Synthetic interposition grafts of the thoracic aorta: postoperative appearance on serial CT studies

PURPOSE: To determine the normal postoperative appearance of thoracic aortic interposition grafts on serial CT studies and to document CT detectable complications. MATERIALS AND METHODS: The 235 CT studies in 114 patients with one or more thoracic aortic interposition grafts were analyzed for the presence or absence of felt rings, felt pledgets, low-attenuation material surrounding the graft, pseudoaneurysm, and dissection flap. A graft was present in the ascending aorta in 93 patients, in the descending aorta in 25, and in the arch in 11. RESULTS: Low-attenuation material was seen adjacent to the ascending graft in 55%-82% of patients and adjacent to the descending graft in 60%-79% of patients, showing diminishing frequency and thickness over time. CT scans in 30 of 53 patients showed residual low-attenuation material adjacent to the graft more than 1 year after surgery. CT scans in four of 93 patients with ascending grafts and one of 25 patients with descending grafts showed a pseudoaneurysm. CONCLUSION: CT studies obtained after aortic interposition grafting show characteristic findings. Knowledge of the type of operative procedure and typical location and CT appearance of surgical materials used is important to correctly diagnose or exclude postoperative complications following thoracic aortic interposition grafting.