Endovascular vs. Medical Management for Uncomplicated Acute and Subacute Type B Aortic Dissection: A Meta-analysis

Objective: The aim was to compare peri-operative and late outcomes of patients with acute and subacute uncomplicated type B aortic dissection (uTBAD) treated by thoracic endovascular aortic repair (TEVAR) or best medical therapy (BMT). Methods: This was a Systematic review and meta-analysis of observational studies and randomised controlled trials (RCTs). The review was undertaken according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered with the International Prospective Register of Systematic Reviews (number: CRD42018094607). Multiple electronic databases were searched to identify relevant articles. The methodological quality of the included studies was assessed. The primary outcome measures were early mortality and re-intervention, late all cause and aorta related mortality, and re-intervention. Meta-analysis was used to produce pooled odds ratios (OR) or risk difference (RD) for peri-operative outcomes. Random effects models were applied. For late outcomes a time to event meta-analysis was conducted using the inverse variance model, reporting the results as hazard ratios (HR). Results: Eight original articles from six studies encompassing 14 706 patients (1 066 TEVARs) were eligible for inclusion. There were no statistically significant differences between TEVAR and BMT with regards to inpatient mortality (RD 0.01, 95% CI -0.01-0.02, p=.46), early re-intervention by TEVAR (RD 0.02, 95% CI -0.01-0.04, p=.19) or surgery (RD 0.00, 95% CI -0.01-0.01, p=1.0). BMT was associated with a significantly lower risk of early stroke (OR 0.64, 95% CI 0.48-0.85, p=.002), whereas the risk of late all cause (HR 1.54, 95% CI 1.27-1.86, p<.001) and aorta related mortality (HR 2.71, 95% CI 1.49-4.94, p=.001) was significantly higher than with TEVAR. No suitable data regarding late aortic re-intervention was found for meta-analysis. Conclusion: Given the limited number and quality of suitable studies it remains uncertain whether TEVAR is beneficial in the management of acute/subacute uTBAD. Further research is required to understand which dissections would benefit from pre-emptive treatment.