Type B aortic dissections have the highest incidence of aorta-specific mortality and are challenging to classify and treat. With the advent of novel thoracic endovascular grafts, there is significant evidence supporting early intervention in complicated type B aortic dissections. Currently however, there is limited discussion regarding optimal timing for TEVAR in uncomplicated aortic dissections particularly considering survival and aorta-specific complication outcomes, and our understanding of aortic remodelling.
A systematic review was performed across multiple online databases yielding 330 articles, and leaving 26 for full assessment based on thorough inclusion and exclusion criteria. A meta-analysis with subgroups based on timing of intervention as hyperacute (< 2 days), acute (1-14 days) and subacute (>2 weeks). For follow-up data, the era of graft was also used as a subgroup analysis.
Early or acute intervention with TEVAR for uncomplicated type B aortic dissections provides a platform for improved aortic remodelling in the long term when compared to later intervention. This comes with no increased 1-year all-cause mortality risk, and no evidence demonstrating increased risk in the 30-day post-operative period when controlling for interventions in the hyperacute stage particularly for mortality and any complications. Aorta-related complications in the 30-days post-operative period are unaffected by the timing of intervention. Overall, the era of grafts used does not have a significant bearing on outcomes either. These results support the broader body of research that suggests that earlier interventions favours improved aortic remodelling though with added peri-operative risk.
While there is not enough prospective randomised data to support an optimal timing for TEVAR in uncomplicated type B aortic dissection, it is evidence that there is a subset of patients with uncomplicated disease that would benefit from intervention in the acute setting from 3- to 14-days post symptom onset. This improves aortic modelling in the long term with improved aorta-related outcomes.