proximal end, a perinephric coil between the distal end and the proximal end, and a secondary lumen extending from the distal end to the proximal end.

The stent can be percutaneously inserted within the patient during surgery and removed from the patient without the use of a cystoscopic procedure. The renal coil and the perinephric coil can be straightened during insertion of the stent but contract back to a coiled configuration once the stent is properly positioned. The stent is properly positioned in the patient when the renal coil is positioned in the kidney, the proximal end extends outside a body wall of the patient, and the distal end of the stent ends in the ureter and does not extend into the bladder. Urine from the kidney passes through the renal coil, into the primary lumen and out of the opening at the proximal end and/or out of the collection portion. The perinephric coil drains the perinephric space in the event of bleeding or urine leakage.

These and other features of the present disclosure will become readily apparent upon further review of the following specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a diagrammatic environmental view of the pyelo-ureteral stent present teachings.

Fig. 2 is a perspective view of the pyelo-ureteral stent according to the present teachings.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

Figs. 1 and 2 show a pyelo-ureteral stent, designated 10, extending through a body wall BW of a subject. The pyelo-ureteral stent 10 includes a hollow, flexible primary tube 12a and a hollow, flexible secondary tube 12b extending along a portion of an outer wall of the primary tube 12a. The primary tube 12a is a generally elongated tube including an open proximal end 14, a closed distal or ureteric end 16, a renal coil or coiled renal drainage portion 22 between the proximal 14 and distal ends 16, a perforated internal collection portion 20 proximate the distal end 16, and a primary lumen extending between the proximal end 14 and the distal end 16. The renal drainage portion 22 can be straightened when tension is applied, but contracts back to a coiled configuration once tension is released.

The internal collection portion 20 can be generally elongated and includes a series of apertures 26 to allow fluid to pass out of the primary lumen. The drainage portion 22 can include a series of apertures 28 to allow fluid to pass into and/or out of the primary lumen. While apertures are shown, the collection and drainage portions 20, 22, can include screen filters with perforations or other suitable structures to allow fluid to pass in and/or out of the primary lumen of the primary tube 12a. Opening 17 (Fig. 2) at proximal end 14 is selectively sealable with a clamp 35 or other sealing device.

An inflatable balloon valve 30 extends through a wall of the primary tube 12a, between the internal collection portion 20 and the internal drainage portion 22. An air tube 38 having opposed open ends extends along the outer wall of the primary tube 12a. The air tube 38 is connected to the inflatable balloon valve 30 at one end and to a one-way external valve 19 and an inflatable balloon 40 at an opposing end. The one-way external valve 19 is configured to receive air for inflating the valve 30. Air injected into valve 19 passes through air tube 38 and into the inflatable balloon valve 30 to block the flow of fluid from the internal drainage portion 22 to the internal collection portion 20, as described in more detail below. The inflatable balloon 40 is configured to swell once valve 30 is inflated, and thereby serve as an indicator of the status of valve 30.

The secondary tube 12b has a closed distal end 34a, an open proximal end 34b (Fig.

2), and a secondary lumen extending from the distal end to the proximal end. As shown, the secondary tube 12b can include a looped or coiled perinephric portion 32 with apertures 33 defined along inner and outer portions of the perinephric coil 32. The apertures 33 of the coiled portion 32 allow fluid to pass into the secondary lumen to drain the perinephric space in the event of bleeding or urine leakage. Like the renal coil 22, the coiled portion 32 can be straightened when tension is applied but contracts back to a coiled configuration once tension is released. The coiled or generally circular configuration of the coiled portion 32 can facilitate improved drainage into the secondary lumen. The proximal end 34b of the secondary tube 12b can be selectively sealed with a suitable sealing device 36, such as a valve or clamp. The proximal end 34b can be secured to a collection bag or container (not shown) to collect drainage from the coiled portion 32. In this manner, a practitioner can determine an exact amount of bleeding and/or urine leakage post-surgery to assess whether or not the patient is healing without significant complications.

The stent 10 is configured to extend through the ureter U and bypass the pelvi-ureteral junction to facilitate drainage from a kidney K to the ureter U when a pelvi-ureteral junction of a patient becomes blocked or obstructed. The stent 10 can be percutaneously inserted within the patient (e.g., via a 14 Fr Angiocath) during the surgery and removed from the patient without the use of a cystoscopic procedure. The renal coil 22 of the primary tube 12a and the coiled portion 32 of the secondary tube 12b (along with the coil of the air tube) can be straightened with application of tension during the percutaneous insertion of the stent 10 and spontaneously reform into a coil once positioned in the body. The coiled configuration of the renal coil 22 helps to secure the stent and prevent migrating. The proximal end 14 can be connected to a collection bag or other suitable container for collecting urine that flows from the kidney through the opening 17 at the proximal end 14 of the primary tube 12a.

In operation, the stent 10 can be implanted in an antegrade manner in the ureter U intraoperatively, under direct vision, to provide drainage of urine from the kidney K to the ureter U around an anastomosis in the perioperative period in the event of a blockage. An anastomosis incision I is made between the patient's renal pelvis and ureter U. The stent 10 is placed into the kidney K and ureter U through the renal pelvis after passing through the abdominal wall BW. The distal end 16 is positioned in the mid- ureter without extending into the bladder B. As shown, the stent 10 is properly positioned when the renal coil 22 is positioned in the kidney K, the proximal end 14 extends outside a body wall BW of the patient, and the distal end 16 of the stent 10 ends in the ureter and does not extend into the bladder. The stent 10 can be shortened if necessary, based on the anatomy of the patient, by cutting along the distal end 16 of the stent. A suitable retention device or fixation component 39, e.g., adhesive material, can secure the stent 10 to the body wall BW. Urine from the kidney K passes through the renal coil 22, into the primary lumen 12a and out of the opening 17 at the proximal end 14 and/or out of the collection portion 20. The secondary lumen drains the perinephric space through the apertures 33 of the coiled portion 32.

When it is desired later to remove the stent 10, the stent 10 may be removed from the patient simply by pulling on the proximal end 14 through the body wall BW. As such, a cystoscopic procedure is not required for removing the stent 10.

For post-operative contrast studies, e.g., one week after surgery, contrast can be injected into the primary tube 12a after inflating balloon valve 30. As described above, the balloon valve 30 can be inflated through the one way external valve 19 and checked for engagement via the pilot balloon 40. When the balloon valve 30 is engaged, contrast material can be injected into the lumen of the primary tube 12a through the opening 17. The inflated valve 30 blocks the passage of contrast from the renal coil to the internal collection portion 20. Thus, contrast will only be released through the apertures 28 of the renal coil 22 into the renal pelvis. In this manner, any leaks around incision I can be tested. Such a procedure can increase the sensitivity of post-operative contrast studies for earlier diagnosis of postoperative obstruction or leak at the anastomotic area.

The stent 10 can be constructed out of any suitable ureteral catheter/stent material. The stent 10 can include a hydrophilic and/or antibacterial coating. The entire stent 10 or at least the renal drainage portion can be produced from one or more malleable materials. In an embodiment, the stent 10 is formed from an inert silicone material and includes a hydrophilic coating. The portion of the stent configured for internal placement may be produced of a softer or more malleable material than that used for the external V-shaped portion of the stent.

The stent 10 can be configured for laparoscopic, robotic and/or open deployment. The stent can be used to study anastomosis without the need for a secondary procedure for removal, and without a need for positioning a distal coil in the bladder. The stent 10 obviates a need to use a separate perinephric drain and cause an extra wound or opening in the skin. The stent 10 provides a closed system, decreasing the potential for bacterial migration and subsequent infections. Further, unlike conventional perinephric drains which measure output indirectly through weighing gauzes and dressings, the stent 10 permits direct and accurate perinephric drainage output. Further, the integrated drainage system of the stent 10 lowers the possibility of dislodgment as it uses the same all-system fixation method. The stent 10 eliminates the discomfort and pain related to the bed-side removal of the traditionally used perinephric drains. The closed distal end of the primary tube 12a eliminates the siphoning effect that might happen in case the distal end inadvertently reaches the bladder through the vesico-ureteric junction.

It is to be understood that the pyelo-ureteral stent is not limited to the specific embodiments described above, but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed pyelo-ureteral stent.