Skin-to-stone distance has no impact on outcomes of percutaneous nephrolithotomy

Skin-to-stone distance (SSD) is a stronger factor than body mass index in predicting the success of shock wave lithotripsy. We aimed to evaluate the impact of SSD on outcomes of percutaneous nephrolithotomy (PCNL).

The medical records of 1,280 patients who had undergone PCNL between April 2007 and February 2012 were evaluated retrospectively. 192 patients who had had preoperative non-contrasted computed tomography and single renal access were included the study. According to this median SSD value, patients were divided into two groups: group 1 (SSD ≤94 mm) (n = 92) and group 2 (SSD >94 mm) (n = 90). The groups were compared according to operative and postoperative parameters.

We found no significant differences between the two groups with regard to stone-free rate, operation time, fluoroscopy time, hospitalization time, visual analog score of pain, stone burden, transfusion rates and complication rates. On the other hand, the mean body mass index of group 1 was significantly lower than that of group 2 (p < 0.05).

In this retrospective review of patients undergoing PCNL, we found that SSD has no impact on operative and postoperative outcomes. These results were in accordance with the safety of PCNL in obese patients.