False Lumen Embolization in Chronic Aortic Dissections to Improve Results of Thoracic Endovascular Aortic Repair: Early Experience of 21 Consecutive Cases

Abstract

Introduction - The failure of endovascular repair of chronic aortic dissections can be explained by the back flow in the false channel through distal re-entry tears. After implantation of a thoracic stent-graft, the false lumen thrombosis occurs in only about 50% of the cases. We evaluated the feasibility of embolization of the false channel in chronic aortic dissections. Methods - Between June 2015 and January 2017, 21 patients with chronic aortic dissection were treated for aneurysmal dilatation of the descending thoracic aorta. They were considered high surgical risk. They were treated by the placement of a thoracic stentgraft and embolization of the false lumen or embolization alone. This was done by placing vascular plugs or coils inside the false lumen. This study is a retrospective analysis of a prospectively collected database. We studied the technical feasibility, the post-operative courses as well as the quality of exclusion of the false channel (determined on late phase CTA). Results - The mean age of the patients was 61 +/- 14 years, 6 patients had residual type A dissection after cardiac surgery, and 15 patients had type B dissection. Five patients were suffering from Marfan disease (24%). Six patients (28%) were symptomatic (painful) preoperatively. Seven patients (33%) had prior aortic arch replacement with elephant trunk procedure. The mean maximum diameter of the thoracic aorta was 63 +/- 14 mm. Spinal fluid drainage was used in 71% of cases (15/21 patients). The embolization was possible in 100% of the cases. Thrombosis of the false lumen at the level of the thoracic dilatation was obtained in 100% of cases but required sometime several sessions. In 81% of cases it was obtained after the 1st embolization. One patient required 2 sessions of embolization and 2 patients required 3 sessions. One patient presented a type A retrograde dissection in relation to the erosion of the arterial wall by the proximal bare stent of a stent-graft. He was operated (open conversion) with simple post-operative course. Only one patient had postoperative medullary ischemia (partially resolving paraparesis). Finally, 2 patients had a replacement of the distal aorta below the stent-graft for a preexisting thoracoabdominal dilatation. The mean follow-up is 10,5 +/- 7 months. Twelve patients (57%) had an aneurysmal shrinkage bigger than 5 mm during follow-up. Conclusion - The embolization of the false lumen of chronic aortic dissections is technically feasible and is easily obtained in the majority of cases. It allows efficient endovascular repair of aortic dissections. The result on aortic remodeling requires longer follow-up. This technique may therefore improve the results of thoracic aortic endovascular repair in chronic aortic dissections.