MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION WATCHMAN TruSteer? Access System; Catheter, percutaneous

Model Number	M635TU90050
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Codes	Low Blood Pressure/ Hypotension (1914); Pericardial Effusion (3271)
Date of Event	08/18/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported a pericardial effusion occurred.A left atrial appendage closure (laac) procedure was being performed.It was noted that the patient had a trace (0.8mm) baseline pericardial effusion prior to the procedure at the right ventricle.A watchman trusteer access system (was) and a 24mm watchman flx pro laa closure device and delivery system (wds) was selected for use.Heparin was administered to achieve an activated clotting time (act) greater than 300 seconds.The was sheath was introduced, and transseptal puncture (tsp) was successfully performed.A guidewire was advanced into the left atrium (la), and the sheath was advanced across the septum into the la.A pigtail catheter was inserted, and an angiogram of the left atrial appendage was performed.The 24mm wds was prepared for deployment.The pigtail catheter was removed, and the wds was advanced through the was sheath.The closure device was unsheathed to flex ball, and an angiogram was obtained at that time.During assessment, an increase in the size of the pericardial effusion was observed.A transesophageal echocardiography (tee) sweep was performed, which confirmed that the effusion had enlarged from its baseline measurement of 0.8mm to approximately 1.4mm.The anesthesiologist noted they had been administering medications (neo-synephrine) to maintain the patient's blood pressure; however, the implanting physician was not aware of these interventions at the time.Heparin was reversed, and pericardiocentesis was performed.A total of 210ml of pericardial fluid was removed and auto-transfused back to the patient.The patient remained stable, and the pericardial effusion decreased back to its baseline size.As a precautionary measure, a pericardial drainage catheter was left in place, and the patient was transferred to the intensive care unit (icu).There were no further complications, and the patient was discharged the next day.

• Brand Name: WATCHMAN TruSteer? Access System
• Common Device Name: Catheter, percutaneous
• 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: 50420744
• Report Number: 2124215-2026-45431
• Device Sequence Number: 21360009
• Product Code: DQY
• UDI-Device Identifier: 00191506022310
• UDI-Public: (01)00191506022310(17)280413(10)39083690
• Combination Product (Y/N): N
• Initial Reporter State: IN
• Initial Reporter Country: US
• PMA/510(K) Number: K240018
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,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?: No
• Operator of Device: Health Professional
• Device Model Number: M635TU90050
• Device Catalogue Number: M635TU90050
• Device Lot Number: 0039083690
• 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: 09/23/2026
• Initial Report FDA Received Date: 08/24/2026
• Supplement Report FDA Received Date: 09/24/2026
• Date Device Manufactured: 04/14/2026
• 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: Hospitalization; Required Intervention
• Patient Age: 89 YR
• Patient Sex: Female