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

Model Number	M635WU24060
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Codes	Stroke/CVA (1770); Dyspnea (1816); Muscle Weakness/Atrophy (1967); Thrombosis/Thrombus (4440); Cough (4457)
Date of Event	08/15/2023
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported cerebral vascular accident (cva) and thrombosis occurred.A left atrial appendage (laa) closure procedure was performed, and a 24mm watchman laa closure device was implanted in (b)(6) 2020.The patient was discharged on warfarin and aspirin (asa) 81mg.A transesophageal echocardiogram (tee) performed on (b)(6) 2020 noted no thrombus on the device or leak and no position change.The patient was transitioned to dual antiplatelet therapy (dapt).Clopidogrel was discontinued on (b)(6) 2021, and patient continued asa 81mg daily.On (b)(6) 2023, the patient was evaluated for right sided weakness and diagnosed with stroke (lacunar infarct) on (b)(6) 2023.No tee was completed at this time.The patient was seen by neurology who felt that it was unlikely cardioembolic.Echocardiogram performed on (b)(6) 2025 made no mention of the device or problems seen on the device.On (b)(6) 2026, the patient presented to the emergency room for evaluation of shortness of breath and a cough.Computed tomography angiography (cta) of pulmonary arteries was completed to rule out pericardial effusion.No effusion was present, but there was suspicious dense tissue around the closure device.On (b)(6) 2025, echocardiography was completed as well as a transesophageal echocardiography (tee) and the pre-existing small pfo with intermittent bidirectional shunting was noted, along with a large mobile echo dense mass covering the entire atrial surface of the closure device.An infectious disease workup is ongoing; however, there is low suspicion the mass is vegetation/endocarditis at this time.The patient was placed on systemic anticoagulation for 4 to 6 weeks with repeat imaging (ct laa +/- tee).
Additional Manufacturer Narrative
With all the available information, boston scientific (bsc) concludes: device technical analysis the watchman 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, part # m635wu24060 batch # 0025393640.The device was processed through all normal operational conditions and passed all acceptance activities.The dhr review did not identify any deviations or non-conformances that could have contributed to the event.Labeling review there was no evidence to suggest that the device was used in a manner inconsistent with the labeling.Watchman instructions for use (ifu) lists potential complications, risks and adverse events that may be associated with the use of this device which include cerebral vascular accident (cva) (weakness) and thrombosis (dyspnea, cough) (hospitalization, imaging and medication required).Risk review a risk review was completed and confirmed that the events of cerebral vascular accident (cva) (weakness) and thrombosis (dyspnea, cough) 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 known inherent risk of device.
Event or Problem Description
It was reported cerebral vascular accident (cva) and thrombosis occurred.A left atrial appendage (laa) closure procedure was performed, and a 24mm watchman laa closure device was implanted in (b)(6) 2020.The patient was discharged on warfarin and aspirin (asa) 81mg.A transesophageal echocardiogram (tee) performed on (b)(6) 2020 noted no thrombus on the device or leak and no position change.The patient was transitioned to dual antiplatelet therapy (dapt).Clopidogrel was discontinued on (b)(6) 2021, and patient continued asa 81mg daily.On (b)(6) 2023, the patient was evaluated for right sided weakness and diagnosed with stroke (lacunar infarct) on (b)(6) 2023.No tee was completed at this time.The patient was seen by neurology who felt that it was unlikely cardioembolic.Echocardiogram performed on (b)(6) 2025 made no mention of the device or problems seen on the device.On (b)(6) 2026, the patient presented to the emergency room for evaluation of shortness of breath and a cough.Computed tomography angiography (cta) of pulmonary arteries was completed to rule out pericardial effusion.No effusion was present, but there was suspicious dense tissue around the closure device.On (b)(6) 2025, echocardiography was completed as well as a transesophageal echocardiography (tee) and the pre-existing small pfo with intermittent bidirectional shunting was noted, along with a large mobile echo dense mass covering the entire atrial surface of the closure device.An infectious disease workup is ongoing; however, there is low suspicion the mass is vegetation/endocarditis at this time.The patient was placed on systemic anticoagulation for 4 to 6 weeks with repeat imaging (ct laa +/- tee).

• Brand Name: WATCHMAN
• 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: 24393314
• Report Number: 2124215-2026-09393
• Device Sequence Number: 10257900
• Product Code: NGV
• UDI-Device Identifier: 08714729838234
• UDI-Public: (01)08714729838234(17)230323(10)25393640
• Combination Product (Y/N): N
• Initial Reporter State: NE
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2020
• 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): 04/16/2026

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 Expiration Date: 03/23/2023
• Device Model Number: M635WU24060
• Device Catalogue Number: M635WU24060
• Device Lot Number: 0025393640
• 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: 02/11/2026
• Supplement Date Received by Manufacturer: 04/14/2026
• Initial Report FDA Received Date: 02/19/2026
• Supplement Report FDA Received Date: 04/16/2026
• Date Device Manufactured: 03/23/2020
• 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; Hospitalization
• Patient Age: 79 YR
• Patient Sex: Female