Multicenter retrospective evaluation of transmural migration of subcutaneous ureteral bypass devices within the digestive tract in cats.

BACKGROUND: Placement of a subcutaneous ureteral bypass (SUB) device is an effective method to relieve all causes of ureteral obstruction in cats. Complications involving migration within the gastrointestinal tract have been seldomly described. OBJECTIVES: To characterize transmural migration of SUB devices within the digestive tract in cats. ANIMALS: Eleven migrated SUB catheters identified in 8 cats between 2017 and 2021. METHODS: Retrospective review of medical records of cats with a SUB device in which migration into the gastrointestinal tract was identified. RESULTS: The median time from SUB device placement to implant migration was 928 days (201-2298 days). Seven cats had obstruction of the SUB device and a positive urine culture at diagnosis. The migration was identified by ultrasound in 6/11, pre-operative contrast radiography in 2/2, and only at time of surgery in 3 SUB devices. All cats underwent surgical correction. Four nephrostomy and 7 cystotomy catheters migrated. Migration occurred into the duodenum (3/11), jejunum (7/11), and colon (1/11). SUB devices were removed in 7 cats and replaced in 2 cats, with 1 cat diagnosed with 2 migration events. Gastrointestinal resection and anastomosis were performed in 7/8 cats and an enterotomy in 2 cats. Six cats survived to discharge. The median follow-up time after migration diagnosis was 365 days (range, 0-1114 days) and 2 cats are still alive. CONCLUSIONS AND CLINICAL IMPORTANCE: Although a rare complication, migration of SUB device should be considered in cats with SUB device obstruction and a positive urine culture.

Clinicopathologic and pathologic characteristics of feline proteinuric kidney disease.

OBJECTIVES: The aim of this study was to describe the causes, clinicopathologic features and outcomes of feline protein-losing nephropathy (proteinuria secondary to glomerular disease [PLN]). METHODS: Kidney biopsy/necropsy samples from proteinuric cats submitted to the International Veterinary Renal Pathology Service were retrospectively reviewed. Diagnoses based on histopathology were categorized by primary disease compartment. Clinicopathologic variables at diagnosis, development of hypoalbuminemia, anemia, hypertension, azotemia and effusion/edema, and survival were compared between cats with immune-complex glomerulonephritis (ICGN) and other causes of PLN. RESULTS: Fifty-eight percent (n = 31/53) of proteinuric cats had ICGN and 74% (n = 31/42) of cats with PLN had ICGN. Cats with glomerular diseases other than ICGN had a higher median urine protein:creatinine ratio than ICGN cats (14.5 vs 6.5; P <0.001). Onset of PLN occurred at a young age; median age at diagnosis was 3.5 years in ICGN cats vs 1.3 years in cats with other glomerular diseases (P = 0.026). Development of complications such as hypoalbuminemia, anemia, hypertension, azotemia and effusion/edema were common, regardless of the cause of PLN, and were not different between ICGN and cats with other glomerular diseases. Male cats were over-represented in the ICGN group (P = 0.003). Median survival time (MST) for all cats with PLN was 94 days (range 3-1848 days). Survival was not different between cats with ICGN and cats with other glomerular diseases. MST in ICGN cats that developed effusion was shorter (94 days) than cats that did not (700 days; P = 0.035). MST in IGCN cats that received immunosuppressive medications was longer (244 days) than cats that did not (17 days, P = 0.039). CONCLUSIONS AND RELEVANCE: Taken together, these data suggest that clinical suspicion for glomerular proteinuria should increase in young, male cats with higher degrees of proteinuria, and immune-mediated disease is common. Further studies are needed to determine the effect of immunosuppression on morbidity and mortality in cats with ICGN.

Interventional Equipment and Radiation Safety.

Interventional radiology in veterinary medicine was adapted from techniques developed in human medicine, and has a variety of applications to treat disease in multiple body systems. Fluoroscopy is required for almost all interventional procedures, requiring knowledge of proper safety techniques for working with ionizing radiation. There are a wide variety of catheters, wires, sheaths, stents, and embolics used in veterinary medicine. Familiarity with their indications and sizing compatibility is essential for procedural success.

Minimally Invasive Management of Uroliths in Cats and Dogs.

Urolithiasis commonly affects cats and dogs. The American College of Veterinary Internal Medicine established guidelines for the treatment of uroliths that reflect modern techniques prioritizing minimally invasive procedures with an emphasis on prevention strategies to limit morbidity and mortality. Extracorporeal shockwave lithotripsy and endoscopic nephrolithotomy constitute some of the minimally invasive treatment modalities available for upper urinary tract uroliths. Cystoscopic-guided basket retrieval, cystoscopic-guided laser lithotripsy, and percutaneous cystolithotomy are minimally invasive options for the management of lower urinary tract uroliths. Following stone removal, prevention strategies are essential to help reduce morbidity and mortality associated with stone recurrence.

Use of a modified Boari flap for the treatment of a proximal ureteral obstruction in a cat.

OBJECTIVE: To describe the use and long term outcome of a novel surgical technique developed to treat a proximal ureteral obstruction in a cat. STUDY DESIGN: Case report. ANIMALS: A 3-year-old female spayed Russian blue cat. METHODS: A 3-year-old female spayed Russian blue cat presented with a fever, decreased appetite, vomiting, and abdominal discomfort. A proximal left ureteral obstruction was noted on ultrasonographic examination. No filling defect was noted on antegrade pyelography. Due to the proximal location of the obstruction, a modification of a Boari flap was performed. In the current technique, the ureter was cut proximal to the level of obstruction, and the distal ureter was resected. A flap was created on the ventral surface of the bladder, the cut end of the ureter was pulled through the flap, and a ureteroneocystostomy was performed. The bladder was closed in a simple interrupted pattern. RESULTS: At re-evaluation 2 and 4 weeks after surgery, azotemia had resolved. According to ultrasonography, the ureteroneocystostomy site appeared to be healing, and pelvic dilation had resolved. One year later, the cat continued to do well, with no lower urinary tract signs and no abnormality noted on blood tests or ultrasonography. CONCLUSION: The tubularized bladder flap originally described by Boari was modified to create a tension-free ureteroneocystostomy, without complication. This technique relied on surrounding native tissues and resulted in long-term resolution of the ureteral obstruction. CLINICAL SIGNIFICANCE: A modified Boari flap can lead to long-term resolution of proximal ureteral obstruction in cats, without requiring stents or permanent implants.

Evaluation for association between urolithiasis and chronic kidney disease in cats.

OBJECTIVE To determine whether urolithiasis is associated with chronic kidney disease (CKD) in cats. DESIGN Retrospective case-control study. ANIMALS 126 cats (59 and 67 with and without urolithiasis, respectively). PROCEDURES Medical records from June 2006 to July 2013 were searched to identify cats that underwent abdominal or focal urinary tract ultrasonography and for which serum creatinine concentration and urine specific gravity data were obtained ≤ 14 days before or after the examination. In cats with (urolithiasis group) and without (control group) urolithiasis, the presence of CKD was determined according to International Renal Interest Society guidelines. Information recorded included signalment, body weight, serum creatinine concentration, and urine specific gravity; when present, the location and number of uroliths were noted. Differences between groups and associations between group and categorical variables were analyzed statistically. RESULTS Age, weight, sex, and breed did not differ between groups. The prevalence of CKD was significantly higher in cats with urolithiasis than in the control group. Among cats with urolithiasis, there was a negative association between CKD and presence of cystoliths. There was no association between urolithiasis and the stage of CKD or between presence of CKD and location of nephroliths in the kidney. CONCLUSIONS AND CLINICAL RELEVANCE Results confirmed a positive association between urolithiasis and CKD in the feline population studied and suggested that cats with urolithiasis should be evaluated for CKD. Further research is warranted to assess the nature of the relationship between CKD and urolithiasis in cats.