Evaluating the accuracy of 3D printing and finite element analysis in transcatheter aortic valveimplantation: a comparative study against post-TAVI CT imaging.

Transcatheter aortic valve implantation (TAVI) is now the standard treatment for aortic stenosis, offering a less invasive alternative to surgery. While 3D printing and finite element analysis (FEA) show promise for pre-procedural planning, their accuracy in predicting post-TAVI device geometry remains unclear. This study evaluates the agreement between patient-specific FEA models, 3D-printed phantoms, and post-TAVI CT imaging in replicating implanted device geometry. Ten patients treated with the SAPIEN 3 Ultra (S3) device were analysed using pre- and post-TAVI CT scans. Both FEA simulations and 3D-printed models were assessed for stent deformation and anatomical fit. Agreement was quantified using statistical tools including concordance correlation coefficient (CCC), intraclass correlation coefficient (ICC), and Bland-Altman plots. FEA showed stronger agreement with post-TAVI CT (ICC = 0.614, CCC = 0.479) than 3D printing (ICC = 0.363, CCC = 0.165), which had higher variability. While FEA closely approximated device expansion at the annular level, both methods had limitations due to material and computational assumptions. The study supports the greater reliability of FEA in pre-procedural planning, highlighting the need for further validation and standardisation.