Outcome of percutaneous nephrolithotomy: effect of body mass index.

Abstract

The surgical management of renal and upper ureteral calculi presents unique challenges in obese patients. We reviewed our recent experience with percutaneous nephrolithotomy (PNL) in obese patients to determine the safety and outcome of this procedure in such group of patients. The surgical records of 1121 patients treated with PNL between 2000 and 2004 were reviewed. Patients were stratified into four groups according to the World Health Organization classification of body mass index (BMI): <25 (average), 25-29.9 (overweight), 30-39.9 (obese), and >40 kg/m(2) (morbidly obese). The outcomes of PNL in these four groups were compared. A total of 1287 procedures were performed on 1155 renal units (1.1 procedures per renal unit). The overall stone-free rate was 85.1% and the mean hospital stay was 3.3+/-2.6 d. Major complications were seen in 72 patients (6.4%). No statistically significant differences were found in decrease in haemoglobin concentration, hospital stay, and complication rate among the four study groups. The need for auxiliary procedures and stone-free rates were comparable. PNL in obese and morbidly obese patients yields a stone-free rate that is comparable to that achieved in nonobese patients. The complication rate and length of hospital stay are also similar.