MODIFIED SUPINE VERSUS PRONE POSITION IN PERCUTANEOUS NEPHROLITHOTOMY

Abstract

Objective: To compare the technical aspects, operative time, safety, and effectiveness of percutaneous
nephrolithotomy (PNL) in the modified supine position versus the standard prone position.
Patients and methods: The present study was conducted at urology department Zagazig University
hospitals, from October, 2008 to March, 2010. Seventy seven patients (47 men, 30 women) with renal
stones were enrolled and systematically randomized into 2 groups: group A, 39 patients, modified supine
position and group B, 38 patients, prone position. Preoperative evaluation included; medical history,
physical examination, standard laboratory investigations, and radiologic investigations. Procedures; for
group A, the patients were placed in modified supine position by putting a suitable cushion (3L water bag
or less) under the ipsilateral shoulder, fixed ipsilateral arm over the thorax, and extended ipsilateral leg
over flexed contralateral leg. For group B, the patients were turned to the standard prone position. The
procedure was accomplished in both groups as consuetude. The patient outcome was considered cure
(successful procedure) if he became stone free or had residual fragments smaller than 5 mm in diameter.
The operative time (from the induction of anesthesia to removal of endotracheal tube) was estimated and
any operative complications or conflicts were recorded. Comparative analysis of different variables
between both groups was done.
Results: Patients in both groups have comparable preoperative clinical data and there was no significant
difference in preoperative clinical characteristics. Successful procedure was reported in 82% and 81.5%
for group A and group B respectively. The operative time was significantly longer in the group B (prone
position) than group A (modified supine position). There was no significant difference between both
groups in fluoroscopy time and patient’s outcome.
Conclusions: The modified supine position with a cushion under the ipsilateral shoulder assimilates
efficacy and safety as prone position in cases of PNL and offers significantly less operative time.
Key words: percutaneous nephrolithotomy, prone position, supine position