OBJECTIVETo evaluate the influences of inferior mesenteric artery (IMA) types and Riolan artery arcade absence on the incidence of anastomotic leakage(AL) after laparoscopic resection of rectal cancer.

METHODSClinical data of 116 local advanced rectal cancer patients who underwent laparoscopic resection in The Sixth Affiliated Hospital of Sun Yat-sen University from January 2012 to December 2014 were analyzed retrospectively. IMA and Riolan artery arcade were examined by preoperative computed tomography angiography (CTA) reconstruction. The influences of IMA type, Riolan artery arcade absence and ligation site (high or low) on AL were analyzed by Logistic regression.

RESULTSThe proportion of IMA types(I(-IIII() was 57.8%(67/116), 10.3%(12/116), 31.0%(36/116) and 0.9%(1/116), respectively. Riolan artery arcade absence was found in 60.3%(70/116). Eight (6.9%) patients suffered from AL. IMA type III( had significantly higher AL incidence as compared to other IMA types [19.4%(7/36) vs. 1.2%(1/80), P=0.001]. Meanwhile, patients with Riolan artery arcade absence also had significantly higher AL incidence[11.4%(8/70) vs. 0.0%(0/46), P=0.030]. However, the difference in AL incidence between high and Low IMA ligation was not statistically significant [8.0%(7/87) vs. 3.4%(1/29), P=0.531]. Seven of these 8 AL patients were found in IMA type III( with Riolan artery arcade absence and high ligation. Multivariate analysis showed that IMA type III( (P=0.001) and Riolan artery arcade absence (P=0.002) were independent risk factors of AL.

CONCLUSIONSIMA type III( with Riolan artery arcade absence increases AL incidence significantly in laparoscopic resection of rectal cancer. IMA type and Riolan aretry arcade absence or not contribute to the selection of IMA ligation site in the operation. For the colorectal cancer patients with IMA type III( and Riolan artery arcade absence, selective low IMA ligation with root lymph node dissection should be recommended.