European Urology

Abstract

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.

Take Home Message

Percutaneous nephrolithotomy (PNL) appears to be safe, with several advantages of the prone position over supine PNL in obese and morbidly obese patients and in patients with staghorn calculi. When comparing prone to supine PNL, prone PNL has shorter operative time with similar bleeding rates and slightly better stone-free rates.