Does extracorporeal shock wave lithotripsy before retrograde intrarenal surgery complicates the surgery for upper ureter stone? The results of the RIRSearch group

Retrograde Intrarenal Surgery Learning Curves of Urology Residents Supervised by an Experienced Endourologist: An RIRSearch Study

INTRODUCTION

Although retrograde intrarenal surgery (RIRS) is being performed with increasing frequency, there are only a limited number of studies about the learning curve (LC). This study aimed to analyze the LC of RIRS for five surgeons who underwent the same training.

MATERIALS AND METHODS

The data of the 410 patients who underwent RIRS between April 2017 and 2022 in a single institution, which were performed consecutively by five surgeons, were analyzed. All 50 cases performed by each surgeon were included and numbered consecutively and separately, according to the date of the operation. The combined stone-free rate (SFR) was calculated for each surgeon's cases in the same row, and the LCs were created using moving average and cumulative sum (CUSUM) analyses. Separate multivariable analyses identified each period's (LC vs. beyond) characteristics.

RESULTS

The LCs from the combined SFRs reached a plateau after approximately 50 cases for both the CUSUM and the moving average. The effect of stone burden on SFR was more evident in the first 50 cases compared to subsequent cases in the multivariable analyses (p = 0.001 and p = 0.047, respectively). Case order and stone density were independent factors in the first 50 cases (OR: 1.02 [95% CI 1.00-1.04], p = 0.04 and OR: 0.99 [95% CI 0.99-1.00], p = 0.04) but not significant in subsequent cases (OR: 0.97 [95% CI 0.94-1.00], p = 0.1 and OR: 1.00 [95% CI 0.99-1.00], p = 0.7, respectively). Compared to single locations except the lower calyx, the unfavorable effect of the multiple-stone localization on SFR grew in strength after the 50th case (OR: 0.42 [95% CI 0.23-0.78], p = 0.01 and OR: 0.20 [95% CI 0.09-0.46], p < 0.001, respectively).

CONCLUSIONS

This is the first study reporting on the RIRS LCs of urology residents. While stone burden, density, and multiple-stone localization were the factors determining SFR in the learning period, after completing the LC, the effect of stone burden weakened and multiple-stone localization became stronger.

Retrograde intrarenal surgery is a safe procedure in severe obese patients. Is it reality or prediction? A propensity score-matching analysis from RIRSearch study group

OBJECTIVE

The aim of the study was to assess whether severely obese patients have an increased risk of complications during and after retrograde intrarenal surgery.

MATERIALS AND METHODS

The data of 639 consecutive patients undergoing retrograde intrarenal surgery for the treatment of upper tract urinary stones were analyzed retrospectively. The patients were divided into two groups according to their body mass index numbers (Group 1, <35; Group 2, ≥35). The patients' demographics, stone characteristics, operative outcomes, and complication rates were compared between the groups. The primary objective was to examine whether the intraoperative and postoperative complication rates were higher in patients with a body mass index of ≥35 kg/m2.

RESULTS

After matching of confounding factors, Group 1 comprised 135 patients, and Group 2 comprised 47 patients. The baseline characteristics were similar between the groups. There were no significant differences between groups for intraoperative complication rates (11.8% and 12.8%, respectively; p=0.97). There was statistically significant difference in favor of Group 2 for postoperative complication rates (12.6% and 29.7%; respectively, p<0.01), overall complication rates (22.9% and 38.2%; respectively, p=0.02), mean operation time (56.15 minute vs 66.45 minute; respectively, p= 0.01) and length of stay (1.4 days vs 2.1 days; p=0.03). Stone free rates (75.5% vs 85.1%; respectively, p=0.17) did not differ between groups.

CONCLUSIONS

Retrograde intrarenal surgery is an efficient and feasible treatment option for upper urinary tract stones in severe obese patients. However, higher possibility of postoperative, especially infectious, complication rates should be taken into account in these patients.