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	09/08/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported thrombosis occurred.A left atrial appendage (laa) closure procedure was being performed, and a 35mm watchman flx pro laa closure device was implanted (b)(6) 2025.The patient was discharged.During a computed tomography angiography (cta) coronary scan a year and a half later, a device related thrombus (drt) on the watchman device was an incidental finding.There were no further complications reported.It was further reported that post implant at 45-days, the patient was on eliquis and aspirin, then at 6 months, aspirin and plavix and afterwards on aspirin only.The thrombus was not mobile and noted on the face of the closure device.
Additional Manufacturer Narrative
B3 date of event - date of event changed following additional information.B5 updated.

• 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: 50740307
• Report Number: 2124215-2026-48812
• Device Sequence Number: 15565795
• Product Code: NGV
• UDI-Device Identifier: 00191506004620
• UDI-Public: (01)00191506004620(17)270902(10)34760221
• Combination Product (Y/N): N
• Initial Reporter State: VA
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 09/23/2026

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: 0034760221
• 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: 09/08/2026
• Supplement Date Received by Manufacturer: 09/11/2026; 09/22/2026
• Initial Report FDA Received Date: 09/11/2026
• Supplement Report FDA Received Date: 09/16/2026; 09/23/2026
• Date Device Manufactured: 09/02/2024
• 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: Required Intervention; Other
• Patient Age: 67 YR
• Patient Sex: Female