A sample evaluation was not performed as the device remains implanted.The manufacturing records were reviewed and it was confirmed that all records were controlled, available for review, and met all specifications per the device master record.All lots passed functional testing and met release specifications.During the investigation no non-conformances or deviations were noted.On (b)(6) 2015 onxae-19 serial number (sn) (b)(6) was implanted in a 35 year old female and on (b)(6) 2023 we were informed by the implanting surgeon that the patient recently started to have high gradients around 40 and he suspected a valve thrombus or pannus as the cause of the high gradients and was reaching out for advice.An investigation was initiated, and additional information was collected as follows: the patient was monitored, and the gradients stayed elevated and on imaging one leaflet opens only 67 degrees and the other to 80 degrees.A current inr was not provided; however, the surgeon did state that the patient had been off anticoagulation for some time.In addition, there is no planned intervention at this time according to communication with the surgeon.The instructions for use (ifu) identify both pannus and valve thrombosis as known potential complications of prosthetic valve replacement [instructions for use].The frequency of occurrence for pannus is not established and has been reported for the on-x valve only anecdotally (see, for example, han 2015 for an aortic case and abad 2016 for a tricuspid case).However, bonnichsen et al.Reiterate the claim by vitale et al.That thrombosis and pannus are both present in as many as 45% of cases of obstructed mechanical valves (on-x was not evaluated in this particular study) [bonnichsen 2015, vitale 1997].Thrombosis is a rare, but a known potential complication of prosthetic valve replacement occurring at a historical rate of 0.2% per patient-year for mechanical mitral heart valves [iso 5840-2:2021 (e)].It is recognized as a potential adverse event for any mechanical valve.Without any records for review, we are unable to arrive at a root cause of the suspected thrombosis, however the most common cause of valve thrombus in this situation is inadequate anticoagulation and this is further supported in this case by the statement from the surgeon that the patient had been off anticoagulation for some time.We are unable to confirm, with the limited available information, if either a suspected pannus formation or a suspected valve thrombosis could be the cause of the high gradients in this patient.Either way pannus formation and valve thrombosis are both known risk factors for foreign body implants such as on-x valves per our instructions for use [ifu].References: abad c, et al.Dysfunction of an on-x heart valve by pannus, j heart valve dis 2016 sep;25(5):634-637.Bonnichsen cr & pellikka pa, prosthetic valve thrombus versus pannus ¿ progress with imaging, circ cardiovasc imaging 2015;8: doi: 10.1161/circimaging.115.004283.Han k, et al.Subprosthetic pannus after aortic valve replacement surgery: cardiac ct findings and clinical features, radiology 2015;v276n3:724-731.Iso 5840-2:2021 (e) cardiovascular implants - cardiac valve prostheses, annex i.On-x instructions for use including aortic valve inr 1.5-2.0 update.Http://www.Onxlti.Com/ifu.Vitale n, et al.Obstruction of mechanical mitral prostheses: analysis of pathologic findings, ann thorac surg 1997;63:1101-1106.This report is being submitted as required by federal regulations and does not constitute an admission that the device caused or contributed to the reported event.Furthermore, this report reflects the event as alleged by the complainant and does not imply that the information reported to artivion- formerly cryolife/jotec is accurate or has been confirmed by artivion.
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