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

Model Number	M635WU60350
Medical Device Problem Codes	Migration (4003); Failure to Seal (4070)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	08/12/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that device leak and thrombosis occurred.A left atrial appendage (laa) closure procedure was performed, and a 35mm watchman flx pro closure device was implanted on (b)(6) 2026.The patient was discharged.During the procedure the closure device met position, anchor, seal and size (pass) criteria.The closure device was positioned at the level of the circumflex artery and successfully released.The anchors appeared to be well engaged, and compression was approximately 30 percent circumferentially.It was suspected that the closure device had shifted distally, resulting in exposure of a proximal lobe that was not recognized during the initial assessment.According to the physicians, the opening measured approximately 4 to 5mm.During a routine follow up computed tomography (ct) the physician informed that the patient had a peri-device leak (pdl).The physician planned to use transesophageal echocardiography (tee) and fluoroscopy to find the leak, access it, and fill the gap with a non-boston scientific (bsc) coils.Most of the patient appendage was clotted, except two (2) proximal lobes on the anterior side.

• 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: 50599999
• Report Number: 2124215-2026-46600
• Device Sequence Number: 10634092
• Product Code: NGV
• UDI-Device Identifier: 00191506004620
• UDI-Public: (01)00191506004620(17)290310(10)38804655
• Combination Product (Y/N): N
• Initial Reporter State: OH
• 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,Followup
• Report Date (Section B): 09/24/2026

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?: Yes
• Operator of Device: Health Professional
• Device Model Number: M635WU60350
• Device Catalogue Number: M635WU60350
• Device Lot Number: 0038804655
• 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: Not provided
• Supplement Date Received by Manufacturer: 09/03/2026; 09/22/2026
• Initial Report FDA Received Date: 09/03/2026
• Supplement Report FDA Received Date: 09/09/2026; 09/24/2026
• Date Device Manufactured: 03/11/2026
• 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; Required Intervention
• Patient Age: 83 YR
• Patient Sex: Female