Impact of body mass index on perioperative outcomes of laparoscopic radical nephrectomy in Japanese patients with clinically localized renal cell carcinoma

Objective: The aim of this study was to review the association between body mass index (BMI) and perioperative outcomes of laparoscopic radical nephrectomy (LRN) in Japanese patients with renal cell carcinoma (RCC). Methods: This study included 108 consecutive Japanese patients undergoing LRN for RCC between April 2001 and March 2009. These patients were divided into the following two groups according to BMI: the non-obese group (n= 58, BMI 25 kg/m2 or less) and the obese group (n= 50, BMI greater than 25 kg/m2). Perioperative outcomes between these two groups were retrospectively compared. Results: There were no significant differences in clinicopathological parameters other than BMI between the non-obese and obese groups. There were no significant differences in operative time, estimated blood loss during LRN, and the incidences of open conversion and postoperative complications between these two groups. In addition, there were no significant differences in parameters related to postoperative recovery, including time to walk, time to oral intake and time until permission for discharge, between these two groups. However, significant trends toward a prolonged operative time (P= 0.0050) and increased blood loss (P= 0.012) during LRN in relation to BMI were documented by linear regression analyses. Conclusions: Although the degree of obesity in patients included in this study was comparatively slight, these findings suggest that LRN can be safely performed for patients with RCC irrespective of BMI. However, the difficulty of LRN may increase with BMI considering the trends toward longer operative time as well as greater blood loss.