Artificial Chord Used To Repair Mitral Valve Regurgitation

With the improvement of people's living standards,the prevalence of atherosclerotic risk factors,the age-related retirement of heart valve disease have increased significantly.Mitral valve prolapse has become an important pathogenesis.Mitral annulus expansion,valve leaflet enlarging and weight gaining,rupture of chordae and other pathologies caused severe mitral regurgitation.The diversification of valvular disease pathology has increased the complexity of surgical treatment,but the continuous advancement and refinement of surgical techniques,especially the development of micro-invasive techniques,have made many patients have the hope of life.For the treatment of mitral valve prolapse disease,the surgical technique of artificial tendon implantation has attracted people's attention gradually,especially the minimally invasive way of apical implantation.The dissertation is based on the phenomenon that the valve leaflets tearing due to Neochord artificial tendon implant device in clinical experiments.To study how much tension on the artificial chordae can make the valve leaflets tearing,resulting in the clinical consequences of secondary regurgitation.An improved artificial chordal implant device,namely Two-wire in different holes accompanied by a gasket of artificial chordal implanting device,is proposed.It is hoped that the device can reduce the stress on the leaflets even if artificial leaflets are pulled by Larger tension will not cause damage to the leaflets,and it is hoped that this artificial chordal transplantation can effectively repair mitral regurgitation and shorten the operation time.In this paper,the leaflet tearing test bench and the static ex vivo test bench were designed.It was verified that the Two-wire in different holes accompanied by a gasket of artificial chordal implanting can withstand greater destructive force and the repair is effective for a short time.This article mainly studies from the following two aspects:1.In order to verify that the maximum destructive force that the leaflets can withstand under the Two-wire in different holes accompanied by a gasket artificial chordal implanting approach is greater than the maximum destructive force sustained by the leaflets under the Neochord artificial chordal implantation method,and the role of the gasket is verified.Thedissertation designed a leaflet tear test bench.The dissected fresh porcine heart mitral valve is fixed on the clamp.The artificial chordal stringing method on the valve leaflet is: two-wire in same hole as Neochord,two-wire in different holes and two-wire in different holes accompanied by a gasket.The artificial chordal are connected with the tension sensor,and the force sensor is fixed on the slide table.The controller drives the linear motor to drive the slide table to move the artificial tendons.The artificial tendons tear the leaflets during the movement,the tension on the artificial chordae during the leaflet tearing process was measured,the tension increases first and then suddenly decreases.The maximum value is the maximum destructive force when the leaflet tears.Comparing and analyzing the maximum destructive forces sustained by the valve leaflets at different positions of the valve leaflets under different artificial tendon implantation methods.It was found that the maximum destructive power of the leaflet tearing was the largest under the two-wire in different holes accompanied by a gasket,indicating that under the same tension conditions,this artificial tendons implantation made leaflets are the most vulnerable to damage.In order to verify the effectiveness of the two-wire in different holes accompanied by a gasket of artificial tendon transplantation device designed for the repair of mitral valve prolapse reversal pathology,a static ex-work bench was designed.The height difference between the water level of the upper and lower tanks formed mitral pressure of gradient caused mitral valve closure.Simulation of mitral valve prolapse by using an expanded valve annulus and shearing the posterior marginal chords.Measuring the mitral valve leakage flow,the transvalvular pressure difference and calculating the effective orifice area for regurgitating under the normal condition,the annulus expansion condition and the pathological condition of the nature chords was cut.A set of artificial tendon was implanted on the leaflets used the artificial chord implantation method of the two-wire in different holes accompanied by a gasket,measuring the parameters and then a set of artificial tendon was implanted again.It was found that the effect of the mitral valve leakage flow after the two sets of artificial tendons were implanted was similar to the mitral valve leakage flow before the chordal was cut,indicating that this method is effective and the number of artificial chordae required were less than the Neochord so that the time required for the treatment wasreduced,providing a reliable and effective surgical method for Mitral valve prolapse.