Beyond Prone Position in Percutaneous Nephrolithotomy: A Comprehensive Review

Context: Percutaneous nephrolithotomy (PNL) is traditionally performed with the patient in the prone position. Objective: To assess the efficacy and safety of the prone and supine positions, particularly in obese patients and in those with staghorn calculi. Evidence acquisition: A Medline search was conducted for articles published during the last 10 yr related to PNL in the prone and supine positions. Evidence synthesis: This search revealed 9 published studies for supine and 25 for prone PNL. None of the supine PNL studies reported visceral injuries, while transfusion rates were 0.0-9.4% and stone-free rates were 69.6-95.0%. One study of supine PNL evaluated a significant proportion of obese patients. Prone PNL studies in obese patients report transfusion rates of 3.2-8.8% and stone-free rates of 79.0-89.2%. In the only randomized study, excluding obese patients and staghorn calculi, operative time favors the supine position. A nonrandomized comparative study demonstrated similar complication rates with insignificant improvement in treatment success for supine PNL; however, when comparing series with similar proportions of staghorn calculi cases, there are slightly improved outcomes for prone PNL. Moreover, comparison of weighted means favors prone PNL. Conclusions: For obese patients and staghorn calculi, prone PNL appears to be associated with decreased operative times with similar bleeding rates and slightly better stone-free rates than supine PNL. (C) 2008 European Association of Urology. Published by Elsevier B.V. All rights reserved.