Effect of supine vs prone position on outcomes of percutaneous nephrolithotomy in staghorn calculi: results from the Clinical Research Office of the Endourology Society Study.

OBJECTIVE: To analyze the effect of patient positioning on outcomes of percutaneous nephrolithotomy (PNL) among patients with staghorn stones. The choice of optimal position for these patients undergoing PNL remains challenging. No previous studies exclusively addressing this point have been performed.

METHODS: From November 2007 to December 2009, prospective data were collected by the Clinical Research Office of the Endourological Society. We included all patients with staghorn stones. Patients were divided on the basis of the position used during PNL (prone/supine). Patient characteristics, stone burden, operative details, and outcomes were compared. Multivariate analysis was performed to evaluate the relationship between patient position and stone-free rate and complication rate adjusting for number of access puncture sites.

RESULTS: A total of 1079 PNLs were performed in prone and 232 in supine positions. There were no differences in comorbidities or preoperative stone burden. A higher percentage of patients in the prone position had access through the upper pole (P <.001). Surgical time was shorter (P <.001) and stone-free rate was higher (P <.001) for patients in the prone position. There were no differences in complication rates. In multivariate analysis, patients in prone position had a higher stone-free rates (P = .0013) after adjusting for the method used for determining stone-free status and number of renal access.

CONCLUSION: Higher stone-free rates are achieved in the prone position during PNL for patients with staghorn calculi. Complication rates were similar for both positions.