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

Model Number	M635WU60350
Medical Device Problem Code	Failure to Seal (4070)
Health Effect - Clinical Code	Stroke/CVA (1770)
Date of Event	05/15/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that cerebral vascular accident occurred.A left atrial appendage (laa) closure procedure was performed, and a 35mm watchman flx pro closure device was implanted on (b)(6) 2025.The patient was discharged.It was reported that the patient experienced a stroke within the two months preceding (b)(6) 2026, the reporter was unable to provide the exact date of event.Following the closure device implant, the patient received a post 45-day computed tomography (ct) scan on (b)(6) 2025 that showed a 4mm peri device leak.Subsequently, a transesophageal echocardiogram (tee) performed on (b)(6) 2026, revealed a 3.5mm gap on the superior access, a small lobe uncovered, and a 2mm posterior device leak.The reporter was unable to provide information regarding the post-procedure medication regimen initiated after the december ct scan or whether any interventions were performed in response to the ct findings.The reporter was also unaware of any medication changes or interventions following the june tee findings.
Event or Problem Description
It was reported that cerebral vascular accident occurred.A left atrial appendage (laa) closure procedure was performed, and a 35mm watchman flx pro closure device was implanted on (b)(6)2025-.The patient was discharged.It was reported that the patient experienced a stroke within the two months preceding (b)(6)2026, the reporter was unable to provide the exact date of event.Following the closure device implant, the patient received a post 45-day computed tomography (ct) scan on (b)(6)2025 that showed a 4mm peri device leak.Subsequently, a transesophageal echocardiogram (tee) performed on (b)(6)2026, revealed a 3.5mm gap on the superior access, a small lobe uncovered, and a 2mm posterior device leak.The reporter was unable to provide information regarding the post-procedure medication regimen initiated after the december ct scan or whether any interventions were performed in response to the ct findings.The reporter was also unaware of any medication changes or interventions following the june tee findings.
Additional Manufacturer Narrative
B3 event date is an approximate date as the actual event date is not known.With all the available information, boston scientific (bsc) concludes: device technical analysis the watchman flx? pro remains implanted; therefore, returned device analysis could not be completed.Device history record review a review was completed of the device history records (dhr) for the watchman flx? pro, part # m635wu60350 batch # 0034387693.The dhr review confirmed that the device met all material, assembly, and performance specifications prior to distribution.Labeling review there was no evidence to suggest that the device was used in a manner inconsistent with the labeling.Watchman flx? pro instructions for use (ifu) lists potential complications, risks and adverse events that may be associated with the use of this device which include improper seal of the appendage, stroke (cva).Risk review a risk review was completed and confirmed that the events of improper seal of the appendage and cerebral vascular accident (cva) were defined in the risk documentation.These event types have been accounted for during product risk analysis to support acceptable risk benefit for the product.Investigation conclusion based on a thorough review of the reported complaint, boston scientific has assigned an investigation conclusion code of cause not established.
Additional Manufacturer Narrative
B3 event date is an approximate date as the actual event date is not known.

• 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 ; EI
• Manufacturer Contact: mary crawford ; 4100 hamline ave n; arden hills, MN 55112 ; +1(651)440-0979
• MDR Report Key: 50114156
• Report Number: 2124215-2026-41408
• Device Sequence Number: 5305826
• Product Code: NGV
• UDI-Device Identifier: 00191506004620
• UDI-Public: (01)00191506004620(17)270708(10)34387693
• Combination Product (Y/N): N
• Initial Reporter State: FL
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Nurse Practitioner
• Type of Report: Initial,Followup
• Report Date (Section B): 09/04/2026

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: 0034387693
• 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: 07/16/2026
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 08/03/2026
• Supplement Report FDA Received Date: 09/04/2026
• Date Device Manufactured: 07/08/2024
• 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: 86 YR
• Patient Sex: Male