Visceral Obesity is Associated with Outcomes of Total Mesorectal Excision for Rectal Adenocarcinoma

Background And Objectives: General obesity, measured by the body mass index (BMI), increases the technical difficulty of total mesorectal excision (TME) but does not affect oncologic outcomes. The purpose of this study is to compare visceral and general obesity as predictors of outcomes of TME for rectal adenocarcinoma.

Methods: Adult patients undergoing TME for rectal adenocarcinoma were retrospectively identified. Preoperative computed tomography scans were used to measure abdominal circumference (AC), visceral (VFA), and subcutaneous fat area (SFA). BMI, AC, VFA, SFA, total fat area (TFA, sum of VFA and SFA), and VFA/SFA ratio were examined for association with operative, postoperative, oncologic, and survival outcomes in a univariate analysis model.

Results: Between 1999 and 2009, 113 patients met inclusion criteria. Increasing VFA and VFA/SFA ratio were associated with reduced lymph node retrieval (P = 0.03 and P = 0.009, respectively). The association between increasing VFA/SFA ratio with delayed resumption of oral intake (P = 0.05) and prolonged overall survival (P = 0.003) were also significant. Increasing BMI was associated with improved overall (P = 0.02) but not disease-free survival (P = 0.14).

Conclusion: Visceral obesity, measured by VFA/SFA ratio, is a better predictor of postoperative, oncologic, and survival outcomes after TME for rectal adenocarcinoma than general obesity measured by the BMI.