comparison of low and high ligation with apical lymph node dissection in the laparoscopy rectal cancer

Conditions: Rectal Cancer

Summary: the purpose of this study is to explore the different impacts of high and low ligation in laparoscopic rectal interior resection on postoperative anastomotic leakage and proximal bowel necrosis and stenosis, as well as the quality of life and long-term survival. in the anterior resection of rectum, the section level of inferior mesenteric artery (ima) is still a controversial subject between the advocates of high and low ligation. the low ligation is defined as the ima is ligated below the origin of the left colic artery while the high ligation refers to the ima is ligated at its origin from the aorta. nowadays the spread of laparoscopy has encouraged more frequent execution of the high ligation, which appears easier to achieve than the low ligation and also with the advantage of lower anastomosis traction but with the disadvantage of worse vascularization of the stumps as well.

it has long been debated that whether to tie off the inferior mesenteric artery (ima) at its origin or just below the origin of the left colic artery (lca) of the anterior resection of the rectum. thus far, no clear consensus has been achieved, and the level of arterial ligation still varies among institutions and patients. in the previous studies, high or low ligation takes advantage on both sides. however, there are still some researches that have demonstrated no significant difference had been found in the incidence of anastomotic leakage and other complications between the high and low ligation groups. therefore, to provide a clear and definite answer to surgeons of how they should deal with the ima in laparoscopy rectal surgery. we plan to explore the impacts of high and low tie in laparoscopic anterior rectal resection on postoperative anastomotic leakage and proximal bowel necrosis and stenosis, as well as the quality of life and long-term survival by prospective and multi-center clinical trial. surgery will be described as follows: for low ligation group: 1. laparoscopic surgery is performed. tie the sigmoid artery and superior rectal artery, lca is preserved. lymphadenectomy to apical lymph nodes is performed. strip the beginning part of upper rectal artery and the first sigmoid artery. strip the left colic artery until reaching the inferior mesenteric vein (imv). the abdominal aorta lymph nodes need to be cleaned if it's been spotted swollen. 2. vascular ligation level: left colonic artery needs to be preserved, the rectal artery and the first sigmoid artery are ligated. ligate inferior mesenteric artery below left colonic artery come across the inferior mesenteric vein level. for high ligation groups: laparoscopic surgery is performed. the ima is ligated and divided at 2 cm. from its origin. dissect the adipose tissue and lymph nodes around ima. the inferior mesenteric vein (imv) is divided and ligated below the duodenal margin. the abdominal aorta lymph nodes need to be cleaned if it's been spotted swollen. for both groups total mesolectal excision (tme) is performed according to the principles of heald.

Eligibility criteria:
inclusion criteria: * 18 years to 75 years (adult, senior). * colonoscopy and pathology shows rectal or sigmoid adenocarcinoma. * tumor located at 4-15 cm from the dentate line. * the clinical staging of tumor by mri within t1-4a when tumor above the peritoneum and t3n0-2 when tumor below the peritoneum. * receive or not receive neoadjuvant chemotherapy based on 5-fluorouracil before surgery and radical resection is available after neoadjuvant chemotherapy. * anus-saving operation is available. * asa class: i-iii. * well tolerate to general anesthesia. * ecog score: 0-1. * patients - can understand and are willing to take part in the clinical trial. exclusion criteria: * severe cardiovascular disease, uncontrollable infection or other severe complications. * severe mental illness. * suffer with other carcinoma simultaneously or sequentially in 5 years. * familial polyposis coli or multiple -colorectal tumor. * history of abdominal surgery and with severe abdominal adhesions. * combine with acute intestinal obstruction, intestinal bleeding, intestinal perforation and emergency surgery is needed. * multiple organs resection surgery is needed. * abdominoperineal resection need to be performed. * asa class: iv to v. * pregnant, suckling period or reject to birth control. * patient who unable to go through the clinical trial because of familial,social or religious factors. * refuse to take part in the trial. * patients without an informed consent. * non-compliant patient * the patient or their family members want to withdraw from the clinical trial. * loss to follow-up * researchers think the participants need to withdraw from the clinical trial.

Keywords: rectal cancer inferior mesenteric artery laparoscopic