Indication, timing and results of endovascular treatment of type B dissection.

Aortic dissection is an uncommon but a highly lethal condition. Dissection of the ascending aorta is associated with a mortality rate of 1-2% per hour within the first 24h and should be managed by an open surgery. An uncomplicated, acute, type B dissection, which should be treated medically, is less frequently lethal, with survival rates of 84% within 1 year. Unfortunately, long-term outcome of medical therapy alone is suboptimal, with a reported 30-50% mortality rate at 5 years and a delayed expansion of the false lumen in 20-50% of patients at 4 years. In this setting, endovascular treatment should be considered when the aortic diameter exceeds 55-60mm, in case of uncontrolled pain, blood pressure and rapid growth of the dissecting aneurysm (>1cm per year). About 30-42% of acute, type B aortic dissections are complicated, as evidenced by haemodynamic instability or peripheral vascular ischaemia with a mortality rate of 50-85% if not treated properly. In this scenario, stent-graft repair is an attractive alternative to surgical repair for correcting ischaemic complications. The long-term therapy of patients with aortic dissection includes aggressive medical therapy, follow-up visits and serial imaging.