Hybrid Coils for Left Subclavian Artery Embolization During Zone 2 Thoracic Endovascular Repair

Introduction: Prevertebral left subclavian artery (LSA) occlusion was traditionally performed using conventional coil embolization or vascular plugs. The Penumbra Occlusion Device (POD) is a hybrid coil specifically designed for embolizing high-flow vessels. This study aims to report the technical and clinical success of the POD for LSA embolization during Zone 2 Thoracic Endovascular Aortic Repair (TEVAR). Materials & methods: All consecutive patients who underwent LSA embolization using the POD in Zone 2 TEVAR in 2 high-volume aortic centers were retrospectively collected and analyzed. Procedural data and clinical outcomes were collected. The primary endpoint was the technical success rate of LSA embolization using the POD. Secondary endpoints included short-term outcomes and freedom from reintervention. Follow-up was performed with Computed Tomography Angiography (CTA) to confirm successful LSA prevertebral embolization without type Ic endoleak and to assess patency of surgical revascularization of the distal LSA. Results: Between January 2020 and April 2024, 37 patients (68% men, median age: 70 years) with degenerative chronic thoracic aortic disease or acute aortic syndromes were included. A single POD was deployed in 49% of cases, primarily via brachial access (81%) using a 4F introducer sheath (68%). In the remaining cases, 1 additional coil was deployed to obtain angiographic occlusion. Technical success of LSA embolization was achieved in 97% of cases, with no evidence of type Ic endoleak on final angiography. At 30-day CTA, 9 patients (24%) had type Ic endoleak: 2 required reintervention with coiling, 4 resolved spontaneously, and 3 were managed conservatively without progression of aortic pathology. Clinical success of LSA embolization at follow-up was 92%, with no reported strokes or transient ischemic attacks. All extra-anatomical bypasses, left vertebral arteries, and distal LSAs remained patent. Conclusion: The POD is an effective tool for LSA embolization during TEVAR. This occlusion system offers a promising alternative to traditional methods by overcoming anatomical limitations, potentially eliminating the need for large introducers in upper extremity access and reducing the number of coils required for permanent occlusion of a high-flow vessel. Clinical Impact: The Penumbra Occlusion Device (POD) represents a practical alternative to conventional coil or plug embolization for large, high-flow vessels. Its design allows controlled deployment through small-caliber access, potentially simplifying the procedure and reducing the number of devices required. This study demonstrates high technical success and acceptable short-term outcomes, suggesting that the POD can achieve reliable left subclavian artery occlusion during Zone 2 TEVAR. These results may guide procedural planning and support wider adoption of the POD as a feasible option in this setting.