Interdisciplinary Expert Consensus Document on Management of Type B Aortic Dissection Published

April 16, 2013—An interdisciplinary expert consensus document on management of type B aortic dissection was published by Rossella Fattori, MD, et al in the Journal of the American College of Cardiology (JACC; 2013;61:1661–1678). A multidisciplinary panel reviewed available literature to develop treatment algorithms using a consensus method. The panel advised that this consensus document proposes strategies based on nonrobust evidence for management of type B aortic dissection, and that literature results were largely heterogeneous and should be interpreted cautiously.

As summarized in JACC, data from 63 studies published from 2006 to 2012 were retrieved for a total of 1,548 patients treated medically, 1,706 patients who underwent open surgery, and 3,457 patients who underwent thoracic endovascular repair (TEVAR). For acute (first 2 weeks) type B aortic dissection, the pooled early mortality rate was 6.4% with medical treatment and increased to 10.2% with TEVAR and 17.5% with open surgery, mostly for complicated cases. Limited data for treatment of subacute (2 to 6 weeks after onset) type B aortic dissection showed an early mortality rate of 2.8% with TEVAR. In chronic (after 6 weeks) type B aortic dissection, 5-year survival of 60% to 80% was expected with medical therapy because complications were likely.

If interventional treatment was applied, the pooled early mortality rate was 6.6% with TEVAR and 8% with open surgery. Medical treatment of uncomplicated acute, subacute, and chronic type B aortic dissection is managed with close image monitoring. Hemodynamic instability, organ malperfusion, increasing periaortic hematoma, and hemorrhagic pleural effusion on imaging identify patients with complicated acute type B aortic dissection requiring urgent aortic repair. Recurrence of symptoms, aortic aneurysmal dilation (> 55 mm), or a yearly increase of > 4 mm after the acute phase are predictors of adverse outcome and need for delayed aortic repair (“complicated chronic aortic dissections”).

According to the investigators, a definition of different clinical patterns of type B aortic dissection and corresponding algorithms of treatment has been made possible for this consensus document, with the analysis of the mortality and complications rates of more than 6,700 patients reported in the available literature. This may substantially help the operating physician in selecting different modalities of treatment for type B aortic dissection. However, stratification of type B aortic dissection outcome by timing (ie, acute, first 2 weeks; subacute, 2 to 6 weeks; and chronic, after 6 weeks from onset of symptoms) might not be representative of the entire clinical scenario and needs to be standardized. Proposed strategies suggest that medical management with close imaging follow-up is the best strategy for uncomplicated type B aortic dissections with acute, subacute, and chronic presentation, whereas TEVAR should be applied to complicated cases and suitable anatomy, to decrease the mortality risk of open surgery.

Nevertheless, the strength of proposals provided by this consensus document is limited, especially for aortic dissections in the subacute phase, because of the large heterogeneity among studies and the lack of high-quality data; most results were from uncontrolled, nonrandomized retrospective trials or registries.

This consensus document analysis should be interpreted cautiously in light of the shortcomings of the available data that are outlined in the document; further higher-level studies on type B aortic dissection stratified by type and timing with long-term assessment of outcomes are required to provide optimal treatment strategy directives on the disease, advised the investigators in JACC.