MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION WATCHMAN FXD Curve? Access System; system, appendage closure, left atrial

Model Number	M635TU80020
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	07/17/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that thrombosis occurred.A left atrial appendage (laa) closure procedure was being performed, and a watchman fxd curve access system (was) was selected to be used.During the procedure, after confirming spontaneous echo contrast (sec) positivity, the physician recommended maintaining the activated clotting time (act) above 300 seconds, which is higher than the standard target.The right femoral puncture was performed, and 5,000 units of heparin was administered, and the act was 377 seconds.After confirming pigtail movement from the pulmonary vein (pv) to the laa, echocardiography revealed findings suspicious for a string-like thrombus attached to the was sheath.The procedure was interrupted and the act was re-measured.The echocardiographer suggested to the physician to administer dobutamine in order to initiate washout as the spontaneous echo contrast was severe.The suspected string-like thrombus was no longer visible and dobutamine was administered.The act was 273 seconds, and 2,000 units of heparin were administered.The spontaneous echo contrast gradually resolved.The previously observed thrombus could no longer be identified anywhere on echocardiography.The physician determined that it was safe to resume the procedure, so it was continued and a 20mm closure device was placed.The closure device was released, and the was sheath was removed.The patient regained consciousness and was extubated.No changes were noted in the neurological examination.

• Brand Name: WATCHMAN FXD Curve? Access System
• 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: 50089824
• Report Number: 2124215-2026-41036
• Device Sequence Number: 13354142
• Product Code: DQY
• UDI-Device Identifier: 00191506013813
• UDI-Public: (01)00191506013813(17)290105(10)38272702
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: K212228
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Other,Foreign,Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 08/25/2026

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: M635TU80020
• Device Catalogue Number: M635TU80020
• Device Lot Number: 0038272702
• 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: 07/17/2026
• Supplement Date Received by Manufacturer: 08/02/2026; Not provided
• Initial Report FDA Received Date: 07/30/2026
• Supplement Report FDA Received Date: 08/04/2026; 09/04/2026
• Date Device Manufactured: 01/06/2026
• 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
• Patient Age: 79 YR
• Patient Sex: Male