title: Opening-closing pattern of four pericardial prostheses: results from an in vitro study of leaflet kinematics.
abstract: Pericardial and porcine stented aortic valves have different leaflet kinematics. To study the biomechanics of a prosthesis thoroughly, the in vitro setting is the most appropriate. The aim of our study was to find out whether the prosthesis design in which the pericardial sheet is outside the stent post might influence the opening and closing patterns of the leaflets. Four pericardial prostheses (Magna Ease [MG] 21, Trifecta [TRI] 21, Soprano-Armonia [SA] 20 and Mitroflow [MF] 23) that fitted aortic roots with a native annulus diameter of 2.1 cm were implanted and their leaflet kinematics was studied by a high-speed digital camera. In the opening phase, MG showed the shortest RVOT and the highest RVOVI, with values of 12 ± 2 and 209 ± 17 ms, respectively. The RVOT of MG was significantly shorter than that of MF (p < 0.01), but not than that of TRI (p = 0.286). Both TRI and SA showed similar opening patterns (TRI: RVOT of 15 ± 3 ms and RVOVI of 132 ± 25 ms; SA: 17 ± 2 ms and 126 ± 19 ms), without statistically significant difference. Conversely, MF showed the slowest profile, with an RVOT of 23 ± 3 ms and an RVOVI of 94 ± 8 ms (Table 1; Fig. 3). The opening/closing profile is not influenced by the position of the pericardial leaflets, but depends on other intrinsic structural characteristics related to the material used for the stent and leaflets. Moreover, the kinematics does not affect the valve performance. Table 1 Kinematics and hydrodynamic results, reported as means and standard deviations, evaluated over the tested heart samples TRI SA MG MF ANOVA TRI versus SA TRI versus MG TRI versus MF SA versus MG SA versus MF MG versus MF p Value p Value p Value p Value p Value p Value p Value ET (ms) 1.0 1.0 1.0 1.0 RVOT (ms) 15 ± 3 17 ± 2 12 ± 2 23 ± 3 <0.01 1.0 0.286 <0.01 0.03 <0.01 <0.01 SVCT (ms) 247 ± 14 231 ± 15 256 ± 26 241 ± 11 0.170 0.463 0.853 0.931 0.213 1.0 1.0 RVCT (ms) 35 ± 19 52 ± 13 32 ± 17 52 ± 4 0.07 0.474 1.0 0.494 0.236 1.0 0.247 TVCT (ms) 283 ± 10 283 ± 19 289 ± 10 293 ± 11 0.584 1.00 1.0 1.0 1.0 1.0 1.0 RVOVI (ms-1) 132 ± 25 126 ± 19 209 ± 17 94 ± 8 <0.01 0.959 <0.01 0.02 <0.01 0.07 <0.01 SVCVI (ms-1) -0.9 ± 0.3 -1.1 ± 0.4 -0.57 ± 0.1 -0.55 ± 0.1 <0.01 1.0 0.353 0.292 0.045 0.04 1.0 RVCVI (ms-1) -16 ± 4 -10 ± 2 -18 ± 6 -10 ± 1 <0.01 0.396 1.0 0.513 0.025 1.0 0.03 Δp (mmHg) 6.7 ± 3.6 10.6 ± 5.5 15.2 ± 7.9 10.7 ± 6.1 <0.01 0.01 <0.01 0.01 0.04 1.0 <0.01 EOA (cm2) 2.2 ± 1.2 1.7 ± 0.9 1.5 ± 0.8 1.7 ± 0.9 <0.01 0.03 <0.01 0.01 0.261 0.617 0.11 El  % 7.3 ± 1 11.9 ± 1 15.4 ± 2 11.8 ± 3 <0.01 <0.01 <0.01 <0.01 0.04 1.00 0.03 CO (L/min) 3.1 ± 0.4 2.8 ± 0.5 3.1 ± 0.3 3.0 ± 0.5 0.534 0.282 0.792 0.702 0.106 0.552 0.559 ET ejection time, RVOT rapid valve-opening time, SVCT slow valve-closing time, RVCT rapid valve-closing time, TVCT total valve-closing time, RVOVI rapid valve-opening velocity index, SVCVI slow valve-closing velocity index, RVCVI rapid valve-closing velocity index, Δp mean pressure drop, EOA effective orifice area, El % energy loss, CO cardiac output.
authors.affiliation: Cardiac Surgery Unit, Cardiovascular Department, Ospedale "A. Manzoni" di Lecco, Via Dell'Eremo 9/11, 23900, Lecco, Italy. giordano.tasca67@gmail.com.|Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy. giordano.tasca67@gmail.com.
authors.forename: Giordano
authors.initials: G
authors.lastname: Tasca
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.|ForCardiolab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Gianfranco Beniamino
authors.initials: GB
authors.lastname: Fiore
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.|Cardiovascular Surgery Depatment, "L. Sacco" Hospital, Università degli Studi di Milano, Milan, Italy.|ForCardiolab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mangini
authors.affiliation: Cardiovascular Surgery Depatment, "L. Sacco" Hospital, Università degli Studi di Milano, Milan, Italy.|ForCardiolab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Romagnoni
authors.affiliation: Cardiac Surgery Unit, Cardiovascular Department, Ospedale "A. Manzoni" di Lecco, Via Dell'Eremo 9/11, 23900, Lecco, Italy.
authors.forename: Amando
authors.initials: A
authors.lastname: Gamba
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.|ForCardiolab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Redaelli
authors.affiliation: Cardiovascular Surgery Depatment, "L. Sacco" Hospital, Università degli Studi di Milano, Milan, Italy.|ForCardiolab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Antona
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.|ForCardiolab, Fondazione per la Ricerca in Cardiochirurgia ONLUS, Milan, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Vismara
mesh_terms: D000818:Animals; D001011:Aorta; D001021:Aortic Valve; D001696:Biomechanical Phenomena; D001705:Bioprosthesis / Q000706:statistics & numerical data*; D002302:Cardiac Output; D006350:Heart Valve Prosthesis / Q000706:statistics & numerical data*; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D066298:In Vitro Techniques; D010496:Pericardium / Q000637:transplantation; D011474:Prosthesis Design; D015607:Stents; D013552:Swine
keywords: Adult; Aortic valve replacement; Prosthesis