Hoda Hatoum1, Pablo Maureira2, Lakshmi Prasad Dasi3. 1. Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio. 2. Department of Cardiovascular Surgery, CHU de Nancy, Nancy, France. 3. Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio. Electronic address: lakshmi.dasi@osumc.edu.
Abstract
OBJECTIVE: The objective of this study was to investigate and compare the hemodynamic and turbulence characteristics upon implantation of St Jude Medical (SJM) (St Jude Medical, St Paul, Minn) and On-X (On-X Life Technologies, Kennesaw, Ga) bileaflet mechanical valves. Both valves are considered highly successful bileaflet mechanical valves characterized by good clinical outcomes despite their numerous design differences. Although thromboembolism remains the main disadvantage of bileaflet mechanical valves, On-X valves have been shown to need less anticoagulation therapy. METHODS: Hemodynamic assessment of a 23-mm On-X bileaflet mechanical valve and a 23-mm bileaflet SJM valve implanted in an aortic root was performed under pulsatile physiologic conditions. Time-resolved and phase-locked particle-image-velocimetry images and high-speed imaging data were acquired. Pressure gradients, effective orifice areas, dimensionless area index, leaflet position tracking, velocity, and principal Reynolds shear stress were calculated. RESULTS: Pressure gradient for the On-X valve was 4.15 ± 0.099 mm Hg versus 4.75 ± 0.048 mm Hg for SJM (P < .001). Effective orifice area for the On-X valve was 2.61 ± 0.045 cm2 versus 2.36 ± 0.022 cm2 for SJM (P < .001). Area index was higher with SJM (0.87 ± 0.008) than with On-X (0.73 ± 0.013) (P < .001). On-X showed fluctuating leaflet behavior during systole, whereas SJM leaflets were stable. At peak systole, the maximal velocity with On-X was 1.86 m/s versus 2.33 m/s with SJM. Reynolds shear stress was higher with On-X compared with SJM at peak systole (95 vs 72 Pa). Higher velocity fluctuation was noted with the On-X valve. CONCLUSIONS: This study shows that despite the design differences that characterize the On-X valve, the hemodynamic and turbulence parameters were not necessarily improved compared with SJM.
OBJECTIVE: The objective of this study was to investigate and compare the hemodynamic and turbulence characteristics upon implantation of St Jude Medical (SJM) (St Jude Medical, St Paul, Minn) and On-X (On-X Life Technologies, Kennesaw, Ga) bileaflet mechanical valves. Both valves are considered highly successful bileaflet mechanical valves characterized by good clinical outcomes despite their numerous design differences. Although thromboembolism remains the main disadvantage of bileaflet mechanical valves, On-X valves have been shown to need less anticoagulation therapy. METHODS: Hemodynamic assessment of a 23-mm On-X bileaflet mechanical valve and a 23-mm bileaflet SJM valve implanted in an aortic root was performed under pulsatile physiologic conditions. Time-resolved and phase-locked particle-image-velocimetry images and high-speed imaging data were acquired. Pressure gradients, effective orifice areas, dimensionless area index, leaflet position tracking, velocity, and principal Reynolds shear stress were calculated. RESULTS: Pressure gradient for the On-X valve was 4.15 ± 0.099 mm Hg versus 4.75 ± 0.048 mm Hg for SJM (P < .001). Effective orifice area for the On-X valve was 2.61 ± 0.045 cm2 versus 2.36 ± 0.022 cm2 for SJM (P < .001). Area index was higher with SJM (0.87 ± 0.008) than with On-X (0.73 ± 0.013) (P < .001). On-X showed fluctuating leaflet behavior during systole, whereas SJM leaflets were stable. At peak systole, the maximal velocity with On-X was 1.86 m/s versus 2.33 m/s with SJM. Reynolds shear stress was higher with On-X compared with SJM at peak systole (95 vs 72 Pa). Higher velocity fluctuation was noted with the On-X valve. CONCLUSIONS: This study shows that despite the design differences that characterize the On-X valve, the hemodynamic and turbulence parameters were not necessarily improved compared with SJM.
Authors: George M Palatianos; Axel M Laczkovics; Paul Simon; Jose Luis Pomar; Dietrich E Birnbaum; Hans H Greve; Axel Haverich Journal: Ann Thorac Surg Date: 2007-01 Impact factor: 4.330
Authors: Hoda Hatoum; Jennifer Dollery; Scott M Lilly; Juan A Crestanello; Lakshmi Prasad Dasi Journal: Ann Biomed Eng Date: 2018-08-27 Impact factor: 3.934
Authors: Hoda Hatoum; Jennifer Dollery; Scott M Lilly; Juan A Crestanello; Lakshmi Prasad Dasi Journal: J Biomech Date: 2018-05-04 Impact factor: 2.712
Authors: Hoda Hatoum; Sunyoung Ahn; Scott Lilly; Pablo Maureira; Juan Crestanello; Vinod H Thourani; Lakshmi Prasad Dasi Journal: JTCVS Open Date: 2022-01-24
Authors: Hoda Hatoum; Milad Samaee; Janarthanan Sathananthan; Stephanie Sellers; Maximilian Kuetting; Scott M Lilly; Abdul R Ihdayhid; Philipp Blanke; Jonathon Leipsic; Vinod H Thourani; Lakshmi Prasad Dasi Journal: JTCVS Open Date: 2022-04-20