Propensity Adjusted Analysis of Open and Endovascular Thoracic Aortic Repair for Chronic Type B Dissection: A Twenty-Year Evaluation

Abstract

Optimal treatment of chronic type B aortic dissection (CBAD), whether open (open descending aortic repair, OAR) or endovascular (thoracic endovascular aortic repair, TEVAR), is controversial, suggesting a comparative analysis is warranted. One hundred twenty-two of 1,049 patients (1993 to 2013) undergoing descending aortic repair required intervention for CBAD 29.2 ± 34.9 months after the initial acute event and formed the study cohort (mean age 59.7 years). Those with degenerated residual type A dissection were excluded (n= 65). Eighty-eight had extent IIIB CBAD; 11 had intramural hematoma. Indications for surgery included aneurysmal degeneration (n= 105), rupture (n= 8), acute or chronic dissection (n= 8), and extension of dissection (n= 1). Open strategy included descending (n= 71) and thoracoabdominal repair (n=19), with hypothermic circulatory arrest used in 70 patients. The TEVAR was performed with (n= 2) or without (n= 30) visceral debranching. A treatment strategy propensity score incorporating time since initial acute event, CBAD extent, year of intervention, age, and selected comorbidities was constructed for multivariable analysis. Early outcome included the following: 30-day mortality 4% (n= 5); stroke 2% (n= 2); permanent paraplegia 3% (n= 4); renal failure requiring dialysis 7% (n= 8, 5 temporary and 3 permanent); and tracheostomy 3% (n= 4). Visceral aorta intervention (odds ratio [OR] 3.5, p= 0.026) and maximum aortic diameter (OR 1.1, p= 0.001) but not treatment type (p= 0.64) independently predicted an early composite outcome comprised of these variables. Ten-year survival was 56.2%. Baseline creatinine (hazard ratio [HR] 1.7, p < 0.001) and peripheral vascular disease (HR 2.5, p= 0.021), but not treatment type (p= 0.225) predicted late mortality. Ten-year freedom from aortic rupture or need for reintervention was 78.3%. Treatment efficacy was improved after OAR (3-year freedom 96.7% vs TEVAR 87.5%, p= 0.026), and this was confirmed after Cox regression (TEVAR, HR 4.6, p= 0.046). Intervention for CBAD can be performed with excellent results, either by an open or endovascular approach. The higher rate of treatment failure after TEVAR warrants modification of current device design or endovascular approach before broad application of this treatment strategy.