Sex‐related clinical characteristics and outcomes after supine PCNL and endoscopic combined intrarenal surgery: a propensity score matching analysis

Objectives To evaluate the adjusted association between female sex and postoperative outcomes after supine percutaneous nephrolithotomy (PCNL) or endoscopic combined intrarenal surgery (ECIRS) using propensity score matching (PSM) to balance observed preoperative differences between women and men. Patients and Methods This observational cohort study used a prospectively collected institutional database of patients undergoing supine PCNL or ECIRS between 2008 and 2025. After applying eligibility criteria, 753 patients were included. Stone‐free status was defined as complete absence of residual fragments on computed tomography performed 3 months after completion of the planned treatment episode. Safety outcomes included overall, infectious, and haemorrhagic complications, graded according to the modified Clavien–Dindo classification. A single propensity score based on pre‐specified preoperative covariates was used for one‐to‐one nearest‐neighbour matching without replacement, with a calliper of 0.2 standard deviations of the logit. Post‐matching associations were assessed using conditional logistic regression. Results Women differed from men in baseline, stone‐related, and procedural characteristics. They were younger and had fewer cardiometabolic comorbidities, but more frequently presented positive preoperative urine cultures and greater stone complexity, as well as differences in stone composition and procedural characteristics. Before matching, female sex was associated with higher odds of infectious complications (odds ratio [OR] 2.11; P = 0.003), lower odds of haemorrhagic complications (OR 0.56; P = 0.032), and lower stone‐free rates ( P = 0.017). After PSM, 562 patients were retained. There was no statistically conclusive association between female sex and overall (OR 0.80, 95% confidence interval [CI] 0.53–1.21; P = 0.293), infectious (OR 1.16, 95% CI 0.63–2.14; P = 0.640), or haemorrhagic complications (OR 0.56, 95% CI 0.30–1.05; P = 0.068), or stone‐free status (OR 0.86, 95% CI 0.61–1.21; P = 0.381). Conclusions Women presented a distinct preoperative profile characterised by greater infectious burden and more complex stone disease. After balancing measured preoperative characteristics, there was no statistically conclusive association between female sex and postoperative safety or stone‐free status. Sex should therefore be considered within the broader preoperative clinical context.