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

Model Number	M635WU60240
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Codes	Air Embolism (1697); Non specific EKG/ECG Changes (1817)
Date of Event	09/04/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that air embolism occurred.A left atrial appendage closure procedure was being performed.Approximately 5 minutes after the 24mm watchman flx pro closure device and delivery system were inserted into the anatomy, the patient experienced st segment elevation.Approximately 5 minutes later, while examining transesophageal echocardiogram (tee), air was visualized first in the appendage, and then later in the apex of the left ventricle.Contrast of the coronary arteries was performed which identified no blockage.The st segment elevation continued but headed back towards baseline and eventually resolved, resuming normal sinus rhythm.The implanting physician determined it was safe to resume the procedure, and a 20mm watchman flx pro closure device was implanted.The patient was kept overnight for observation.
Additional Manufacturer Narrative
Although this report is for a watchman delivery system, we are notifying you of the field action for product advisory on the watchman access systems since these two components are used together in left atrial appendage closure procedures.

• 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: 50736613
• Report Number: 2124215-2026-48768
• Device Sequence Number: 10620712
• Product Code: NGV
• UDI-Device Identifier: 00191506004590
• UDI-Public: (01)00191506004590(17)290314(10)38840966
• 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
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Remedial Action: Other
• Type of Report: Initial
• Report Date (Section B): 09/11/2026

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: M635WU60240
• Device Catalogue Number: M635WU60240
• Device Lot Number: 0038840966
• 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: 09/04/2026
• Initial Report FDA Received Date: 09/11/2026
• Date Device Manufactured: 03/15/2026
• 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
• If action reported to FDA under 21 USC 360i(g), list FDA-assigned Recall Number or include a statement: 97423085-FA
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Hospitalization; Other
• Patient Age: 87 YR
• Patient Sex: Female