MAUDE Adverse Event Report: MICROVENTION, INC. WEB SL 17 SINGLE LAYER; INTRASACCULAR FLOW DISRUPTION DEVICE

Model Number	W5-5-2-MVI-3
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Aneurysm expansion (4597)
Date of Event	01/21/2026
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Investigation findings: based on a review of the device¿s risk documentation, the reported event did not indicate there were the presence of any potential or new manufacturing, design, quality, or other systemic issues, or non-conformances.The complaint code is monitored through the trending process; corrective action is determined, as needed, through this process.Investigations of historic complaint files with similar complaint category coding are recorded in the complaint handling system; without the ability to perform an analysis of the device, this investigation cannot identify with certainty any potential root causes.Batch review: a search for non-conformances associated with this part/lot number combination did not reveal any production-related issues relevant to the complaint that occurred during manufacturing of the device.Complaint system review: there are three (3) complaints from the last 2 years recorded in the complaint handling system with this batch number at the time of this investigation.Based on a review of the last 2 years of complaint data, and at the time of this investigation, no systemic issues have been identified for this batch number that would have caused or contributed to the reported event.Ifu review (additional information can be found in the ifu): potential complications potential complications include but are not limited to the following: vessel puncture site hematoma, aneurysm perforation or rupture, hemorrhage, edema, thromboemboli, transient ischemic attack, ischemic stroke, neurologic deficits, parent artery occlusion, ischemia, vessel dissection or perforation, vascular thrombosis, vasospasm, device migration or misplacement, premature detachment, headache, post-embolization syndrome, infection and death.Warnings: advance and retract the web embolization device slowly.Do not advance the delivery device with excessive force.Determine the cause of any unusual resistance.Remove the web embolization device if excessive friction is noted and check for damage.Do not rotate the delivery device during or after delivery of the web embolization device.Rotating the web embolization device may result in damage or premature detachment.The web embolization device cannot be detached with any other power source other than a web detachment control device.Ensure that at least two web detachment control devices are available before initiating an embolization procedure - instructions for use detachment of the web embolization device 34.The detachment control device is pre-loaded with batteries and will activate when the delivery device is properly connected.35.Verify that the rhv is firmly locked around the delivery device before attaching the detachment control device to ensure that the web embolization device does not move during the connection process.36.Ensure that the delivery device gold connectors are clean and free from blood or contrast.If necessary, wipe the connectors with sterile water and dry before connecting.37.Insert the proximal end of the delivery device into the detachment control device.When the delivery device is properly connected, the light will flash green and an intermittent tone will be heard.38.Verify the web embolization device position before pressing the detachment button.39.Push the detachment button.During firing, the light should be solid green and the beep should be continuous.40.Verify detachment by first loosening the rhv valve, then pulling back slowly on the delivery device and verifying that there is not web embolization device movement.If the web embolization device does not detach, push the detachment button again.If the web embolization device is still not detached, obtain a new detachment control device and attempt detachment up to two additional times.If it does not detach, remove the delivery device.41.Verify the position of the web embolization device angiographically through the guide catheter.42.Prior to removing the microcatheter from the treatment site, place an appropriately sized guidewire completely through the microcatheter lumen to ensure that no part of the web embolization device remains within the microcatheter.Investigation conclusion: the physical device was not available for evaluation to investigate if a condition existed that would have contributed to the reported event.Supplemental imaging was also unavailable for review; without imaging, the investigation cannot verify the event occurred as described, nor could the investigation further examine the cause of the reported event.This information may be updated if additional information is provided at a later date.
Event or Problem Description
As reported through the clinical study web pas: originally noted as possible, probable or causal relation to study device or index procedure event term: recurrent r mca aneurysm.The index procedure was on (b)(6) 2025.Per the hospital, follow-up imaging in (b)(6) 2026 showed: 3d rotational angiogram with right ica injection demonstrates a 1.7 x 2.1 mm residual right mca bifurcation aneurysm dome/neck status post prior web treatment.There has been no additional treatment outside of imaging done to identify aneurysm recurrence.Currently there has been no additional treatment and none noted to be planned.The patient is awaiting 2-year follow-up.Event start date: 21-jan-2026 was this a serious ae? no intervention: x was the ae caused by or associated with a technical event? : no relationship to study device: probable relationship to index endovascular procedure: possible relationship to use of ancillary device: not related relationship to study disease: possible relationship to concomitant disease: not related ae outcome: ongoing additional auto alert received noted: was this a serious ae? no none: x relationship to study device: causal the recurrent r mca aneurysm is now indicated as related to the study device, web.No further information has been received.

• Brand Name: WEB SL 17 SINGLE LAYER
• Common Device Name: INTRASACCULAR FLOW DISRUPTION DEVICE
• Manufacturer (Section D): MICROVENTION, INC.; 35 enterprise; aliso viejo CA 92656
• Manufacturer (Section G): MICROVENTION, INC.; 35 enterprise; aliso viejo CA 92656
• Manufacturer Contact: terrence callahan ; 35 enterprise; aliso viejo, CA 92656 ; 7142478000
• MDR Report Key: 24391375
• Report Number: 2032493-2026-00103
• Device Sequence Number: 21392488
• Product Code: OPR
• UDI-Device Identifier: 00842429110843
• UDI-Public: (01)00842429110843(11)240318(17)270228(10)0000543966
• Combination Product (Y/N): N
• Initial Reporter State: NY
• Initial Reporter Country: US
• PMA/510(K) Number: P170032
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Study
• Initial Reporter Occupation: Physician
• Type of Report: Initial
• Report Date (Section B): 02/19/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Operator of Device: Health Professional
• Device Model Number: W5-5-2-MVI-3
• Device Lot Number: 0000543966
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Was the Report Sent to FDA?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 01/27/2026
• Initial Report FDA Received Date: 02/19/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 03/18/2024
• Is the Device Labeled for Single Use? (Y/N): Yes
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Other
• Patient Sex: Unknown