Technical Feasibility and Oncological Safety of Low and High Ligation of the Inferior Mesenteric Artery in Colorectal Cancer Surgery for Asian Populations: a Systematic Review and Meta-analysis

Abstract

Background: The level of ligation of the inferior mesenteric artery (IMA) is controversial. There is still no consensus on whether to preserve the left colon artery (LCA). The aim of this updated meta-analysis was to compare the technical feasibility and oncological safety of low ligation (LL) and high ligation (HL) of IMA in the treatment of colorectal cancer for Asian populations.Methods: A systematic search was conducted in the PubMed, Embase, Web of Science and China Biomedical Literature Database (CBM) for relevant studies that compared HL and LL for sigmoid or rectal cancer were published between January 2010 and August 2020 from Asian countries. The outcomes of interest include anastomotic leak, operation time, blood loss, early complications, the postoperative first anal exhaust time, lymph node yield outcomes and involvement state, 5-year overall survival (OS), 5-year disease-free survival (DFS), and overall recurrence.Results: Twenty-one studies including 8 randomized controlled trials (RCTs) and 13 retrospective cohort studies (non-RCTs) with a total of 5947 patients (2519 patients in LL group and 3428 patients in HL group) were involved in this meta-analysis. LL group showed a lower incidence of anastomotic leakage (WMD=0.59; 95%CI=0.46~0.76; P<0.05) and earlier postoperative first anal exhaust time (WMD=-4.55; 95%CI=-8.87~-0.24; P<0.05). In term of operation time, blood loss, early complications, the first postoperative anal exhaust time, lymph node yield outcomes and involvement state, 5-year OS, 5-year DFS, and overall recurrence, there were no significant differences between LL and HL group.Conclusions: Compared with HL, LL significantly reduced the incidence of anastomotic leakage and accelerated the postoperative recovery time of bowel function in Asian populations. What's more, LL can obtain equivalent lymph node yield and long-term survival benefit as compared to HL.