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

Model Number	M635TU90050
Medical Device Problem Code	Air/Gas in Device (4062)
Health Effect - Clinical Code	Thrombosis/Thrombus (4440)
Date of Event	09/10/2026
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 under transesophageal echocardiography (tee) guidance.Anticoagulation had been held for two days prior to the procedure.Following right femoral venous access and an 18 french non-boston scientific (bsc) sheath insertion, a watchman trusteer access system (was) and versacross system were advanced for transseptal puncture.Heparin was ordered prior to transseptal access; however, the non-bsc sheath stopcock was noted to be closed to the patient, and the initial bolus was not delivered.Heparin was subsequently administered within approximately one minute after transseptal puncture.The activated clotting time (act) was 213 seconds.A diagnostic pigtail catheter was advanced into the laa and the was was positioned at the ostium.Air was then noted within the manifold and subsequently visualized within the was under fluoroscopy.The physician immediately stopped the procedure, aspirated the system, and withdrew the was to the right side of the heart.Tee then identified thrombus attached near the transseptal puncture site and extending into the left atrium with movement within the chamber.The procedure was aborted.The patient remained intubated, anticoagulation was initiated, and the patient was transferred to the intensive care (icu) for monitoring.The patient remained hospitalized at the time of reporting.

• 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: 50789763
• Report Number: 2124215-2026-49401
• Device Sequence Number: 13142802
• Product Code: DQY
• UDI-Device Identifier: 00191506022310
• Combination Product (Y/N): N
• Initial Reporter State: GA
• 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
• Report Date (Section B): 09/16/2026

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?: Yes
• Operator of Device: Health Professional
• Device Model Number: M635TU90050
• Device Catalogue Number: M635TU90050
• Device Lot Number: 0038942930
• 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: 09/10/2026
• Initial Report FDA Received Date: 09/16/2026
• Date Device Manufactured: 03/27/2026
• 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: 86 YR
• Patient Sex: Female