MR angiographic evaluation of complications in surgically treated type A aortic dissection.

Thoracic aortic dissection is a life-threatening disease with a high mortality rate and an elevated incidence of early and long-term complications. Advances in surgical treatment of ascending (Stanford type A) aortic dissection have helped improve patient survival, but follow-up imaging is critically important for the identification of postsurgical complications. Gadolinium-enhanced three-dimensional (3D) magnetic resonance (MR) angiography, along with multisection computed tomography, is the technique of choice for this purpose. For accurate assessment of 3D MR angiograms, it is important to know what surgical procedure was performed and to be familiar with the appearance of the normal postsurgical anatomy. A thorough understanding of potential postsurgical complications also is essential. Some complications (eg, formation of a periprosthetic hematoma or pseudoaneurysm, stenosis in a graft anastomosis) may derive from the prosthesis. Complications also may occur in the remnant of the native aorta, where persistent dissection distal to the prosthesis is common and may result in false channel thrombosis or aneurysmatic dilatation with collapse of the true lumen. Residual dissection that involves the supra-aortic trunks or the visceral aortic branches may produce neurologic effects or renal and mesenteric ischemia, respectively. Copyright RSNA, 2006