Endovascular versus conventional medical treatment for chronic type B aortic dissection (a tear in the lining of the aortic artery)

Aortic dissection is a potentially life-threatening condition that occurs when a tear in the inner lining of the aorta (usually in the chest portion of the artery) causes bleeding between the inner and outer layers of the wall of the aorta. The layers become separated (or dissected) creating a false channel for blood to flow. It is the most common emergency affecting the aorta. Symptoms include sudden, severe, sharp chest pain that spreads to the neck or down the back, sudden difficulty speaking, a weak pulse and loss of consciousness. Aortic dissections typically occur in adults aged between 60 and 70 years, with more males than females. The main cause is thought to be high blood pressure. An aortic dissection is classified depending on where it begins in the aorta and if it is acute or chronic. Acute dissections are diagnosed within 14 days after the first symptoms appear; while chronic ones are diagnosed after 14 days. This review looked at chronic type B dissections, which begin in the descending part of the aorta (the section of the artery that moves down through the chest and abdomen). Patients with this type of aortic dissection have traditionally been treated with blood pressure lowering medications, with good short-term results (annual survival in excess of 80%). They have, however, increased long-term mortality. In the long term, medical treatment alone may put some patients at risk of serious complications such as progressive aortic enlargement, poor blood flow to some organs or the extremities, and aortic rupture. Patients with these life-threatening complications require urgent treatment of the dissected aorta by open surgery or, more recently, endovascular thoracic aortic stent grafting (TEVAR). TEVAR reduces the number of early deaths compared with open surgical treatment.

For people with chronic uncomplicated aortic dissection, there is uncertainty about whether stent grafting in addition to best medical therapy improves patient outcomes. This review identified a single trial that randomised 140 patients with uncomplicated chronic type B aortic dissection to medical treatment alone or medical treatment plus stenting. The trial was methodologically sound but did not show a meaningful difference in two-year survival between the two treatment options. The number of deaths observed in the trial did not meet the number expected from registry data, so the trial was underpowered for that end point. Longer-term data from the trial are awaited. Over 20% of the patients initially randomised to the optimal medical care group 'crossed over' to receive TEVAR or open surgery because of the degree of expansion of the aorta with medical therapy alone.

Authors' conclusions: 

Overall, the data at two years were insufficient to make any practice recommendations. However, the data on the anatomic remodeling of dissected aortas observed after TEVAR + OMT is encouraging and future studies should follow up cases for at least five years to see if early endovascular interventions, even in stable initially uncomplicated type B patients, are of long-term benefit.

Read the full abstract...

Aortic dissection is a potentially life-threatening condition that occurs when a tear forms in the inner lining of the aorta. It has traditionally been treated by blood pressure control (medical treatment) or open surgery, both with high mortality rates. More recently stent-graft repair has been suggested as an alternative.


To identify the best management for uncomplicated (without rupture of the organs or malperfusion of the extremities) subacute or chronic type B aortic dissection.

Search strategy: 

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched their Specialised Register (last searched May 2012) and CENTRAL (2012, Issue 4). Clinical trials databases were searched for ongoing or unpublished studies.

Selection criteria: 

All randomised controlled trials designed to compare the outcome of uncomplicated (without rupture of the organs or malperfusion of the extremities) chronic (occurring more than two weeks previously) type B aortic dissection when treated by stenting adjunctive to best medical treatment versus best medical treatment alone were included.

Data collection and analysis: 

Data on all cause and aorta-related mortality at two years was collected and analysed. In addition, secondary outcome measures were analysed, including morbidity, complications (additional endovascular or open surgery for rupture, expansion or malperfusion) and quality of life.

Main results: 

A single trial was identified that fulfilled the inclusion criteria (INSTEAD trial). The two-year all cause survival was not statistically significantly different between study groups (95.6% ± 2.5% in the optimised medical therapy (OMT) group and 88.9% ± 3.7% in the thoracic endovascular aneurysm repair (TEVAR) + OMT group; log rank test P = 0.15).