June's 'Paper of the Month' is a systematic review and meta-analysis which aimed to provide comprehensive evidence-based assessment of the discontinuity of the marginal artery at the splenic flexure and the rectosigmoid junction.
Discontinuity of marginal artery at splenic flexure and rectosigmoid junction: A systematic review and meta-analysis
Cirocchi, R, Randolph, J, Cheruiyot, I, Davies, RJ, Gioia, S, Henry, BM, et al.
Colorectal Dis. 2023; 00: 1-10
What is known about the subject?
Anastomoses between the branches of the middle colic artery and branches of right and left colic arteries contribute to formation of the marginal artery (MA), also called Drummond's artery, located in the mesentery along the entire length of the colon. This longitudinal vascular anastomosis may, however, be deficient in the so-called “watershed” areas, two of which have been well documented in the literature, namely the Griffiths’ point at the splenic flexure (SF) and the Sudeck’ point at the rectosigmoid junction (RSJ). The clinical implications of these vascular points remain unclear. In theory, discontinuity/absence of the MA at these points would be associated with a high risk for ischaemia during surgical resection. Despite the potential clinical implications of these watershed areas in surgery for left-sided colonic pathology, their prevalence remains unclear. The literature is fraught with confusion and uncertainties regarding nomenclature, presence, number and location of these anastomotic channels.
What the study adds?
The aims of this systematic review and meta-analysis were to evaluate the prevalence and anatomical features of the MA at the SF and the RSJ. A total of 21 studies (n = 2,864 patients), published between 1965 and 2021, were included. The MA was present at the SF in 82% (95% CI: 62–95%) of patients. Approximately 81% (95% CI: 63–94%) of patients had a large macroscopic anastomosis, while the remainder (19%) had small bridging ramifications forming the vessel. The marginal artery was present at the RSJ in 82% (95% CI: 70–91%) of patients. The mean vessel size at this point is 1.9 mm and approximately 68% of the vessels had a mean external vessel diameter of >1 mm.
Implications for colorectal practice
The presence of numerous anastomotic channels in the blood supplying of the colon provides confluent and collateral circulation, maintaining adequate colonic perfusion in normal and disease states. A proper understanding of vascular colonic anatomy is a requisite for safe and successful colorectal surgery. The marginal artery may be absent at the SF and the RSJ in up to 18% of individuals, which may confer a higher risk of ischaemic colitis.
The current study provides a comprehensive review of the anatomy of the MA at the SF and the RSJ. It is part of recent attempts that have been made to clarify the vascular anatomy of the colon with proposing a standardized classification, topography and relation to mesocolon in future studies [1].
Reference
- Kuzu, M.A., Güner, M.A., Kocaay, A.F., İsmail, E., Arslan, M.N., Tekdemir, İ. and Açar, H.İ. (2021), Redefining the collateral system between the superior mesenteric artery and inferior mesenteric artery: a novel classification. Colorectal Dis, 23: 1317-1325