A unique proposed etiology for inferior mesenteric artery aneurysm: A case report.

The etiology of large artery aneurysms has long been established as secondary to atherosclerotic disease and degenerative changes in the vessel walls. Less common, are aneurysms of the visceral arteries; the splanchnic and renal arteries. Rarer yet, are inferior mesenteric artery aneurysms, accounting for approximately 1% of visceral artery aneurysms. While causes range from inflammatory to congenital disease, a proposed etiology of proximal, solitary inferior mesenteric artery aneurysms, is correlated to the "jet disorder phenomenon," first described in a 1990 case report by Sugrue, and Hederman. This paradigm states that aneurysm formation may occur secondary to celiac and superior mesenteric artery occlusion, causing increased, and turbulent arterial flow distally. We present a case that demonstrates a small inferior mesenteric artery aneurysm without findings of celiac or superior mesenteric artery stenosis or occlusion. This patient did, however, have a large thrombosed common hepatic artery aneurysm which may serve as an alternate cause of jet disorder phenomenon. The findings in this case offers support for focused screening of proximal arterial vasculature when an inferior mesenteric artery aneurysm is encountered.