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.