Supplementary Material for: Does Body Mass Index Impact the Outcomes of Ultrasound-Guided Percutaneous Nephrolithotomy?

Background and Purpose: To evaluate whether body mass index (BMI) has an impact on the outcomes of ultrasound-guided percutaneous nephrolithotomy (PCNL). Materials and Methods: The data of 359 patients who required PCNL at ShengJing hospital between June 2013 and July 2015 were reviewed, with the patients divided into 4 groups based on different ranges of BMI: <25, 25–29.9, 30–34.9, and ≥35 kg/m². Baseline characteristics and outcomes were compared between the groups. Multivariable logistic regressions were used to evaluate the independent contribution of BMI as a predictor of outcomes. The Modified Clavien classification system was used for reporting complications. Results were compared between the groups using the chi-square and multivariate logistic regression tests. Results: No significant differences were noted in the demographic data between the 4 groups. Ultrasound screening time, total operative time, and hospital stay all increased with increasing BMI. No difference was found in the complication rate, stone free rate, or need for auxiliary procedures. Conclusion: Obesity does not increase the incidence of complications in ultrasound-guided PCNL, and the efficacy of the technique for obese patients is similar to that for normal weight patients. The lateral decubitus position was preferred in patients with higher BMI.