Subcutaneous ureteral bypass explantation in 21 cats (2015-2023): outcomes and owner perceptions

Subcutaneous ureteral bypass (SUB) can be an effective treatment for ureteral obstruction in cats, but SUB explantation is little documented.

Describe reasons for SUB explantation, outcomes, and owner experiences. We hypothesized that explantation would be effective in managing common SUB-related complications.

Twenty-one cats (31 SUBs) that underwent 29 explantations.

Retrospective case-series of cats undergoing explantation between 2015 and 2023 with medical record review and 20 owners emailed for follow-up. Results are median (range).

Explantation was performed 1.8 years (0.2-4.1 years) after placement because of positive urine culture (PUC; 15/21), SUB obstruction (8/21), sterile cystitis (4/21), and suspected SUB failure (2/21). Twenty-six out of 31 ureters had documented patency. Seventeen cats had all implants removed (9 unilateral, 8 bilateral). Two underwent unilateral explantation and ipsilateral ureteronephrectomy. Two with bilateral SUBs underwent unilateral explantation. Follow-up after explantation was 596 days (3-2310 days). Four cats had ureteral re-obstruction (1 after partial obstruction at explantation), 10 did not re-obstruct and the remainder were undetermined. Seven cats died at 614 days (405-2200 days), 11 were lost to follow-up at 135 days (19-1774 days) after explantation, and 3 remained alive. Four deaths were renal related (2/4 re-obstructions). Nine of 15 cats explanted due to PUC had a negative postoperative urine culture. Three of 15 cats had clinical signs related to PUC postoperatively. Questionnaire response was 9 of 20, and 8 of 9 owners would consider explantation if in the same situation again.

For SUB cats with complications, explantation is a viable option. A small proportion of cats had clinical signs of PUC, or ureteral re-obstruction postoperatively.