Evaluation of the technical difficulty performing laparoscopic resection of a rectosigmoid carcinoma: visceral fat reflects technical difficulty more accurately than body mass index

Background: In general, visceral fat and adhesion greatly influence the technical difficulty in performing abdominal surgery. Body mass index (BMI) has been widely used to express the degree of obesity, but it does not always properly reflect the degree of visceral fat. This retrospective study investigated the impact of visceral fat on the operation time to examine whether a quantified visceral fat area (VFA) could be used as a sensitive predictor of technical difficulty in performing a laparoscopic resection of rectosignioid carcinoma. Methods: Between February 1999 and April 2004, 58 consecutive patients underwent a laparoscopically assisted sigmoidectomy or anterior resection. After a review of the medical charts, the relationship between the operation time and the following variables was analyzed: sex, depth of invasion, approach (medial-to-lateral, lateral-to-medial), subjectively graded degree of visceral fat and adhesion, history of previous abdominal surgery, and BMI. The correlations between VFA, VFA/body surface area (BSA) measured by the "Fat-Scan," software package for quantifying the VFA from the preoperative CT images, and operation time were investigated. Next, the impact of the VFA amount on the early surgical outcome was examined. Results: According to the intraoperative findings, two patients with a severe adhesion required a significantly longer operation time. A history of previous abdominal surgery was not a significant factor in the operation time. Instead, the VFA/BSA had a stronger correlation with the operation time than the BMI. A significantly longer operation time (209 42 vs 179 37 min; p = 0.031) was observed for the patients in the high VFA/BSA group (>= 85 cm(2)/m(2)) group than in the normal VFA/BSA group (< 85 cm(2)/m(2)). Conclusion: For predicting the technical difficulty of performing a laparoscopic resection of rectosigmoid carcinoma, VFA/BSA may be a more useful index than BMI.