Nonsurgical Repair of the Ascending Aorta: Why Less Is More

Objective: Advanced endovascular options for acute and chronic pathology of the ascending aorta are emerging; however, several problems with stent grafts placed in the ascending aorta have been identified in patients unsuitable for surgical repair, such as migration and erosion at aorta interface. Method: Among the six cases analysed in this report, three were treated with a stent graft in the ascending aorta to manage chronic dissection in the proximal aorta; dimensions of those stent grafts varied between 34 and 45 mm in diameter, and from 77 to 100 mm in length. Three patients, matched by age, sex and their nature of pathology, were subjected to the focal closure of a single communicating entry by the use of an occluding device (Amplatzer ASD and PFO occluders between 14 and 18 mm disc diameter) with similar Charlson comorbidity score. Results: Both conceptually different nonsurgical management strategies were technically feasible; however, with stent grafts, an early or delayed erosion to full re-dissection was documented with stent grafts, in contrast to complete seal, with an induced remodelling and a long-term survival after the successful placing of coils and occluder devices. Moreover, aortic root motion was not impaired by the focal occlusion of a communication with an occluder, while free motion was impeded after stent graft placement. Conclusions: The intriguing observation in our small series was that stent grafts placed in the ascending aorta portends the risk of an either early (post-procedural) or delayed migration and erosion of aortic tissues at the landing site or biological interface between 12 and 16 months after the procedure, a phenomenon not seen with the use of focal occluding devices up to 5 years of follow-up. Obviously, the focal approach avoids the erosion of the aortic wall as the result of minimal interaction with the biological interface, such as a diseased aortic wall. Potential explanations may be related to a reduced motion of the aortic root after the placement of stent graft in the ascending aorta, whereas the free motion of aortic root was preserved with an occluder. The causality of erosion may however not be fully understood, as besides the stiffness and radial force of the stent graft, other factors such as the induced inflammatory reactions of aortic tissue and local adhesions within the chest may also play a role. With stent grafts failing to portend long-term success, they may still have a role as a temporizing solution for elective surgical conversion. Larger datasets from registries are needed to further explore this evolving field of interventions to the ascending aorta.