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

Model Number	M635WU60200
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	03/19/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that there was a thrombus.A left atrial appendage (laa) closure procedure was being performed.A watchman trusteer access system (was) and a 20mm watchman flx pro laa closure device & delivery system (wds) were selected to be used.The physician positioned the was in the laa of the patient and then inserted the wds.The closure device was deployed in the patient and the physician noted a thrombus on the face of the device.The sheath was aspirated then the closure device was recaptured and removed from the patient.Transesophageal echocardiogram (tee) imaging showed another thrombus in the patient that was also aspirated and removed from the patient.A new 24mm wds was then used to successfully complete the procedure with the closure device successfully implanted in the laa of the patient.There were no other complications that were reported to have occurred during the procedure.Post procedure the patient was admitted to the hospital since a code stroke was called.The patient was back to baseline later that night.Magnetic resonance imaging the next day showed that the patient did not experience a stroke.The physician believes that some of the patients presentation could have been anesthesia plus the patients history of traumatic brain injury.
Event or Problem Description
It was reported that there was a thrombus.A left atrial appendage (laa) closure procedure was being performed.A watchman trusteer access system (was) and a 20mm watchman flx pro laa closure device & delivery system (wds) were selected to be used.The physician positioned the was in the laa of the patient and then inserted the wds.The closure device was deployed in the patient and the physician noted a thrombus on the face of the device.The sheath was aspirated then the closure device was recaptured and removed from the patient.Transesophageal echocardiogram (tee) imaging showed another thrombus in the patient that was also aspirated and removed from the patient.A new 24mm wds was then used to successfully complete the procedure with the closure device successfully implanted in the laa of the patient.There were no other complications that were reported to have occurred during the procedure.Post procedure the patient was admitted to the hospital since a code stroke was called.The patient was back to baseline later that night.Magnetic resonance imaging the next day showed that the patient did not experience a stroke.The physician believes that some of the patients presentation could have been anesthesia plus the patients history of traumatic brain injury.
Additional Manufacturer Narrative
The device was not returned for analysis as the device was discarded; 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.

• 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: rachel shields ; 4100 hamline ave n; arden hills, MN 55112 ; 6512422111
• MDR Report Key: 24706021
• Report Number: 2124215-2026-16735
• Device Sequence Number: 18751815
• Product Code: NGV
• UDI-Device Identifier: 00191506004583
• UDI-Public: (01)00191506004583(17)281002(10)37614078
• Combination Product (Y/N): N
• Initial Reporter State: WA
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 04/14/2026

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: M635WU60200
• Device Catalogue Number: M635WU60200
• Device Lot Number: 0037614078
• 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: 03/19/2026
• Supplement Date Received by Manufacturer: 04/09/2026
• Initial Report FDA Received Date: 03/26/2026
• Supplement Report FDA Received Date: 04/14/2026
• Date Device Manufactured: 10/03/2025
• 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; Hospitalization
• Patient Age: 74 YR
• Patient Sex: Male