ABSTRACT
An anastomotic aneurysm (AA) is an aneurysm that occurs at an anastomotic interface between a graft and an artery. Although such aneurysms may rarely involve autogenous grafts, they are almost exclusively the result of prosthetic grafting procedures. Historically such aneurysms are believed to be false aneurysms resulting from an anastomotic defect. Extravasation of blood through such a defect leads to a reactive inflammatory response by surrounding tissues and formation of a fibrous capsule. As a result of sustained arterial pressure, the anastomotic defect and associated soft tissue capsule gradually expand resulting in the formation of a false aneurysm. Recently, it has been recognized that an increasing number of AAs may in fact be true aneurysms occurring at the junction of a prosthetic graft and an artery. In this situation the aneurysm results from degeneration of the native arterial wall; this aneurysmal degeneration may be primary (due to inherent structural abnormalities in the arterial wall) or secondary to changes induced by the prosthetic grafting procedure. True aneurysms involving the artery adjacent to an anastomosis have also been termed juxta-anastomotic and lumped together with the more traditional false AAs using the term para-anastomotic. In practice it is frequently difficult to distinguish whether such aneurysms are true or false in nature and the diagnosis and treatment are usually very similar. In the present discussion, the term anastomotic aneurysm (AA) is used to refer to any aneurysm (true or false) occurring at an anastomosis. Regardless of etiology most AAs require repair because of the risk of complications (e.g., rupture, thrombosis) and the resulting potential for loss of life or limb.
