Entry Site Is Associated With Aortic Enlargement After Pre-emptive Endovascular Repair for Uncomplicated Type B Aortic Dissection.

Objectives: We aimed to examine the mid-term results corresponding to the entry site in patients who underwent pre-emptive thoracic endovascular aortic aneurysm repair (TEVAR) for uncomplicated type B aortic dissection (TBAD).

Methods: We included 27 patients who underwent pre-emptive TEVAR for uncomplicated TBAD between September 2014 and December 2019. We divided the patients into 2 groups depending on the proximal landing zone (zone 2 group, zone ≥3 group) and retrospectively analyzed the risk of all-cause and aorta-related mortality, aortic events (rupture, open conversion, and secondary intervention), and aortic enlargement (≥5 mm).

Results: The median age of the patients was 53 (47-65) years. The median duration from the onset of uncomplicated TBAD to TEVAR was 43 (30-99) days, and the median follow-up duration was 48 (36-57) months. The maximum preoperative diameter of the dissected aorta was 40 mm in the zone 2 group and 35 mm in the zone ≥3 group (p=0.134). There was no case of hospital death or spinal cord ischemia; however, there was 1 (3.7%) case of perioperative stroke in the zone 2 group. Multivariate analysis of the risk factors for aortic enlargement following pre-emptive TEVAR for uncomplicated TBAD revealed that only zone 2 landing was an independent risk factor. The estimated Kaplan-Meier curve showed a higher rate of aortic enlargement in the zone 2 group at 4 years after pre-emptive TEVAR (46.4% vs 0%, log-rank test; p=0.011).

Conclusions: In this study on TBAD, we found that zone 2 landing was associated with aortic enlargement after pre-emptive TEVAR. In cases where the distance from the left subclavian artery to a major entry point was short, there were more cases of aortic dilatation.

Clinical impact: The effectiveness of entry closure for type B aortic dissection was demonstrated in the INSTEAD XL trial. The cause of aortic enlargement after pre-emptive endovascular treatment for type B aortic dissection remains controversial. In the present study, zone 2 landing was a risk factor for aortic enlargement after pre-emptive thoracic endovascular aortic aneurysm repair (TEVAR) for uncomplicated type B dissection. Patients with zone 2 landing should be closely followed up after pre-emptive TEVAR.