Aortic diameter remodelling after the frozen elephant trunk technique in aortic dissection: results from an international multicentre registry

OBJECTIVES: The frozen elephant trunk (FET) technique allows one-stage hybrid repair approach in aortic dissection (AoD). Even if the effect of the FET technique on promoting false lumen (FL) thrombosis has been proved in the past, the relative importance of FL thrombosis on aortic remodelling at different levels of the distal aorta and the magnitude of this effect is not well known. The aim of the study was to evaluate aortic remodelling following a FET technique for AoD. METHODS: A multicentre international registry database was searched to identify all patients who underwent a FET procedure for an AoD. A total of 383 patients with AoD were operated on between January 2005 and March 2014 with the FET technique; 137 patients (65 acute AoD and 72 chronic AoD) who survived the initial repair with at least a 1-year follow-up CT scan were included in the study. RESULTS: The rate of FL thrombosis was higher in the mid-descending thoracic aorta (99.3%) and lower in the distal abdominal aorta (13.9%) but similar between acute and chronic AoDs. The negative remodelling rate was similar between acute and chronic AoDs in the abdominal aorta, but chronic AoD exhibited a higher rate of negative remodelling in the descending thoracic aorta (33% vs 17.5%, P = 0.040). CONCLUSIONS: The FET technique provides an effective treatment for AoD, promoting FL thrombosis and remodelling in the descending thoracic aorta. Changes in the diameter of the aortic lumen depend mainly on the status of the FL and are similar between acute and chronic AoD. Changes in the diameter of true lumen are affected by both the FL status and the timing of the presentation. However, increased FL thrombosis and positive remodelling rates are not maintained at the level of the abdominal aorta, and strict follow-up is mandatory to detect early changes in the aortic dimensions, which may warrant further interventions.