Stimwave quality has investigated the details surrounding a complaint resulting from a migration reported to stimwave on (b)(6) 2019, by stimwave territory manager.On (b)(6) 2018, following a successful trial with the stimq peripheral nerve stimulator (pns) system, the patient had a permanent procedure performed.A stimq stimulator (stq4-rcv-a0) and stimq spare lead (stq4-spr-b0) were implanted in the patient's back next to his left superior cluneal nerve for his low back pain.There were no complications during the procedure, and the patient was discharged the same day, reporting similar coverage and pain relief compared to the trial.The territory manager reported that she met with the patient on (b)(6) 2018, (b)(6) 2018, and (b)(6) 2018 to reprogram his device because he was not experiencing the same pain relief that he received with the trial device and immediately following the permanent implant.After each programming session, the patient reported pain reduction, but the coverage was not the same as the trial.On (b)(6) 2019, the territory manager met with the implanting clinician and the patient for a scheduled evaluation and potential revision.At this appointment the territory manager was made aware by the patient that he had fallen several times since the implantation, as early as two (2) weeks following the permanent procedure.The implanting clinician took x-rays of the patient, which revealed that the devices had migrated laterally from the original placement.The implanting clinician recommended revising the devices.However, the patient decided that he would rather have the devices explanted since he had not been using the system for a few months and he had some scheduled tests for his comorbidities.The clinician completed the explant that same day and did not report any complications with the explant procedure.The patient expressed interests in getting a replacement for the devices that were explanted in the future since his pain relief was significant with the trial and immediately following the permanent procedure.Immediately following notification, stimwave quality and management reviewed the events leading up to the migration.The territory manager reported that the patient is elderly, and had undergone several reconstructive surgeries.The patient had also failed other chronic pain therapies including spinal cord stimulation and a pain pump.All devices were explanted before the patient completed the trial with stimq pns system.The territory manager also stated because the patient struggled with constant falls given his age and comorbidities; it is possible that these traumatic events may have contributed to the device migration.Additionally, stimwave quality and management reviewed the implanting clinician's procedure compared to the receiver instructions for use with the territory manager.The territory manager states that the implanting clinician fixated the receiver in compliance with the receiver instructions for use (05-0669-2, page 26, k171366), but the clinician did not perform the steps associated with securing the stimulator (05-0669-2, page 24, k171366).The procedure for securing the stimulator instructs clinicians to ensure the stimulator is sutured to the tissue, and for fixating the receiver, physicians may need to cut down in order to find a suitable tissue structure for anchoring (05-0669-2, page 26, k171366).The source of the issue was not traced back to inadequate documentation of implant procedure, and the device did not fail to meet performance or safety specifications.It is possible that noncompliance to migration mitigation steps as detailed in the receiver instructions for use may have contributed to the issue.Stimwave believes that impact of the patient's falls contributed to the migration of the devices.Given that the patient had fallen often following the permanent implant procedure, and without adequate device securement to surrounding tissue, any jarring or significant impact a human body experiences affects the final position of newly implanted device.For this reason, newly implanted patients are advised to refrain from strenuous activity to allow time for scar tissue to help stabilize the devices in the body in addition to anchoring techniques employed by implanting clinician.Stimulator migration is a known adverse event for peripheral nerve stimulators and the stimq pns system and is mitigated as far as possible in the product's risk management file.Stimwave believes that if the implanting clinician would have followed the ifu, securing the stimulator and anchoring the receiver, this kind of adverse event is less likely to occur.The root cause of the complaint is not attributed to device failure, the inability of the device to meet performance or safety specifications, nor nonconformance to physical or functional device specifications.The root cause is attributed to the implanting clinician's noncompliance to migration mitigation steps detailed in the product's ifu, and insufficient suturing technique.The stimwave product was not the source of the issue.Corrective action is not required to remedy the root cause of the complaint.The device did not fail to meet performance or safety specifications.Stimwave has confirmed that the issue is a known adverse event, mitigated as far as possible, and documented in the stimwave's risk management file.Stimwave was in constant contact with the territory manager from (b)(6) 2019, onward regarding the complaint and the root cause investigation.Stimwave confirmed that the implant procedure details steps to mitigate migration, and the product did not fail to meet performance and safety specifications.The source of the issue is attributed to the implanting clinician's noncompliance to migration mitigation steps detailed in the product's ifu, and insufficient suturing technique, and the unanticipated, jarring impact experienced as a result of the multiple patient falls.Stimwave has informed all parties that the product was not the source of the issue.Stimwave reiterated the steps for the receiver instructions for use with the territory manager on (b)(6) 2019.The territory manager affirmed that she would communicate the receiver instructions for use steps with the implanting clinician to ensure that all future cases with the stimq pns system comply with documented implant procedures and migration mitigation steps.In compliance with medical device reporting requirements and responsibilities, stimwave quality and its chief medical officer have determined that this issue is considered reportable as migration can lead to an injury, and medical or surgical intervention was required to preclude permanent impairment or damage.Stimwave has reported this as an adverse event.
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