Patent Description:
Ureteral obstructions are a major surgical and endourological problem in both human and veterinary medicine. These obstructions can occur for various reasons, the most common of which include but are not limited to ureterolithiasis, urinary tract (intrinsic) or extrinsic neoplasia, and ureteral strictures. The traditional treatment in human medicine has involved the use of minimally invasive endourological procedures, for example, ureteral stenting, lithotripsy, ureteroscopic laser ablation, laparoscopic ureteral resection and anastomosis, and ureteropyelotomy. Minimally invasive treatments have nearly replaced open surgical procedures. In contrast, open surgical procedures such as ureterotomy, ureteral reimplantation and ureteronephrectomy are routinely performed for most causes of ureteral obstructions in companion animals (for example, canine and feline) due to the small nature of the canine (about <NUM> to <NUM>) and feline (about <NUM> to <NUM>) ureters and the minimal options available for interventional devices in animals of this size. Recently, the development of feline and canine double-pigtail ureteral stents has occurred, and interventional treatments have become progressively more available in larger patients. Unfortunately, situations arise, particularly in small pediatric and veterinary patients, in whom ureteral decompression is necessary but traditional surgery or endourological procedures are associated with excessive morbidity or mortality, are impossible due to the size or anatomy, or are contraindicated.

In human medicine, if diversion procedures fail, implantation of an externalized percutaneous nephrostomy tube is usually necessary to provide either temporary or long-term drainage of the renal collection system. Placement of an externalized percutaneous nephrostomy tube is also possible in veterinary and pediatric patients for in-hospital stabilization but is not feasible for long-term use. Major disadvantages associated with long-term use include the need for regular catheter exchanges, the risk of urinary tract infections, urinary leakage and catheter dislodgement, social embarrassment, discomfort, and an impaired quality of life reported for patients. Subcutaneous (or intra-abdominal) urinary diversion devices can internalize a nephrostomy catheter and allow the urine to drain to the urinary bladder through a subcutaneous or intra-abdominal catheter. This eliminates most of the major disadvantages associated with externalized nephrostomy catheters because infection, regular nursing care, leakage, dislodgement, and an impaired quality of life are no longer prominent issues. Subcutaneous or intra-abdominal urinary diversion (bypass) devices have become a more useful solution for patients with very complicated medical problems for whom externalized catheters are not a realistic option outside of a hospital setting.

A few variations on ureteral bypass devices have been reported in the past, varying from non-locking pigtail catheters, non-fenestrated double-pigtail stents, and non-locking double-lumen catheters with an inner silicone tube and an outer polyester sheath. For example, such devices have been reported or offered by Coloplast A/S (Pyelovesical Bypass). These various devices have been placed subcutaneously with surgical approaches requiring suturing of the tube to the bladder wall and renal capsule to prevent dislodgement and leakage. Short-term and long-term complications have been reported, with the major concerns being infection (<NUM>%), bleeding/hematoma (<NUM>%), discomfort (<NUM>%), occlusion (encrustation) (<NUM>%), and kinking (<NUM>%) (Wrona et al. However, these devices remain promising when all other traditional options have failed.

There is an ongoing need for devices that can treat various causes of ureteral obstruction, regardless of etiology, patient species, or size, in a rapid, simple, safe, and effective manner. In particular, there is a need for a ureteral bypass device capable of overcoming the shortcomings of the prior art, particularly infection, discomfort, invasiveness, the large size of the device, occlusion via encrustation, or kinking of the device.

A subcutaneous ureteral bypass (SUB) device disclosed in <CIT> has solved some of the problems with previous techniques for providing urinary drainage due to ureteral obstruction. This device has been reported to function well with minimal complications compared to traditional surgery or ureteral stent placement. The most common complications encountered have included occlusion/encrustation (approximately <NUM>%), chronic infections (approximately <NUM>%), and tube kinking when passing through the body wall (at least <NUM>%), not unlike some of the complications encountered with the pyelovesical bypass device. <CIT> describes a kidney catheter prior art device, <CIT> describes a ureteral bypass prior art device, and <CIT> describes an occluding collector prior art device.

The present invention provides a ureteral bypass device suitable for performing internalized urinary diversions within patients, including large patients such as human adults, as well as small patients such as children and animals, even when growth is anticipated. A ureteral bypass device is the first aspect of the present invention and is provided in claim <NUM>. Preferred embodiments are provided in the dependent claims. Any embodiments of the disclosure below which are not encompassed by the claims are provided for reference only, i.e. the non-claimed procedures.

According to the disclosure, but not presently claimed, the procedure disclosed herein includes creating an incision in the patient, implanting a first catheter and securing a distal end of the first catheter within the renal pelvis or ureter of a patient, implanting a cystostomy catheter through the incision and securing a distal end of the cystostomy catheter within the urinary bladder of the patient, fluidically connecting proximal ends of the first and cystostomy catheters to an adapter (Y-connector for a single kidney; X-connector for both kidneys), and then subcutaneously implanting a sampling/flushing port and fluidically connecting a proximal end of the sampling/flushing port to the adapter via a third catheter to yield an artificial ureteral bypass device, in which the first and cystostomy catheters are fluidically connected together and fluidically connected to the subcutaneously-placed sampling/flushing port. The incision is then closed. The subcutaneously-placed sampling/flushing port has a septum that defines an entry site of the subcutaneously-placed sampling/flushing port and is accessible through the skin of the patient to provide means for performing diagnostic and therapeutic procedures, and the third catheter defines a non-dynamic volume between the adapter and the sampling/flushing port through which urine does not flow so that the non-dynamic volume serves as an anti-infection, anti-encrustation reservoir.

According to a first aspect of the invention, an artificial ureteral bypass device includes a nephrostomy catheter or ureterostomy catheter having a proximal end, an oppositely-disposed distal end, and means for securing the distal end within the renal pelvis of a kidney of a patient, a cystostomy catheter having a proximal end, an oppositely-disposed distal end, and means for securing the distal end of the cystostomy catheter within the urinary bladder of the patient, an adapter fluidically connected to the proximal ends of the first and cystostomy catheters so as to fluidically connect the first and cystostomy catheters together through the adapter, and a sampling/flushing port that is fluidically connected to the adapter via a third catheter. The first and cystostomy catheters are fluidically connected together through the adapter without any subcutaneous connection and are fluidically connected to the sampling/flushing port. The sampling/flushing port defines an entry site that is accessible through the skin of the patient when the sampling/flushing port is subcutaneously placed to provide means for performing diagnostic and therapeutic procedures, and the third catheter defines a non- dynamic volume between the adapter and the sampling/flushing port through which urine does not flow so that the non-dynamic volume defines as an anti- infection, anti-encrustation reservoir.

A technical effect of the invention is that the device is capable of use in the treatment of many, if not all, causes of ureteral obstruction, regardless of etiology, patient size or species. The subcutaneously-placed sampling/flushing port and its entry site can be placed so that the entry site is accessible for testing, sampling and flushing of the device, and therefore enables occlusions, encrustation, and the like to be cleared or avoided without necessitating the removal of the device from the patient or the need for future surgical manipulation. Additionally, the port and its fluidic connection to the adapter (e.g., a catheter) in combination create a relatively large internal and non-dynamic reservoir for fluids/medications introduced into the device via the entry site of the port, for example, flushing fluids introduced for the purpose of treating or clearing occlusions and encrustation and antiseptic fluids for treating infections. The device is also well suited for remaining indwelling long-term within a patient, preferably for periods of at least <NUM> months but often much longer extended to the life of the patient. In young children with anatomical anomalies, this allows the time for the urinary system to grow prior to the consideration of more dramatic reconstructive surgeries that would ideally be done at an older age.

Other aspects and advantages of this invention will be appreciated from the following detailed description.

The intended purpose of the following detailed description of the invention and the phraseology and terminology employed therein is to describe what is shown in the drawings, which include the depiction of one or more nonlimiting embodiments of the invention, and to describe certain but not all aspects of the embodiment(s) depicted in the drawings. The following detailed description also identifies certain but not all alternatives of the depicted embodiment(s). Therefore, the appended claims, and not the detailed description, are intended to particularly point out subject matter regarded as the invention, including certain but not necessarily all of the aspects and alternatives described in the detailed description.

The embodiments depicted in the drawings will be referred to as ureteral bypass devices (UBD) that are capable of treating causes of ureteral obstruction. The devices can be used in humans (children and adults) and animals, regardless of etiology, species, or patient size, and can be optimized for the patient. In addition, the UBDs of this invention beneficially allow for secure and facile placement of the devices within a patient, as will be evident from the following discussion.

<FIG> and <FIG> represent a first nonlimiting embodiment of a UBD <NUM> as comprising a pair of catheters <NUM> and <NUM> and an adapter <NUM> to which the catheters <NUM> and <NUM> are coupled. Distal ends <NUM> and <NUM> of the catheters <NUM> and <NUM> (i.e., remote from the adapter <NUM>) are adapted to be placed within, respectively, the renal pelvis (or ureter) and urinary bladder of a patient. As such, the catheters <NUM> and <NUM> can be referred to as nephrostomy (or ureterostomy) and cystostomy (or bladder) catheters, respectively, though it should be evident that the catheters <NUM> and <NUM> are configured differently from prior art catheters of types used in ureteral bypass procedures. Suitable sizes for the catheters <NUM> and <NUM> will depend on the size of the patient and the drainage requirements. The diameters of the catheters <NUM> and <NUM> are preferably larger than traditional ureteral stents (limited by natural ureteral size) to provide better drainage. As nonlimiting examples, catheter sizes of <NUM> to <NUM> Fr will typically be suitable for cats, <NUM> Fr will typically be suitable for dogs, <NUM> to <NUM> Fr will typically be suitable for children and adults, though larger sizes (for example, <NUM> to <NUM> Fr) are possible and could be used if necessary. The lengths of the catheters <NUM> and <NUM> can also be tailored or trimmed to meet the particular requirements of a patient.

Each catheter <NUM> and <NUM> may be equipped with a locking mechanism that retains its respective distal end <NUM> and <NUM> within the renal pelvis or urinary bladder of the patient, respectively. As represented in <FIG> and <FIG>, the distal end <NUM> of the nephrostomy catheter <NUM> may be configured as a locking loop (pigtail) 26A capable of retaining the distal end <NUM> within the renal pelvis of a kidney for nephrostomy placement. To keep the locking loop 26A coiled after being placed inside the renal pelvis, a string (not shown) may be passed inside the catheter <NUM> from its locking distal end <NUM> and through a proximal end <NUM> of the catheter <NUM> at which the catheter <NUM> will be connected to the adapter <NUM> (<FIG> and <FIG>). For example, the catheter <NUM> may be fluidically connected to the adapter <NUM> via one of three male fittings <NUM> of the adapter <NUM> (<FIG>), to which the catheter <NUM> is secured with a boot <NUM> to prevent leaks at the catheter/adapter interface. The boot <NUM> is preferably formed of a biocompatible material, for example, silicone. The locking configuration shown for the distal end <NUM> in <FIG> and <FIG> can be maintained by entrapping the string between the proximal end <NUM> of the catheter <NUM> and the fitting <NUM> (represented in <FIG> as a graduated barb). Alternatively, the catheter can be passed down the ureter (ureterostomy catheter) when the renal pelvis is small (<FIG>).

Similar to the nephrostomy catheter <NUM>, the proximal end <NUM> of the cystostomy catheter <NUM> may be fluidically connected to the adapter <NUM> via a second of the male fittings <NUM> of the adapter <NUM>, and secured thereto with a boot <NUM> formed of a biocompatible material, for example, silicone. The distal end <NUM> of the cystostomy catheter <NUM> may be configured as a locking loop (pigtail) similar to the nephrostomy catheter <NUM> and its distal end <NUM>. Alternatively, <FIG> and <FIG> represent the catheter <NUM> as a straight catheter with a fenestrated tip comprising at least one fenestration <NUM> and a cuff 26B adapted for adherence to the external serosal surface of a bladder. A particular example is a silicone catheter with a DACRON® cuff (or any other adhered material) 26B for organ pexy to prevent leakage and ensure stability. As represented in <FIG> and <FIG>, the nephrostomy catheter <NUM> can also be equipped with a cuff 26B, wherein the cuff 26B can be provided instead of, or in addition to, the locking loop 26A. The addition of a cuff 26B to each catheter <NUM> and <NUM> can be advantageous, in that the cuff 26B is able to form a secure adhesion without the need for direct attachment to the body wall for the kidney or urinary bladder (nephropexy or cystopexy), and in this manner promotes the ability of the catheters <NUM> and <NUM> to remain secure to the kidney capsule and bladder wall (serosa) and prevent leakage of urine during healing. The distal end <NUM> of the catheter <NUM> is also represented as fenestrated, in this case, with multiple fenestrations <NUM>. As is visible for the catheter <NUM> in <FIG> and <FIG>, a radio-opaque marker band <NUM> can be placed behind the last (most proximal) fenestration <NUM> to allow for fluoroscopic assurance that the entire loop 26A and all fenestrations <NUM> are within the renal pelvis to prevent any extravasation or leakage of urine.

<FIG> and <FIG> further depict the UBD <NUM> as comprising a third catheter <NUM> having a proximal end <NUM> fluidically connected to the adapter <NUM> via a third of the male fittings <NUM>, and secured thereto with a boot <NUM> formed of a biocompatible material, for example, silicone. The catheter <NUM> further has a port <NUM> at a distal end <NUM> thereof (i.e., remote from the adapter <NUM>), and as such may be referred to herein as the port catheter <NUM>. The port <NUM> is represented in <FIG> and <FIG> as configured as a sampling and/or flushing (hereinafter, "sampling/flushing") port with an entry site <NUM>, though from the following discussion it will become apparent that certain features of the port <NUM> would not be necessary in all embodiments of the invention.

<FIG> and <FIG> represent the catheters <NUM>, <NUM>, and <NUM>, the adapter <NUM>, and the port <NUM> as separate components that must be assembled, though it is also within the scope of the invention that the UBD <NUM> could be manufactured as a single unitary component. In either case, the catheters <NUM> and <NUM> and adapter <NUM> are adapted to be entirely implanted within a patient, in particular, within the abdominal cavity (intra-abdominally) of a patient, whereas the port <NUM> and a distal portion of the port catheter <NUM> are not placed in the abdominal cavity but instead are placed subcutaneously. The fittings <NUM> of the adapter <NUM> are represented in <FIG> as male barbed fittings configured to provide male-to-male couplings with the catheters <NUM>, <NUM>, and <NUM>, and are therefore preferably sized to correspond to the size of the catheters <NUM>, <NUM>, and <NUM> and drainage requirements of the UBD <NUM>. In the embodiment of <FIG> and <FIG>, the adapter <NUM> is equipped with three fittings <NUM>, one for each of the catheters <NUM>, <NUM>, and <NUM>, so that the cystostomy catheter <NUM> fluidically communicates with a single nephrostomy catheter <NUM> through the adapter <NUM> and the port <NUM> communicates with both catheters <NUM> and <NUM> through the adapter <NUM>. As seen in <FIG> and <FIG>, the adapter <NUM> can be equipped with additional fittings <NUM>, for example, a fourth fitting <NUM> that enables a second nephrostomy catheter <NUM> to be coupled to the adapter <NUM>, such that the UBD <NUM> can be implanted in the renal pelvis (or ureter) of each kidney of the patient and the cystostomy catheter <NUM> fluidically communicates with both nephrostomy catheters <NUM> (in the event of a bilateral ureteral obstruction). Advantageously, such a four-way design for the adapter <NUM> eliminates the requirement in prior bilateral ureteral bypass procedures to implant two separate cystostomy catheters when necessary.

As a result of being placed subcutaneously, the port <NUM> provides a subcutaneous access to the port catheter <NUM>, which is fluidically coupled to the catheters <NUM> and <NUM> via the adapter <NUM>. The subcutaneous port <NUM> allows for testing, sampling and flushing of the UBD <NUM>, and therefore enables occlusions, encrustation, and the like to be cleared or avoided. A benefit of the port <NUM> and its entry site <NUM> is that they allow for the UBD <NUM> to be tested using contrast material and fluoroscopic guidance to ensure the patency of the system, as well as for urine sampling of the system directly, in a sterile manner. The entry site <NUM> of the port <NUM> is preferably configured as a septum that can be punctured by a needle, for example, a Huber point non-coring needle, which enables for multiple sampling and needle access without leakage. The port <NUM> is placed subcutaneously so that its entry site <NUM>, and particularly its septum, is in proximity to the patient's skin. As with ports employed with implantable venous access systems, the septum can be made of a self-sealing silicone rubber that can be punctured numerous and preferably thousands of times. Through the entry site <NUM>, the UBD <NUM> can be tested, such as with a contrast material and fluoroscopy to ensure patency and no leakage, sampled for infection, urinalysis, etc., and flushed if an occlusion is determined to exist within the catheters <NUM> and <NUM> or the adapter <NUM>. If encrustation or occlusion has occurred, a needle can be used to inject a contrast material into the adapter <NUM> via placing the needle through the patient's skin, through the entry site <NUM> of the port <NUM>, and from there instilled in the catheters <NUM> and <NUM> via the port catheter <NUM> and adapter <NUM> to enable documentation of the occlusion site, all while the patent is awake. The entire UBD <NUM> can then be flushed of debris through the entry site <NUM> of the port <NUM> to remove the occlusion. Access to the UBD <NUM> through the entry site <NUM> is able to promote the safety and effectiveness of long-term management of the UBD <NUM> without necessitating the need for testing using an invasive procedure, such as renal puncture. Furthermore, the ability to flush the entire UBD <NUM> of debris to remove an occlusion is not only diagnostically beneficial, but can also be potentially therapeutic for the patient using antibiotics, disinfectants, or anti-encrustation materials.

An important benefit of the port <NUM> and its port catheter <NUM> is that they define in combination a relatively large internal reservoir for fluids/medications introduced into the UBD <NUM> via the entry site <NUM>, for example, flushing fluids introduced for the purpose of treating or clearing occlusions and encrustation and antiseptic fluids for treating infections. In particular, the combined internal volume of the port <NUM> and port catheter <NUM> is outside the urine flowpath within the catheters <NUM> and <NUM>, and is preferably sized to retain a portion of the flushing (or other) fluid so that the fluid is not subject to being quickly flushed through the catheters <NUM> and <NUM> as a result of urine flow. As such, the retained portion continues to be dispensed from the port <NUM> and port catheter <NUM> to the catheters <NUM> and <NUM> to provide a residual benefit to the patient. This capability is believed to be particularly beneficial for reducing the incidence of complications such as occlusions, encrustations, and chronic infections. This is demonstrated in <FIG> wherein the contrast material remains within the port <NUM> and port catheter <NUM> but has been flushed out of the catheters <NUM> and <NUM> due to the urine flowpath. The reservoir of contrast could be disinfectant or other medications preventing ascending infections (from port access) or encrustation.

A preferred non-claimed procedure for placing the UBD <NUM> within a patient is to use a modified version of the well-known modified-Seldinger technique utilizing a guidewire and preferably under fluoroscopic guidance. Alternatively, a direct-stick method can be performed without guidewire access. Using a modified-Seldinger technique, an incision is made at a sterilized site through which the components of the UBD <NUM> will be implanted. It is not necessary to implant the completed assembly for the UBDs <NUM> shown in <FIG>, but instead, the catheters <NUM>, <NUM>, and <NUM>, adapter <NUM>, and port <NUM> can be implanted separately (if not manufactured as a unitary component). Punctures can be made in each of the renal pelvis and the urinary bladder with separate renal access needles (not shown), suitably sized for the desired guidewire size (typically an <NUM>-gauge renal access needle with a <NUM>" guidewire), For both nephrostomy (ureterostomy) and cystostomy placement, a guidewire can then be advanced through the access needle and coiled inside the renal pelvis (or ureter) or urinary bladder. The access needle is then removed over the wire and the distal ends <NUM> and <NUM> of the catheters <NUM> and <NUM> can be respectively placed over the wire, inside the renal pelvis and urinary bladder. Each catheter <NUM> and <NUM> is preloaded with a hollow trocar <NUM> (<FIG> and <FIG>) to maintain the stiffness and pushability to advance the respective catheter <NUM>/<NUM> over the wire. Whether the patient is human or animal, if the distal end <NUM> of the nephrostomy catheter <NUM> is configured as a locking loop 26A, the renal pelvis is preferably dilated to accommodate the locking loop 26A. The uncoiled catheter <NUM> could also be advanced over the guidewire down the ureter in cases with small renal pelvises. An alternative is to use the hollow trocar <NUM> with a sharp stylette <NUM> (the sharp tip and cap of which are seen in <FIG> and <FIG>) to directly puncture the renal pelvis or urinary bladder without the use of the modified-Seldinger technique or need for a guidewire.

The distal end <NUM> of the nephrostomy catheter <NUM> can then be actuated with a string to form the locking loop 26A, which prevents the catheter <NUM> from becoming dislodged once placed within the patient. Similarly, the distal end <NUM> of the cystostomy catheter <NUM> is secured with the cuff 26B (or, if so equipped, a locking loop 26A) to prevent the catheter <NUM> from becoming dislodged from the urinary bladder. Both catheters <NUM> and <NUM> can be cut to an appropriate length, based on patient needs, prior to being fluidically connected to the adapter <NUM> via the fittings <NUM>. The boots <NUM> can then be advanced onto the proximal ends <NUM> and <NUM> of the catheters <NUM> and <NUM> to connect and secure the catheters <NUM> and <NUM> to the adapter <NUM> (e.g., the Y-connector of <FIG> and <FIG> or the X-connector of <FIG> and <FIG>). The locking string(s) of the catheter(s) <NUM> and/or <NUM> are further secured to the adapter <NUM> by advancing the fittings <NUM> into the catheters <NUM> and <NUM>. The additional port catheter <NUM> is similarly attached the remaining fitting <NUM> of the adapter <NUM>, passed through the body wall, and attached to the port <NUM>, which can then be implanted and secured under the skin to subcutaneous tissue, after which the incision can be closed. As previously noted, the incision is preferably closed so that the entry site <NUM> of the port <NUM> is accessible through the patient's skin with simple needle access. The completed assembly of the UBD <NUM> is entirely located internally of the patient, with the catheters <NUM> and <NUM> and the adapter <NUM> placed completely intra-abdominal, with only the port <NUM> and a distal portion of its port catheter <NUM> located subcutaneously at the surface of the abdominal wall. The entry site <NUM> is accessible through the patient's skin to provide a leak-free access port for testing, sampling and flushing of the UBD <NUM> with an appropriate needle, such as a non-coring Huber needle.

From the above, it should be appreciated that the device of the present invention provides for facile and secure implantation of the UBD <NUM> within a patient. The UBD <NUM> provides the capability for easy sampling of the UBD <NUM> for infection, urinalysis, or the like, allows for testing the entire UBD <NUM> with contrast material to ensure patency and no leakage. The UBD <NUM> can also be flushed if an occlusion is discovered within the UBD <NUM>, or serially to prevent an occlusion. Needle access directly into this UBD <NUM> (via the entry site <NUM>) makes long-term management of the UBD <NUM> safe, non-painful, non-invasive, and effective without the requirement for risky, invasive testing procedures that provide only diagnostic utility without any therapeutic options. In patients that require bilateral diversion (about <NUM> to <NUM>%, depending on cause), the adapter <NUM> equipped with for four fittings <NUM> (<FIG> and <FIG>) allows a second nephrostomy catheter <NUM> to be connected to the single cystostomy catheter <NUM> through the adapter <NUM>. As a result, only a single access point is required to the urinary bladder, and less artificial material is implanted in the patient.

The most common complications reported for prior pyelovesical bypass and subcutaneous ureteral bypass devices include encrustation, infection, bleeding/hematoma, and kinking. There are considerable advantages of the UBDs <NUM> represented in <FIG> over such devices.

Encrustation: Pyelovesical bypass and subcutaneous ureteral bypass devices have urine flowing directly through the device with no ability to instill antiseptics that would not be immediately washed through the device with passing urine. Additionally, existing subcutaneous ureteral bypass devices have urine flowing through a shunting port within which inevitably contains regions of slower flow and stagnation where there are opportunities for mineral debris to settle out and accumulate. The UBDs <NUM> described herein, with a separate port catheter <NUM> attached to the port <NUM>, allow a non-dynamic segment of catheter volume to retain anti-encrustation substances, such as Tetra-edta, within it (similar to a catheter lock), such that the flow of urine does not flush out this medication. This reduces the chances of catheter and port encrustation. <FIG> and <FIG> are ventrodorsal radiographs showing the UBDs <NUM> of <FIG> and <FIG> and <FIG> and <FIG>, respectively, implanted in patients, and <FIG> shows contrast retained within the port catheter <NUM> because no urine flow occurs within the port catheter <NUM>.

Infection: Pyelovesical bypass and subcutaneous ureteral bypass devices report chronic infections as a complication. For subcutaneous ureteral bypass devices, it is believed infections are introduced through needle access to a subcutaneous sampling/flushing port when traversing the skin. Even when antibiotics or antiseptics are injected into a sampling/flushing port, the flow or urine quickly flushes the medications from the nephrostomy and cystostomy catheters. The UBDs <NUM> described herein, with a separate port catheter <NUM> attached to the port <NUM>, allows the non-dynamic segment of volume of the port catheter <NUM> to retain a portion of the antibacterial substances to reduce the chances of introducing infections into the system.

Hemorrhage: Pyelovesical bypass and subcutaneous ureteral bypass devices are passed subcutaneously. This involves considerable subcutaneous dissection that results in risk of patient discomfort and hemorrhage/hematoma formation. The UBDs <NUM> described herein require considerably less subcutaneous dissection to accommodate the sampling/flushing port <NUM>.

Catheter Kinking with Obstruction: Pyelovesical bypass and subcutaneous ureteral bypass devices are passed through the abdominal wall. This allows patient repositioning and muscle tone to possibly result in kinking of the nephrostomy and cystostomy catheters that can obstruct urine flow and lead to the original symptoms that prompted placement of the device in the first place. The UDSs <NUM> described herein have an artificial ureteral bypass portion of the device (catheters <NUM> and <NUM>) retained entirely within the abdominal cavity; and only a portion of the port catheter <NUM> connecting to the adapter <NUM> is passed through the abdominal wall. This important difference resolves the concern about positional kinking of the UBDs <NUM> as it does not disrupt urine flow from the kidney to the urinary bladder.

A UBD <NUM> of the type described herein has been trialed in thirty feline patients and multiple canine patients for various causes of ureteral obstruction. The trials showed the UBD <NUM> to be successful and patent for urinary drainage long-term with very few associated complications. None of the devices developed intractable encrustation or occlusion, none developed kinking leading to obstruction, or and there were no incidences of dislodgement in the long-term with the practice of serial flushing (every <NUM>-<NUM> months when necessary on an out-patient basis). <FIG> and <FIG> are images of one feline patient with the artificial ureteral bypass device of <FIG> and <FIG> implanted, with the legs of the patient extended and flexed, respectively, and evidencing no kinks in the catheters of the device.

Claim 1:
A ureteral bypass device (<NUM>) comprising:
a first catheter (<NUM>) having a proximal end (<NUM>), an oppositely-disposed distal end (<NUM>), and means for securing the distal end within the renal pelvis or ureter of a patient, wherein the first catheter is a nephrostomy or ureterostomy catheter;
a cystostomy catheter (<NUM>) having a proximal end (<NUM>), an oppositely-disposed distal end (<NUM>), and means for securing the distal end of the cystostomy catheter within the urinary bladder of the patient;
an adapter (<NUM>) fluidically connected to the proximal ends of the first and cystostomy catheters so as to fluidically connect the first and cystostomy catheters together through the adapter; and
a sampling/flushing port (<NUM>) that is fluidically connected to the adapter with a third catheter (<NUM>),
wherein the first and cystostomy catheters are fluidically connected together through the adapter without any subcutaneous connection and are fluidically connected to the sampling/flushing port, the sampling/flushing port defines an entry site that is accessible through the skin of the patient when the sampling/flushing port is subcutaneously placed to provide means for performing diagnostic and therapeutic procedures, and the third catheter defines a non-dynamic volume between the adapter and the sampling/flushing port through which urine does not flow so that the non-dynamic volume defines as an anti-infection, anti-encrustation reservoir.