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. 2025 Oct;16(5):537-550.
doi: 10.1007/s13239-025-00792-z. Epub 2025 Jul 14.

Role of Neo-Sinus on Thrombogenicity of Aortic Valve Prostheses: Experimental Proof-of-Concept Study

Saskia Thoenissen  1 , Ilona Mager  1 , Claudio A Luisi  1 , Markus Mous  1 , Thomas Schmitz-Rode  2 , Ulrich Steinseifer  1 , Johanna C Clauser  3
Affiliations

Role of Neo-Sinus on Thrombogenicity of Aortic Valve Prostheses: Experimental Proof-of-Concept Study

Saskia Thoenissen et al. Cardiovasc Eng Technol. 2025 Oct.

Abstract

Purpose: Transcatheter aortic valve replacement (TAVR) is the standard treatment for patients with aortic diseases at high surgical risk. Transcatheter heart valve prostheses (THV) are inserted into the aortic valve, creating a new area between the native and artificial leaflets. This area, known as neo-sinus, increases the thrombogenicity of THVs. But there is a lack of testing methods that evaluate thrombogenicity in vitro.

Methods: To analyze the flow field within the native sinus and the neo-sinus, Particle Image Velocimetry (PIV) was performed with a thrombosis tester. Additionally, a comparative study was conducted with porcine blood on two polycarbonate urethane valves, with and without neo-sinus, respectively. Blood samples collected every hour were analyzed for platelet count, coagulation via ROTEM parameters, and plasma-free hemoglobin. Thrombus formation was detected optically.

Results: The PIV measurements yield a physiological flow field in the aortic root that were consistent with those reported in literature. The analyzed blood parameters reveal no obvious difference between the valve with neo-sinus and the valve without. A higher amount of thrombus material for the valve with neo-sinus was found.

Conclusion: The visualized flow field shows low velocities and stagnation zones due to the presence of native leaflets. Clot formation at the heart valve prostheses are in accordance with in-vivo findings. The benchmark of the two valves indicates an increased thrombogenic potential due to the neo-sinus. The thrombosis tester simulates the natural environment after TAVR. Thereby, newly developed THVs can be evaluated in vitro and consequently optimized regarding their thrombogenicity.

Keywords: Blood test; In-vitro testing; Neo-sinus; PIV measurements; Thrombogenicity; Transcatheter aortic valve replacement.

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Conflict of interest statement

Declarations. Ethics Approval, Consent to Participate & to Publish: Not applicable. Conflict of Interest: The authors have no competing interests to declare that are relevant to the content of this article.

Figures

Fig. 1
Fig. 1
Schematic of the aortic root (LCA, left coronary artery; RCA, right coronary artery)
Fig. 2
Fig. 2
THIA 3 for (a) PIV measurements and (b) blood tests
Fig. 3
Fig. 3
In-house designed PCU valve with native leaflets
Fig. 4
Fig. 4
Arrangement of test device, test bench, camera and laser in the conducted PIV experiment
Fig. 5
Fig. 5
Pressure and flow curves produced a) by Linde et al. (Reprint permission license number: 5924141470067), b) of the PIV THIA 3, c) of the blood experiment with test chamber without neo-sinus and d) of the blood experiment with test chamber with neo-sinus
Fig. 6
Fig. 6
Flow field in the aortic root during one heart cycle in the central plane: (1) end of diastole; (2) beginning of systole; (3) maximum systole; (4) systole; (5) end of systole; (6) beginning of diastole; (7) diastole; (8) diastole; (9) flow through valve showing the selected time points
Fig. 7
Fig. 7
Flow field in the aortic root during one heart cycle at the 6 mm shifted observation plane: (1) end of diastole; (2) beginning of systole; (3) maximum systole; (4) systole; (5) end of systole; (6) beginning of diastole; (7) diastole; (8) diastole; (9) flow through valve showing the selected time points
Fig. 8
Fig. 8
Progression of blood values during blood experiment
Fig. 9
Fig. 9
Clot formation (a) on the PCU valve without neo-sinus after drying; in detail: stent tip and stent ring and (b) on the PCU valve with neo-sinus after drying; in detail: stent tip and neo-sinus
See this image and copyright information in PMC

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