Split-leg modified lateral versus prone position in percutaneous nephrolithotomy: a prospective, randomized trial

Standard prone position (PP) during percutaneous nephrolithotomy (PNL) has multiple drawbacks. We aimed to compare PNLs performed in split-leg (SL) modified lateral position (MLP) and those performed in standard PP.

A prospective, randomized, unblind, double arm trial was conducted at a tertiary care academic medical center in Egypt, between November 2017 and October 2019. Adult patients with renal stones undergoing PNL were included. According to renal anatomy and stone complexity, stratified randomization was performed and study participants were allocated into either SL-MLP group or PP group. The stone free rate (SFR), total operative time, track formation time, fluoroscopy time, auxiliary procedures, and complications were compared.

There were 61 patients in SL-MLP group and 63 patients in PP group. Both groups had similar baseline characteristics. The SFR was comparable between groups: 75.4% in SL-MLP group and 77.8% in PP group (p = 0.755). The mean total operative time was shorter and mean track formation time was longer in SL-MLP group (55.33 ± 20.73 vs. 98.49 ± 9.23, p < 0.001 and 7.89 ± 3.68 vs. 6.52 ± 1.77, p = 0.002). There was no significant difference in fluoroscopy time, total complication rates, hemoglobin reduction and need for blood transfusion between the groups. In SL-MLP group, all PNL procedures as well all the associated procedures were performed with the patients in the same position.

SL-MLP PNL has a short operative time and similar SFR and complication rate compared to PP PNL. SL-MLP allowed antegrade and retrograde access to the urinary tract without patient repositioning.