Difference in operative time according to stone location for endoscopic management of ureteral and renal stones

Abstract

Objective: To study the difference in operative time for endoscopic management of ureteral and renal stones according to the stone location.

Materials and methods: We hypothesized that these cases are not equivalent in terms of the surgeon's work as measured by the operating time, and we assessed whether significant variations exist within the umbrella of the Common Procedural Terminology code 52353: "ureterorenoscopic lithotripsy." We retrospectively reviewed the records of all patients undergoing unilateral ureteroscopic laser lithotripsy or retrograde intrarenal surgery under the care of 1 fellowship-trained endourologist from 2008 to 2010. The patients who underwent simultaneous additional endoscopic procedures, including bilateral ureteropyeloscopy, were excluded. The demographics, stone size and location, presence of a previously placed stent, and operative time were assessed and compared. The cohorts were designated according to the stone location--ureteral or renal.

Results: Of the total 213 ureteroscopic laser lithotripsy and retrograde intrarenal surgery cases reviewed, 115 were ureteral stones and 98 were renal stones. The renal stones required a significantly increased mean operative time (112 minutes) than did the ureteral stones (70 minutes; P <.001). The renal stone size was significantly larger (11.3 vs 7.7 mm, P <.001), and these cases had a greater preoperative stent rate (55% vs 37%, P = .014).

Conclusion: Despite bundling within a single Current Procedural Terminology code, endoscopic management of renal stones and ureteral stones were markedly different, with a significant increase in the operative time for renal stones. The renal stone size was significantly larger, as expected. Current Procedural Terminology differentiation should be considered to appreciate the difference between ureteral and renal ureterorenoscopic lithotripsy in terms of resource requirements.