Randomized Comparison of Strategies for Type B Aortic Dissection

Abstract

Background-Thoracic endovascular aortic repair (TEVAR) represents a novel concept for type B aortic dissection.Although life-saving in acute emergencies, outcomes and survival of TEVAR in stable dissection are unknown. Methods and Results-One hundred forty patients in stable clinical condition at least 2 weeks after index dissection were randomly subjected to elective stent-graft placement in addition to optimal medical therapy (nϭ72) or to optimal medical therapy alone (nϭ68) with surveillance (arterial pressure according to World Health Organization guidelines Յ120/ 80 mm Hg). The primary end point was all-cause death at 2 years, whereas aorta-related death, progression (with need for conversion or additional endovascular or open surgery), and aortic remodeling were secondary end points. There was no difference in all-cause deaths, with a 2-year cumulative survival rate of 95.6Ϯ2.5% with optimal medical therapy versus 88.9Ϯ3.7% with TEVAR (Pϭ0.15); the trial, however, turned out to be underpowered. Moreover, the aorta-related death rate was not different (Pϭ0.44), and the risk for the combined end point of aorta-related death (rupture) and progression (including conversion or additional endovascular or open surgery) was similar (Pϭ0.65). Three neurological adverse events occurred in the TEVAR group (1 paraplegia, 1 stroke, and 1 transient paraparesis), versus 1 case of paraparesis with medical treatment. Finally, aortic remodeling (with true-lumen recovery and thoracic false-lumen thrombosis) occurred in 91.3% of patients with TEVAR versus 19.4% of those who received medical treatment (PϽ0.001), which suggests ongoing aortic remodeling. Conclusions-In the first randomized study on elective stent-graft placement in survivors of uncomplicated type B aortic dissection, TEVAR failed to improve 2-year survival and adverse event rates despite favorable aortic remodeling. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00525356.

What makes the difference between the natural course of a remaining type B dissection after type A repair and a primary type B aortic dissection?

“…Consequently, as was also the case in our study, closure of the primary entry tear warrants any kind of surgical or interventional means [11]. As the current status of knowledge recommends TEVAR merely in patients with complicated type B aortic dissection-mainly due to malperfusion, a high percentage of patients with type B aortic dissection remain being treated by medical means and therefore do show a persisting patent entry [12]. The current classification defines a primary entry tear, multiple re-entries between lumina and a 'final' re-entry.…”

Tratamento endovascular da dissecção crônica de aorta tipo B complicada

“…However, the clinical follow-up showed a significant number of patients who had to migrate to endovascular treatment. 22 In patients such as of the present study, i.e., symptomatic patients with complications (malperfusion syndrome, progression of dissection, increased aneurysmal dilation, and impaired blood pressure control), the indication for endovascular treatment is already established in the literature. 21,23 Concerning the group with chronic type B dissections, the literature also raises questions about the long-term survival of these patients, as well as the need for endovascular treatment of aortic remodelling.…”

An extensive chronic aortic dissection presenting with acute embolic stroke

“…With chronicity of dissection, aortic remodelling continues, but there is a decline in morbidity, mortality and need for intervention. Therefore, the distinction between acute and chronic dissection is important to make [20]. Chronic aortic dissections are treated with antihypertensive drugs while keeping the patient on strict periodic follow-up with imaging surveillance and careful periodic clinical follow-up.…”