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

Model Number	M635WU60270
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	08/25/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that thrombosis occurred.A left atrial appendage (laa) closure procedure was being performed, and a 27mm watchman flx pro closure device was selected to be used.During the procedure, after deployment of the closure device, a mobile thrombus was noted inside the closure device but seemed to be biased towards the mitral annulus or posterior side of the appendage.The closure device was proximal, but safe to leave, so was evaluated for position, anchor, size and seal (pass) criteria which was met and was released.The patient's activated clotting time (act) was greater than 400 during the procedure and was taken five (5) minutes after the second dose of heparin.Half of the heparin was administrated prior to transseptal and the other half after transeptal.

• 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: 50670555
• Report Number: 2124215-2026-47802
• Device Sequence Number: 10234782
• Product Code: NGV
• UDI-Device Identifier: 00191506004606
• UDI-Public: (01)00191506004606(17)290512(10)39323219
• Combination Product (Y/N): N
• Initial Reporter State: OR
• 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: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 09/30/2026

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: M635WU60270
• Device Catalogue Number: M635WU60270
• Device Lot Number: 0039323219
• 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: 08/25/2026
• Supplement Date Received by Manufacturer: 09/30/2026
• Initial Report FDA Received Date: 09/08/2026
• Supplement Report FDA Received Date: 09/30/2026
• Date Device Manufactured: 05/13/2026
• 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: 84 YR
• Patient Sex: Female