To explore repeat surgery as a primary outcome measure in long-term follow-up after ureteroscopic laser lithotripsy (URS) with attempted complete extraction of fragments.

Retrospective review of the medical records of consecutive patients undergoing URS performed by a single surgeon. Repeat surgery was defined as any return to the operating room for management of stone or complications. For our survival analysis, we used the Kaplan-Meier method.

From April 2003 through May 2005 at our institution, URS was performed in 226 renal units in 216 patients. At a median follow-up of 4.1 years, 19 patients required repeat surgery. At 1 year, the cumulative repeat surgery rate (CRR) was 5.8% (95% confidence interval, 3.4%-9.8%), rising to 8.6% (5.6%-13.1%) at 5 years. CRR was strongly related to evidence of residual stone on postoperative computed tomography (P <.001). At 5 years, CRR was 3.5% (1.1%-10.3%) in patients with renal units with no detectable fragments, 8.2% (3.5%-18.6%) with fragments ≤4 mm, and 46.2% (24.0%-75.2%) with fragments >4 mm. The Cox proportional hazards ratio was 9.08 (2.11-38.00; P = .003) with fragments that were >2 mm; the ratio was 22.14 (5.15-95.14; P <.001) with fragments >4 mm.

Repeat surgery after URS is proportional to the size of residual fragments. Repeat surgery is a discrete objective metric that is consistent with, but does not require, rigorous postoperative radiologic assessment.