A Case Report: Is the Lack of Sufficient Radial Force Unfreezing the "Frozen Elephant Trunk"?

The "frozen elephant trunk" is a hybrid technique to treat aortic arch and proximal descending aortic pathologies in a single step. Despite its encouraging early and long-term results, some stent-graft-related adverse events have been reported. Here, we describe a possible treatment option to "re-freeze" the FET in case of loss of landing zone. We report a patient who developed significant kinking of the FET over the course of the first 2 postoperative years. The 1-year follow-up computed tomography angiography (CTA) showed significant kinking and proximal migration of the endograft portion of the FET, resulting in new thrombus formation. Due to kinking and thrombus progression in subsequent CTA follow-ups (2 years and 2½ years) with risk for peripheral embolization, a secondary endovascular repair was indicated. Transfemoral relining of the stent component with a thoracic aortic endovascular repair (ZenithTX230142) stent-graft was performed. In the context of postoperative aneurysm sac shrinkage, the low radial force and lack of longitudinal stiffness of the hybrid graft may lead to proximal migration, thus secondary kinking, emphasizing the importance of an adequate degree of oversizing of the primary graft and an appropriate follow-up. Selection of a suitable graft for a particular pathology concerning the radial force and longitudinal stiffness is furthermore important.