Efficacy and safety of percutaneous nephrolithotomy in patients with body mass index over 30 kg/m2

Introduction and objective: With the increasing prevalence of urolithiasis, the world is also witnessing an epidemic of obesity. Management of such patients is challenging due to the body habitus and the presence of multiple comorbidities. It is unclear whether percutaneous nephrolithotomy (PCNL) has similar efficacy and safety in obese patients as compared to patients with normal body mass index (BMI). The objective of this study is to assess the impact of body mass index on the efficacy and safety of PCNL in patients with BMI > 30 kg/m2. Material and methods: The medical records of 124 obese patients with BMI > 30 kg/m2, treated between January 2017 and September 2022 were retrospectively reviewed. All patients underwent standard PCNL with ultrasound probe disintegration of stones. Data on patients preoperative characteristics, stone free rates, operating times, intra- and postoperative complications were analysed. Results: Patients’ mean age was 57.0±9.2. The majority of patients had at least one comorbidity – 53 (43.4%) had diabetes, 45 (36.3%) – hypertension and 7 (5.6%) had ischemic heart disease. 100 (80.6%) patients had BMI between 30-34 kg/m2, 12 (9.7%) – between 35-39.9 kg/m2 and 12 (9.7%) patients had BMI measured over 40 kg/m2. Mean stone length was 40.0±14.9 mm and mean stone width 29.3±28.7 mm. In the majority of patients 118 (95.2%) lower pole puncture was performed for access to the stone. 54 (43.5%) of the patients had staghorn stones and 58 (46.8%) had stones composed of uric acid. Mean operative time was 50.3±12.2 min and mean hospital stay 3.5±0.9 days. Stone-free rate after a single procedure was 80.6%. Postoperative complications were fever in 5 (4%) patients, haematuria in 2 (1.6%), formation of AV fistula in 2 (1.6%) and renal colic – in 3 (2.4%) patients. Management of these complications included medical treatment in 7 (5.6%) patients, double JJ stent insertion in 4 (3.2%) and angioembolization in 2 (1.6%). Conclusions: PCNL is safe and effective procedure in obese patients with BMI > 30 kg/m2. BMI seems to have no impact the stone-free or complication rates, despite the potential difficulties in performing it in obese patients.