title: Simultaneous in- and out-of-plane Mitral Valve Annular Force Measurements.
abstract: Mitral valve repair with annuloplasty is often favoured over total valve replacement. In order to develop and optimize new annuloplasty ring designs, it is important to study the complex biomechanical behaviour of the valve annulus and the subvalvular apparatus with simultaneous in- and out-of-plane restraining force measurements. A new flat D-shaped mitral valve annular force transducer was developed. The transducer was mounted with strain gauges to measure strain and calibrated to provide simultaneous restraining forces in- and out of the mitral annular plane. The force transducer was implanted and evaluated in an 80 kg porcine experimental model. Accumulation of out-of-plane restraining forces, creating strain in the anterior segment were 0.7 ± 0.0 N (towards apex) and an average force accumulation of 1.5 ± 0.3 N, creating strain in the commissural segments (away from apex). The accumulations of in-plane restraining forces, creating strain on the inner side of the ring were 1.7 ± 0.2 N (away from ring center). A new mitral annular force transducer was successfully developed and evaluated in vivo. The transducer was able to measure forces simultaneously in different planes. Initial indications point towards overall agreement with previous individual force measurements in- and out-of the mitral annular plane. This can provide more detailed insight into the annular force distribution, and could potentially improve the level of evidence based mitral valve repair and support the development of future mitral annuloplasty devices.
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark. soeren.skov@clin.au.dk.|Department of Engineering, Faculty of Science and Technology, Aarhus University, Aarhus, Denmark. soeren.skov@clin.au.dk.
authors.forename: Søren N
authors.initials: SN
authors.lastname: Skov
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Røpcke
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.|Department of Engineering, Faculty of Science and Technology, Aarhus University, Aarhus, Denmark.
authors.forename: Kristine
authors.initials: K
authors.lastname: Telling
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Christine
authors.initials: C
authors.lastname: Ilkjær
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Marcell J
authors.initials: MJ
authors.lastname: Tjørnild
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Nygaard
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Sten L
authors.initials: SL
authors.lastname: Nielsen
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.|Department of Engineering, Faculty of Science and Technology, Aarhus University, Aarhus, Denmark.
authors.forename: Morten O
authors.initials: MO
authors.lastname: Jensen
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002318:Cardiovascular Diseases / Q000150:complications / Q000191:economics / Q000401:mortality; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods*; D008943:Mitral Valve / Q000473:pathology / Q000502:physiology* / Q000601:surgery*; D058386:Mitral Valve Annuloplasty / Q000295:instrumentation* / Q000379:methods*; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D019651:Plastic Surgery Procedures / Q000295:instrumentation / Q000379:methods; D013314:Stress, Mechanical; D013552:Swine; D016277:Ventricular Function, Left / Q000502:physiology
keywords: Biomechanics; Mitral valve; Mitral valve annuloplasty; Reconstruction surgery; Strain gauge