Frozen Elephant Trunk Completion:Endovascular Extension in The Distal Thoracic Aorta

Introduction: Complex pathologies involving the aortic arch can be treated using the frozen elephant trunk (FET) technique, which is versatile and continues to be improved with different innovations to further reduce, for example, circulatory arrest time and the need for hypothermia. FET may or may not be a definitive repair, however. Distal extension or completion—especially endovascular—is common but not well described in the literature. This review describes the considerations that are necessary during FET planning and preparation, how pathology specifics and sizing decisions will affect the subsequent need for treatment, and how outcomes might be better reported to improve understanding of the advantages and limitations of the technique.Materials and Methods: This literature review was performed to identify reports of second-stage endovascular completion after FET repair, and included any literature that described such interventions after index FET, for any aortic arch pathology.Results: Secondary intervention after FET is an important parameter to establish the success or failure of the index procedure. However, unplanned extensions are often reported with insufficient detail and follow up, and studies rarely differentiate between unplanned or adjunctive procedures. In addition, prediction of the need for extension is complicated by the response of the pathology to the index procedure.Conclusion: FET is a versatile, established surgical technique that allows for several applications in different pathologies and innovative adaptations. How, when, and why FET is extended needs to be reported in greater detail, with specific consideration given to the interaction of FET and endovascular devices in sizing, integrity, and possible complications.