Own Clinical Observations of Treatment Outcome in Acute Type B Aortic Dissection

Thoracic endovascular aortic repair or best medical therapy for uncomplicated type B aortic dissection? A meta-analysis

INTRODUCTION

The aim of this meta-analysis was to investigate all studies comparing thoracic endovascular aortic repair (TEVAR) and best medical therapy (BMT) for the treatment of uncomplicated type B aortic dissection (TBAD).

EVIDENCE ACQUISITION

PubMed/Medline and Web of Knowledge were searched until September 2014 for relevant studies published in English. Pooled odds ratio (OR) and its corresponding 95% CI were analyzed with Cochrane Review Manager (RevMan v.5.3).

EVIDENCE SYNTHESIS

Our analysis showed that compared with BMT, TEVAR did not significantly affect 30-day (hospital) mortality. A significantly lower 1-year and 2- or 3-year survival rates was observed with TEVAR vs. BMT. Interestingly, a trend just short of statistical significance towards higher 4- or 5-year survival was found with TEVAR treatment (P=0.08). No significant differences were found in false lumen (FL) thrombosis formation with TEVAR vs. BMT treatment. However, a trend toward less incomplete or no FL thrombosis was noted with TEVAR. No significantly impact on the risk of later re-intervention was found with TEVAR vs. BMT.

CONCLUSIONS

TEVAR did not provide obvious early survival advantage for uncomplicated TBAD over BMT, especially in the patients using TEVAR alone. It may remain a treatment option in uncomplicated TBAD patients with high risks for later complications. More randomized, prospective, long-term studies are needed to further clarify whether TEVAR could be a better first-line treatment strategy vs. BMT for uncomplicated TBAD.

Type B Aortic Dissection: A Review of Prognostic Factors and Meta-analysis of Treatment Options

According to international guidelines, stable patients with uncomplicated Type B aortic dissection (TBAD) should receive optimal medical treatment. Despite adequate antihypertensive therapy, the long-term prognosis of these patients is characterized by a significant aortic aneurysm formation in 25-30% within four years, and survival rates from 50 to 80% at five years and 30 to 60% at 10 years. In a prospective randomized trial, preemptive thoracic endovascular aortic repair (TEVAR) in patients with chronic uncomplicated TBAD was associated with an excess early mortality (due to periprocedural hazards), but the procedure showed its benefit in prevention of aortic-specific mortality at five years of follow-up. However, preemptive TEVAR may not be the treatment of choice in all patients with uncomplicated TBAD because of the inherent periprocedural complications like stroke, paraparesis, and death, as well as stent graft-induced complications (i.e., retrograde dissection or endoleaks). Thus, the TEVAR-related deaths and complications (especially paraplegia and stroke) raise concerns that moderate the better survival with TEVAR at five years. By timely identification of those patients prone for developing complications, early intervention, preferably in the subacute or early chronic phase, may improve the overall long-term outcome for these patients. Therefore, early detectable and reliable prognostic factors for adverse events are essential to stratify patients who can be treated medically and those who will benefit from rigorous follow-up and, in the long-term, from timely, or even prophylactic, TEVAR. Several studies have identified prognostic factors in TBAD such as aortic diameter, partial false lumen thrombosis, false lumen thickness, and location of the primary entry tear. Combining these clinical and radiological predictors may be essential to implement a patient-specific approach designed to intervene only in those patients who are at high risk of developing complications to improve the long-term outcomes of patients with uncomplicated Type B aortic dissection.

Endovascular Versus Medical Therapy for Uncomplicated Type B Aortic Dissection

Background:

Uncomplicated type B dissections have been traditionally managed with antihypertensive therapy. In the endovascular era, this dictum has been revisited. This review pooled the available studies to compare the outcomes of best medical therapy (BMT) to thoracic endovascular aortic repair (TEVAR) for uncomplicated type B dissections.

Methods:

A literature search was performed to identify studies on uncomplicated type B dissections managed with BMT with and without TEVAR. The primary outcome measures were mortality rates at 30 days and at 2 years following intervention.

Results:

A total of 6 studies included 123 patients who underwent TEVAR/BMT, and 566 patients who had BMT alone. The mortality rates at 30 days (6.5% TEVAR/BMT vs 4.8% BMT, P = .21) and at 2 years (9.7% vs 11.9%, P = .32) were similar. Renal failure was greater in TEVAR/BMT (15.4% vs 2.1%, P < .01). Rates of surgical reintervention/intervention were similar (17.6% vs 20.1%, P = .31).

Conclusion:

The TEVAR with BMT does not provide survival benefit compared to BMT alone, 2 years following uncomplicated type B aortic dissection.