# A gender-based investigation of risk factors for infectious complications after percutaneous nephrolithotomy for kidney stones: insight for personalized management

## TL;DR

This study finds that women have a higher risk of infections after kidney stone surgery than men, with different risk factors for each gender.

## Contribution

The study identifies gender-specific risk factors and thresholds for postoperative infections after PCNL.

## Key findings

- Females had a higher rate of postoperative infectious complications than males.
- In females, longer operative time and residual stones were key infection predictors.
- In males, preoperative urine culture and residual stones were significant predictors.

## Abstract

To investigate gender-related predictors of infectious complications after percutaneous nephrolithotomy (PCNL) in a large cohort of patients with kidney stones.

We retrospectively analysed data from 492 consecutive patients who under-went PCNL at a single tertiary-referral academic center (01/2016-09/2024). Patient’s demographics, stones characteristics and operative data were collected. Stone-free status was defined as no residual stones. Complications were graded according to modified Clavien classification. Descriptive statistics and logistic regression models were used to identify factors associated with postoperative infectious complications according to patient’s gender.

Females accounted for 39.2% of the population and showed a significantly higher rate of postoperative infectious complications compared to males (24.9% vs. 16.7%, p = 0.02). Preoperative positive bladder urine cultures were more frequent in females (27.9% vs. 16.1%, p = 0.01), as were infected stones (32.6% vs. 17.4%, p = 0.001). When stratified by gender, in males, infections were significantly associated with preoperative positive urine culture (p < 0.001) and residual stone status (p = 0.02), in females, longer operative time (p = 0.01) and residual stones (p = 0.02) were the main predictors. ROC curve analysis confirmed sex-specific thresholds for infection risk: in females, a stone volume ≥3.9 cm³ and operative time ≥96 minutes; in males, a stone volume ≥5.1 cm³ and operative time ≥137 minutes.

Female patients had higher risk of infections post PCNL than men. Surgical factors are associated with infections complications in female, while a combination of procedural and patient’s factors were found in men. In females, infectious complications occurred at lower stone volume and shorter operative time, suggesting that a gender-based risk strategy should be performed to prevent infections after PCNL.