RESUMO
PURPOSE: The literature reports the presence of the intermesenteric artery (IA), an anastomosis connecting the superior mesenteric artery (SMA) to the inferior mesenteric artery (IMA) in 9-18% of human cadaver dissections. This is the first study describing the morphological and demographic characteristics of the IA based on in vivo imaging. METHODS: A total of 150 consecutive abdominal computed tomography (CT) angiographies of adult patients identified by sex and age were analyzed. The IA was assessed for its presence, point of origin, pathway, point of insertion, and diameter at its origin. The diameters of the SMA, IMA, and other arteries from which the IA originated and into which it inserted were measured by CT angiography using Radiant™ and Osirix MD™ software. RESULTS: The IA was found in 17 (51.5%) of the females and 60 (51.3%) of the males. The diameters of the SMA and IMA were larger in the males than in the females, but there was no sex difference in the diameter of the IA. The diameter of the SMA was larger than that of the IMA, and the diameter of the IA was smaller than that of the other arteries evaluated. An IA connecting the SMA and IMA trunks was found in 25.9% of the cases, while other connections between the branches of those trunks through an IA occurred less frequently. CONCLUSIONS: The intermesenteric artery is more frequently found than the literature refers and in most of cases directly connects the upper and lower arterial mesenteric circulations.