The results of stent graft versus medication therapy for chronic type B dissection

This prospective multicenter comparative study examined early and midterm results of medication and stent-graft therapies on chronic type B aortic dissection in China.

The study consisted of 303 consecutive patients with chronic type B aortic dissection from four centers in China from January 2007 to December 2010 who were prospectively enrolled and treated by either optimal medical therapy (OMT) or thoracic endovascular aorta repair (TEVAR). Of the patients, 219 were male and 84 were female (average age, 53.6 ± 20.3 years; range, 29-81 years). Baseline diameter of the thoracic aorta was 41.2 (19.1) mm (mean [standard deviation]), and dissection extended beyond the celiac axis in 87.1% of cases.

In total, there were 208 patients in the TEVAR group and 95 patients in the OMT group. Procedural success was 100%, and no deaths occurred during index hospitalization in the two groups. In the TEVAR group, two patients (0.9%) suffered from retrograde type A dissection, and two (0.9%) suffered from paraplegia or paraparesis. For in-hospital outcome, multivariate analysis revealed that age >75 years and American Society of Anesthesiologists class greater than III were independent predictors of major early adverse events. Average follow-up time for hospital survivors was 28.5 ± 16.3 months (range, 1.0-58 months). In the OMT group, five patients died from rupture of an enlarged false lumen, and six patients died suddenly of unknown reasons. Fourteen cases required crossover to TEVAR (n = 12) or surgical conversion (n = 2). In the TEVAR group, nine patients required reintervention or surgical conversion, and one died of postoperative multi-organ failure. One patient died of delayed retrograde type A dissection, and four died suddenly of unknown reasons. The Kaplan-Meier analysis of survival probability at 2 and 4 years was 87.5% and 82.7% with TEVAR, respectively, and 77.5% and 69.1% with OMT, respectively (P = .0678, log-rank test). The estimated cumulative freedom from aorta-related death at 2 and 4 years was 91.6% and 88.1% with TEVAR, respectively, and 82.8% and 73.8% with OMT, respectively (P = .0392, log-rank test). The thoracic aorta diameter decreased from 42.4 (23.1) mm to 37.3 (12.8) mm in the TEVAR group and increased from 40.7 (18.6) mm to 48.1 (17.3) mm in the OMT group.

This was the first prospective multicenter comparative study on the treatment of type B aortic dissection in China. TEVAR had a significantly lower aorta-related mortality compared with OMT but failed to improve overall survival rate or lower the aorta-related adverse event rate.