Risk Factors for Early Postoperative Small Bowel Obstruction After Anterior Resection for Rectal Cancer

The aim of the study was to evaluate risk factors for small bowel obstruction (SBO) in early postoperative period after anterior resection for rectal cancer. Patients who underwent anterior resection (AR) [high AR (HAR) or low AR (LAR)] for rectal cancer between January 2009 and April 2016 were enrolled into the study after fulfilling selection criteria. In included patients, risk factors for early postoperative SBO (EPSBO) were analyzed by means of univariate and multivariate analysis. Cases with perioperative major complications other than intestinal obstruction and with simultaneous resection of other organs were excluded. The same analyses were also performed for cases of redo surgery due to EPSBO. EPSBO was defined as clinically and radiologically confirmed SBO that developed after resuming oral intake within 30 days following surgery. The logistic regression method was used for statistical analyses. In enrolled 180 patients, EPSBO occurred in 23 (12.8%). In univariate analysis, male sex [odds ratio (OR) = 2.17, 95% CI = 0.82-6.84, p < 0.0001], previous abdominal surgery (OR = 0.20, 95% CI = 0.03-0.73, p = 0.0117), low tumor (OR = 3.26, 95% CI = 1.28-8.13, p = 0.0140), LAR (OR = 17.25, 95% CI = 3.49-312.55, p < 0.0001), D3 node dissection (OR = 13.61, 95% CI = 2.75-246.69, p = 0.0002), defunctioning ileostomy (DI) formation (OR = 9.88, 95% = 3.80-29.14, p < 0.0001), and prolonged operation time (OR = 1.01, 95% CI = 1.00-1.01, p = 0.0122) were significantly related to EPSBO. Multivariate analysis demonstrated that D3 node dissection (OR = 10.93, 95% CI = 1.94-208.23, p = 0.0038) and DI formation (OR = 5.82, 95% CI = 1.55-25.31, p = 0.0083) were independent risk factors for EPSBO. Four cases (17.4%) with EPSBO required re-operation because conservative therapies failed; all were laparoscopic DI formation cases. In three of those four cases, stenosis of stoma at the level of the posterior sheath of rectus abdominis muscle was the reason of SBO, and in one case it was kinking of the stomal limb. D3 lymph node dissection and DI formation are independent risk factors for EPSBO in AR.