False Lumen Intercostal Artery Embolization to Halt Type R Entry Flow in Chronic Type B Aortic Dissection

Background: Treatment of aneurysmal type B aortic dissection often involves thoracic endovascular aortic repair (TEVAR). However, persistent patency of the false lumen from type R entry flow is common and is associated with late complications including rupture. We describe 9 patients with aneurysmal chronic type B aortic dissections and patent false lumens and 7 despite prior thoracic endovascular aortic repair. The goal of the false lumen intercostal embolization in these patients was to achieve propagation of false lumen thrombosis (FLT) and to prevent spinal cord ischemia (SCI) using a staged approach in the overall treatment of their complex aortic aneurysm.Methods: A multicenter retrospective review was performed of all consecutive false lumen intercostal embolization procedures; 9 were identified. Preoperative and postoperative computed tomographic angiograms were compared. We hypothesized that embolization was a safe and feasible treatment option. The primary outcome was procedural characteristics and SCI to establish safety and feasibility. Secondary outcomes included a change in supraceliac patent false lumen length and other perioperative clinical outcomes.Results: In total, 30 of 31 (97%) targeted false lumen intercostal arteries were successfully coiled. Median procedural time was 57 min (interquartile range [IQR] 23-99), median air kerma was 585 mGy (IQR 398-1,644), and median contrast dose was 141 mL (IQR 74-240). After embolization, all patients demonstrated propagation of FLT, with mean false lumen length decreasing by 48% from 13.8 cm to 6.6 cm. There was no mortality associated with this procedure; 2 patients suffered a lumbar drain-related complication; 1 with cerebrospinal fluid leak and 1 with a spinal hematoma that was managed conservatively with no neurological deficit. No other complications occurred.Conclusions: In this review, false lumen intercostal coil embolization was technically feasible and did not result in any cases of SCI. The procedures required acceptable amounts of operative time, fluoroscopic dose, and contrast. All patients experienced propagation of FLT and no longterm procedure-related morbidity was noted. More data will be required to ascertain whether this procedure is effective at halting type R entry flow, preventing future type II entry flow, and promoting aortic remodeling over time.