A gross and visual inspection was performed on the returned device.The returned valve was received in an explant kit, inserted in a plastic jar of a competitor tissue valve (reasonably that one implanted instead of the returned valve presence of pannus is visible in both side of the prosthesis and, despite its presence, the leaflets opening was normal.Fibrous pannus depositions and reddish areas, due to coagulated blood entrapment, were present on both sides of the sewing ring.Small thrombus depositions were present on the inflow side of the sewing ring.In the outflow side of the sewing ring the fibrous pannus slightly protrudes in the lumen.Some calcifications were present inside the fibrous pannus that covers the outflow side of the sewing ring.The valve was then sent to the external laboratory (life & device s.R.L.Of the university of turin) with the results extracted from their histo-morphological report.Histological analyses were performed on four samples (a ¿ b ¿ c).The sample a was sampled from a portion of the inflow side of sewing ring covered by fibrous pannus depositions.Calcification, calcium debris and inflammatory cells (neutrophils and lymphocytes) were present inside the fibrous pannus deposition that covers the inflow side of sewing ring.The sample b was sampled from a portion of the outflow side of sewing ring covered by fibrous pannus depositions in relation to the calcification.Calcifications and calcium debris were present inside the fibrous pannus deposition that covers the outflow side of sewing ring.The sample c was sampled from a portion of the outflow side of sewing ring covered by fibrous pannus depositions in relation to the calcification.Calcifications and calcium debris were present inside the fibrous pannus deposition that covers the outflow side of sewing ring.Bacteria were not detected inside all sample.Once returned from the external laboratory, the functional subassemby of the valve (cphv pyrolite subassembly) was removed from the sewing cuff and thoroughly cleaned and inspected.The visual assessment on the subassembly, did not highlight any anomalies.The hydrodynamic testing conducted on the cphv subassembly #29 of the valve m7-031 ¿ sn a551471-h was performed using the r0706 - vivitro pulse duplicator equipment.The valve showed a correct movement of the leaflets during opening and closure phases.No anomalies were observed both in normotensive and in hypotensive conditions.The reason of the reported leaflet mobility dysfunction can be reasonably attributed to the presence of pannus on the outflow side of the sewing cuff, around the lumen of the orifice, which would have compromised the correct closing and/or opening movement.Based on the performed analysis, the reported issue is not related to the device quality.Based on the performed analysis the investigation conclusion is thus deemed to be no device problem detected, and the root cause can be attributed to pannus formation.
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