A Finite Element Analysis Study from 3D CT to Predict Transcatheter Heart Valve Thrombosis

Francesco Nappi; Laura Mazzocchi; Irina Timofeva; Laurent Macron; Simone Morganti; Sanjeet Singh Avtaar Singh; David Attias; Antonio Congedo; Ferdinando Auricchio

doi:10.3390/diagnostics10040183

A Finite Element Analysis Study from 3D CT to Predict Transcatheter Heart Valve Thrombosis

Diagnostics (Basel). 2020 Mar 26;10(4):183. doi: 10.3390/diagnostics10040183.

Authors

Francesco Nappi¹, Laura Mazzocchi², Irina Timofeva³, Laurent Macron³, Simone Morganti⁴, Sanjeet Singh Avtaar Singh⁵, David Attias⁶, Antonio Congedo⁷, Ferdinando Auricchio²

Affiliations

¹ Department of Cardiac Surgery, Centre Cardiologique du Nord de Saint-Denis, 93200 Paris, France.
² Department of Civil Engineering and Architecture, University of Pavia, 27100 Pavia, Italy.
³ Department of Imaging, Centre Cardiologique du Nord de Saint-Denis, 93200 Paris, France.
⁴ Department of Electrical, Computer, and Biomedical Engineering University of Pavia, 27100 Pavia, Italy.
⁵ Department of Cardiac Surgery, Golden Jubilee National Hospital, G81 4DY Glasgow, UK.
⁶ Department of Cardiology, Centre Cardiologique du Nord de Saint-Denis, 93200 Paris, France.
⁷ Department of Electronic Engineering, AKTIVE Reeds Manufacturing, Computer Science, 80123 Naples, Italy.

Abstract

Background: Transcatheter aortic valve replacement has proved its safety and effectiveness in intermediate- to high-risk and inoperable patients with severe aortic stenosis. However, despite current guideline recommendations, the use of transcatheter aortic valve replacement (TAVR) to treat severe aortic valve stenosis caused by degenerative leaflet thickening and calcification has not been widely adopted in low-risk patients. This reluctance among both cardiac surgeons and cardiologists could be due to concerns regarding clinical and subclinical valve thrombosis. Stent performance alongside increased aortic root and leaflet stresses in surgical bioprostheses has been correlated with complications such as thrombosis, migration and structural valve degeneration.

Materials and methods: Self-expandable catheter-based aortic valve replacement (Medtronic, Minneapolis, MN, USA), which was received by patients who developed transcatheter heart valve thrombosis, was investigated using high-resolution biomodelling from computed tomography scanning. Calcific blocks were extracted from a 250 CT multi-slice image for precise three-dimensional geometry image reconstruction of the root and leaflets.

Results: Distortion of the stent was observed with incomplete cranial and caudal expansion of the device. The incomplete deployment of the stent was evident in the presence of uncrushed refractory bulky calcifications. This resulted in incomplete alignment of the device within the aortic root and potential dislodgment.

Conclusion: A Finite Element Analysis (FEA) investigation can anticipate the presence of calcified refractory blocks, the deformation of the prosthetic stent and the development of paravalvular orifice, and it may prevent subclinical and clinical TAVR thrombosis. Here we clearly demonstrate that using exact geometry from high-resolution CT scans in association with FEA allows detection of persistent bulky calcifications that may contribute to thrombus formation after TAVR procedure.

Keywords: image; thrombosis; transcatheter implantation; valve replacement.