Clinical and Morphologic Outcomes of Endovascular Repair for Subacute and Chronic Type B Aortic Dissection

BACKGROUND: The objective of the study was to assess long-term remodeling, survival, and reintervention outcomes after thoracic endovascular aortic repair (TEVAR) for subacute and chronic type B aortic dissection (TBAD). METHODS: All patients who underwent TEVAR for subacute or chronic TBAD at a tertiary referral center between 1999 and 2015 were included in this cohort study. The primary outcome was aortic remodeling, and secondary outcomes included survival, rate of major complications, and reinterventions. RESULTS: Fifty patients were included, with mean age of 62.4 years, 10 (20%) DeBakey type IIIA and 40 (80%) DeBakey type IIIB dissection; 45 standard TEVAR, 2 branched TEVAR, 3 TEVAR combined with fenestrated or branched EVAR. Indication for TEVAR was intact (n = 40) or ruptured (n = 1) postdissection aneurysm, hypoperfusion (n = 4), treatment-refractory pain (n = 2), or a combination (n = 3). Mean clinical follow-up was 76 months, and median radiological follow-up was 46 months. Thirty-day survival was 96%, stroke 4%, renal failure 0%, paraplegia 0%. Three- and five-year survival was 92% (95% confidence interval (CI) [79; 97]) and 77% (95% CI [61; 87]), respectively. Of 19 late deaths, 6 were confirmed aorta related. Five-year freedom from reintervention was 69% (95% CI [53-80]). Distal stent graft extension due to aortic dilatation composed most reinterventions. Mean maximal aortic diameter was 58.7 mm preoperatively and 51.9 mm on last follow-up (P = 0.003). On thoracic level, true lumen expanded (+10.0 mm, 95% CI [6.4; 13.6]) (P < 0.001) and false lumen decreased (-11.9 mm, 95% CI [-15.2; -8.5]) (P < 0.001) from baseline to the last computed tomography. In the abdominal aorta, true lumen diameter change was +3.1 mm (95% CI [1.4; 4.8]) (P = 0.001); false lumen diameter change was +1.0 mm (95% CI [-1.8; 3.8]) (P = 0.464). CONCLUSIONS: TEVAR for subacute and chronic TBAD results in favorable remodeling of the thoracic but not the abdominal aorta. Five-year survival is almost 80%, but late aortic deaths still occur. Aortic dilatation distal to the treated segment requiring reintervention is common, emphasizing the importance of follow-up.