Laparoscopic colorectal cancer resections in the obese: a systematic review

Background: Laparoscopic colorectal cancer operations in obese patients pose technical challenges that may negatively impact oncologic adequacy. A meta-analysis was performed to assess the oncologic outcomes of laparoscopic colorectal cancer resections in obese compared to non-obese patients. Short- and long-term outcomes were assessed secondarily. Methods: A systematic literature search was conducted from inception until October 01, 2014. Studies that compared outcomes of laparoscopic colorectal malignant neoplasms in obese and non-obese patients were selected for meta-analysis. Studies that defined obesity as body mass index (BMI) ≥ 30 kg/m2 were included. Oncologic, operative, and postoperative outcomes were evaluated. Pooled odds ratios (OR) and weighted mean differences (WMD) with 95 % confidence intervals (CI) were calculated using fixed-effects models. For oncologic and survival outcomes, a subgroup analysis was conducted for rectal cancer and a secondary analysis was conducted for Asian studies that used a BMI cutoff of 25 kg/m2. Results: Thirteen observational studies with a total of 4550 patients were included in the meta-analysis. Lymph node retrieval, distal, and circumferential margins, and 5-year disease-free and overall survival were similar in the obese and non-obese groups. Conversion rate (OR 2.11, 95 % CI 1.58–2.81), postoperative morbidity (OR 1.54, 95 % CI 1.21–1.97), wound infection (OR 2.43, 95 % CI 1.46–4.03), and anastomotic leak (OR 1.65, 95 % CI 1.01–2.71) were all significantly increased in the obese group. Conclusions: Laparoscopic colorectal cancer operations in obese patients pose an increased technical challenge as demonstrated by higher conversion rates and higher risk of postoperative complications compared to non-obese patients. Despite these challenges, oncologic adequacy of laparoscopic colorectal cancer resections is comparable in both groups.