MAUDE Adverse Event Report: MICRO THERAPEUTICS, INC. DBA EV3 ONYX; AGENT, INJECTABLE, EMBOLIC

Model Number UNK-NV-ONYX

Device Problem Entrapment of Device (1212)

Patient Problems Foreign Body In Patient (2687); Vascular Dissection (3160); Unspecified Nervous System Problem (4426); Thrombosis/Thrombus (4440)

Event Date 10/10/2019

Event Type  Injury  

Event Description

S.Pal, f.Nicholson, r.Boet, a.Laing, w.Collecutt, a.Lim, k.Hitos; journal of clinical neuroscience; 2020; 73: 74¿79; multimodality treatment of intracranial arteriovenous malformations in south island, new zealand; doi.Org/10.1016/j.Jocn.2020.01.035.Medtronic received information that patients treated with onyx had complications including death. the aim of this study was to present the experience of one facility on treatment approach and outcomes of favouring surgical resection for arteriovenous malformations (avms) that are sufficiently small and safely accessible, and utilising embolization (often in a staged, multiprocedure fashion) with adjuvant stereotactic radiotherapy for a nidus that is larger and more challenging, as determined by amultidisciplinary discussion.  a total of 40 patients treated over a 10 year period (2004¿2014) are analysed here. the endovascular group of 31 patients had 16 (52%) males and 15 (48%) females.Almost half the patients (45%) presented with haemorrhage, and seizures accounted for 12 cases (38.7%).Three patients presented with a headache (9.7%) and two with a neurological deficit (6.5%) as their sole presenting symptom.Endovascular procedure: the embolization cases all involved the cellulose acetate polymer, onyx, with the dmso-compatible microcatheter sonic.The onyx was prepared in a shaker for a minimum of 20 min in all cases.In a minority of cases, iv heparin was administered with a bolus dose of 5000 iu and titrated doses as necessary to achieve an activated clotting time between 200 and 300.This was decided at the interventionalist¿s discretion and generally in cases requiring accessing a small vessel or concerns about compromising flow.Heparin was allowed to wear off naturally and reversal agents were not used.All patients were managed in a neurological high dependency unit with 24 hours access to neurosurgery and intensive care services if necessary.Stereotactic radiosurgery was reserved for cases where the nidus cannot be obliterated by surgical or endovascular modalities, or whether the balance of risk to benefit with further embolization was deemed not in the best interests of the patient. all cases were embolized using onyx and the median volume used was 5.5 mls with a mean volume of 6.4 ml.This was achieved over a total of 54 sessions, with the number of sessions per patient ranging from 1 to 4.Almost half of the cohort (15, 48%) had one treatment session only; 10 patients (32%) had two, 5 (16%) had three and 1 patient (3%) had four sessions, endovascular results: overall mrs scores deteriorated slightly immediately post treatment, ranging from 0 to 4 with a mean of 1.2 and a median value of 1.0.Although not significant, the trend reflected a slight improvement compared to pre-treatment scores at final follow up (range 0¿2, mean 0.8) with a median value of 1.0.Overall, the mrs scores were significantly worse in the surgical group at presentation, post treatment however no difference was detected at follow up when compared to the embolization group. of the fifteen patients who had a single embolization session, complete obliteration of nidus was achieved in 3 cases (9.7%).These cases required an average of 1 ml of onyx (range 0.5¿1.5 ml).After an average follow-up period of 22 months (median, 33.0 months), none of these malformations had recanalized, confirmed with digital subtraction angiography (dsa) in two cases and magnetic resonance angiography (mra) in one.Out of the total of 54 sessions, there was one delayed mortality of a rebleed while awaiting radiosurgery in a patient with a sm grade iii deep seated avm (mortality rate 3%).The total rate of temporary neurological deficit was 4 cases (13%), and permanent deficit in 2 (6.5%).Procedural complications totaled 3 cases (9.6%) of which one was a retained catheter, one carotid dissection and one internal carotid artery (ica) thrombus; however none of these cases suffered clinically detectable morbidity.Of the 28 patients with residual nidus after safe embolization options had been exhausted, 23 agreed to be referred on for radiosurgery, of these 8 were planned from the outset to have embolization then stereotactic radiosurgery and the remaining 15 were referred for radiosurgery once obliteration of nidus could not be achieved with staged embolization procedures.At the end of all procedures, nidus obliteration was achieved with in a further 8 cases (25%) with embolization then stereotactic radiosurgery after an average latency of 29 months (range 3¿53).In summary, with the multimodality approach, the complete cohort of 40 patients treated at christchurch hospital over this ten year period had a nidus obliteration rate of 50% (20 cases: 9 surgical, 3 interventional, 8 combined intervention/radiosurgery).

Manufacturer Narrative

Event related to regulatory report: 2029214-2023-01545.Medtronic is submitting this report to comply with fda reporting regulations under 21 cfr parts 4 and 803.This report is based upon information obtained by medtronic, which the company may not have been able to fully investigate or verify prior to the date the report was required by the fda.Medtronic has made reasonable efforts to obtain more complete information and has provided as much relevant information as is available to the company as of the submission date of this report.This report does not constitute an admission or a conclusion by fda, medtronic, or its employees that the device, medtronic, or its employee caused or contributed to the event described in the report.In particular, this report does not constitute an admission by anyone that the product described in this report has any ¿defects¿ or has ¿malfunctioned¿.These words are included in the fda 3500a form and are fixed items for selection created by the fda to categorize the type of event solely for the purpose of regulatory reporting.Medtronic objects to the use of these words and others like them because of the lack of definition and the connotations implied by these terms.This statement should be included with any information or report disclosed to the public under the freedom of information act.Any required fields that are unpopulated are blank because the information is currently unknown or unavailable.A good faith effort will be made to obtain the applicable information relevant to the report.If information is provided in the future, a supplemental report will be issued.

• Brand Name: ONYX
• Type of Device: AGENT, INJECTABLE, EMBOLIC
• Manufacturer (Section D): MICRO THERAPEUTICS, INC. DBA EV3; 9775 toledo way; irvine CA 92618
• Manufacturer (Section G): MICRO THERAPEUTICS, INC. DBA EV3; 9775 toledo way; irvine CA 92618
• Manufacturer Contact: glen belmer ; 9775 toledo way; irvine, CA 92618 ; 6122713209
• MDR Report Key: 17656211
• MDR Text Key: 322470527
• Report Number: 2029214-2023-01546
• Device Sequence Number: 1
• Product Code: MFE
• Combination Product (y/n): N
• Reporter Country Code: NZ
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Foreign,Literature,Health Professional
• Reporter Occupation: Physician
• Type of Report: Initial
• Report Date: 08/30/2023

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 08/30/2023
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Health Professional
• Device Model Number: UNK-NV-ONYX
• Device Catalogue Number: UNK-NV-ONYX
• Device Lot Number: UNKNOWN
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 08/22/2023
• Is the Device Single Use?: Yes
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Initial
• Patient Sequence Number: 1
• Patient Outcome(s): Required Intervention
• Patient Sex: Male