CT findings following thoracic aortic surgery.

Complications following thoracic aortic graft surgery are rare. They are not always clinically apparent and may occasionally be detected at computed tomography (CT) even in asymptomatic patients. Normal postoperative findings that may simulate complications include graft kinks, graft side branches, felt pledgets or rings, small amounts of low-attenuation perigraft material, native aortic wraps, and bovine pericardial wraps. Postoperative complications include anastomotic dehiscence and graft infection, which may lead to perigraft hematomas, pseudoaneurysms, abscesses, or fistulas. At CT, these complications may manifest as abnormally large collections of low-attenuation perigraft material, contrast material extravasation, perigraft gas collections, or fistulas to adjacent structures. Familiarity with both normal and abnormal postoperative CT findings and knowledge of the surgical technique used are essential to avoid misdiagnosing normal findings and to correctly diagnose potentially life-threatening complications. Following graft surgery, surveillance imaging may be needed, since the time of onset of complications seems highly variable. RSNA, 2007