title: In vitro study of aortic valves treated with neo-chordae grafts: hydrodynamics and tensile force measurements.
abstract: Reparative surgery of the aortic root functional unit (ARFU) allows for a better preservation of the functionality of the native structure compared to prosthesis implantation. Post-operative results are satisfactory, whereas mid- and long-term results are challenging, for example in terms of cusps prolapse recurrence. At the Cardiothoracic Surgery Unit of the Sacco Hospital, a new surgical technique aimed at the stabilization in time of the results of standard ARFU repair operations has been applied. This technique, inspired by the mitral neo-chordae (NC) implantation, consists of implanting an e-PTFE suture thread between the prolapsed cusp and the sinotubular junction. Aim of this study was to assess the influence of NC implantation on the ARFU functioning by evaluating with an owned pulsatile in vitro apparatus the force magnitude acting on the NC and the dynamic behavior of porcine ARFUs treated according to the operating-room procedures. The maximum recorded values of the mean and peak diastolic forces were 0.064 and 0.186 N, respectively, and were linearly dependent upon the mean diastolic pressure across the valve. In addition, the measurements of the opening-closing times and valve leakage volumes, performed at pre- and post-surgeries, yielded that the valve functionality was not significantly influenced by NC implantation.
authors.affiliation: Department of Bioengineering, Politecnico di Milano, via Golgi 39, Milan, Italy. riccardo.vismara@polimi.it
authors.forename: R
authors.initials: R
authors.lastname: Vismara
authors.forename: C
authors.initials: C
authors.lastname: Antona
authors.forename: A
authors.initials: A
authors.lastname: Mangini
authors.forename: M
authors.initials: M
authors.lastname: Cervo
authors.forename: M
authors.initials: M
authors.lastname: Contino
authors.forename: E
authors.initials: E
authors.lastname: Bosisio
authors.forename: A
authors.initials: A
authors.lastname: Redaelli
authors.forename: G B
authors.initials: GB
authors.lastname: Fiore
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000502:physiology* / Q000601:surgery*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D019544:Equipment Failure Analysis; D006801:Humans; D011474:Prosthesis Design; D019651:Plastic Surgery Procedures / Q000295:instrumentation*; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures; D013552:Swine; D013718:Tensile Strength