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

Model Number	M635WU60350
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	07/31/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported thrombosis occurred.A left atrial appendage (laa) closure procedure was performed, and a 35mm watchman flx pro closure device was implanted on (b)(6) 2026.The patient was discharged.At the 45-day routine follow up transesophageal echocardiography (tee), the physician noted a pedunculated asymmetrical device related thrombus on the device.The closure device was still in a good position with no leaks present.The patient was on dual anti platelet therapy (dapt) and was changed to oral anticoagulation (oac) and aspirin until the thrombus resolves.

• Brand Name: WATCHMAN FLX? Pro
• 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: 50223122
• Report Number: 2124215-2026-43197
• Device Sequence Number: 17529081
• Product Code: NGV
• UDI-Device Identifier: 00191506004620
• UDI-Public: (01)00191506004620(17)290426(10)39188087
• Combination Product (Y/N): N
• Initial Reporter State: KY
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2026
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Nurse
• Type of Report: Initial,Followup
• 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?: No
• Operator of Device: Health Professional
• Device Model Number: M635WU60350
• Device Catalogue Number: M635WU60350
• Device Lot Number: 0039188087
• 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: 08/07/2026
• Supplement Date Received by Manufacturer: 09/17/2026
• Initial Report FDA Received Date: 08/12/2026
• Supplement Report FDA Received Date: 09/21/2026
• Date Device Manufactured: 04/27/2026
• 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: 74 YR
• Patient Sex: Male