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, and target vessels frequently originating in the false lumen. We have used transcatheter electrosurgical aortic septotomy (TEAS) prior to 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 transcatheter electrosurgical aortic septotomy. The primary end point was technical success with secondary end points including proximal and distal seals, target vessel instability, aortic and iliac true lumen and cross-sectional area expansion, and aortic-related death. During the procedure, the aortic septum is crossed through a pre-existing entry or via electrocautery-activated .018-in Astato XS20 wire (Asahi-Intecc, Tokyo, Japan) 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 #15 blade, and positioned at the apex of the septum. Both ends of the Astato wire are insulated with .018-in microcatheters, while 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 60-80 W. Results The technical success of the septotomy was 100%. No incidences of visceral or lower extremity malperfusion, vascular injury, or distal embolization occurred. Four patients underwent thoracic endovascular aneurysm repair, two patients underwent endovascular aortic repair, and eleven underwent fenestrated/branched endovascular aneurysm repair after septotomy. All target vessels were successfully stented. A distal landing zone seal with the exclusion of false lumen was achieved in 16 out of 17 patients (94.1%). One patient required embolization of the false lumen of the celiac artery following septotomy. The true lumen mean diameter and cross-sectional area of the descending thoracic aorta after septotomy was expanded by 7.01 ± 1.9 mm (relative mean diameter expansion 42.3%, p<0.0001) and 2.71 ± 0.4 cm2 (relative mean cross-sectional area expansion 57.3%, p<0.0001). For patients who required septotomy through the common iliac arteries, the mean true lumen was expanded by 8.1 ± 3.7 mm (relative mean diameter expansion 76%, p<0.0001) and 1.76 ± 0.91 cm2 (relative mean cross-sectional area expansion 209%, p<0.0001). The 1-year freedom from target vessel instability was 91%. Conclusion IVUS and fusion-guided TEAS offers a promising technique to facilitate true lumen expansion and false lumen exclusion in chronic dissecting aortic aneurysm prior to repair. The durability and long-term outcomes of this technique in a larger cohort remain to be elucidated.