Early results of transcatheter electrosurgical aortic septotomy for endovascular repair of chronic dissecting aortoiliac aneurysms

Objective: Endovascular repair of chronic dissecting aortoiliac aneurysms is challenging given the rigid septum, compressed true lumen (TL), and target vessels frequently originating in the false lumen. We have used transcatheter electrosurgical aortic septotomy (TEAS) before stent graft implantation under intravascular ultrasound (IVUS) and fusion guidance. The purpose of this study is to assess the outcomes of TEAS during complex endovascular repair of dissecting aneurysms. Methods: From 2021 to 2023, 17 patients underwent TEAS. The primary end point was technical success, with secondary end points of proximal and distal seals, target vessel instability, aortic and iliac TL and cross-sectional area (CSA) expansion, and aortic-related death. During the procedure, the aortic septum is crossed through a pre-existing entry or via electrocautery-activated 0.018-in. Astato XS20 wire (Asahi-Intecc) under IVUS and fusion guidance. The penetrated wire is then snared in the false lumen and pulled through the ipsilateral femoral access. A 1-cm length of the middle of the Astato wire coating is kinked in a three-sided polygonal configuration, denuded the inner surface of the wire using a no. 15 blade, and positioned at the apex of the septum. Both ends of the Astato wire are insulated with 0.018-in. microcatheters, and the back end of the wire is denuded and connected to cautery. Gentle traction is applied to the wire, and short bursts of electrocautery cutting are applied at 60 to 80 W. Results: The technical success of the septotomy was 100%. No incidence of visceral or lower extremity malperfusion, vascular injury, or distal embolization occurred. Of the 17 patients, 4 underwent thoracic endovascular aneurysm repair, 2 underwent endovascular aortic repair, and 11 underwent fenestrated/branched endovascular aneurysm repair after septotomy. All target vessels were successfully stented. A distal landing zone seal with exclusion of the false lumen was achieved in 16 of the 17 patients (94.1%). One patient required embolization of the false lumen of the celiac artery after septotomy. The TL mean diameter and CSA of the descending thoracic aorta after septotomy was expanded by 7.01 ± 1.9 mm (relative mean diameter expansion, 42.3%; P < .0001) and 2.71 ± 0.4 cm² (relative mean CSA expansion, 57.3%, P<.0001). For patients who required septotomy through the common iliac arteries, the mean TL was expanded by 8.1 ± 3.7 mm (relative mean diameter expansion, 76%; P < .0001) and 1.76 ± 0.91 cm² (relative mean CSA expansion, 209%; P < .0001). The 1-year freedom from target vessel instability was 91%. Conclusions: The use of IVUS and fusion-guided TEAS offers a promising technique to facilitate TL expansion and false lumen exclusion in chronic dissecting aortic aneurysms before repair. The durability and long-term outcomes of this technique in a larger cohort remain to be elucidated.