The Early And Midterm Results Of Stent-graft Versus Medication Therapy For Type B Dissection

Objective: This prospective multi-center comparative study examined earlyand midterm results of medication and stentgraft therapies on the type Baorta dissection in China.Methods:335patients collected from four centers in China from January2007to Dec2010with type B aorta dissection were prospectively enrolledand treated by either optimal medication therapy (OMT) or thoracicendovascular aorta repair (TEVAR). There were246male and89femalepatients with an age of53.7±18.1years. American Society ofAnesthesiologists (ASA) classification greater than class III was present in15.2%patients. The baseline maximum diameter of thoracic aorta was41.2±19.1mm, the distance from the left subclavian artery to the proximal entrytear was32.6±28.9mm, and dissection extended beyond the celiac axis in87.8%of cases.Results: there were208patients in the TEVAR group and95patients in theOMT group. Procedural success was100%, and there was no death duringindex hospitalization in both groups. In the TEVAR group, two patients(0.9%) suffered from retrograde type A dissection, six (2.9%) from brachialaccess pseudo-aneurysm, and two (0.9%) suffered from paraplegia orparaparesis. For in-hospital outcome, multivariate analysis showed that agegreater than75years and ASA class greater than III were independentpredictors of major early adverse events. Average follow-up time for hospitalsurvivors was28.5±16.3months (range1.0–58). In the OMT group, fivepatients died for rupture of enlarged false lumen, and six patients expiredsuddenly for unknown reasons. Fourteen cases required crossover to TEVAR (n=12) or surgical conversion (n=2). In the TEVAR group, ninepatients required reintervention or surgical conversion, and one died ofpostoperative multi-organ failure. One patient expired for delayedretrograde type A dissection, and four expired suddenly for unknownreasons. The Kaplan-Meier analysis of survival probability at two years andfour years was87.5%and82.7%with TEVAR and77.5%and69.1%respectively with OMT (log-rank test P=0.0678). The estimated cumulativefreedom from aorta-related death at two and four years were91.6%and88.1%with TEVAR and82.8%and73.8%with OMT (log-rank testP=0.0392). The maximum thoracic aorta shrank from42.4±23.1mm to37.3±12.8mm in the TEVAR group, and the maximum thoracic aorta in theOMT group expanded from40.7±18.6mm to48.1±17.3mm. Theincidence of increased thoracic aorta is significantly higher in the OMT(60.3%) than in the TEVAR (5.1%)(P=0.001).Conclusion: This was the first prospective multi-center comparative study onthe treatment of type B aorta dissection in China. TEVAR turned out to havea significantly lower aorta-related mortality compared with OMT, and aseemingly lower overall mortality and adverse events rate. Furthermore,TEVAR was also found to be able to enhance the thoracic remodeling rate.