Diagnosis and surgical management of obstructive ureteral calculi in cats: 11 cases (1993-1996)

Abstract

Objective - To evaluate diagnostic methods, surgical treatment, perioperative management, and renal function of cats with obstructive calcium oxalate ureteroliths. Design - Retrospective case series. Animals - 11 cats that underwent surgery for removal of calcium oxalate ureteroliths. Procedure - Medical records were reviewed, and the following information was recorded: signalment; results of physical examination, clinicopathologic analyses, and abdominal imaging; surgical procedure; postoperative management; and results of ureterolith quantitative analysis. Results - Ureteroliths in the proximal portion of the ureter were removed from 5 cats (pyelotomy, 1 cat; unilateral ureterotomy, 2 cats; bilateral ureterotomies, 2 cats). Calculi in the middle and distal part of the ureter were removed by partial ureterectomy and ureteroneocystostomy (6 cats). Ten cats recovered from surgery and were discharged from the hospital. One cat died from unknown causes 4 months after surgery, and 1 cat had a nephrectomy elsewhere 5 weeks after ureterolith removal. Eight cats were evaluated 12 to 20 months after surgery. Of these, 2 cats that were markedly azotemic before surgery improved after surgery, and 2 cats developed nephroliths after surgery. Also, of 5 cats that had nephroliths that were not removed at the time of surgery, 4 still had visible nephroliths. One cat had recurrent ureteral obstruction from a ureterolith and persistent urinary tract infection. Ureteroliths or ultrasonographic evidence of ureteral obstruction were not detected in other cats. Clinical Implications - A combination of microsurgical techniques and intensive postoperative care is necessary to minimize morbidity of cats after removal of a ureterolith. Renal function may improve or stabilize after removal of the ureteral obstruction.