Does Increased Stone-skin Distance Due to Obesity Affect Outcomes of Percutaneous Nephrolithotomy?

Abstract

Objective:Numerous factors may affect the outcomes of percutaneous nephrolithotomy (PCNL). Skine-to-stone distance (SSD) is a stronger predictor of the success of extracorporeal shock wave lithotripsy. In this study, we investigated the effect of SSD on PCNL.Materials and Methods:Data of 957 patients, who underwent PCNL between January 2007 and September 2018, were analyzed retrospectively. Of those, 424 patients, who underwent single access and had computed tomography imaging within 3 months preoperatively and post-operatively, were included in the study. The length of tract, which is the distance from the skin to the calyx of access, was measured by means of preoperative computed tomography imaging. The patients were divided into 2 groups with respect to the mean SSD: group 1 (239 patients, SSD≤100.1 mm) and group 2 (185 patients, SSD>100.1 mm). Stone-free rates were determined by detecting no-fragment status in postoperative imaging. The groups were compared by preoperative, peroperative and postoperative parameters.Results:There was no significant difference in terms of age, gender, body mass index, stone location, site of operation, length of hospital stay, operative time, fluoroscopy time, drop in hematocrit, stone-free status and access places between the groups. Stone burden and density and transfusion requirements were found to be significantly higher in group 1 than in group 2 (p<0.05).Conclusion:In this study, we found that body mass index did not affect the stone-free rate in patients who underwent PCNL. Our results suggest that PCNL is a safe, effective and favorable treatment method in patients of various body mass indices.

Keywords

• extracorporeal shock wave lithotripsy
• obesity
• percutaneous nephrolithotomy
• stone-free rate
• stone-skin distance