Burst wave lithotripsy for the treatment of obstructive ureteroliths in cats

Ureteroliths are a major source of morbidity and mortality in cats, and limited non-surgical options are available for their treatment. Ultrasound-guided, burst wave lithotripsy (BWL) is approved by the Food and Drug Administration to fragment renal and ureteral calculi noninvasively in awake human patients.

Assess the safety and efficacy of a veterinary BWL device for the treatment of obstructive ureteroliths in cats.

Eleven client-owned cats; 10 with unilateral ureteral obstruction and 1 with bilateral ureteral obstruction.

In this single-arm clinical trial, BWL was performed under general anesthesia in treatments ≤90 min. Outcomes included apparent fragmentation, ureterolith passage, decrease in pyelectasia or hydroureter, and decrease in serum creatinine concentration. Adverse events were characterized by severity and relationship to BWL.

In total, 12 ureters with 17 ureteroliths were treated with BWL. Five ureters received 1 treatment, 6 received 2, and 1 received 3, resulting in 20 total treatments. Ureterolith fragmentation was apparent in 11 of 12 treated ureters. Of 10 ureters with follow-up imaging, 8 had ureterolith passage and an accompanying decrease in ureteral dilatation. For the cats with ureterolith passage, the median serum creatinine concentration change was -29% (range, -56% to 28%) at 1-3 weeks. One serious BWL-related adverse event of worsening obstruction from residual fragments occurred, but was solved with retreatment.

Burst wave lithotripsy shows promise as a minimally invasive treatment for obstructive ureteroliths in cats. With the system used in our study, more than 1 treatment was often necessary.