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

Model Number	M635WU50350
Medical Device Problem Code	Failure to Seal (4070)
Health Effect - Clinical Codes	Stroke/CVA (1770); Chest Pain (1776); Cardiac Enzyme Elevation (1838); Hematoma (1884); Thrombosis/Thrombus (4440)
Date of Event	06/04/2023
Type of Reportable Event	Serious Injury
Event or Problem Description
Reported via patient call center.It was reported that device did not seal, stroke, thrombosis, and hematoma occurred.A left atrial appendage closure procedure was performed and a 35mm watchman flx laa closure device was implanted on (b)(6) 2023.Post-procedure the patient was taking blood thinning medication.At the 45-day follow-up, imaging showed that the 35mm watchman flx closure device did not have a complete seal.The patient was instructed to take aspirin 81mg.In october (year not specified) the patient experienced a stroke.Transesophageal echocardiogram (tee) was performed which identified thrombus on the 35mm watchman flx closure device.The patient was started on intravenous heparin for 5 days which partially resolved the thrombus.The patient was placed on eliquis.At an unspecified time, another tee was performed which showed persistence of small thrombus.Another tee was later performed which showed the thrombus had resolved.On (b)(6) (year unspecified) the patient visited the hospital due to chest pain.The patient's troponin was elevated, and another thrombus was identified on the 35mm watchman flx closure device.The patient was started on lovenox.The patient developed a large abdominal hematoma.The patient reports that the physician would like to use a vacuum system to remove the thrombus.
Additional Manufacturer Narrative
B3 - event date estimated as event was reported to have been identified at the 45-day follow-up appointment.
Event or Problem Description
Reported via patient call center it was reported that device did not seal, stroke, thrombosis, and hematoma occurred.A left atrial appendage closure procedure was performed and a 35mm watchman flx laa closure device was implanted on (b)(6)2023.Post-procedure the patient was taking blood thinning medication.At the 45-day follow-up, imaging showed that the 35mm watchman flx closure device did not have a complete seal.The patient was instructed to take aspirin 81mg.In october (year not specified) the patient experienced a stroke.Transesophageal echocardiogram (tee) was performed which identified thrombus on the 35mm watchman flx closure device.The patient was started on intravenous heparin for 5 days which partially resolved the thrombus.The patient was placed on eliquis.At an unspecified time, another tee was performed which showed persistence of small thrombus.Another tee was later performed which showed the thrombus had resolved.On (b)(6) (year unspecified) the patient visited the hospital due to chest pain.The patient's troponin was elevated, and another thrombus was identified on the 35mm watchman flx closure device.The patient was started on lovenox.The patient developed a large abdominal hematoma.The patient reports that the physician would like to use a vacuum system to remove the thrombus.
Additional Manufacturer Narrative
Section b1 adverse event/product problem: added product problem.B3 - event date estimated as event was reported to have been identified at the 45-day follow-up appointment.

• 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: 22965518
• Report Number: 2124215-2025-61866
• Device Sequence Number: 21084468
• Product Code: NGV
• Combination Product (Y/N): N
• Initial Reporter State: TX
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2023
• Reporter Type: Manufacturer
• Report Source: Consumer
• Type of Report: Initial,Followup
• Report Date (Section B): 05/20/2026

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?: Yes
• Operator of Device: Health Professional
• Device Expiration Date: 06/01/2025
• Device Model Number: M635WU50350
• Device Catalogue Number: M635WU50350
• Device Lot Number: 0029520450
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Was the Report Sent to FDA?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 08/19/2025
• Supplement Date Received by Manufacturer: 05/08/2026
• Initial Report FDA Received Date: 09/04/2025
• Supplement Report FDA Received Date: 05/20/2026
• Date Device Manufactured: 06/02/2022
• 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: Hospitalization; Other
• Patient Age: 75 YR
• Patient Sex: Unknown