Nephrocystostomy Technique for Ureteral Bypass in Cats. Schmiedt CW1, Hardie RJ2, Shessel BE1, Gendron K1, Rissi D3, Moss L1, Boesl A1. 1University of Georgia, Athens, GA; 2University of Wisconsin-Madison, Madison, WI; 3University of Georgia, Athens Veterinary Diagnostic Laboratory, Athens, GA.
Use of native tissues in surgical treatment of ureteral obstruction continues to be a challenge. The objective was to describe a novel technique for nephrocystostomy (NCT). Nine adult purpose-bred cats were used. The proximal ureter was ligated. A cuff of mucosa was created on the bladder apex. A 6 mm caudal defect was created in the right or left kidney. A 3 cm catheter was placed through the defect and secured. The mucosal cuff was advanced over the catheter and secured within the renal pelvis. The bladder seromuscularis was sutured to the kidney. Catheters were removed at 60–118 days. Cats were evaluated 30 (n = 6) and 90 (n = 3) days after catheter removal. Median surgical time was 102 minutes (range 83–120). No leakage or obstruction of the NCT occurred. All cats had hematuria immediately postop. Four developed clot-associated urethral obstruction requiring catheterization. All four developed UTI that responded to antibiotics. One cat had NCT catheter dislodgement. CT revealed patent NCT but loss of normal renal shape, caudally. Histopathology revealed epithelialization of bladder mucosa to the renal pelvis and degenerative changes in the caudal pole. NCT is feasible in normal cats and can remain patent for at least 90 days. Methods to limit nephrostomy track hemorrhage should be investigated. Degenerative changes may be related to vascular impairment. The significance of these changes is unknown. Complete ureteral bypass is possible in cats using only native tissues.