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

Model Number	M635WU60270
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Pericardial Effusion (3271)
Date of Event	09/14/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that pericardial effusion occurred.A left atrial appendage closure procedure was being performed.Transseptal puncture was performed with a versacross connect and a watchman fxd double curve access system.Difficulty was noted in obtaining transseptal puncture.A 27mm watchman flx pro closure device was implanted.Post-implant, a pericardial effusion was noted around the ventricle during the final sweep.Additional protamine was administered and the patient was monitored on the table with physician present.The patient was still intubated, and transesophageal echocardiography was still in place.Transthoracic echocardiogram was performed as well.After some time, the physician determined the pericardial effusion was not large enough for additional treatment and the patient was sent to the recovery unit.A few hours later, a pericardiocentesis was performed.A drain was placed and the patient was kept overnight for observation.The next day, the patient was confirmed to be doing well and was discharged.The physician believed the pericardial effusion had been caused during transseptal puncture.

• 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: 50810128
• Report Number: 2124215-2026-49811
• Device Sequence Number: 10581086
• Product Code: NGV
• UDI-Device Identifier: 00191506004606
• UDI-Public: (01)00191506004606(17)290624(10)39671656
• Combination Product (Y/N): N
• Initial Reporter State: AR
• 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
• Report Date (Section B): 09/17/2026

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: M635WU60270
• Device Catalogue Number: M635WU60270
• Device Lot Number: 0039671656
• 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: 09/14/2026
• Initial Report FDA Received Date: 09/17/2026
• Date Device Manufactured: 06/25/2026
• 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: 81 YR
• Patient Sex: Female