Comparison of open and laparoscopic nephrectomy in obese and nonobese patients: outcomes stratified by body mass index.

PURPOSE: Laparoscopic radical nephrectomy has been accepted as the preferred management for low stage renal masses not amenable to partial nephrectomy. Early in the mid 1990s several studies suggested that obesity should be a relative contraindication to laparoscopy. We present our surgical outcomes and complications in patients undergoing open and laparoscopic nephrectomy, stratified by body mass index. MATERIALS AND METHODS: We retrospectively identified 88 patients, of whom 43 underwent open nephrectomy and 45 were treated laparoscopically. All patients were stratified by body mass index to compare multiple perioperative end points and pathological outcomes of laparoscopy. RESULTS: Overall our data showed that compared to open nephrectomy laparoscopic nephrectomy resulted in statistically significant lower estimated blood loss (147.95 vs 640.48 cc, p <0.0002), operative time (156.11 vs 198.95 minutes, p <0.003) and hospital stay (3.7 vs 5.9 days, p <0.004). When stratified by body mass index less than 25, 25 to 29.9 and 30 kg/m(2) or greater, there was a statistically significant difference in estimated blood loss and hospital stay that was in favor of the laparoscopic approach in each body mass index category. Operative time did not show a statistical difference in the subgroups but all laparoscopic procedure times were shorter than open procedure times in each body mass index category. When patients with a body mass index of greater than 30 kg/m(2) were further subgrouped into 35 kg/m(2) or greater and 40 kg/m(2) or greater, there was a statistically significant difference in estimated blood loss and hospital stay that was again in favor of the laparoscopic method. CONCLUSIONS: Laparoscopic radical nephrectomy is technically more challenging as body mass index increases due to many factors but our data show that it is feasible and safe in experienced hands. Laparoscopy appears to result in perioperative outcomes that are superior to those of open nephrectomy in this high risk population with a complication profile that is equivalent to that of the open method for each stratified body mass index category.