MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION WATCHMAN FLX? Pro; system, appendage closure, left atrial

Model Number	M635WU60350
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	08/24/2026
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 baseline pericardial effusion prior to the procedure.A watchman access system (was) and a 35mm watchman flx pro laa closure device and delivery system (wds) was selected for use.The transseptal puncture (tsp) site was identified on intracardiac echocardiography (ice) as being in a mid and slightly posterior location.The physician encountered difficulty advancing the ice catheter from the right side to the left side of the heart.As a result, the ice catheter was positioned on the right side of the heart, and the procedure was continued under transesophageal echocardiography (tee) guidance.The left atrial appendage (laa) was engaged using a pigtail catheter, and the 35mm wds was advanced, deployed, and released without any recaptures.Prior to removal of the tee probe, an effusion sweep was performed.The trace pericardial effusion was observed and considered unchanged from baseline.After the procedure was completed and the physician had left the sterile field and entered the control room, the anesthesiologist noted a decrease in the patient's blood pressure and requested the physician return to the procedure room.The physician obtained a subcostal transthoracic echocardiographic image, which showed that the pericardial effusion had become circumferential and appeared larger in size.The tee probe was reinserted, and pericardiocentesis was performed removing approximately 900ml of blood.Following the intervention, the patient remained intubated and was transferred to the intensive care unit (icu) for recovery.The patient remained in stable condition and is being discharged home.

• 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 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: 50601424
• Report Number: 2124215-2026-45869
• Device Sequence Number: 16094576
• Product Code: NGV
• UDI-Device Identifier: 00191506004620
• UDI-Public: (01)00191506004620(17)290226(10)38708183
• Combination Product (Y/N): N
• Initial Reporter State: IL
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2026
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 10/01/2026

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: M635WU60350
• Device Catalogue Number: M635WU60350
• Device Lot Number: 0038708183
• 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: 09/30/2026
• Initial Report FDA Received Date: 09/04/2026
• Supplement Report FDA Received Date: 10/01/2026
• Date Device Manufactured: 02/27/2026
• 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: Required Intervention; Hospitalization
• Patient Age: 85 YR
• Patient Sex: Male