LAUSR

Most patients with uncomplicated thoracic aortic dissections are effectively treated by medical therapy, but long-term outcomes remain sobering for those surviving to the chronic phase. It is estimated that >50% of these patients develop aneurysmal dilation in the thoracic and thoracoabdominal aorta requiring repair or leading to rupture. Failure of medical therapy is noted most often after 3 to 5 years, when aortic events began to occur and usually involve the thoracic or thoracoabdominal aorta. In these cases, open surgical repair carries significant morbidity and mortality. Coselli and associates reported a 30-year experience with 3309 patients, of whom 36% had chronic dissections. Although operative mortality was commendable (8%), there were significant complications, such as respiratory failure (25%), vocal cord paralysis (23%), tracheostomy (9%), spinal cord injury (9%), dialysis (8%), and stroke (4%). Other reports have shown similar mortality rates (5%-15%), with pooled mortality of 11% in a systematic review of 970 patients. Outside of large centers, 30-day mortality is even more sobering, reaching 19% in Medicare beneficiaries. Thoracic endovascular aortic repair (TEVAR) has emerged as a less invasive alternative and gained widespread acceptance for treatment of chronic dissections complicated by aortic enlargement. The primary goal is to cover the proximal entry tear with stent graft extension, usually to the distal thoracic aorta. This approach has been shown to promote false lumen thrombosis and to effectively decrease maximal aortic diameter in the stent-grafted aorta, although distal aortic segments tend to continue to enlarge in 15% to 30% of patients. Of these, up to 34% of patients require additional procedures. Moreover, in the Investigation of Stent Grafts in Aortic Dissection (INSTEAD) and INSTEAD-XL trials, TEVAR showed benefit in survival only beyond 2 years of follow-up, indicating that most aortic events occur late.