In vivo performance of a tri-leaflet mechanical heart valve prosthesis in an ovine model

Tom Langenaeken; Pieter De Meester; Peter Verbrugghe; Filip Rega; Marie Lamberigts; Manon Van Hecke; Lucas Van Hoof; Bart Meuris

doi:10.1093/icvts/ivad142

In vivo performance of a tri-leaflet mechanical heart valve prosthesis in an ovine model

Interdiscip Cardiovasc Thorac Surg. 2023 Aug 3;37(2):ivad142. doi: 10.1093/icvts/ivad142.

Authors

Tom Langenaeken¹, Pieter De Meester², Peter Verbrugghe¹, Filip Rega¹, Marie Lamberigts¹, Manon Van Hecke³, Lucas Van Hoof¹, Bart Meuris¹

Affiliations

¹ Department of Cardiovascular Diseases, Research Unit of Cardiac Surgery, University Hospitals Leuven, Leuven, Belgium.
² Congenital and Structural Cardiology, University Hospitals Leuven, Leuven, Belgium.
³ Department of Pathology, University Hospitals Leuven, Leuven, Belgium.

Abstract

Objectives: We present the long-term results of a trileaflet (Triflo) versus bileaflet (On-X) mechanical valve in both aortic and pulmonary positions in a sheep model.

Methods: The Triflo valve was implanted in 21 female sheep in aortic (n = 8) and pulmonary position (n = 13). The On-X valve was implanted in 7 female sheep in aortic (n = 1) and pulmonary (n = 6) positions. No antithrombotic medication of any kind was given postoperatively. In the aortic group, survival cohorts were 3 and 5 months. In the pulmonary group, survival cohorts were 10 and 20 weeks. Valve performance was assessed using haematology, echocardiography and acoustic measurements combined with post-mortem pathology analysis of the downstream organs.

Results: The mean gradients were lower for the Triflo valve in both pulmonary [4.30 mmHg (3.70-5.73) vs 6.80 mmHg (4.63-7.96), P = 0.012] and aortic [5.1 mmHg (4.2-7.7) vs 10.7 mmHg (8.7-12.9), P = 0.007] positions. Peak gradients were lower for the Triflo valve in both pulmonary [8.05 mmHg (6.75-10.23) vs 13.15 mmHg (9.20-14.76), P = 0.005] and aortic [8.7 mmHg (7.5-12.5) vs 16.5 mmHg (14.2-19.6), P = 0.009] positions. In both positions, leaflets and housing surface were free from any deposits macro- and microscopically and comparable to nonimplanted control valves. Peripheral organs showed no signs of thrombo-embolic damage. Biochemical and haematological were comparable to preoperative. The closing click sound pressure level of the Triflo was significantly lower in both aortic [108.4 sound pressure level (102.0-115.7) vs 111.7 sound pressure level (105.5-117.0), P < 0.001] and pulmonary [103.6 sound pressure level (99.1-108.9) vs 118.5 sound pressure level (116.7-120.2), P < 0.001] position.

Conclusions: Preliminary in vivo results of the Triflo valve are promising in both aortic and pulmonary positions in an ovine model. Excellent haemodynamics, stable long-term function, low valve noise and no thrombo-embolic events in the absence of antithrombotic medication lay the foundation to a future clinical first-in-man trial.

Keywords: Haemodynamics; On-X; Preclinical testing; Sheep model; Trileaflet mechanical valve.

Grants and funding

Experimental Research Fund Cardiovascular Surgery