Effect of obesity on percutaneous nephrolithotomy outcomes in Staghorn stones

Abstract

Objective: In this study, we aimed to compare the success and complication rates of percutaneous nephrolithotomy (PCNL) in obese patients with staghorn renal stones. Material and Methods: Between January 2012 and December 2017, 183 patients who had single access PCNL for staghorn renal calculi were evaluated retrospectively. Patients were divided into two groups according to body mass index (BMI). The patients with BMI 30 kg/mm2 were defined group-1 and group-2, respectively. Among the groups, we compared demographic characteristics, perioperative and postoperative datas. Postoperatively, >4 mm stone was identified as residual fragment. Complications were classified according to the Clavien scoring system. Results: In our study, there were 127 and 56 patients with staghorn renal calculi in the Group-1 and Group-2, respectively. The mean BMI were 24.5±2.7 kg/mm2 and 32.3±2.2 kg/ mm2 in the Group-1 and Group-2, respectively ( p=0.001). The number of patients with metabolic syndrome was also statistically significant higher in group-2 ( p=0.001). The mean stone size were 848±302 mm2 and 1020±197 mm2 in the Group-1 and Group-2, respectively ( p=0.535). Operation, nephroscopy and fluoroscopy times were similar between the groups (p=0.800, p=0.123, p=0.107 respectively). When we evaluated the postoperative results, stone-free rates were 55.6% and 62.5% in group-1 and group-2, respectively (p=0.381). Total complication rates were 38.9% and 33.9% in group-1 and group-2, respectively (p = 0.523). Investigating the subgroups of complications according to the Clavien scoring system, the rate of minor complications were 27.6% and 25.0% in the group-1 and group-2, respectively and this difference was not statistically significant (p = 0.697). Major complication rates were 11.0% and 8.9% in the group-1 and group-2, respectively (p=0.657). Conclusion: PCNL is an effective and safe treatment method for staghorn stones in obese patients. Keywords: Percutaneous nephrolithotomy, Staghorn renal calculi, Clavien scoring system, obesity, body mass index.