The Endovascular Management of Visceral Artery Aneurysms

Abdominal visceral artery aneurysms (VAAs) are defined as aneurysms which involve branches of the celiac, superior mesenteric, inferior mesenteric or renal arteries. Owing to the improvements in imaging technology and the use of cross-sectional imaging modalities (ultrasound, computed tomography [CT], and magnetic resonance imaging), there is increase in the frequency of VAAs diagnosis. Although classically treated by open surgery, modern treatment strategies generally place interventional radiology techniques at the top of the treatment algorithm. Therefore, vascular interventional radiologists must become familiar with the indications for the treatment of VAA, become experienced in the different techniques, and know when to recommend treatment of VAA by interventional radiology techniques or to advocate open surgical repair.

VAAs are subdivided into true and false aneurysms. A true aneurysm involves all three layers of the arterial wall. Classically, a true aneurysm is defined as a localized dilatation of the artery by more than 1.5 times the expected arterial diameter. True aneurysms occur as a result of underlying arterial pathology such as atherosclerosis, fibromuscular dysplasia, and arteritis. The prevalence of true VAAs is 0.1-2%, and most true VAAs are asymptomatic. A minority may cause abdominal pain, which may be a harbinger of imminent rupture. VAAs are almost never large enough to be palpable by examination. False aneurysms, or pseudoaneurysms, are effectively contained ruptures of the artery that are lined by adventitia or by the perivascular tissues. False aneurysms may occur as a result of inflammation, infection, or trauma.