MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION WATCHMAN FLX?; SYSTEM, APPENDAGE CLOSURE, LEFT ATRIAL

Model Number	M635WU50310
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Codes	Stroke/CVA (1770); Thrombosis/Thrombus (4440)
Date of Event	03/03/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
Reported via patient call center.It was reported a cerebral vascular accident (cva) and thrombosis occurred.A left atrial appendage (laa) closure procedure was performed and a 31mm watchman flx closure device was implanted.At an unknown date post index procedure, the patient reported having a cva and a thrombus was found to be attached to the closure device.The physicians started the patient on eliquis in response to the thrombus and will have the patient take another test in three (3) months to see if the thrombus has dissolved.
Additional Manufacturer Narrative
B3: bsc aware date used as event date, as it is unknown.
Additional Manufacturer Narrative
The device was not returned for analysis as the device remains implanted; therefore, a technical analysis could not be performed.It was confirmed this device met manufacturing specification prior to distribution and there were no manufacturing deviations which could have contributed to the reported event.Based on a thorough review of the reported complaint, boston scientific has assigned an investigation conclusion code of known inherent risk of device.
Event or Problem Description
Reported via patient call center.It was reported a cerebral vascular accident (cva) and thrombosis occurred.A left atrial appendage (laa) closure procedure was performed and a 31mm watchman flx closure device was implanted.At an unknown date post index procedure, the patient reported having a cva and a thrombus was found to be attached to the closure device.The physicians started the patient on eliquis in response to the thrombus and will have the patient take another test in three (3) months to see if the thrombus has dissolved.

• 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 ; EI
• Manufacturer Contact: rachel shields ; 4100 hamline ave n; arden hills, MN 55112 ; 6512422111
• MDR Report Key: 24546027
• Report Number: 2124215-2026-12858
• Device Sequence Number: 12177957
• Product Code: NGV
• UDI-Device Identifier: 08714729860518
• UDI-Public: (01)08714729860518(17)250907(10)30111372
• Combination Product (Y/N): N
• Initial Reporter State: CA
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2023
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Consumer
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 04/24/2026

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: 09/07/2025
• Device Model Number: M635WU50310
• Device Catalogue Number: M635WU50310
• Device Lot Number: 0030111372
• 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: 03/03/2026
• Supplement Date Received by Manufacturer: 04/17/2026
• Initial Report FDA Received Date: 03/09/2026
• Supplement Report FDA Received Date: 04/24/2026
• Date Device Manufactured: 09/08/2022
• 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: Required Intervention
• Patient Age: 72 YR
• Patient Sex: Male