Outcome evaluation of ureteral stenting versus subcutaneous ureteral bypass for feline ureteral obstruction

Approximately 10% of cats presenting with acute kidney injury harbour a ureteral obstruction that demands prompt surgical decompression, yet the choice between ureteral stenting and subcutaneous ureteral bypass (SUB) remains debated. This retrospective research compared short- and long-term outcomes of 64 cats treated for ureteral obstruction at the Toronto Metropolitan University of Veterinary Medicine teaching hospital between January 2020 and June 2024. Thirty-one cats received double-pigtail ureteral stents (Stent group), while 33 underwent SUB device placement (SUB group). Signalment, pre-operative serum creatinine, obstruction aetiology, surgical duration, peri-operative mortality, and complication rates at 30 days, 6 months, and 12 months were recorded and analysed. Calcium oxalate uroliths accounted for the majority of obstructions in both groups (59.4% Stent, 57.6% SUB). Median pre-operative creatinine was comparable (Stent 487 µmol/L vs SUB 512 µmol/L; p = 0.41). Surgical time was shorter for stent placement (median 68 min) than for SUB implantation (median 94 min; p = 0.003). Peri-operative mortality within 14 days did not differ between groups (Stent 6.5% vs SUB 6.1%; p = 0.94). At 30 days, the Stent group displayed a higher rate of dysuria or pollakiuria (31.2% vs 6.3%; p = 0.012) and stent migration occurred in 14.7% of stented cats. Re-obstruction within 12 months was more frequent in the Stent group (23.4%) than the SUB group (8.6%; p = 0.038). Conversely, subcutaneous port occlusion occurred in 15.4% of SUB cats, requiring port flush under sedation. Median serum creatinine at 6 months decreased to 194 µmol/L in the Stent group and 201 µmol/L in the SUB group (p = 0.73). One-year survival was 74.2% for stented cats and 78.8% for SUB cats (p = 0.67). These findings suggest that both techniques offer similar survival rates and renal function recovery, but their complication profiles differ substantially. Ureteral stents are faster to place and less expensive, yet carry higher risks of lower urinary tract signs and re-obstruction. SUB devices demand ongoing port maintenance but appear to provide more durable ureteral patency. Clinicians should weigh obstruction location, ureteral diameter, owner compliance with follow-up, and surgeon experience when selecting the appropriate intervention.