Abstract

Background:
The surgical excision of transitional cell carcinoma (TCC) of the bladder, the second most common urinary tract tumor in cats, improves survival. When TCC involves the trigone, resection is particularly challenging because the primary blood supply to the bladder, the caudal vesical artery, runs along its dorsal aspect, and removal of this region can lead to bladder necrosis. Therefore, a total cystectomy is generally required. Urinary diversion following total cystectomy is technically demanding in cats owing to the extremely narrow ureters and urethra, and successful ureterourethral anastomosis has not yet been reported.

Case Description:
An 11-year-old neutered male domestic short-haired cat was diagnosed with trigonal TCC. Subtotal cystectomy, including the trigone, was performed while preserving the ventral bladder wall, allowing for bilateral ureterovesical reimplantation without ureterourethral anastomosis. Postoperatively, right ureteral dehiscence developed, requiring revision surgery and right nephrectomy. Five months later, pyelonephritis developed, and tumor recurrence was confirmed 185 days postoperatively.

Conclusion:
Preservation of the ventral bladder wall during subtotal cystectomy demonstrated the technical possibility of ureteral reimplantation without ureterourethral anastomosis in a cat with trigonal TCC. However, this procedure was associated with major postoperative complications, including ureteral dehiscence, pyelonephritis, persistent urinary incontinence, and tumor recurrence. The reconstructive concept itself, which involves preservation of residual urothelium, may carry risks of local recurrence and secondary urinary tract obstruction. Therefore, the clinical applicability of this reconstructive strategy remains uncertain and should be interpreted cautiously. Future studies should accumulate additional cases and long-term follow-up data to determine the safety, reproducibility, and oncological suitability of this technique in feline TCC.

Key words: Bladder trigone; Cat; Subtotal cystectomy; Transitional cell carcinoma; Ureterovesical anastomosis.