Use of a modified B oari 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.