Vascular anatomy of the splenic flexure, focusing on the accessory middle colic artery and vein

Abstract

Aim Recently, the accessory middle colic artery (AMCA) has been recognized as the vessel that supplies blood to the splenic flexure. However, the positional relationship between the AMCA and inferior mesenteric vein (IMV) has not been evaluated. Herein, we aimed to evaluate the anatomy of the AMCA and the splenic flexure vein (SFV). Method Two hundred and five patients with colorectal cancer who underwent enhanced CT preoperatively were enrolled in the present study. The locations of the AMCA and IMV were evaluated, focusing on the positional relationship between the vessels and pancreas – below the pancreas or to the dorsal side of the pancreas. Results The AMCA was observed in 74 (36.1%) patients whereas the SFV was found in 177 (86.3%) patients. The left colic artery (LCA) was the major artery accompanying the SFV in 87 (42.4%) of patients. The AMCA accompanied the SFV in 65 (32.7%) patients. In 15 (7.8%) patients, no artery accompanied the SFV. The origin of the AMCA was located on the dorsal side of the pancreas in 15 (20.3%) of these 74 patients. Similarly, the destination of the IMV was located on the dorsal side of the pancreas in 65 (31.7%) of patients. Conclusion The SFV was observed in most patients, and the LCA or AMCA was the common accompanying artery. In some patients these vessels were located on the dorsal side of the pancreas and not below it. Preoperative evaluation of this anatomy may be beneficial for lymph node dissection during left‐sided hemicolectomy.

Surgical anatomy of the accessory middle colic artery: a meta‐analysis with implications for splenic flexure cancer surgery

“…The PP of the AMCA was highest in imaging studies (28.8%) and lowest in cadaveric studies (17%). In patients without a LCA, the PP of the AMCA was 83.2% (95% CI 70.4–93.1) [18,19]. No notable variations in the PP were seen in the leave‐one‐out sensitivity analysis (Table 3).…”

“…Preoperative identification of the AMCA may be achieved using various imaging techniques. Three-dimensional computed tomography angiography (3D-CTA) has been recognized as a less invasive modality of assessing the vascular anatomy of the gastrointestinal tract [3,7,18,19]. However, visualizing the AMCA using this imaging technique may be challenging in cases where the vessel is of small calibre or when it runs close to the transverse pancreatic artery [18].…”

“…A total of 16 studies (n = 2203 patients) were included [3,7,8,[14][15][16][17][18][19][20][21][22][23][24][25][26]. Most of the studies were performed in Asia (12 studies, 1923 patients) while the rest were from North America (2 studies, 240 patients); Europe (1 study, 13 patients) and the Middle East (1 study, 27 patients).…”

Redefining the collateral system between the superior mesenteric artery and inferior mesenteric artery: a novel classification

“…After the transverse colon, splenic flexure and descending colon were mobilized, the IMA, left colic artery (LCA), ascending and descending branches of the LCA (LCAa and LCAd), sigmoidal arteries, SMA, middle colic artery (MCA), right and left branches of the MCA (MCAr and MCAl) and the aMCA were exposed. In addition to the MCA, if a second arterial tributary exited from the SMA to supply the distal transverse colon towards splenic flexure, it was defined as an aMCA [15]. The anastomoses between the SMA and IMA in the mesocolon around the splenic flexure were displayed.…”

Laparoscopic sigmoid colectomy with preservation of the inferior mesenteric artery for diverticular disease – a video vignette

“…A 42‐year‐old man presented with a medical history of DD, including an episode of complicated diverticulitis (Hinchey 1b) treated medically. The presentation of this case shows the preoperative vascular anatomical study [6,7] by 3D CT scan, the surgical steps of laparoscopic sigmoid colectomy including splenic flexure take down, colonic mobilization and the techniques adopted for a nerve‐sparing vascular approach (Video ). Sectioning sigmoid arteries close to the intestinal wall avoids denervation of the colonic stump, thus preserving the parasympathetic nerves ascending from the pelvic plexus and the sympathetic nerve distributed around the IMA.…”