Percutaneous stone surgery in the obese: outcome stratified according to body mass index

OBJECTIVE To report our experience of percutaneous surgery for treating renal pelvicalyceal stones over 6 years, to show that this approach is feasible and safe in obese and morbidly obese patients, as the prevalence of obesity and stone disease has risen in the last 20 years. PATIENTS AND METHODS We retrospectively reviewed the results of 223 percutaneous nephrolithotomies (PCNLs) by one urologist between 1995 and 2001. Patients were stratified into four groups according to the World Health Organization classification of body mass index (BMI), i.e. < 25, 25-29.9 (overweight), 30-39.9 (obese) and > 40 kg/m(2) (morbidly obese). The outcomes of surgery in these four groups were compared. RESULTS There were no statistically significant differences in operative duration, decrease in haemoglobin concentration, postoperative analgesic use, hospital stay and stone-free rates; nor was there a higher complication rate in patients who were obese. CONCLUSION The outcome of PCNL is independent of the patients' BMI and results can be favourable in most patients. We therefore advocate treating obese patients with symptomatic stone disease based on individual status, using percutaneous surgery where appropriate.