Association between stent graft landing zone angle and aneurysm remodelling after total arch replacement with frozen elephant trunk for distal aortic arch aneurysm.

OBJECTIVES: Total arch replacement combined with the frozen elephant trunk (TARFET) technique using the FROZENIX prosthesis is widely adopted for distal aortic arch aneurysms; however, factors influencing postoperative aneurysm remodelling in true degenerative aneurysms remain unclear. We aimed to identify computed tomography (CT)-derived stent-graft parameters associated with aneurysm shrinkage. METHODS: Between July 2014 and June 2024, 113 patients underwent total arch replacement (TAR) for true distal arch aneurysm. Of 57 who underwent TARFET using FROZENIX, 9 were excluded (3 scheduled secondary thoracic endovascular aortic repair; 6 lost to CT follow-up), leaving 48 patients. The following CT parameters were measured at discharge and at 6 months, 1 year, and 2 years: distal landing zone level, stent migration, landing zone angle, and stent-to-aorta diameter ratio. Patients were classified as the shrinkage group (>10% diameter decrease) or the no-change group (≤10% change or expansion). RESULTS: Mean age was 75.6 years and mean aneurysm diameter was 58.1 mm. In-hospital mortality was 0%; stroke and spinal cord injury (paraparesis) each occurred in 2 patients (4.2%). Type Ib endoleak occurred in 1 patient (2.1%). Aneurysm shrinkage was achieved in 31 patients (64.6%). The initial landing zone angle was clinically and statistically smaller in the shrinkage group than in the no-change group (15.1 ± 11.5° vs 26.8 ± 21.1°, a difference of approximately 12°; P = 0.046). No significant differences were observed in angle change (P = 0.63), landing length (P = 0.95), diameter ratio (P = 0.91), or migration (P = 0.44). CONCLUSIONS: In this exploratory subgroup analysis, a larger initial stent graft landing zone angle was associated with failure of aneurysm shrinkage after TARFET for true degenerative distal arch aneurysms. Preoperative three-dimensional CT assessment of the predicted landing angle may be a useful adjunct to surgical planning.