Outcomes and aortic remodelling after proximal thoracic endovascular aortic repair of post type B aortic dissection thoracic aneurysm

Background: The objective was to explore the outcomes and aortic remodelling after proximal thoracic endovascular aortic repair (TEVAR) in post type B aortic dissection thoracic aneurysm with a maximal diameter >= 5.5cm. Patients and methods: 34 cases of type B aortic dissection thoracic aneurysm undergoing proximal TEVAR ( coverage of the primary entry and the aneurysm extent) from 2008 to 2013 were retrospectively reviewed with follow-up for at least 2 years. The primary endpoints were 30-day mortality and survival at 2 years. The secondary endpoints were major complication and re-intervention. The aortic remodelling was investigated by comparison of the maximum diameter of the aneurysm and the diameter of true and false lumen at the same level between baseline and 2 years after TEVAR. Besides, we also analysed the possible relevant factors of aortic remodelling including the course of dissection, the involvement of dissection, and the length and shape of the stent graft. Results: The 30 day mortality was 2.9 % (1/34). The paraplegia rate post-TEVAR was 2.9 % (1/34). Overall, 32 out of the 34 cases were followed-up for 24 - 79 months. At 2 years, the overall and aortic specific survival were 87.5 % and 90.3 % respectively. The two year freedom from re-intervention rate was 87.5 %. Compared to the preoperative data, maximum diameter of descending aorta at 2 years demonstrated a slight increase (65.4 +/- 14.1mm Vs 63.9 +/- 9.1mm), but without significance (P>0.05). Meanwhile, we noticed a significant increase of true lumen (P < 0.01) and decrease of false lumen (P < 0.01) at the same level. Relevant analysis showed that positive aortic remodelling of the maximum diameter was associated with chronic phase (>= 90 days of dissection onset) (P < 0.05) and the application of 150 - 170mm stent grafts (P < 0.05). Conclusions: Proximal TEVAR of post type B dissection thoracic aneurysm had generally favourable short- and mid-term outcomes with low paraplegia rate. Besides, it can achieve a certain extent of aortic remodelling.