High ligation versus low ligation of the inferior mesenteric artery in laparoscopic rectal cancer surgery: a retrospective study on surgical and long-term outcome

Background In laparoscopic low anterior resection for rectal cancer surgery, there has been controversy to whether the inferior mesenteric artery (IMA) should be ligated at the origin of its aorta (high ligation (HL)) or below the branches of the left colonic artery (LCA) (low ligation (LL)). This study was intended to clarify oncological outcome and long-term prognosis of retrospective analysis. Methods Analyzed the cases who underwent laparoscopic low anterior resection (LAR) in Shanghai Ruijin Hospital from January 2015 to December 2016, 357patients scheduled into 2 groups according to the level of IMA ligation: HL ( n = 247) versus LL ( n = 110). Results The primary endpoint is long-term outcomes, and the secondary endpoint is the incidence rate of major postoperative complications. There were no significant differences in 5-year overall survival ( P = 0.92) and 5-year disease-free survival ( P = 0.41). There were no differences between the clinical baseline levels in each group. The incidence of low anterior resection syndrome (LARS) in the two groups was statistically significant ( P = 0.037). No significant differences were observed in operative time ( P = 0.092) and intraoperative blood loss ( P = 0.118). In the HL group, 6 cases (2.4%) had additional colonic excision due to poor anastomotic blood supply; none of the colonic anastomosis in the low ligation group had ischemic manifestations, and length from the proximal margin ( P = 0.076), length from the distal margin ( P = 0.184), the total number of lymph nodes excised ( P = 0.065), and anastomotic leakage incidence ( P = 0.33). Conclusion Low ligation of the IMA which reserved LCA with vascular root lymph node dissection in laparoscopic low anterior resection for rectal cancer surgery may help protect the blood supply of the anastomosis, and will not increase postoperative complications while enhance recovery, without compromising radical excision and long-term prognosis.