Modified lateral decubitus position with endoscopic combined intrarenal surgery for the management of complex calculi in solitary kidneys

BACKGROUND: This study compared the safety and efficacy of endoscopic combined intrarenal surgery (ECIRS) and minimally invasive percutaneous nephrolithotomy (mPCNL) in the treatment of solitary kidney calculi. METHODS: A retrospective analysis was conducted on patients with solitary kidneys and complex renal calculi treated at our center between July 2021 and December 2024. RESULTS: Twenty-eight patients underwent ECIRS, and thirty underwent mPCNL. The median operative time was significantly shorter in the mPCNL group (P<0.05), while postoperative hospital stay, drainage duration, and hemoglobin reduction were comparable between groups. The 3-month stone-free rate (SFR) was significantly higher in the ECIRS group (89.30% vs. 66.70%, P = 0.039); multivariate analysis identified surgical approach and stone volume as independent predictors of 3-month SFR. Postoperative day 1 Scr was significantly lower in the ECIRS group (P = 0.001), with surgical approach predicting immediate Scr. Overall complication rates (21.43% vs. 33.33%) showed no difference (P>0.05). CONCLUSION: Compared with mPCNL, ECIRS provides significantly higher 3‑month SFR and better perioperative renal protection in patients with solitary kidney calculi, despite longer operative time. Complication rates are comparable between the two modalities. Therefore, ECIRS represents a safe and effective minimally invasive option for complex solitary kidney stones.