Ureteroscopic lithotripsy in Trendelenburg position for proximal ureteral calculi: a prospective, randomized,...

We conducted a prospective, randomized, comparative study to compare the clinical outcome between the Trendelenburg position ureteroscopic lithotripsy (tURSL) and the conventional position ureteroscopic lithotripsy (cURSL) for the management of single proximal ureteral stone.

From January 2012 to September 2013, consecutive patients with single proximal ureteral calculi less than 2 cm and planned for ureteroscopic lithotripsy at our institution were enrolled in this study. The eligible patients were randomized into cURSL group and tURSL group according to sequence of random numbers generated by computer. In tURSL group, patients were turned into a Trendelenburg lithotomy position with head down 30° while the conventional lithotomy position was applied in cURSL group. URSL was performed using a 6/7.5F semi-rigid ureteroscope with holmium laser. When retropulsion occurred, the stones fragments were followed by semi-rigid ureteroscope up to the renal collecting system. The Olympus P5 flexible ureteroscope was used if there was any suspicion of stone migration into lower calices or incomplete stone fragmentation by semi-rigid ureteroscope. Patients' demographics between the two groups, perioperative course, clinical outcome and complication rates were compared. Data were analyzed using Chi-square test, Fisher's exact test or Student's t test. Binary logistic regression analysis was applied to estimate the effects of surgical position and stone size on stone migration.

A total of 355 cases were finally analyzed in this study (176 in cURSL group and 179 in tURSL group). The mean operative time was significantly prolonged in cURSL group than in tURSL group, while the stone-free rate (SFR) at 4 weeks was significantly higher in tURSL group. A statistically significant difference was found in stone migration rate between the two groups (26.7 vs. 43.6 %, P = 0.001). In the stone migration subsetting, less stones fragments were found to migrate into lower calices in tURSL stone migration subgroup (P = 0.000). Also, the flexible ureteroscope utilization as well as the operative time was significantly decreased in tURSL stone migration subgroup (25.5 vs. 72.3 %, P = 0.000), (44.96 ± 11.0 min vs. 59.17 ± 9.2 min, P = 0.000) with higher SFR after retrograde intrarenal surgery (RIRS) (96.2 vs. 74.5 %, P = 0.000).

The tURSL was safe and highly efficacious for the management of proximal ureteral calculus, especially in nonobese patient. Even with important stone migration risk, it rendered higher SFR and less operative time compared with cURSL. Moreover, less utilization of flexible ureteroscope and decreased deflection time in tURSL could potentially reduce the medical cost.