Application of a new position in endoscopic combined intrarenal surgery: modified prone split-leg position

Abstract

Background: Endoscopic combined intrarenal surgery (ECIRS) well established as a minimally invasive procedure for is treatment of multiple urolithiasis. The position is the key to the perfect combination of Percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). Galdakao-modified supine Valdivia (GMSV) and prone split-leg position are widely used. However, both positions have their own advantages and disadvantages. This study aimed at evaluating the effect of ECIRS in the treatment of multiple urolithiasis in the modified prone split-leg position.Patients and methods: Total 96 patients with multiple urolithiasis underwent ECIRS in modified prone split-leg position from September 2017 and January 2021. Relevant demographic and clinical data were analysed retrospectively. Clinical outcomes such as stone free rate, complications and postoperative hospital stay were evaluated. Factors predicting stone free rate were also evaluated. Chi-square test was used to compare categorical variables and Student t test was applied for continuous variables of the treatment groups.Results: The mean renal stones size was 32.5 ± 10.7 mm and renal stone surface area was 712.2 ± 264.8 mm2. The mean ureteral stones size was 24.8 ± 12.3 mm. The mean surgical time was 82.2 ± 38.3 min. The incidence of complications was 16.7%, mainly grade 1 and grade 2. No complications occurred above grade 3. The stone was completely removed in 75 (78.1%) patients in a single operation. The risk factors affecting the stone free rate of ECIRS were analyzed, only the number of involved calyces by stone was found to be significant (p=0.01).Conclusion: ECIRS is safe and effective in the treatment of multiple renal calculi or multiple renal calculi with ipsilateral ureteral calculi in the modified prone split-leg position. The modified of prone split-leg position makes the retrograde operation more convenient, which is conducive to the combination of RIRS and PCNL.