Compare Outcomes After High and Low Ligation of Inferior Mesenteric Artery in Colorectal Cancer

Colon cancer represents a significant clinical surgical burden, accounting for approximately 10% of all cancer cases. It is assumed that it is the second leading cause of cancer-related deaths worldwide. Surgery and chemotherapy are considered the main lines of treatment. Left colonic and rectal cancers represent approximately two-thirds of all colorectal malignancies. The mainstay of treatment is surgical resection, including tumor removal with adequate safety margins with adequate lymphadenectomy. Several lifestyle factors contribute to the development of colorectal cancer, such as a high intake of processed meats and low intake of fruits and vegetables, a sedentary lifestyle, obesity, smoking, and excessive alcohol consumption. In colon and rectal cancer surgery, the approach toward the inferior mesenteric artery (IMA) has always been debated among surgeons regarding the "high tie" and "low tie" techniques. According to the consensus statement of definitions of anorectal Physiology and Rectal Cancer of the American Society of Colon and Rectal Surgeons (ASCRS), a low tie of the IMA is meant as a ligation after the origin of the left colic artery. In contrast, the high tie a ligation of the IMA at its aortic root. High ligation of the IMA for rectal and left colonic cancers may improve lymph node yield rate, thus facilitating more accurate tumor staging and better oncological outcomes. Several studies have shown the importance of lymph node dissection up to the root of the IMA in terms of better survival and precise staging. The high ligation also enables tension-free colonic anastomosis during low anterior resection. However, high ligation of the IMA has been known to decrease blood flow to the anastomosis, increasing the risk of anastomotic leak. In contrast, the low-ligation technique allows for adequate blood supply to the colon proximal to the anastomotic stoma during low anterior resection that might prevent vascular inefficiency of the anastomotic marginal colic arteries and decrease the risk of anastomotic leak, especially in elderly patients. On the other hand, low ligation limits the opportunity for lymph node clearance at the origin of the IMA. This incomplete lymphatic clearance may decrease survival while increasing the possibility of metastasis and cancer recurrence.