Prospective evaluation of an extra-anatomic ureteric bypass device for management of cats with ureteric obstruction by Zoe Halfacree and colleagues at the RVC
Use of a subcutaneous ureteral bypass (SUB) to overcome ureteral obstructions in cats was found to be associated with a high prevalence of complications but a median survival time exceeding 2 years. Ultrasonography was useful in the initial assessment of SUB usage and fluoroscopy was essential in identifying leaks, blockages or SUB displacement, and for guiding surgical treatment.Ureteral obstructions are becoming increasingly diagnosed in cats, and are commonly caused by calcium oxalate kidney stones. An SUB consisiting of an extra‐anatomic device consisting of a locking loop nephrostomy catheter connected to a cystostomy catheter via a subcutaneous port was retrospectively assessed in cats treated for benign ureteral obstruction.
The major complication rate was 48%, with most major complications occurring after discharge from hospital. However, adequate monitoring and addressing complications as they occurred meant that long‐term survival was favourable, with a median survival time exceeding 2 years. This suggests that most complications were manageable. Greater creatinine concentration at discharge and at 3 months post‐operatively was associated with a worse prognosis.
Bypass abnormalities, mainly tube blockages, occurred frequently in cats treated with SUBs. Imaging was found to be essential for routine checks of cats with signs of SUB complications. Ultrasonography was shown to be useful in documenting a reduction in the renal pelvic diameter, a sign of a successful procedure, while fluoroscopy was important in identifying sites of blockages, leaks and kinks.