Type B Aortic Dissection Complicated by Intimo-Intimal Intussusception and Extensive Intimal Denuding: Case Report with Long-term Follow-up.

Background: Acute aortic dissection rarely results in circumferential dissections of the aortic intima that may lead to intimo-intimal intussusception (IIS) with complete separation from the aortic wall. Circumferential dissection may then result in distal embolization of the involved intima and media, adding considerable complexity to the management of such cases. Despite the severity of this complication, the natural history of aortic disease following extensive intimal denuding and IIS is not well documented in the literature. Here we present a case with long-term follow-up of type B aortic dissection (TBAD) complicated by IIS and embolization of the intima into the distal aorta following thoracic endovascular aortic repair.

Methods: Medical records and imaging studies were retrospectively reviewed with the approval of the Institutional Review Board. A single patient underwent repair of a TBAD that was complicated by IIS, with follow-up for 6 years. Aortic recovery was monitored with serial computerized tomography scans.

Results: During endovascular stent deployment, the patient's dissection progressed circumferentially, leading to distal embolization of the intima and aortic occlusion. An open transabdominal aortic exploration was performed to extract the embolized intima. Despite this severe aortic structural disruption, the patient recovered well postoperatively and exhibited favorable aortic remodeling over long-term follow-up. The denuded aorta did not rupture or develop progressive worsening aneurysmal dilation and the diameter of the involved aortic segment remained stable during follow-up.

Conclusions: Acute TBADs can progress to circumferential intimal separation and IIS when managed with endovascular stenting and balloon dilation. Continued endovascular management once IIS has occurred may lead to further intimal damage, resulting in distal embolization of the intima and aortic occlusion. Thus, IIS may require conversion to open repair. However, in the event that loss of the aortic intima does occur following IIS, it is possible for the denuded aorta to recover well and remain stable with favorable remodeling over long-term follow-up.