Splenic Flexure Mobilisation for Anterior Resection Performed for Sigmoid and Rectal Cancer

Standard text books support the concept of routine splenic flexure mobilisation for anterior resection performed for sigmoid and rectal cancer. But dogma is not necessarily evidence-based, and Kennedy and Jenkins argue convincingly that selective splenic flexure mobilisation with preservation of the left colic artery is necessary in only a minority of selected cases where tension is a problem. There are two issues-oncological and the impact on anastomotic dehiscence. It is generally accepted that preservation of the left colic artery (splenic flexure not mobilised) does not compromise oncological outcome. Prognosis is unaffected by the level of inferior mesenteric artery ligation. Vascularity after inferior mesenteric artery division, with or without left colic artery preservation, and the level of colon used for anastomosis is contentious. Dehiscence is the end-point. Finan believes that routine mobilisation of the splenic flexure for all anterior resections for cancer should be the norm, to avoid anastomosing thickened sigmoid colon and especially to achieve a safe ultra-low anastomosis without tension. He implies that any compromise, using the sigmoid to anastomose, with preservation of the left colic artery, increases the risk of dehiscence, on the grounds that the limiting factor for length, and therefore anastomotic tension, is the inverted left colic artery. There is reasonable evidence that division of the inferior mesenteric artery results in partial sigmoid ischaemia, but preservation of the left colic artery may overcome this; the literature remains unclear. Low leak rates are certainly possible after high anterior resection with preservation of the left colic artery. More contentious is whether low leak rates can be achieved after TME and colopouch-anal anastomosis, especially with the extra length of colon needed to construct a colopouch.