Gross examination performed on (b)(6) 2018 displayed the following results.The returned prosthesis was received with calcifications on leaflets.Visible pannus was present both on the inflow and outflow side.One leaflet appeared twisted.The manufacturing and material records for the mitroflow bioprosthetic pericardial heart valve, model # lxa19, s/n (b)(4), as they pertain to the reported event, were retrieved and reviewed by quality engineering at livanova (b)(4) corp.The results confirmed that this valve satisfied all material, visual, and performance standards required for a lxa19 mitroflow aortic pericardial heart valve at the time of manufacture and release.Leaflets calcification, detected with visual, x-ray and histological analyses, caused stiffening and led to progressive valve stenosis.Pannus tissue overgrowth into the inflow lumen also contributed to valve stenosis.Aortic insufficiency likely resulted from leaflets tears.There was no evidence of endocarditis in the returned valve.As reported in the scientific literature (1,2,3,4,5), structural dysfunction is the major cause of failure of bioprosthetic heart valves and the principal underlying pathologic process is cuspal calcification.Calcification can also cause stenosis due to cuspal stiffening.Calcific deposits are usually localized to cuspal tissue (intrinsic calcification).Histological analysis, performed in this mitroflow valve, showed the presence of lipid infiltration (cholesterol clefts) in the leaflet pericardial tissue.This lipid infiltration, as supported from the scientific literature (2,3,4,5) may contribute to localized leaflet stiffness, and if associated with a degeneration of collagen fibers, as detected in the samples from this mitroflow valve, may lead to leaflet tears.The presence of focal gram + is not attributable to an infective endocarditis in the acute phase.Calcification in a biological valve is a known inherent risk identified in the manufacturing ifu.The analysis provides evidence that the root cause of the adverse event leading to explant was a result of structural valve deterioration.However, because the exact date of patient death is unknown, it is inconclusive if the valve explant resulted in patient death.Frederick j.Schoen, md, phd, and robert j.Levy, md; calcification of tissue heart valve substitutes: progress toward understanding and prevention.Ann thorac surg 1073 2005; 79:1072-80.Shetty r, girerd n, cote n, arsenault b, despres jp, pibarot p, mathieu p; elevated proportion of small, dense low-density lipoprotein particles and lower adiponectin blood levels predict early structural valve degeneration of bioprostheses.Cardiology ,2012 ;121(1):20-6.Shetty r, pibarot p, audet a, et al.; lipid-mediated inflammation and degeneration of bioprosthetic heart valves.Eur j clin invest.2009 jun;39(6):471-80.Nollert g, miksch j, kreuzer e, reichart b.; risk factors for atherosclerosis and the degeneration of pericardia! valves after aortic valve replacement.J thorac cardiovasc surg 2003;126:965-8.Martin briand, ms; philippe pibarot, dvm, phd; jean-pierre despre·s, phd; pierre voisine, md;jean g.Dumesnil, md; francois dagenais, md; patrick mathieu, md; metabolic syndrome is associated with faster degeneration of bioprosthetic valves.Circulation.2006;114:1-512-1-517.
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