[Significance of the preservation of left colic artery in laparoscopic resection of rectal cancer].

Controversy remains on how to manage left colic artery (LCA) when it comes to laparoscopic proctectomy. With regard to the level of detachment, a high tie of inferior mesenteric artery (IMA) is meant as a ligation at the origin of aorta, while the low tie is the ligation of IMA below the initiation part of left colic artery which is left. Several key points of LCA preservation, including clinical value, oncologic safety and the difficulty of operation, have always been debated. Some scholars hold the point of view that the preservation of LCA will hamper the lymph nodes dissection around the inferior mesenteric artery, resulting in incorrect pathological staging and dismal outcome. Of note, low tie prolongs the duration of operation and increases the anastomotic tension. However, increasing research results have established its clinical values. The value for reducing the risk of anastomotic leakage and the effect on the lymph nodes dissection at the root of inferior mesenteric artery will be discussed based on previous studies and our clinical practice. We came up with a novel concept of "the lymph nodes in the triangular domain of inferior mesenteric artery which consists of abdominal aorta, inferior mesenteric vein(IMV)/LCA and IMA" instead of traditional No.235 lymph nodes. In our innovative approach of total mesorectal excision guided by vessel, a crack was made at the root of aorta and the dissection was performed along IMA, reaching the origin of LCA. The lymph nodes will be harvested as a whole. After achieving process standardization, vessel-oriented approach and left colic artery preservation makes this region susceptible to lymphadenectomy, protecting submesenteric plexus and guarantying the oncological safety without increasing operative difficulty.