Surgical removal of small, asymptomatic kidney stones minimizes relapse

During a surgery to remove ureteral or contralateral kidney stones, the concurrent removal of small and asymptomatic kidney stones contributes to a lower incidence of relapse when compared with nonremoval, according to a study.

The study included 38 patients who were scheduled for endoscopic removal of ureteral or contralateral kidney stones. They were randomized to groups where the remaining small (≤6 mm), asymptomatic kidney stones were removed (n=38, treatment group) or not removed (n=35, control group) during the surgery. The primary outcome was relapse, which was measured by future emergency department visits, surgeries, or growth of secondary stones.

Over a mean follow-up of 4.2 years, relapse occurred significantly later in the treatment group than in the control group (p<0.001 by log-rank test), with the restricted mean time to relapse being 75 percent longer in the former (1,631.6 vs 934.2 days).

Multivariable Cox regression analysis confirmed that the risk of relapse was significantly lower in the treatment group than the control group (hazard ratio, 0.18, 95 percent confidence interval, 0.07–0.44), with fewer patients in the treatment group experiencing relapse (16 percent vs 63 percent).

Meanwhile, the removal of the small asymptomatic stones added a median of 25.6 minutes to the surgery time. Five patients in the treatment group and four in the control group had emergency department visits within 2 weeks after surgery. Finally, eight patients in the treatment group and 10 in the control group reported passing kidney stones.