OBJECTIVETo explore the feasibility and clinical significance of precision low inferior mesenteric artery (IMA) ligation with the left colonic artery (LCA) preservation and root lymph node dissection in laparoscopic radical resection for rectal cancer, according to the inferior mesenteric artery (IMA) types.

METHODSOne Hundred and fore cases of rectal cancer patients who underwent laparoscopic resection in The Sixth Affiliated Hospital of Sun Yat-sen University from October 2015 to June 2016 were selected and divided into study group and control group according to different surgical methods. The study group (52 cases) accepted precision low IMA ligation with the LCA preservation and root lymph node (No.253) dissection, according to the IMA types and length examined by preoperative computed tomography angiography (CTA) reconstruction. The control group (52 cases) accepted the traditional high IMA ligation. The perioperative efficacy indexes and postoperative recovery situation of the two groups were compared.

RESULTSThe IMA types, IMA length and preoperative clinical stages were not significantly different between the two groups (all P>0.05). The surgery was completed smoothly for patients in both groups, with no conversion to open surgery. But two patients in the study group underwent left colonic artery ligation for intra-operative need. There were no significant differences in the operative time, intra-operative blood lose, the rate of protective ileostomy and post-operative pathological stages between the two groups (all P>0.05). More total lymph nodes [(24.9±5.7) vs. (16.9±4.2), P=0.001] and No.253 lymph nodes [(2.4±1.1) vs. (1.5±0.8), P=0.001] were harvested in study group as compared to control group. However, the positive rate of total harvested lymph nodes and No.253 lymph nodes between the two groups were not significantly different (P>0.05). There were no significant differences between the two groups in postoperative first anal exhaust time, postoperative hospital stay, total volume of postoperative intraperitoneal drainage, postoperative abdominal drainage tube retention time, postoperative anal drainage tube retention time and postoperative catheter retention time (All P>0.05). There were 2 cases of postoperative dysuria and 1 case of anastomotic bleeding in study group. There were 3 cases of postoperative dysuria and 2 cases of anastomotic leak in control group. Less postoperative complications (5.8% vs. 9.6%, P<0.05) in study group as compared to control group. There was no rehospitalization or death case in two groups within 30 days after operation.

CONCLUSIONSIn the laparoscopic radical resection of rectal cancer, preserving LCA and cleaning the root lymph nodes according to IMA types, which could increase the number of harvested lymph nodes and reduce the postoperative complications was safe and effective.