Re-interpreting mesenteric vascular anatomy on 3D virtual and/or physical models: positioning the middle colic artery bifurcation and its relevance to surgeons operating colon cancer

Abstract

Background The impact of the position of the middle colic artery (MCA) bifurcation and the trajectory of the accessory MCA (aMCA) on adequate lymphadenectomy when operating colon cancer have as of yet not been described and/or analysed in the literature. The aim of this study was to determine the MCA bifurcation position to anatomical landmarks and to assess the trajectory of aMCA. Methods The colonic vascular anatomy was manually reconstructed in 3D from high-resolution CT datasets using Osirix MD and 3-matic Medical and analysed. CT datasets were exported as STL files and supplemented with 3D printed models when required. Results Thirty-two datasets were analysed. The MCA bifurcation was left to the superior mesenteric vein (SMV) in 4 (12.1%), in front of SMV in 17 (53.1%) and right to SMV in 11 (34.4%) models. Median distances from the MCA origin to bifurcation were 3.21 (1.18–15.60) cm. A longer MCA bifurcated over or right to SMV, while a shorter bifurcated left to SMV (r = 0.457, p = 0.009). The main MCA direction was towards right in 19 (59.4%) models. When initial directions included left, the bifurcation occurred left to or anterior to SMV in all models. When the initial directions included right, the bifurcation occurred anterior or right to SMV in all models. The aMCA was found in 10 (31.3%) models, following the inferior mesenteric vein (IMV) in 5 near the lower pancreatic border. The IMV confluence was into SMV in 18 (56.3%), splenic vein in 11 (34.4%) and jejunal vein in 3 (9.4%) models. Conclusion Awareness of the wide range of MCA bifurcation positions reported is crucial for the quality of lymphadenectomy performed. The aMCA occurs in 31.3% models and its trajectory is in proximity to the lower pancreatic border in one half of models, indicating that it needs to be considered when operating splenic flexure cancer.

Re-interpreting mesenteric vascular anatomy on 3D virtual and/or physical models, part II: anatomy of relevance to surgeons operating splenic flexure cancer

“…The third challenge is aMCA. The aMCA is present in about 1/3 of the patients (31.3% in our previously published data [9], which is similar to the 36.4% of patients reported by Bruzzi et.al [18]). It is more often present than the right colic artery proper which is present in 12.2% of patients [19], and aMCA runs directly towards the splenic flexure irrigating the area of the tumour.…”

“…The MCA bifurcation was most often located in front of SMV, i.e., in 17 patients. The aMCA was found in ten patients, following the IMV near the caudal pancreatic border in five of the patients [ 9 ].…”

“…It is more often present than the right colic artery proper which is present in 12.2% of patients [ 19 ], and aMCA runs directly towards the splenic flexure irrigating the area of the tumour. The trajectory of aMCA has been previously described as running equally along the body of the pancreas to the flexure or higher through the transverse mesocolon [ 9 ]. In this way it presents another possible pathway for direct lymphatic dissemination to the lymph nodes at its origin from SMA [ 17 ].…”

“…The datasets were derived from the prospective multicentre “Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic MDCT Angiography” trial (Norwegian Ethical Committee approval REK 2010/3354 and ClinicalTrial Identifier NCT01351714). Different results from the same dataset have been presented in our previous article Re-interpreting mesenteric vascular anatomy on 3D virtual and/or physical models [ 9 ].…”

Gaining Mesenteric Length following Colorectal Resection: Essential Maneuvers to Avoid Anastomotic Tension

“…The distance from the IMV to the middle colic artery and SMA on average is nearly 4 cm. 36 After dividing the IMV at the inferior border of the pancreas, the transverse colon mesentery can be freed over the ligament of Treitz and the fourth portion of the duodenum to reach the left branch of the middle colic artery. This additional mobilization will change the pivot point of the bowel to over SMA and aorta rather than the ligament of Treitz.…”