Clinical and oncological outcomes of the low ligation of the inferior mesenteric artery with robotic surgery in patients with rectal cancer following neoadjuvant chemoradiotherapy

The aim of this study is to compare clinical and oncologic outcomes of the high and low ligation techniques of the inferior mesenteric artery (IMA) in rectal cancer patients treated with robotic surgery after neoadjuvant chemoradiotherapy (nCRT). In this retrospective study, 77 patients with T3/T4-node negative rectal cancer with tumor penetration through the muscle wall (Stage 2) or node positive disease without distant metastases (Stage 3) who were treated electively with robotic surgical resection following nCRT at a single institution between January 2014 and January 2018 were analyzed. Patients were divided into 2 groups (38 patients were included in the low ligation group and 39 patients in the high ligation group). There was no statistical difference between the high ligation group and low ligation group in univariate analysis for 2-year overall survival and disease-free survival (OR = 1.146; 95% CI = 0.274 to 4.797; P = 0.950, and OR = 1.141; 95% CI = 0.564 to 2.308; P = 0.713, respectively). There was no significant difference between the 2 groups in the mean number of harvested lymph nodes and mean number of metastatic lymph nodes (P = 0.980 and P = 0.124, respectively). Anastomosis stricture was observed significantly less frequently in the low ligation group versus the high ligation group (2.6% and 28.2%, respectively) (P = 0.002). Also, the difference for the median length of hospital stay for the high and low ligation groups was statistically significant in favor of the low ligation group (P = 0.011). In robotic rectal surgery, the low ligation technique of the IMA can reduce the rate of anastomosis stricture and provide similar oncological results as the high ligation technique.