Endoscopy Brief: Using an arthroscope to identify and remove renal and ureteral calculi

A 5-year-old spayed female Birman cat was presented for evaluation of a three-month history of recurrent depression, vomiting, and urinary tract infections. It was not having difficulty urinating. The cat was thin, but otherwise, the physical examination results were normal. A serum chemistry profile revealed mildly elevated blood urea nitrogen and creatinine concentrations. Complete blood count, urinalysis, and thoracic radiographic examination results were unremarkable. Lateral (Figure 1) and ventrodorsal abdominal radiographs revealed multiple renal and ureteral calculi bilaterally.

Figure 1

Abdominal exploratory surgery was performed by using a standard midline approach. The ureters were markedly dilatated proximal to the ureteral calculi. Bilateral ureterotomies were performed at the point of maximal ureteral curvature medial to the kidney. A 30-degree arthroscope with a 1.9-mm diameter was placed into the ureter to allow visualization of the calculi in the renal pelvis and ureter. A large calculus in the left kidney (Figure 2) was removed with 2-mm-diameter arthroscopic grasping forceps.

Figure 2

Multiple small calculi were found in the right kidney (Figure 3) and were removed with irrigation and the forceps. Many of these calculi were too small to see without the arthroscope. Complete removal of the calculi from the renal pelves was confirmed with the arthroscope (Figure 4). The ureteral calculi were also removed. The ureterotomies were closed with 6-0 polyglyconate suture by using an operating microscope. The abdomen was closed with a routine technique, and the cat recovered well.

Figure 3

This technique, indicated for ureteral and renal calculi, is difficult to perform. Ureteral size can be evaluated at the time of the procedure. If a ureter is dilatated, a ureterotomy is performed. If only renal calculi are present, the scope can be placed through a renal pelvis wall incision or an incision through the renal parenchyma. I have performed this procedure in cats and small dogs. The most common problem I have seen is leakage at the ureterotomy site. To detect this, I perform excretory urography before the animal is released from the hospital. In some cases, leakage has been due to small missed calculi in the distal ureter, causing obstruction and increased ureteral pressure. Supportive treatment is based more on the patient's needs than on the procedure. I recommend one to three days of hospitalization after surgery.

Figure 4

The photographs and information for this case were provided by Timothy C. McCarthy, DVM, PhD, DACVS, Surgical Specialty Clinic for Animals, 4525 S.W. 109th Ave., Beaverton, OR 97005.