Thoracic Endovascular Aortic Repair of Highly Tapered Type B Aortic Dissection with Proximal Tapered Stent Grafts and Distal Restrictive Stent Grafts

Abstract

This study evaluated aortic remodeling in highly tapered type B aortic dissection (TBAD) patients who underwent thoracic endovascular aortic repair (TEVAR) with a proximal tapered stent graft plus a distal restrictive stent graft to maximize thoracic coverage while avoiding distal excessive oversizing. Thirty-four patients presenting with highly tapered TABD were randomized to restricted TEVAR (r-TEVAR) and standard TEVAR groups. Highly tapered TBAD was defined as the maximal diameter of the true lumen at proximal and distal thoracic aorta landing zone tapers greater than 8mm or taper ratio greater than 20%. Patients in the r-TEVAR group underwent proximal tapered stent grafts plus distal restrictive stent grafts, to match the taper ratio of the descending thoracic aorta (DTA) and extend the length of stent coverage. Patients in the standard TEVAR group underwent proximal tapered stent grafts implantation without distal restrictive stent grafts. Aortic remodeling was estimated by computed tomography angiography (CTA) during the follow-up. In total, 16 patients underwent r-TEVAR, and 18 patients underwent standard TEVAR. The taper ratio of the stent graft matched the DTA in the r-TEVAR group (24.7±3.4% vs. 27.3±4.2%, P=0.068), but did not match that in the standard TEVAR group (13.5±3.3% vs. 30.5±9.6%, P<0.001). The length of stent graft coverage in the r-TEVAR group was longer than that in the standard TEVAR group (220.4±21.1mm vs. 175.3±17.8mm, P<0.001). Compared with the standard TEVAR group, the r-TEVAR group had better complete remodeling of the DTA at 6months (40% vs. 5.6%, P=0.03), 12months (60% vs. 16.7%, P=0.027), and 24months (78.6% vs. 41.2%, P=0.036) after the operation. There was no difference in the cumulative survival rate between the r-TEVAR and standard TEVAR groups (P=0.166). The r-TEVAR with overlapping proximal tapered stent grafts and distal restrictive stent grafts can match the taper of highly tapered TABD, extend the length of stent graft coverage, and lead to better remodeling of the DTA than standard TEVAR.