Riolan's arch: confusing, misnomer, and obsolete. A literature survey of the connection(s) between the superior and inferior mesenteric arteries.
BACKGROUND
There are 2 interpretations of Riolan's arch: (1) Riolan's arch is identical to a central part of the marginal artery (MA), connecting the superior (SMA) and the inferior mesenteric (IMA) arteries; and (2) Riolan's arch represents a rare artery, connecting the SMA and the IMA. The current review aims to emphasize the clinical importance of the colon's vasculature and to show the feasibility of abolishing the terms "Riolan's arch" and "meandering mesenteric artery."


METHODS
A literature survey was performed.


RESULTS
It appears that no distinct identity can be ascribed to Riolan's arch and that the "meandering mesenteric artery" represents an angiographically hypertrophied MA and/or the ascending branch of the left colic artery. However, a rare, centrally located, communicating artery has been described. Generally, the MA is sufficient for left colic circulation after ligation of the IMA, but at the splenic flexure, patency of the ascending branch of the left colic artery can be primordial.


CONCLUSIONS
As connections between the SMA and the IMA can be adequately described using structures mentioned in Terminologica Anatomica, the terms "Riolan's arch" and "meandering mesenteric artery" should be abolished.
Lange
Johan F
JF
Lowlands Institute of Surgical and applied Anatomy, Department of Neurosciences, Faculty of Medicine, Erasmus Medical Centre, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.
Komen
Niels
N
Akkerman
Germaine
G
Nout
Erik
E
Horstmanshoff
Herman
H
Schlesinger
Frans
F
Bonjer
Jaap
J
Kleinrensink
Gerrit-Jan
GJ
D000792:Angiography; D003106:Colon / Q000098:blood supply*; D006801:Humans; D017537:Mesenteric Artery, Inferior / Q000033:anatomy & histology*; D017538:Mesenteric Artery, Superior / Q000033:anatomy & histology*