Stone Disease

Modified Supine versus Prone Position in Percutaneous Nephrolithotomy for Renal Stones Treatable with a Single Percutaneous Access: A Prospective Randomized Trial

By: Marco De Sioa lowast , Riccardo Autorinoa, Giuseppe Quartoa, Francesco Calabròb, Rocco Damianoc, Francesco Giuglianoa, Salvatore Mordentea and Massimo D’Armientoa

European Urology, Volume 54 Issue 1, July 2008, Pages 196-203

Published online: 01 July 2008

Keywords: Percutaneous nephrolithotomy, Renal stones, Supine position

Abstract Full Text Full Text PDF (252 KB)



To compare operative time, safety, and effectiveness of percutaneous nephrolithotomy in the supine versus prone position in a prospective randomized trial.

Material and methods

From October 2005 to June 2007, 75 patients (33 men, 42 women; mean age, 39.3 yr) were prospectively enrolled and randomly divided into group A (39 patients, supine position) and group B (36 patients, prone position). Inclusion criteria were diagnosis of single or multiple renal stones (pelvic-caliceal) treatable with a single percutaneous access, stone diameter >2.5 cm, body mass index (BMI) <30 kg/m2, and no contraindications to perform the operation in the prone position. Exclusion criteria were stones in more than one calyx, complete staghorn stones, and coexisting renal anomalies.


The two groups were comparable in age, BMI, male-to-female ratio, and stone size. No significant difference was ascertained between the two groups in terms of stone-free rate (group A, 88.7% vs. group B, 91.6%, p = 0.12), mean blood loss (group A, Δ hemoglobin −2.3 g/dl vs. group B, −2.2 g/dl, p = 0.23), and mean hospital stay (group A, 4.3 d vs. group B, 4.1 d, p = 0.18). The only significant difference reported was mean operative time (group A, 43 min vs. group B, 68 min, p < 0.001). No blood transfusions were needed and no organ injuries were reported.


In this carefully selected patient population with uncomplicated renal stones, the supine position was similar to the prone position for percutaneous stone removal.

Take Home Message

Percutaneous nephrolithotomy in the supine position is a safe and effective procedure that results in significantly reduced operating room time.

Keywords: Percutaneous nephrolithotomy, Renal stones, Supine position.


a Clinica Urologica, Seconda Università degli Studi, Naples, Italy

b Laboratorio di Analisi Numerica, University of Cassino, Cassino, Italy

c Cattedra di Urologia, Università Magna Graecia, Catanzaro, Italy

Corresponding author. Clinica Urologica, Seconda Università degli Studi di Napoli, AOU Policlinico, Piazza Miraglia, 2 - 80138 Naples, Italy. Tel. +39 0815665050; Fax: +39 081446664.

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