Results of the ACSSim study: Computational prediction of Gore Excluder conformable endoprosthesis

Objective

The Gore® Excluder® Conformable (EXCC) device offers a less invasive and less risky alternative to open surgery and complex endovascular repair of abdominal aortic aneurysms for patients with hostile aortic neck anatomies.

Indeed, its specific structure has sufficient conformability to prevent proximal sealing complications. Nevertheless, its mechanical behavior is more complex than the one of standard devices, and in complex anatomies, its deployment in the proximal neck of the aortic aneurysm remains difficult to predict.

The aim of the present study was to develop and validate a digital twin of EXCC deployment that could accurately predict proximal endoprosthesis sealing.

Methods

Twenty patients who underwent endovascular aortic aneurysm repair with the EXCC device for complex anatomies in one aortic center were selected.

Endoprosthesis deployment in each aorta was simulated by the finite element (FE) method. We compared the positions predicted by the FE simulations with post-operative computed tomography angiography (CTA), focusing on the proximal axis angle, the stent center positions and stent-rings diameters through a principal component analysis.

Results

A successful FE simulation of endoprosthesis deployment could be performed for each of the twenty patients. Relative diameter and vector mean deviations were 4.65 ± 3.85 % and 3.00 ± 1.41 mm, respectively.

Axis angle mean deviation was 10.64 ± 5.09°. Outputs show satisfying agreement between numerical simulations and post-operative CTA. Mean proximal apposition was 81.64 ± 11.35 %. Minimal and maximal endoprosthesis appositions were 54.27 % and 95.11 %, respectively.

Conclusions

The FE model predicted accurately stent-graft positions in 20 patients presenting complex anatomies. High endoprosthesis appositions were observed. This shows the potential of computer simulation to anticipate endoprosthesis proximal sealing complications such as endoleaks and migration before intervention.