Tips and tricks in laparoscopic management of left colonic vessels – a video vignette

The inferior mesenteric artery (IMA) has different branching pattern. Since Latarjet’s classification of 1949, many authors, even when using volume-rendered 3DCT, have tried to preoperatively assess the vascular anatomy of the IMA [1–3]. In summary, three different patterns, types I, II and III, have been described. In type I the left colic artery (LCA) originates separately several centimetres after the origin of the IMA. The sigmoid arteries (SAs) originate from a common pedicle several centimetres after the origin of the LCA. In type II the trunks of the LCA and SAs share a common origin. In type III the LCA, SAs and superior rectal artery branch off at the same point. Absence of the LCA has also been reported in the literature, and another interesting point is the course of LCA: under (the majority of cases) or above the inferior mesenteric vein (IMV). The aim of this didactic video (Video S1 in the online Supporting Information) is to show how to manage with left colic vessels during two different laparoscopic colonic resections: a splenic flexure resection with CT-confirmed absence of the left branch of the middle colic artery and a sigmoidectomy. The video is focused on the key vascular steps needed to ligate or preserve the left colic vessels. During resection of the splenic flexure, as described in a multicentre study of 117 cases [4], the first step of our technique is the identification and the sealing of the left colic pedicle, using the energy device Ligasure AdvanceTM (Covidien, Mansfield, Massachusetts, USA), which combines monopolar tip dissection and a vessel sealer divider and is associated with reduced blood loss and operative time [5]. During the sigmoidectomy a low tie (LT) of the inferior mesenteric pedicle with preservation of the LCA and left colic vein (LCV) is performed with the same energy device. Nowadays, there is still no consensus on the level of arterial ligation in sigmoid and rectal cancer surgery. The advantages of the LT technique are the preservation of the vascularization and autonomous innervation of the colon limb with a potentially lower chance of anastomotic leakage and comparable survival and lymph node retrieval. [6–8]. There is still some debate about the expertise that is required to perform a laparoscopic LT and the possibility of achieving a tension-free anastomosis. Interestingly, in their study about the technical difficulties of the LT procedure, Patroni et al. [9] focused on the risk of damage to the LCA. In fact, the LCA may be damaged at its root during dissection of the IMA or in the mesocolon during dissection of the IMV when a high IMV ligation, at the inferior border of the pancreas, is performed. In patients with a LCA–IMV distance of less than 20 mm, the LCA is more frequently damaged next to the IMV.Considering the variability of the vascular pattern of the left colic vessels, a preoperative assessment of the vascular anatomy is highly recommended. Even though laparoscopic resection of the splenic flexure and sigmoidectomy with the LT technique are both technically demanding procedures, they are feasible and safe in highvolume centres.