MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION WATCHMAN FLX?; system, appendage closure, left atrial

Model Number	M635WU50270
Medical Device Problem Code	Migration (4003)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	09/09/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that thrombosis and device migration occurred.The patient previously underwent a left atrial appendage (laa) closure procedure in 2023, and a 27mm watchman flx closure device was implanted.Approximately two years post implant, the patient was scheduled to undergo an ablation procedure.Prior to the procedure, thrombus was identified within the laa and the ablation was cancelled.The patient was also informed that the closure device had shifted distally within the appendage.The patient was subsequently treated with anticoagulation and was advised that long-term blood thinner therapy would be required.At the time of reporting, the thrombus had resolved.
Additional Manufacturer Narrative
B3: bsc aware date used as event date as it is unknown.

• Brand Name: WATCHMAN FLX?
• Common Device Name: system, appendage closure, left atrial
• Manufacturer (Section D): BOSTON SCIENTIFIC CORPORATION; 300 boston scientific way; marlborough MA 01752
• Manufacturer (Section G): Boston Scientific Corporation; ballybrit business park; galway H91 Y 868; EI H91 Y868
• Manufacturer Contact: mary crawford ; 4100 hamline ave n; arden hills, MN 55112 ; +1(651)440-0979
• MDR Report Key: 50843400
• Report Number: 2124215-2026-50239
• Device Sequence Number: 13271788
• Product Code: NGV
• UDI-Device Identifier: 08714729860501
• Combination Product (Y/N): N
• Initial Reporter State: FL
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2023
• Reporter Type: Manufacturer
• Report Source: Consumer
• Initial Reporter Occupation: Physician
• Type of Report: Initial
• Report Date (Section B): 09/21/2026

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?: Yes
• Operator of Device: Health Professional
• Device Expiration Date: 11/08/2025
• Device Model Number: M635WU50270
• Device Catalogue Number: M635WU50270
• Device Lot Number: 0030508372
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 09/09/2026
• Initial Report FDA Received Date: 09/21/2026
• Date Device Manufactured: 11/09/2022
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Other
• Patient Sex: Male