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

Model Number	M635WU50240
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	07/20/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
Reported via clinical study.It was reported thrombosis occurred.A left atrial appendage (laa) closure procedure was performed, and a 24mm watchman flx closure device was implanted on (b)(6)2022.The patient was discharged.On (b)(6)2026, the patient underwent transesophageal echocardiography (tee) prior to a cardioversion procedure to treat recent atrial fibrillation.Tee imaging revealed a thrombus on the atrial surface of the closure device.The cardioversion procedure was cancelled, and the patient was restarted on eliquis (bid).

• 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: 50059137
• Report Number: 2124215-2026-40389
• Device Sequence Number: 21515365
• Product Code: NGV
• UDI-Device Identifier: 08714729860495
• UDI-Public: (01)08714729860495(17)241004(10)28147565
• Combination Product (Y/N): N
• Initial Reporter State: NY
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2022
• Reporter Type: Manufacturer
• Report Source: Study,Health Professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 09/01/2026

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 Expiration Date: 10/04/2024
• Device Model Number: M635WU50240
• Device Catalogue Number: M635WU50240
• Device Lot Number: 0028147565
• 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: 07/22/2026
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 07/28/2026
• Supplement Report FDA Received Date: 09/04/2026
• Date Device Manufactured: 10/05/2021
• 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 Age: 78 YR
• Patient Sex: Female
• Patient Weight: 159 LB