Preoperative parameters (signalment, digital radiography, urinalysis, urine microbiological culture) and novel algorithm improve prediction of canine urocystolith composition.

OBJECTIVE: To determine the accuracy of 4 preoperative parameters (signalment, urinalysis, urine microbiological culture, and digital radiography) in predicting urocystolith composition, compare accuracy between evaluators of varying clinical experience and a mobile application, and propose a novel algorithm to improve accuracy. ANIMALS: 175 client-owned dogs with quantitative analyses of urocystoliths between January 1, 2012, and July 31, 2020. METHODS: Prospective experimental study. Canine urocystolith cases were randomly presented to 6 blinded "stone evaluators" (rotating interns, radiologists, internists) in 3 rounds, each separated by 2 weeks: case data alone, case data with a urolith teaching lecture, and case data with a novel algorithm. Case data were also entered into the Minnesota Urolith Center mobile application. Prediction accuracy was determined by comparison to quantitative laboratory stone analysis results. RESULTS: Prediction accuracy of evaluators varied with experience when shown case data alone (accuracy, 57% to 82%) but improved with a teaching lecture (accuracy, 76% to 89%) and further improved with a novel algorithm (accuracy, 93% to 96%). Mixed stone compositions were the most incorrectly predicted type. Mobile application accuracy was 74%. CLINICAL RELEVANCE: Use of the 4 preoperative parameters resulted in variable accuracy of urocystolith composition predictions among evaluators. The proposed novel algorithm improves accuracy for all clinicians, surpassing accuracy of the mobile application, and may help guide patient management.

Bladder wall adhesion causing a vesicular septum in a dog following surgical cystotomy.

CASE DESCRIPTION: An 8-year-old spayed female Yorkshire Terrier-Poodle dog was evaluated for persistent pollakiuria and stranguria following routine cystotomy for calcium oxalate cystoliths. CLINICAL FINDINGS: The dog presented for a cystotomy with intermittent hematuria. Postoperative radiographs revealed no remaining cystoliths. Urine, cystolith, and bladder mucosal aerobic cultures were negative. Pollakiuria, stranguria, and hematuria developed immediately after surgery and persisted despite antibiotics. Ultrasound revealed suspected fibrous adhesions within the urinary bladder lumen connecting the dorsal and ventral bladder wall creating a septum. This was confirmed cystoscopically 4 weeks after surgery. TREATMENT AND OUTCOME: Cystoscopic-guided laser ablation was performed to incise abnormal tissue connecting the ventral and dorsal bladder wall using a holmium:yttrium-aluminum-garnet laser. Three weeks later, ultrasound revealed adhesion resolution though mild pollakiuria and stranguria persisted. Oxybutynin was prescribed and clinical signs resolved. At 27 months after ablation, hematuria occurred with recurrent cystoliths. These cystoliths were removed by percutaneous cystolithotomy, documenting a cystoscopically normal bladder wall. The patient had normal urination for 55.5 months after ablation, with normal bladder wall thickness on ultrasound repeated at 27 and 36 months after ablation. CLINICAL RELEVANCE: To the authors' knowledge, an adhesion creating a septum between the dorsal and ventral bladder wall has not been previously reported as a complication after cystotomy in any species and should be considered as a cause of persistent lower urinary signs after surgery. Ultrasound identified the lesion in this dog. Because bladder abnormalities can develop quickly after surgery, ultrasound might be considered if urine testing is not supportive of infection. Cystoscopic-guided laser ablation was a successful minimally invasive treatment in this case.

Assessment of serum symmetric dimethylarginine and creatinine concentrations in cats with urethral obstruction.

OBJECTIVES: The aims of this study were to evaluate serum symmetric dimethylarginine (SDMA) and creatinine concentrations in cats with urethral obstruction pre- and post-decompression of the obstruction, and to determine if pre-decompression values were predictive of post-decompression renal function, as measured by SDMA and creatinine. METHODS: This was a prospective observational study. Twenty-five client-owned cats with urethral obstruction were hospitalized for decompression of the obstruction. Serum SDMA and creatinine were prospectively assessed at presentation, 24 h post-decompression and 5-20 days post-decompression. Urinalysis and culture were assessed at presentation and at the final follow-up. Exclusion criteria included positive urine culture, reobstruction or failure to obtain required samples. RESULTS: Mean SDMA concentration dropped by 41.8% from an initial pre-decompression concentration of 17.6 µg/dl to 10.3 µg/dl 24 h post-decompression (P <0.001). The mean creatinine value dropped by 38.4% from an initial pre-decompression concentration of 2.5 mg/dl to 1.5 mg/dl 24 h post-decompression (P <0.001). There was no association between SDMA concentration at initial presentation and SDMA concentration 5-20 days after urethral catheterization (Spearman's ρ = 0.205, P = 0.314). Creatinine concentration upon initial presentation was associated with the 5-20 day values after urethral catheterization (Spearman's ρ = 0.583, P <0.002). Twenty percent of cases were excluded due to bacterial growth on initial urine culture. SDMA and creatinine concentrations were significantly higher in these cases (median 59 µg/dl and 10.9 mg/dl, respectively) compared with those with negative cultures (median 14 µg/dl and 1.6 mg/dl [P <0.002 and P <0.001], respectively). CONCLUSIONS AND RELEVANCE: Both SDMA and creatinine decreased significantly after urethral catheterization, suggesting that renal function post-decompression cannot be predicted by the pre-decompression concentrations of these values.

Use of tissue plasminogen activator to alleviate postoperative subcutaneous ureteral bypass obstruction secondary to blood clot in seven cats.

CASE SERIES SUMMARY: Seven cats were found to have postoperative subcutaneous ureteral bypass (SUB) occlusion secondary to blood clot formation. An increase in serum creatinine led to imaging and clot detection in all but one case. Alteplase, a tissue plasminogen activator, was infused into the SUB via the port in four cats, intravesicularly via a transurethral urinary catheter in one cat, and by both routes in two cats. Patency of the SUB was re-established in all cats within 2 days. No short- or long-term complications directly attributed to alteplase administration were observed. RELEVANCE AND NOVEL INFORMATION: The results of this case series suggest that alteplase infusion via either the SUB port and/or a transurethral catheter should be considered prior to surgical intervention for the treatment of postoperative SUB occlusion secondary to a blood clot.

Therapeutic use of tetrasodium ethylenediaminetetraacetic acid solution for treatment of subcutaneous ureteral bypass device mineralization in cats.

BACKGROUND: Subcutaneous ureteral bypass (SUB) device placement is an increasingly popular treatment option for decompression of ureteral obstruction in cats. Mineralization occlusion of the device occurs in a minority of cases but is the most common complication. OBJECTIVE: To evaluate a 2% tetrasodium ethylenediaminetetraacetic acid (tEDTA) solution for treatment of mineralization occlusion in cats with SUBs. ANIMALS: Six client-owned cats (8 obstructed devices). METHODS: Case series. Each cat was found to have device occlusion based on a combination of ultrasound examination, SUB irrigation, and failure to identify another cause of device obstruction. Each SUB was drained, irrigated using sterile saline, and infused with 1-2 mL of 2% tEDTA solution. Success was defined as normalization of flow during subsequent ultrasound visualization while irrigating. The volume and frequency of tEDTA instillations, time to achieve device patency, follow-up biochemical and ultrasound findings, and future reobstruction events were recorded. RESULTS: Resolution of mineralization was documented in all 8 SUBs. Reobstruction events occurred in 2 cats, all of which resolved after additional tEDTA infusions, but 1 cat ultimately required device exchange at 356 days from the first tEDTA infusion. In 1 cat, a single infusion was prematurely discontinued because of persistent pelvic dilatation after 1.25 mL of tEDTA had been instilled. No complications were observed. CONCLUSIONS AND CLINICAL IMPORTANCE: Tetrasodium EDTA infusions can be safely considered as a treatment option for mineralized SUB devices in cats. This solution was easily infused, well tolerated, and avoided the need for SUB device exchange in the majority of cats in which it was used.

Endoscopic nephrolithotomy for the removal of complicated nephroliths in dogs and cats: 16 kidneys in 12 patients (2005-2017).

OBJECTIVE: To describe techniques and outcomes for dogs and cats undergoing endoscopic nephrolithotomy (ENL) for the removal of complicated nephroliths. ANIMALS: 11 dogs and 1 cat (n = 16 renal units) with complicated nephroliths that underwent ENL via a surgically assisted ENL approach (12 renal units) or a percutaneous nephrolithotomy approach (4 renal units) between December 2005 and June 2017. PROCEDURES: Data were obtained from the medical records regarding preoperative, operative, and postoperative findings. Follow-up information on complications and outcomes was also collected. RESULTS: Indications for nephrolith removal included massive calculi displacing parenchyma (n = 7), recurrent urinary tract infections (5), and ureteral outflow obstruction (4). Median nephrolith diameter was 2.5 cm (range, 0.5 to 5.7 cm). Nephrolith composition differed among patients; calcium oxalate was the most common type (n = 7 [including 2 mixed nephroliths containing ≥ 60% calcium oxalate]). Following ENL (median duration, 180 minutes), 15 of 16 renal units were completely nephrolith free. Procedure-related complications included renal puncture-associated hemorrhage requiring a blood transfusion (n = 1), renal capsule tear (1), and ureteral puncture (1); all were managed without adverse consequence. Five of 12 patients remained alive at the final follow-up (median, 557 days after ENL), and none died from the procedure. CONCLUSIONS AND CLINICAL RELEVANCE: ENL as performed was safe and effective in removing complicated nephroliths in a renal-sparing manner for the patients in this study. This procedure requires technical training and could be considered for the treatment of complicated nephrolithiasis in dogs and possibly cats.

Vesicovaginal fistula in a dog with urinary incontinence.

CASE DESCRIPTION: A 5-year-old spayed female Maltese mixed-breed dog was referred for evaluation because of severe urinary incontinence refractory to medical management. CLINICAL FINDINGS: Physical examination revealed constant dribbling of urine and urine scalding. Culture of a urine sample yielded methicillin-resistant Staphylococcus pseudintermedius and Proteus mirabilis. Abdominal ultrasonographic examination revealed absence of the left kidney, a small, nondistended urinary bladder, and diffuse hepatopathy. Urinary incontinence persisted despite appropriate antimicrobial treatment. Cystourethroscopy and vaginoscopy were subsequently performed and revealed a hypoplastic bladder and a vesicovaginal fistula with urinary leakage through the vaginal diverticulum; no left ureterovesicular junction was identified, consistent with suspected left renal aplasia. TREATMENT AND OUTCOME: Exploratory laparotomy was performed, and the cranial aspect of the vagina was circumferentially ligated immediately caudal to the fistula. The urinary incontinence resolved immediately after surgery, and lower urinary tract signs improved over the next 2 weeks. Moderate urinary incontinence recurred approximately 6 months later, and a urinary tract infection with Escherichia coli was subsequently identified and treated; clinical signs resolved ≤ 48 hours after treatment was initiated. CLINICAL RELEVANCE: To the author's knowledge, vesicovaginal fistulas in dogs have not been previously described and should be considered a differential diagnosis for persistent urinary incontinence and recurrent urinary tract infections in female dogs. Vaginoscopy in addition to cystourethroscopy was required to identify the abnormality in this patient. Because multiple concurrent anomalies can be present, both procedures should be performed in female dogs with these clinical signs, even if an abnormality is identified cystoscopically.

Use of cystoscopy or cystourethroscopy in treating benign macroscopic hematuria caused by lower urinary tract hemorrhage in three dogs.

CASE DESCRIPTION: A 5-year-old 11.5-kg (25.3-lb) castrated male Boston Terrier (dog 1), an 8-year-old 27.8-kg (61.2-lb) castrated male Boxer (dog 2), and a 10.5-year-old 15.9-kg (35.0-lb) spayed female Pembroke Welsh Corgi (dog 3) were evaluated because of severe, gross hematuria and suspected idiopathic renal hematuria. CLINICAL FINDINGS: All 3 dogs had hematuria, anemia, blood clots in their urinary bladders, and unremarkable findings on coagulation and mucosal bleeding time assessments. With cystourethroscopy, lower urinary tract hemorrhage originating from a small lesion in the urinary bladder (n = 2) or urethra (1) and normal-appearing yellow urine jetting from both ureterovesicular junctions were visualized in each dog. TREATMENT AND OUTCOME: Cystoscopically guided surgical resection of a hemorrhagic lesion of the urinary bladder was performed on dog 1, and histologic evaluation of the resected tissue confirmed urinary bladder telangiectasia. Dogs 2 and 3 each underwent cystourethroscopically guided laser ablation of a hemorrhagic lesion (presumptively diagnosed as hemangioma, angioma, or telangiectasia) in the urinary bladder (dog 2) or urethra (dog 3). The longest follow-up duration was 7 years, and none of the 3 dogs had subsequent recurrence of gross hematuria. CLINICAL RELEVANCE: Findings suggested that cystourethroscopy should be considered part of the diagnostic plan for hematuria in dogs before pursuing major surgical treatment or when results of conventional diagnostic procedures do not indicate the underlying cause. In addition, histologic results for dog 1 indicated urinary bladder telangiectasia, previously an unreported cause of severe, chronic lower urinary tract hematuria in dogs.

Endoscopic laser-ablation for the treatment of orthotopic and ectopic ureteroceles in dogs: 13 cases (2008-2017).

BACKGROUND: Ureteroceles are a rare condition in dogs in which conventional treatments can result in substantial morbidity. Cystoscopic and fluoroscopic-guided laser ablation (CLA) of ureteroceles can successfully relieve obstruction. OBJECTIVES: To describe the technique and outcomes of attempting CLA for treatment of ureteroceles in dogs. ANIMALS: Thirteen client-owned dogs that underwent CLA for treatment of ureteroceles. METHODS: Retrospective multicentered study. Medical records were reviewed in all dogs that underwent CLA for ureterocele(s). A laser was used to extend the opening of the ureteral orifice (UO) unless surgical conversion was necessary. Data collected included signalment, clinicopathologic data, imaging, procedural findings, complications, and short- and long-term outcome. RESULTS: Thirteen dogs with 13 ureteroceles associated with 14 UOs resulting in ureteral obstruction were included. One ureterocele extended bilaterally. Treatment was initiated via retrograde cystoscopy (7 females), percutaneous perineal urethrocystoscopy (4 males), or percutaneous antegrade cystoscopy (2 males). Surgical conversion was necessary in 2 males. Ten of 14 (71%) UOs associated with the ureteroceles were ectopic. Thirteen of 14 had stenotic or imperforate UOs. No postoperative complications were noted. Preoperative incontinence or pollakiuria was present in 9 of 13 and 3 of 13 dogs and resolved in 8 of 9 and 3 of 3 dogs, respectively. Follow-up imaging showed resolution of all ureteroceles and improved ureteral/renal pelvic dilatation. Median follow-up time was 27 months (range, 3-96 months). CONCLUSIONS AND CLINICAL IMPORTANCE: Cystoscopic-guided laser ablation was effective for the treatment of ureteroceles(s) in 11 of 13 dogs.

Use of a subcutaneous ureteral bypass device for treatment of benign ureteral obstruction in cats: 174 ureters in 134 cats (2009-2015).

OBJECTIVE To determine outcomes of subcutaneous ureteral bypass (SUB) device placement for treatment of benign ureteral obstruction in cats. DESIGN Retrospective case series. ANIMALS 134 cats with SUB devices placed in 174 obstructed ureters during 144 hospitalizations. PROCEDURES Medical records of cats that underwent SUB device placement for treatment of benign ureteral obstruction between 2009 and 2015 were reviewed. The SUB device was placed by use of fluoroscopic and surgical methods. Signalment, history, diagnostic imaging results, postprocedural results, duration of hospitalization, complications, and short- and long-term outcomes were recorded. RESULTS Ureteral obstructions were caused by ureterolithiasis (114/174 [65.5%]), stricture (28/174 [16.1%]), both ureterolithiasis and stricture (29/174 [16.7%]), or pyonephrosis (1/174 [0.6%]); in 2 (1.1%) cats, the cause was not recorded. Fifty-two of the 134 (39%) cats had bilateral ureteral obstruction. At admission, 127 (95%) cats were azotemic. Median serum creatinine concentrations at admission and 3 months after SUB device placement were 6.6 and 2.6 mg/dL, respectively. Median renal pelvis diameters before and after the procedure were 9.2 and 1.5 mm, respectively. Postsurgical complications included device occlusion with blood clots (14/172 [8.1%]), device leakage (6/172 [3.5%]), and kinking of the device tubing (8/174 [4.6%]). Cats survived to hospital discharge after 135 of the 144 (94%) hospital admissions. The most common long-term complication was catheter mineralization (40/165 [24.2%]), which was documented a median of 463 days after device placement. A high postoperative serum ionized calcium concentration was significantly associated with SUB device occlusion. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that SUB device placement may be a viable option for treatment of cats with benign ureteral obstruction.

Treatment of pyonephrosis with a subcutaneous ureteral bypass device in four cats.

CASE DESCRIPTION 4 cats were examined because of ureteral obstruction. CLINICAL FINDINGS Clinical and clinicopathologic abnormalities were nonspecific and included anorexia, lethargy, weight loss, anemia, leukocytosis, neutrophilia, lymphopenia, and azotemia. A diagnosis of pyonephrosis was made in all cats. The presence of bacteriuria was confirmed by means of urinalysis in 2 cats, bacterial culture of a urine sample obtained by means of preoperative cystocentesis in 2 cats, and bacterial culture of samples obtained from the renal pelvis intraoperatively in 3 cats. Ureteral obstruction was caused by a urolith in 3 cats; ureteral stricture associated with a circumcaval ureter was identified in 1 cat. TREATMENT AND OUTCOME All 4 cats underwent renal pelvis lavage and placement of a subcutaneous ureteral bypass (SUB) device for treatment of obstructive pyonephrosis. Postoperatively, the cystostomy tube became occluded with purulent material in 1 cat, requiring exchange. The procedure was successful in relieving the obstruction and pyonephrosis in all cats. Three of 4 cats had documented resolution of urinary tract infection. One cat had persistent bacteriuria without clinical signs 1 month after SUB device placement. CLINICAL RELEVANCE Results of this small series suggested that renal pelvis lavage with placement of an SUB device may be a treatment option for cats with obstructive pyonephrosis.

Outcome of ureteral stent placement for treatment of benign ureteral obstruction in dogs: 44 cases (2010-2013).

OBJECTIVE To describe the technique and short- and long-term outcomes for dogs undergoing double-pigtail ureteral stent placement for treatment of benign ureteral obstruction. DESIGN Retrospective case series. ANIMALS 44 dogs (57 ureters). PROCEDURES Medical records of dogs that underwent ureteral stenting for treatment of benign ureteral obstruction between 2010 and 2013 were reviewed. Signal-ment, history, pertinent diagnostic imaging results, endourologic and post-procedural details, duration of hospitalization, complications, and outcome (short term, 7 to 30 days; long term, > 30 days) were recorded. Ureteral stent placement was performed endoscopically, surgically, or both, with fluoroscopic guidance. RESULTS 57 ureters (44 dogs) underwent stenting because of obstructive ureterolithiasis (n = 48 [84%]), stricture (5 [9%]), or both (4 [7%]). Endoscopic or surgical techniques were successful for stent placement in 45 of 55 and 12 of 12 ureters (34/42 and 10/10 dogs), respectively. Median hospitalization time was 1 day. Median creatinine concentration was 2 mg/dL prior to stenting and 1.3 mg/dL 3 months after the procedure. Urinary tract infections were present in 26 of 44 (59%) dogs prior to stenting and in 11 of 43 dogs (26%) after stenting. One of the 44 (2%) dogs died after undergoing stenting, but the cause of death was not related to the procedure. Median follow-up time was 1,158 days (range, 3 to > 1,555 days), with 30 of 44 dogs alive at the time of last follow-up. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ureteral stenting may be a viable option for first-line treatment of dogs with benign ureteral obstruction. However, patients should be monitored for urinary tract infection following stenting.

Surgical and endoscopic treatment of bladder exstrophy-epispadias complex in a female dog.

CASE DESCRIPTION A 14-week-old 7.7-kg (16.9-lb) sexually intact female Golden Retriever was evaluated because of urine dripping from the caudoventral aspect of the abdomen. CLINICAL FINDINGS Ultrasonography, radiography, excretory CT urography, and vaginocystourethroscopy were performed. Results indicated eversion of the bladder through the ventral abdominal wall with exposure of the ureterovesicular junctions, pubic diastasis, and an open vulva and clitoral fossa. Clinical findings were suggestive of bladder exstrophy, a rare congenital anomaly. TREATMENT AND OUTCOME The dog was anesthetized and bilateral ileal osteotomies were performed. Two ureteral catheters were passed retrograde into the renal pelves under fluoroscopic guidance. The lateral margins of the bladder, bladder neck, and urethra were surgically separated from the abdominal wall, and the bladder was closed, forming a hollow viscus. The symphysis pubis was closed on midline with horizontal mattress sutures. The defects in the vestibule and clitoral fossa were closed. Lastly, the iliac osteotomies were stabilized. The dog was initially incontinent with right hind limb sciatic neuropraxia and developed pyelonephritis. Over time, the dog became continent with full return to orthopedic and neurologic function, but had recurrent urinary tract infections, developed renal azotemia likely associated with chronic pyelonephritis, and ultimately was euthanized 3.5 years after surgery because of end-stage kidney disease. CLINICAL RELEVANCE Bladder exstrophy and epispadias is a treatable but rare congenital abnormality. The procedure described could be considered for treatment of this condition, but care should be taken to monitor for urinary tract infections and ascending pyelonephritis.

Use of a percutaneously controlled hydraulic occluder for treatment of refractory urinary incontinence in three female cats.

CASE DESCRIPTION 3 cats were referred for evaluation of chronic urinary incontinence. CLINICAL FINDINGS A presumptive diagnosis of urethral sphincter mechanism incompetence (USMI) was made in all 3 cats. Preoperatively, incontinence was mild in 1 cat (incontinence during sleep) and moderate to severe (incontinence while awake and at rest) in 2. Structural abnormalities noted during cystoscopy included urethrovestibular junction stenosis (n = 1), vaginal stenosis (1), short urethra (1), and intrapelvic bladder (1). TREATMENT AND OUTCOME All 3 cats were treated by means of implantation of an inflatable silicone hydraulic occluder (HO) via a ventral midline celiotomy. Immediately prior to HO implantation, patients underwent cystoscopy to detect any anatomic abnormalities and confirm the absence of ureteral ectopia. Following surgery, all 3 patients attained complete continence, needing 0 or 1 inflation of the device. Complications included cystoscopy-associated urethral tear (n = 1), constipation (1), stranguria (1), hematuria (2), and urinary tract infection (2). Device explantation was performed 14 weeks after surgery in 1 cat because of postoperative constipation. Constipation persisted and urinary incontinence recurred but was markedly improved following device removal in this cat (leakage of urine only when sleeping at follow-up 29 months after surgery [26 months after device explantation]). At the time of last follow-up, 2 of the 3 cats remained fully continent approximately 3 and 6 years after device implantation. CLINICAL RELEVANCE Findings suggested that implantation of an HO may be a safe and effective long-term treatment for some cats with USMI. Further studies are necessary to evaluate the potential for treatment-related complications and the long-term outcome.

EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AND ENDOSCOPIC URETERAL STENT PLACEMENT IN AN ASIAN SMALL-CLAWED OTTER (AONYX CINEREA) WITH NEPHROLITHIASIS.

Urolithiasis is a significant disease concern in Asian small-clawed otters (Aonyx cinerea), with over 60% of captive animals affected. Bilateral ureteral stent placement, using endoscopic and fluoroscopic guidance, and extracorporeal shock wave lithotripsy (ESWL) were performed as salvage procedures in a 13-yr-old intact female Asian small-clawed otter following a 7-yr history of nephrolithiasis and progressive renal insufficiency. Following the procedure, radiographs revealed a slight shifting of urolith position, although a decrease in urolith mass was not observed. As a result of declining quality of life related to severe osteoarthritis, the otter was euthanized 5 wk after the procedure. While this treatment approach was unsuccessful in this case, the technique was clinically feasible, so ESWL and ureteral stent placement may remain a consideration for other individuals of this species presented earlier in the course of this disease.

Double pigtail ureteral stenting and renal pelvic lavage for renal-sparing treatment of obstructive pyonephrosis in dogs: 13 cases (2008-2012).

OBJECTIVE: To describe the technical aspects and clinical outcome of endoscopic- and fluoroscopic-guided ureteropelvic lavage and ureteral stent placement for treatment of obstructive pyonephrosis in dogs. DESIGN: Retrospective case series. ANIMALS: 13 client-owned dogs (14 obstructed ureters). PROCEDURES: All patients with obstructive pyonephrosis were treated with a ureteral stent. Medical records were reviewed for history, clinical signs, pre- and postprocedural clinical and imaging data, and short- and long-term outcomes. RESULTS: 13 dogs (14 ureters) had unilateral or bilateral ureteral obstructions and pyonephrosis due to ureterolithiasis (n = 13) or a suspected ureteral stricture (1). Eleven dogs had positive results of bacteriologic culture of urine obtained from the bladder, renal pelvis, or both. Ten were thrombocytopenic, and 8 were azotemic. Stents were placed fluoroscopically with endoscopic (n = 11) or surgical (3) assistance. Median hospitalization time was 48 hours (range, 6 to 260 hours). Median follow-up time was 480 days (range, 2 to 1,460 days). Intraoperative complications occurred in 2 patients (stent occlusion from shearing of a guide wire, and wire penetration of the ureter at the location of a stone). Short-term complications included a bladder hematoma (n = 1) and transient dysuria (1). Long-term complications included stent encrustation (n = 1), stent migration (1), and tissue proliferation at the ureterovesicular junction (5), which had no clinical implications. Recurrent urinary tract infections were documented in 7 dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Ureteral stenting was a successful renal-sparing treatment for obstructive pyonephrosis in dogs and could often be performed in a minimally invasive manner. There were few major complications. This technique may be considered as an effective treatment option for this condition in dogs.

Endoscopic mucosal resection and snare polypectomy for treatment of a colorectal polypoid adenoma in a dog.

CASE DESCRIPTION: An 11-year-old castrated male mixed-breed dog was examined for a 3-month history of hematochezia and tenesmus. Abdominal ultrasonography and rectal examination prior to referral had revealed a colorectal polyp, diagnosed as a benign colorectal polypoid adenoma after histologic examination of tissue samples. The patient was referred for treatment. CLINICAL FINDINGS: A 2-cm-diameter sessile polypoid mass was located approximately 6 cm orad to the anus in the right dorsolateral region of the descending colon just caudal to the pubis. There was no evidence of metastasis on thoracic radiography or abdominal ultrasonography. Results of a CBC and serum biochemical analysis were within reference limits. TREATMENT AND OUTCOME: Endoscopic mucosal resection (EMR) and snare electrocautery were used to resect the mass and a definitive histopathologic diagnosis of a sessile colorectal polypoid adenoma was made. A 9.9-mm gastroduodenoscope was used during colonoscopy to inspect the mass. To aid in EMR, a 25-gauge endoscopic injection needle was used to infuse sterile saline (0.9% NaCl) solution under the base of the polyp, into the submucosa to elevate the mucosa from the muscularis layer beneath the polyp prior to polypectomy. This was necessary because of the sessile, rather than pedunculated, base of the mass. The entire polyp was successfully removed with endoscopic guidance. The clinical signs of hematochezia and tenesmus resolved immediately, and serial rectal examinations were performed over the following 36 months with no palpable evidence of recurrence. CLINICAL RELEVANCE: The patient described in the present report underwent successful colonic EMR and snare polypectomy with no known evidence of mass recurrence during the following 36 months, suggesting that this minimally invasive procedure may be a valuable treatment option for sessile polyps. The advantage of this technique was that elevation of the mucosa via injection of saline solution improved visibility of the polyp and helped to separate the polyp base from the deeper submucosal colorectal tissue, making complete resection possible.

Technical and clinical outcomes of ureteral stenting in cats with benign ureteral obstruction: 69 cases (2006-2010).

OBJECTIVE--To evaluate the technical, short-term, and long-term outcomes in cats with benign ureteral obstructions treated by means of double-pigtail ureteral stent placement. DESIGN--Retrospective case series. ANIMALS--69 cats (79 ureters). PROCEDURES--The diagnosis of benign ureteral obstruction was made via abdominal ultrasonography, radiography, and ureteropyelography. Ureteral stent placement was attempted endoscopically, surgically, or both, with fluoroscopic guidance. The medical records were reviewed for pre-, intra-, and postoperative data; complications; and outcome. RESULTS--69 cats (79 ureters) had stent placement attempted for various causes: ureterolithiasis (56/79 [71%]), stricture (10/79 [13%]), both ureterolithiasis and stricture (12/79 [15%]), or a purulent plug (1/79 [1%]). Stent placement was successful in 75 of 79 ureters (95%). Median number of stones per ureter was 4 (range, 0 to > 50), and 67 of 79 (85%) had concurrent nephrolithiasis. Preoperative azotemia was present in 95% (66/69) of cats (median creatinine concentration, 5.3 mg/dL [range, 1.1 to 25.8 mg/dL]), and 71% (49/69) remained azotemic (median, 2.1 mg/dL [range, 1.0 to 11.8 mg/dL]) after successful surgery. Procedure-related, postoperative (< 7 days), short-term (7 to 30 days), and long-term (> 30 days) complications occurred in 8.7% (6/69; 7/79 ureters), 9.1% (6/66), 9.8% (6/61), and 33% (20/60) of cats, respectively; most of these complications were minor and associated with intermittent dysuria or the need for ureteral stent exchange. The perioperative mortality rate was 7.5% (5/69), and no deaths were procedure related. The median survival time was 498 days (range, 2 to > 1,278 days). For patients with a renal cause of death, median survival time was > 1,262 days, with only 14 of 66 cats (21%) dying of chronic kidney disease. Nineteen (27%) cats needed a stent exchange (stricture in-growth [n = 10], migration [4], ureteritis [2], dysuria [2], pyelonephritis [1], or reflux [1]). No patient died of the procedure or recurrent ureteral obstruction. CONCLUSIONS AND CLINICAL RELEVANCE--Results of the present study indicated that ureteral stenting is an effective treatment for benign ureteral obstructions in cats regardless of obstructive location, cause, or stone number. The perioperative morbidity and mortality rates were lower than those reported with traditional ureteral surgery. The short- and long-term complications were typically minor but may necessitate stent exchange or use of an alternative device, particularly with ureteral strictures. The prognosis for feline ureteral obstructions after ureteral stenting could be considered good when the procedure is performed by trained specialists.

Endoscopic-guided sclerotherapy for renal-sparing treatment of idiopathic renal hematuria in dogs: 6 cases (2010-2012).

OBJECTIVE: To describe the use of sclerotherapy for the renal-sparing treatment of idiopathic renal hematuria (IRH) in dogs and report clinical outcomes. DESIGN: Retrospective case series. ANIMALS: 6 dogs (8 renal pelvises) with IRH. PROCEDURES: Medical records of dogs that underwent sclerotherapy were reviewed. Each ureterovesicular junction was identified cystoscopically to determine the side of bleeding, and a retrograde ureteropyelogram was performed with endoscopic and fluoroscopic guidance. A ureteropelvic junction balloon was used for ureteral occlusion, and pelvis filling volumes were recorded. A povidone iodine mixture, followed by a sterile silver nitrate solution, was infused into the renal pelvis. A double-pigtail ureteral stent was placed after the procedure. Information on preprocedure and postprocedure biochemical changes, imaging parameters, and clinical outcomes was obtained. RESULTS: 6 dogs (5 males and 1 female) had sclerotherapy for unilateral (4) or bilateral (2) bleeding. Five were right-sided and 3 were left-sided. The median age and weight of dogs were 3 years and 42.4 kg (93.28 lb), respectively. Median procedure time was 150 minutes. One dog that did not have a ureteral stent placed following the procedure developed short-term signs of renal pain and pyelectasis. Cessation of macroscopic hematuria occurred in 4 of 6 dogs (median, 6 hours). Two additional dogs improved moderately. Median follow-up time was 8 months (range, 3.5 to 20.5 months). CONCLUSIONS AND CLINICAL RELEVANCE: Topical sclerotherapy for IRH was safe and effective. Local sclerotherapy for IRH in dogs could be considered a valuable and minimally invasive renal-sparing treatment over ureteronephrectomy.

Evaluation of outcome following urethral stent placement for the treatment of obstructive carcinoma of the urethra in dogs: 42 cases (2004-2008).

OBJECTIVE: To evaluate the outcome following urethral stent placement for the palliative treatment of obstructive carcinoma of the urethra in dogs. DESIGN: Retrospective case series. ANIMALS: 42 dogs with obstructive carcinoma of the urethra. PROCEDURES: Medical records for dogs in which a self-expanding metallic stent (SEMS) was used for the treatment of obstructive carcinoma of the urethra were reviewed. Signalment, diagnostic findings, clinical signs before and after SEMS placement, and patient outcome were analyzed. Fluoroscopic images were evaluated to determine the effects of stent size, obstruction length, tumor length, and urethral length and width on the incidence of incontinence or stranguria. RESULTS: Resolution of urinary tract obstruction was achieved in 41 of 42 (97.6%) dogs. After SEMS placement, 6 of 23 male and 5 of 19 female dogs developed severe incontinence, and 1 of 23 male and 1 of 17 female dogs developed stranguria. Stent length, diameter, and location were not associated with incidence of incontinence or stranguria. Median survival time after SEMS placement was 78 days (range, 7 to 536 days). Treatment with NSAIDs before and chemotherapeutics after SEMS placement increased median survival time to 251 days (range, 8 to 536 days). CONCLUSIONS AND CLINICAL RELEVANCE: Urethral SEMS placement was an effective palliative treatment for dogs with obstructive carcinoma of the urethra; however, severe incontinence subsequently developed in 11 of 42 (26%) treated dogs. Adjunctive treatment of affected dogs with NSAIDs and chemotherapeutics significantly increased the median survival time.