A 17-week-old spayed female Sphinx was referred for evaluation because of a 3-day history of inappetence, lethargy, and vomiting and a 1-day history of small bowel diarrhea. The kitten had undergone routine elective ovariohysterectomy, with no reported complications, at approximately 14 weeks of age. Prior to ovariohysterectomy, no abnormal clinical signs were evident, and the kitten was reported to be bright and active. The kitten's vaccination status was current, and there was no known dietary indiscretion or exposure to toxins. The kitten was housed indoors with no other pets.
Evaluation by the referring veterinarian the day prior included a CBC, serum biochemical analysis, and urinalysis. The CBC revealed monocytosis (850 monocytes/μL; reference range, 500 to 670 monocytes/μL), but other findings were unremarkable. Serum biochemical analysis revealed mildly high BUN concentration (37 mg/dL; reference range, 16 to 33 mg/dL) and normal creatinine concentration (0.8 mg/dL; reference range, 0.6 to 1.6 mg/dL); the remainder of the findings was unremarkable. Urine specific gravity was 1.060; other results of urinalysis were considered normal. Abdominal ultrasonography revealed an enlarged left kidney (length, 4.71 cm), with moderate pyelectasia (renal pelvis measured 6 mm in height on sagittal images) and a distended proximal portion of the left ureter (diameter, 5 mm).
The kitten was referred for further evaluation. On initial evaluation, the kitten was quiet and alert; rectal temperature (38.3°C [101°F]), pulse rate (220 beats/min), and respiratory rate (40 breaths/min) were within reference ranges. The kitten weighed 1.3 kg (2.86 lb) and had a body condition score of 4 on a scale from 1 to 9. Abdominal palpation revealed a markedly enlarged left kidney (approx 4.5 cm), and a pain response was elicited during renal palpation. A healed 1-cm laparotomy scar was visible on the caudal ventral abdominal midline. No other abnormalities were detected during physical examination.
A blood sample was collected for hematologic evaluation and serum biochemical analysis. A CBC revealed leukopenia (3,340 leukocytes/μL; reference range, 4,500 to 14,000 leukocytes/μL), with mild neutropenia (2,839 neutrophils/μL; reference range, 3,000 to 10,500 neutrophils/μL) and lymphopenia (134 lymphocytes/μL; reference range, 1,000 to 7,000 lymphocytes/μL). Serum biochemical analysis findings included hypoproteinemia (6.4 g/dL; reference range, 6.8 to 8.3 g/dL), hypoglobulinemia (2.4 mg/dL; reference range, 2.8 to 5.4 mg/dL), high aspartate aminotransferase activity (83 U/L; reference range, 17 to 58 U/L), high creatine kinase activity (5,190 U/L; reference range, 73 to 260 U/L), and high alkaline phosphatase activity (100 U/L; reference range, 14 to 71 U/L). The kitten was nonazotemic (BUN concentration, 27 mg/dL [reference range, 18 to 33 mg/dL]; creatinine concentration, 1.1 mg/dL [reference range, 1.1 to 2.2 mg/dL]), although an increase in serum creatinine concentration (previously 0.8 mg/dL) was noted. Urine specific gravity was 1.015, with no other abnormalities detected by urinalysis. Results of bacteriologic culture of urine were negative.
The kitten was hospitalized and administered lactated Ringer's solution (continuous rate IV infusion at 3 mL/kg/h [1.4 mL/lb/h]), hydromorphone hydrochloride (0.05 mg/kg [0.023 mg/lb], IV, q 6 h), ampicillin-sulbactam (21 mg/kg [9.55 mg/lb], IV, q 8 h), and ondansetron (0.5 mg/kg [0.23 mg/lb], IV, q 12 h). The kitten's appetite was considered normal. No vomiting was observed overnight; however, moderate small bowel diarrhea continued.
Abdominal ultrasonography was performed the next day and revealed renomegaly and moderate hydronephrosis of the left kidney; the left renal pelvis measured 0.9 × 1.9 cm on sagittal images and 1.6 × 2.2 cm on transverse images (Figure 1). The proximal portion of the left ureter was tortuous and moderately dilated (diameter, 3.2 mm) from the origin to the level of the midureter, where it abruptly tapered (diameter, 0.9 mm). No discrete cause of obstruction was observed. Diffusely hyperechoic small intestinal mucosa was also noted. There were no other ultrasonographic abnormalities. On the basis of these findings, the kitten was suspected to have a ureteral obstruction at the level of the left midureter. Given the recent ovariohysterectomy, iatrogenic ureteral ligation was a primary differential diagnosis. The kitten was hospitalized overnight; the previously initiated treatment was continued, aside from antimicrobial treatment, which was discontinued. The kitten continued to have a good appetite and had 2 normal bowel movements.
Sagittal (A) and transverse (B) ultrasonographic images of the left kidney of a 17-week-old spayed female Sphinx that was evaluated after a 3-day history of inappetence, lethargy, and vomiting. Notice the renomegaly and hydronephrosis. In both panels, the scale at the right is in centimeters.
Citation: Journal of the American Veterinary Medical Association 247, 8; 10.2460/javma.247.8.924
The kitten was anesthetized on the third day of hospitalization for exploratory laparotomy. Hydromorphone hydrochloride (0.05 mg/kg, SC, once) and atropine sulfate (0.02 mg/kg [0.009 mg/lb], SC, once) were administered as premedications, and anesthesia was induced with propofol (1.7 mg/kg [0.77 mg/lb], IV), midazolam (0.2 mg/kg [0.09 mg/lb], IV), and ketamine hydrochloride (2.3 mg/kg [1.05 mg/lb], IV). An endotracheal tube was placed, and anesthesia was maintained via inhalation of isoflurane in oxygen; the kitten was also administered midazolam (loading dose of 0.2 mg/kg, IV, followed by continuous rate infusion at 0.2 mg/kg/min, IV), dopamine hydrochloride (continuous rate infusion at 10 μg/kg/min [4.5 μg/lb/min], IV), mannitol (continuous rate infusion at 100 mg/kg/h [45.45 mg/lb/h], IV), and lactated Ringer's solution (continuous rate infusion at 11.5 mL/kg/h [5.23 mL/lb/h], IV). The kitten also received cefazolin sodium (22 mg/kg [10 mg/lb], IV) once during surgery.
The kitten was placed in dorsal recumbency, and the ventral aspect of the abdomen was shaved and aseptically prepared for surgery. A 10-cm ventral midline celiotomy was performed, and the abdomen was explored. The left kidney was grossly enlarged, and the distal portion of the ureter was irregular and had evidence of fibrosis (Figure 2), with adhesions to the mesentery and pancreas. There was no visible suture material (the suture type used during the ovariohysterectomy was not known) or other extraluminal obstruction that could be removed.
Intraoperative images of the normal right kidney and ureter (A) and the enlarged left kidney and irregular distal portion of the ureter (B) in the kitten in Figure 1.
Citation: Journal of the American Veterinary Medical Association 247, 8; 10.2460/javma.247.8.924
An 18-gauge over-the-needle cathetera was inserted into the caudal pole of the left kidney equidistant ventrally and dorsally and directed to the renal pelvis. The needle was removed from the catheter. Urine was obtained from the catheter for bacteriologic culture, and a syringe with a mixture of iodinated contrast mediumb and saline (0.9% NaCl) solution (1:1) was attached to the catheter. The mixture of contrast medium and saline solution was injected into the renal pelvis, and the renal pelvis and proximal portion of the ureter were observed with fluoroscopy. Contrast medium did not pass beyond the region of the midureter.
Having confirmed nonpatency of the left ureter, the placement of a subcutaneous ureteral bypassc system (as described by Berent et ald) was elected to provide renal decompression. A 0.035-inch J-tipped guide wiree was placed into the 18-gauge catheter and coiled in the renal pelvis (Figure 3). The 18-gauge catheter was removed over the guide wire. A 6.5F pigtail locking-loop nephrostomy tubec was placed over the guide wire into the renal pelvis. The suture present on the exposed end of the nephrostomy tube was pulled tight to lock the tube, and a hemostat was placed across the suture to maintain the lock. The cuff of the nephrostomy tube was then glued to the capsule of the kidney at the caudal pole.
Intraoperative images of subcutaneous ureteral bypass device placement in the left kidney of the kitten in Figure 1. A—The guide wire is placed through the catheter into the renal pelvis prior to placement of the nephrostomy tube over the guide wire. B—The nephrostomy tube is placed over the guide wire and in readiness for introduction into the renal pelvis. C—Both the nephrostomy and cystostomy tubes are in position but are not yet connected to the port. D—The nephrostomy and cystostomy tubes are connected to the port, which is sutured in position subcutaneously.
Citation: Journal of the American Veterinary Medical Association 247, 8; 10.2460/javma.247.8.924
A purse-string suture was placed into the left apex of the urinary bladder, and a stab incision was made inside the purse string. A 7F cystostomy tubec was inserted into the stab incision, and the purse-string suture was secured. The cuff of the cystostomy tube was placed into apposition with the bladder wall and was glued to the bladder wall. Four sutures of 4–0 polydioxanone were also placed between the cuff and the bladder wall to further secure the cystostomy tube.
The ends of both the nephrostomy tube and cystostomy tube (Figure 3) were tunneled through the body wall; the nephrostomy tube was tunneled caudally and the cystostomy tube was tunneled cranially to decrease the risk of kinking. The nephrostomy tube was shortened by incising the tubing surrounding the locking suture, and a subcutaneous access portc was attached to the nephrostomy tube. A boot present on the nephrostomy tube was pushed onto the male adapter of the port to secure the tube more effectively. The cystostomy tube was also attached to the subcutaneous port, and a boot was secured in similar fashion. Injection of contrast medium into the port, combined with fluoroscopic evaluation, confirmed patency of the nephrostomy and cystostomy tubing and demonstrated that no leaking from the subcutaneous ureteral bypass system was present (Figure 4). The abdomen was copiously lavaged with saline solution and suctioned prior to routine closure of the linea alba, subcutaneous tissue, and skin layers. A 3.5F red rubber urinary catheterf was placed into the urethra and bladder, secured with nylon sutures, and attached to a closed urinary catheter system prior to recovery of the kitten from anesthesia. The catheter was placed to allow recording of urine output and to minimize expansion of the urinary bladder in the immediate postoperative period. Postoperative radiography revealed appropriate positioning of the subcutaneous ureteral bypass system (Figure 5).
Fluoroscopic image of the left renal pelvis and urinary bladder in the kitten in Figure 1. Injection of contrast medium into the port reveals appropriate flow into both the renal pelvis and bladder.
Citation: Journal of the American Veterinary Medical Association 247, 8; 10.2460/javma.247.8.924
Postoperative ventrodorsal (A) and lateral (B) radiographic views of the abdomen of the kitten in Figure 1 after positioning of the subcutaneous ureteral bypass system.
Citation: Journal of the American Veterinary Medical Association 247, 8; 10.2460/javma.247.8.924
After recovery from anesthesia, a venous blood sample was collected; blood gas and electrolyte analyses revealed marked hypokalemia (2.5 mmol/L; reference range, 3.6 to 4.9 mmol/L). Packed cell volume was 32% (reference range, 25% to 45%), and plasma total protein concentration was 5.9 g/dL. The kitten was treated with lactated Ringer's solution (continuous rate infusion, 4.6 mL/kg/h [2.1 mL/lb/h], IV) supplemented with potassium chloride (60 mEq/L). The kitten was also administered hydromorphone hydrochloride (0.05 mg/kg, IV, q 6 h) for analgesia and ondansetron (0.5 mg/kg, IV, q 12 h). After 4 hours of fluid therapy, serum potassium concentration was 3 mmol/L. The kitten had no postoperative complications, and it seemed bright and was eating and drinking several hours after surgery.
The morning after surgery, the kitten continued to recover and maintained a normal mentation, had an excellent appetite, and defecated formed feces; urine output was approximately 6.4 mL/kg/h (2.91 mL/lb/h). Serum biochemical analysis revealed improved potassium status (3.6 mmol/L) and mild hyperphosphatemia (phosphorus concentration, 7 mg/dL; reference range, 3.2 to 6.3 mg/dL). Other acid-base and electrolyte variables were within reference limits, as were BUN concentration (28 mg/dL) and creatinine concentration (0.8 mg/dL). The PCV was 30%, and plasma total protein concentration was 6.5 g/dL. The incision site was non-inflamed, with no signs of discharge or dehiscence, and no signs of pain were elicited on abdominal palpation. The analgesic agent was changed from hydromorphone hydrochloride to buprenorphine hydrochloride (0.01 mg/kg [0.005 mg/lb], IV, q 6 h), and fluid therapy with lactated Ringer's solution (continuous rate infusion at 3 mL/kg/h, IV) supplemented with potassium chloride (40 mEq/L) was continued. Urine output was approximately 5.8 mL/kg/h (2.64 mL/lb/h). The kitten was provided free access to water and frequent feedings of a maintenance canned and kibble diet. The kitten remained hypothermic throughout the day, with a rectal temperature of 36°C (96.8°F), despite supplemental heat administration.
The second day after surgery, fluid therapy with lactated Ringer's solution was decreased (continuous rate infusion, 1.5 mL/kg/h [0.68 mL/lb/h], IV, supplemented with potassium chloride [50 mEq/L]). The urine output decreased from 3.8 to 1.5 mL/kg/h (1.73 to 0.68 mL/lb/h), but the kitten's weight remained stable. Hematologic analysis revealed that the PCV was 29%, and plasma total protein concentration was 6.5 g/dL. The urinary catheter was removed after the kitten chewed through the connective tubing. Despite intake of resting energy requirements, the kitten remained hypokalemic (2.9 mmol/L). Thereafter, the kitten was offered kibble free choice. Other acid-base and electrolyte variables were within reference ranges, and the kitten remained nonazotemic.
The third day after surgery, IV fluid therapy and ondansetron administration were discontinued. The kitten had no signs of discomfort while being treated with buprenorphine hydrochloride (0.01 mg/kg, transmucosally, q 8 h). The kitten remained hypokalemic (2.7 mmol/L), with no other serum biochemical abnormalities. Given persistent hypokalemia, supplementation with potassium gluconateg was initiated (0.7 mEq/kg, PO, q 24 h). The kitten continued to eat and drink well; urination and defecation were considered normal. Hematologic analysis revealed that the PCV was 26%, and plasma total protein concentration was 6.1 g/dL. Recheck focal urinary tract ultrasonography was performed, which revealed complete resolution of the left-sided hydronephrosis and left ureteral dilation (Figure 6). The subcutaneous ureteral bypass system was in an appropriate position. No free abdominal or retroperitoneal fluid was present. The incision site remained non-inflamed with no signs of discharge or dehiscence, but the kitten developed acute fluctuant and nonpainful focal swelling surrounding the port site that was presumed to be a seroma.
Sagittal ultrasonographic image of the left kidney of the kitten in Figure 1 after positioning of the subcutaneous ureteral bypass system. Notice that the hydronephrosis has resolved. The nephrostomy catheter (white arrow) is visualized within the renal pelvis, exiting through the renal cortex.
Citation: Journal of the American Veterinary Medical Association 247, 8; 10.2460/javma.247.8.924
The fourth day following surgery, the kitten was bright and active and maintained a rectal temperature between 36.1° and 38.3°C (97° and 101°F) without thermal support. It was eating and drinking well with seemingly normal defecation and urination. Slight progression of the swelling surrounding the port was noted, but the kitten appeared comfortable, and the incision site seemed to be healing normally. Hematologic analysis revealed that the PCV was 29% and plasma total protein concentration was 6.8 g/dL. Serum electrolyte concentrations were within reference limits, and potassium concentration was 3.6 mmol/L.
Results of a recheck CBC indicated that the kitten had leukocytosis (total WBC count, 19,590 WBCs/μL; neutrophil count, 9,717 neutrophils/μL; lymphocyte count, 8,522 lymphocytes/μL; and monocyte count, 646 monocytes/μL [reference range, 50 to 600 monocytes/μL]). Regenerative anemia was also present (Hct, 32.3% [reference range, 30% to 50%]; reticulocyte count, 351,000 reticulocytes/μL [reference range, 7,000 to 60,000 reticulocytes/μL]; and plasma total protein concentration, 7.0 g/dL). Bacteriologic culture of the urine collected directly from the renal pelvis during surgery yielded no growth.
The kitten was discharged from the hospital to the owners on the fifth day after surgery. The owners reported that the kitten continued to have a good appetite and normal bowel movements for the first 2 days after surgery, but then developed small amounts of mixed-bowel diarrhea with mucus 2 to 3 times/d and subjectively seemed depressed. The diet was adjusted to a kitten maintenance diet, and within 1 day after the diet change, the kitten's feces became normally formed and energy level improved dramatically; no immediate recheck examination was conducted.
The kitten was reevaluated 3 weeks following surgery. The owners reported that the kitten was doing well at home. The kitten weighed 2.05 kg (4.51 lb) and had a body condition score of 4 on a scale from 1 to 9. Physical examination findings were within normal limits, and the previously noted swelling around the port had resolved. Findings on recheck focal abdominal ultrasonographic evaluation were similar to those of previous evaluations: left renomegaly (length, 4.6 cm) with scant pelvic dilation around the nephrostomy pigtail tubing was noted. Hematologic analyses revealed that the PCV was 38% and plasma total protein concentration was 7.5 g/dL. Results of serum biochemical analyses were unremarkable (BUN concentration, 27 mg/dL; creatinine concentration, 0.6 mg/dL) with the exception of mild hyperphosphatemia (8.6 mg/dL), mild hypercalcemia (11.1 mg/dL) attributed to the kitten's age, and mild hypochloremia (115 mmol/L).
At a recheck examination 11 weeks following surgery, the kitten had continued to do well. The kitten's weight was 2.37 kg (5.21 lb), and it had a body condition score of 4 on a scale from 1 to 9. Heart rate, respiratory rate, and rectal temperature were within reference ranges. Findings on recheck abdominal ultrasonographic evaluation were unchanged from findings of previous evaluations, with the exception of mild thickening of the urinary bladder at the level of the cystostomy tubing and scant anechoic fluid and hypoechoic tissue around tubing at the apex of the urinary bladder, presumed to represent postsurgical change rather than mild inflammation. The PCV was 40%, and plasma total protein concentration was 7.1 g/dL. Serum biochemical analysis revealed no abnormalities (BUN concentration, 28 mg/dL; creatinine concentration, 0.7 mg/dL). A urine sample was obtained via cystocentesis for urinalysis and bacteriologic culture; culture of urine yielded Enterococcus faecalis (105 CFUs/mL), which was susceptible to amoxicillin. The kitten was discharged from the hospital, and treatment with amoxicillin (20 mg/kg [9.09 mg/lb], PO, q 12 h) for 4 weeks was prescribed. The owners were given instructions to return the kitten for recheck urinalysis and bacteriologic culture of urine 1 week after finishing the antimicrobial treatment.
At 18 weeks after surgery, the kitten underwent a recheck evaluation. Clinically, the kitten was doing well at home, with no abnormalities reported by the owners. The kitten's weight was 2.6 kg (5.72 lb), and it had a body condition score of 5 on a scale from 1 to 9; findings on physical examination were unremarkable. Serum biochemical variables were within reference ranges. Bacteriologic culture of urine again yielded E faecalis, which was susceptible to amoxicillin. The port was flushed with ampicillin (22 mg/kg) diluted in 6 mL of saline solution (via Huber needle injection into the port), and introduction of the antimicrobial agent into the kidney was confirmed by observation of bubbles in the renal pelvis during ultrasonography. Treatment with amoxicillin (20 mg/kg, PO, q 12 h) for 4 weeks was prescribed. Bacteriologic culture of urine was performed after 2 weeks of antimicrobial treatment and 1 week after discontinuation of treatment; on both occasions, results were negative. Results of bacteriologic culture of urine were negative at last follow-up 16 months after surgery, and the cat was clinically normal.
Discussion
Iatrogenic ureteral obstruction as a result of ligation is a potential complication of ovariohysterectomy and is infrequently reported as a cause of hydronephrosis and hydroureter.1–7 The actual incidence of this complication is unknown, and in instances of unilateral ligation, adequate contralateral renal function may prevent development of uremia and clinical signs, thereby delaying diagnosis. Considering that the kitten of this report was nonazotemic at the time of initial evaluation, the authors suspect that the gastrointestinal signs were unrelated to the hydronephrosis, which may have represented an incidental finding.
Results of physical examination and diagnostic imaging are crucial for the diagnosis and management of cats with ureteral obstruction. Although ultrasonography revealed dilation of the renal pelvis and ureter, suggesting obstruction, in the case described in the present report, the ultrasonographic findings could not be used to identify a specific ligation site. The use of intraoperative antegrade pyelography confirmed obstruction of the ureter in this kitten. This technique is highly sensitive and specific for diagnosis of ureteral obstruction in cats, and the associated risk of contrast-induced nephropathy is lower than that associated with IV excretory urography.8
Historically, treatment options for unilateral ureteral obstruction in dogs and cats have included procedures such as unilateral ureteronephrectomy, ureterotomy, and ureteral reimplantation.9–11 Given the high incidence of chronic kidney disease and an increasing frequency of diagnosis of ureterolithiasis and ureteral obstruction in cats,12,13 it was deemed worthwhile to consider alternative options that would preserve maximal renal function in the kitten of this report. As methods for correcting extraluminal obstruction in this case, ureteral resection and anastomosis or ureteroneocystostomy reflected potentially less optimal options, given that the small diameter and limited length of the ureter in cats make ureteral surgery challenging,14 and surgery would be even more difficult in a juvenile cat. Surgical manipulation of the ureter is associated with the risk of stricture formation, often resulting in recurrence of obstruction.1,11,15,16 In the case of ureteral obstruction described in this report, the subcutaneous ureteral bypass system provided an alternative, functional option for preserving remaining renal function. Initial data regarding use of the subcutaneous ureteral bypass system indicate fewer long-term complications and less risk of reobstruction, compared with traditional ureteral surgery.17
Assuming the obstruction occurred at the time of ovariohysterectomy in the kitten of the present report, the duration of the obstruction was approximately 3 weeks. According to experimental studies18 in dogs, the severity of renal damage correlates with the duration of ureteral obstruction. In 1 study,19 normal renal and ureteral function could be recovered if the occlusion was removed and ureteral patency was restored within 7 days, whereas an obstruction lasting > 4 weeks resulted in complete loss of renal function. Those studies18,19 were performed in dogs without preexisting renal disease and were designed to mimic an acute complete ureteral obstruction, comparable to the ureteral obstruction in the kitten of the present report. For this kitten, renal scintigraphy was not performed to confirm remaining glomerular filtration rate of the obstructed kidney prior to surgery; however, efficacy of this and other measures of glomerular filtration rate is still questionable.20 Placement of the subcutaneous ureteral bypass device was pursued with the anticipation of recovering any existing renal function of the kitten's left kidney, and the decrease of serum creatinine concentration from 1.1 to 0.8 mg/dL after surgery likely reflected improved renal function.
The subcutaneous ureteral bypass system appears to be a therapeutic option for ureteral obstruction, providing immediate renal decompression and ureteral patency by bypassing the ureteral abnormality. This device can be used as a first-line treatment for ureteral obstruction or in situations where traditional interventional techniques have failed or are contraindicated, such as in animals with ureteral strictures following ureteral surgery or those with ureteral stent reactions or intolerance. For the kitten of this report, the use of the subcutaneous ureteral bypass system was both therapeutic and preventative, serving to preserve renal function in lieu of resection and anastomosis, reimplantation, or stent placement. A ureteral stent was not chosen in this particular case because stents are generally not recommended in cats with ureteral strictures. Ureteral stents stimulate passive dilation of the ureter around the stent,21 a phenomenon that would likely not occur in the scenario of a ureteral stricture.
Similar to placement of a ureteral stent, the subcutaneous ureteral bypass procedure is a salvage procedure. The device is placed through a ventral midline laparotomy under fluoroscopic guidance to ensure proper placement and to test for leakage. The subcutaneous ureteral bypass system is comprised of 3 main components: a locking-loop nephrostomy catheter, a fenestrated cystostomy catheter, and a titanium shunting port connecting the 2. The locking sutures of the nephrostomy catheter maintain the coiled shape of the catheter within the renal pelvis, preventing catheter migration. The polyethylene terephthalate cuffs are secured to the kidney capsule and bladder with cyanoacrylate tissue glue, thereby reducing the risk of urine leakage from the nephrostomy and cystostomy tubes. The purpose of looping the nephrostomy tube caudally and the cystostomy tube cranially is to prevent kinking by making a gentle turn through the body wall. The port is placed under the skin and is used for sample collection and flushing to help maintain long-term patency.
Risks of the procedure in the immediate postoperative period include hemorrhage, urine leakage, and, rarely, kinking of the subcutaneous ureteral bypass system. The most common long-term complication according to 1 report22 is urinary tract infection, although the presence of a urinary catheter may be a predisposing factor.23 Urinary tract infection may require prolonged treatment because of the possibility of biofilm formation with an indwelling device. In the kitten of the present report, a urinary tract infection with E faecalis was detected on 2 occasions; Enterococcus infections are commonly associated with urinary tract implants, and the postoperative urethral catheterization of this kitten may have had a role in the development of the infections.24,25 Recurrence of obstruction by occlusion of the system with calculi or debris is less common than that associated with stent placement and is generally prevented by routine flushing of the subcutaneous ureteral bypass system. In general, cystocentesis should be performed with image guidance by an experienced clinician to prevent accidental puncture of the tubing but can be avoided altogether with use of the subcutaneous access port. Patient activity and abdominal palpation should be restricted to a minimum early after placement to prevent dislodgement of the components of the subcutaneous ureteral bypass system.
To the authors’ knowledge, this is the first report of use of a subcutaneous ureteral bypass system to treat a kitten with otherwise normal renal function. The system had enough laxity to allow for the amount of growth the kitten underwent as it matured, and there were no signs of displacement or leakage of the device. However, no long-term data are available on the usage of the subcutaneous ureteral bypass system to allow prediction of longevity. Overall durations of continued functioning of the affected kidney and subcutaneous ureteral bypass system are unclear, and it is yet to be determined whether additional complications will develop as the device ages. Nonetheless, the short-term outcome was positive in the kitten of this report. This surgical procedure may provide a successful alternative to other common options for treatment of ureteral obstruction secondary to iatrogenic ligation in cats. Moreover, as highlighted by the case described in this report, use of a subcutaneous ureteral bypass device may be tolerated well by healthy juvenile patients.
Angiocath, Becton, Dickinson and Co, Franklin Lakes, NJ.
Isovue 370, Bracco Diagnostics Inc, Princeton, NJ.
SUB, Norfolk Medical, Skokie, Ill.
Berent A, Weisse C, Bagley D. The use of a subcutaneous ureteral bypass device for ureteral obstructions in cats (abstr). Vet Surg 2010;39:E30.
Guide wire, Norfolk Medical, Skokie, Ill.
Red rubber catheter, Bard Medical, Murray Hill, NJ.
Tumil-K, Virbac Corp, Fort Worth, Tex.
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