Free-flank modified supine vs. prone position in percutaneous nephrolithotomy: A prospective randomised trial

Objective: To compare the technical aspects, operative time, safety and effectiveness of percutaneous nephrolithotomy (PCNL) in the free-flank modified supine position (FFMSP) vs. the standard prone position (SPP). Patients and methods: Seventy-seven patients (47 men and 30 women) with renal stones were enrolled and systematically randomised into two groups, A (39 patients) treated using the FFMSP, and B (38 patients) in the SPP. The outcome was consid- ered as a cure (successful procedure) if the patient became stone-free or had residual fragments of 4 mm in diameter. The operative time (from the induction of anaes- thesia to the removal of the endotracheal tube) was measured and any operative complications or conflicts were recorded. The different variables were compared and analysed between the groups. Results: Patients in both groups had comparable preoperative clinical data and there were no significant differences in the preoperative clinical characteristics. The procedure was successful in 84.6% and 84% of group A and B, respectively. The operative time was significantly longer in group B (SPP) than A (FFMSP). There was no significant difference between the groups in fluoroscopy time and patients’ outcome. Conclusions: The FFMSP (with a cushion under the ipsilateral shoulder) has sim- ilar efficacy and safety as the SPP for PCNL and is associated with a significantly quicker operation.