Safety and Performance of Multilayer Stents in Patients With Type B Aortic Dissection: Long-term Results From a Multicenter, Single-Arm Clinical Trial

Purpose: To investigate the safety and performance of multilayer stents in patients with type B aortic dissection (TBAD) and high-risk features. Materials and Methods: Prospective, multicenter, single-arm clinical trial. All patients were identified, treated, and managed according to each site’s standard procedures for thoracic endovascular aortic repair (TEVAR). Clinical and radiographic evaluations were performed to assess the device safety and its technical and clinical performance. All computed tomography (CT) scans were analyzed by an independent imaging core laboratory. Statistical analyses were performed by an independent statistician based on predefined analysis plans. The intention-to-treat cohort was used to analyze device safety and technical success, and the per-protocol cohort for technical and clinical performance. Results: Twenty-seven participants (21 males, 6 females; mean SD age: 51.4 13.2 years) were enrolled. The dissection extended distally into the abdominal aorta in all evaluable participants. Mean (SD) follow-up was 54.9 (10.2) months for the intention-to-treat cohort and 54.1 (13.6) months for the per-protocol. A total of 63 aortic multilayer stents were implanted (mean SD of 2.3 (0.7) per participant). In 94.7% of the participants, the aorta was treated distally up to zone 9. Technical success was achieved in all but 1 participant (96.3%). No ischemic events (paraplegia/paraparesis or stroke) were observed, neither within 30 days nor during the follow-up period. Seven participants (25.9%) had 1 serious adverse event more than 30 days postoperatively; of these, 4 were possibly or probably device-related. Estimated 5-year survival was 90%. No device deficiencies (eg, stent kinking, collapse, fracture, migration, or separation) were reported. No dissection extension occurred. Stable or decreasing maximum transverse aortic diameter at last follow-up was observed in 78.6% of participants. Distal flow was preserved in 98.3% of major side branches. All participants were free from aortic rupture, reintervention, and open conversion during the long-term follow-up. Conclusion: Treatment of high-risk TBAD patients with multilayer stents is feasible, has an acceptable safety profile, and stabilizes the dissection. Further research is warranted to confirm these findings in other populations of patients. Clinical Impact New therapeutic options are needed to meet the ACC/AHA primary goals for thoracic endovascular aortic repair (TEVAR) in patients with type B aortic dissection (TBAD) extending into the abdominal aorta, namely, to prevent aortic rupture, retrograde extension, and antegrade propagation and alleviate malperfusion. The findings of this study indicate that these goals can be met in patients with high-risk TBAD by using multilayer stents, as these devices allow to treat extensively the dissected aorta with adequate survival, a low risk of ischemic complications, and stabilization of the transaortic diameter over long-term follow-up. Interestingly, multilayer stents can meet these clinical goals without sealing the primary tear or inducing complete false lumen thrombosis. The unique design characteristics and mechanism of action offer a new approach to TEVAR treatment for patients with TBAD.