It was reported that the patient had low flow alarms that occurred every morning.The alarms were deteriorating the patient's quality of life.There was no health problem to the patient.The computed tomography (ct) image showed that the inflow cannula was facing in the upward direction away from the mitral valve, which might have been the cause of sucking and frequent low flow alarms.Therefore, it is determined that the pump needed to be exchanged to adjust the direction of the inflow cannula toward the mitral valve.It was judged that the patient's heart function was recovered.On (b)(6) 2022, the pump explant was performed instead of the planned pump exchange.
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Manufacturer's investigation conclusion: no device-related issues were identified through the evaluation of heartmate ii left ventricular assist system (lvas), serial number (b)(6).The report of inflow cannula malposition could not be confirmed through this evaluation as there were no x-ray images or computed tomography (ct) scans provided for analysis.(b)(6) was returned assembled with the driveline (dl) cut approximately 4¿ from the pump housing and the remaining distal portion of the driveline was not returned.The sealed inflow conduit (inlet tube, flex section, and inlet elbow) was returned attached to the pump¿s inlet port.The outflow elbow was returned attached to the pump's outlet port.The sealed outflow graft was returned attached to the outflow elbow.The bend relief collar was returned detached from the device.The sealed outflow graft bend relief was not returned.Examination of the pump's blood-contacting surfaces upon disassembly of the device also revealed no adhered depositions or thrombus formations.The device was cleaned.The pump's bearings, rotor, and blood-contacting surfaces were then examined under a microscope and no anomalies were observed.Electrical continuity testing of the returned portion of the driveline did not reveal any discontinuities or shorts.Functional testing of the pump under normal operating conditions revealed normal pump power consumption and pressure values comparable to the data recorded during the manufacturing process.The pump operated as intended.The relevant sections of the device history records for (b)(6) were reviewed and showed no deviations from manufacturing or quality assurance specifications.The implant kit was shipped on 13jun2019.The heartmate ii left ventricular assist system (lvas) instructions for use (ifu) is currently available.Section 5, ¿surgical procedures¿ outlines considerations for pump placement and orientation and also provides instructions regarding the preparation, installation, and orientation of the sealed inflow conduit.Section 5 (under ¿inserting the sealed inflow conduit¿) states to ¿select the optimal sealed inflow conduit orientation at the ventricular apex.The following is critical in determining orientation: the opening of the sealed inflow conduit should be directed toward the mitral valve and away from the intraventricular septum.Care must be taken to avoid excessive angulation of the sealed inflow conduit once the left ventricular assist device is in-situ.The ideal orientation will anticipate that the dilated lv may shrink in size as its workload is assumed by the pump.¿ the heartmate ii ifu also contains a section on ¿pump performance monitoring¿ under patient care and management which explains that pump performance is sensitive to changes in systemic vascular resistance and left ventricular filling.Section 4.4 ¿clinical screen¿, contains sections on pump flow, pump speed, pulsatility index, and pump power.Per design, when the estimated flow value is calculated at less than 2.5 liters per minute (lpm), a low flow status is posted to the log file.If the flow remains below 2.5 lpm for 10 seconds, a low flow hazard alarm is triggered.The heartmate ii patient handbook contains a section on ¿alarms and troubleshooting¿ which provides information on all system alarms, including low flow hazard alarms, and the actions associated to resolve the alarms.A section on ¿handling emergencies¿ is also provided.No further information was provided.The manufacturer is closing the file on this event.
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