Removal of ureteral calculi in two geldings via a standing flank approach

Abstract

Two geldings, aged 11 and 17 years, were examined for treatment of ureteroliths located approximately 10 cm proximal to the bladder. Ureteral obstruction was an incidental finding in 1 horse that was referred because of urinary tract obstruction and a cystic calculus. This horse did not have clinical or laboratory evidence of renal failure, although severe hydronephrosis was evident on transabdominal ultrasonography. The second patient had a serum creatinine concentration of 6.3 mg/dL (reference range, 0.8 to 2.2 mg/dL) and mild hydronephrosis of the affected left kidney. In both patients, the obstructed ureter was exteriorized through a flank incision as a standing procedure, and the calculus was crushed and removed with a uterine biopsy forceps introduced through a ureterotomy approximately 25 cm proximal to the calculus. The cystic calculus was removed through a perineal urethrostomy by lithotripsy, piecemeal extraction, and lavage. The horse without azotemia developed pyelonephritis in the affected kidney and was euthanatized because of complications of a nephrectomy 13 months later. In the horse with azotemia, the serum creatinine concentration decreased after surgery, and the horse returned to its intended use. However, it was euthanatized approximately 2 years after surgery because of progressive renal failure, and a large nephrolith was found in the previously unobstructed right kidney. The technique used for ureterolith removal was successful in both horses in this report, did not require sophisticated equipment, and could be effective in the early stages of ureteral obstruction as a means of restoring urine flow and renal function. The outcome in the horse with advanced unilateral renal disease without azotemia would suggest that nephrectomy should be considered as a treatment in such patients.