V24 - Inferior mesenteric artery lymphadenectomy with left colic artery preservation in rectal cancer

Purpose/Background: Surgical oncological resection in rectal cancer mandates inferior mesenteric artery (IMA) lymphadenectomy, but it is discussed whether a high ligation or a selective IMA branches ligation with left colic artery preservation would be more beneficial. Some authors suggest advantages of granting better anastomotic blood supply, lowering the risks for anastomotic leakage, better autonomic nerve preservation, sparing colon length and avoiding splenic flexure mobilization. The potential disadvantage of selective ligation is an incomplete lymphadenectomy. We propose a change of concept for the approach to the IMA, with preservation of the left colic artery, selective branch ligation and lymphadenectomy of the IMA trunk.

Methods/Interventions: Preservation of the left colic artery, selective branch ligation and lymphadenectomy of the IMA trunk approach is currently standardized in our service and therefore we present an illustrative case. The patient is a 49 years old male with a T2N0 mid rectal adenocarcinoma, submitted to upfront surgery. We performed a robotic low anterior resection with total mesorectal excision with selective ligation of the superior rectal and sigmoid branches and preservation of the left colic artery. Lymphadenectomy of the IMA was carried out from its emergence in the aorta preserving the left colic artery and the autonomic plexus. This approach was feasible with no difficulty allowing more colon length, tension free anastomosis and no need for splenic flexure mobilization. The patient had an uneventful postoperative evolution, was discharged on the third postoperative day and had no anastomotic leakage.

Results/Outcomes: We initiate the dissection presenting the sigmoid with tension and incising the peritoneum two centimeters above the promontory. We bluntly lower the retroperitoneal structures aiming towards the inferior mesenteric artery from the bottom up and afterwards dissecting under the inferior mesenteric vein, isolating the artery from both sides. We perform the IMA lymphadenectomy circumferentially from its emergence in the aorta, preserving the autonomic plexus on its origin. The dissection proceeds cautiously with the hook cautery until the left colic artery is identified and the sigmoidean branches clipped. Then we free the lateral attachments and proceed to total mesorectal excision. A tension free robotic single stapled anastomosis is performed with no need for splenic flexure mobilization. Distal blood flow is certified through indocyanine green testing.

Conclusion/Discussion: Inferior mesenteric artery selective branch ligation and left colic artery preservation show a potential benefit in lowering anastomotic leakage rates and a clear benefit in sparing colon and avoiding splenic flexure mobilization.