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

Model Number	M635WU60240
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Pericardial Effusion (3271)
Date of Event	09/21/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that pericardial effusion occurred.A left atrial appendage closure (laac) procedure was being performed.A watchman trusteer access system (was) and a 24mm watchman flx pro laa closure device and delivery system (wds) were selected for use.During the transeptal puncture (tsp) the landing zone was low and posterior.The physician did not cross at that position.The physician then came to a mid/mid location and crossed the septum there.The pigtail wire did not advance in its normal shape.The wire was retracted back into the dilator, and the wire was readvanced into the la where it then took its normal curl.The trusteer sheath was then advanced into the la and an angiography was completed to compare preprocedural measurements.The 24mm device was prepped and advanced in the wds.The physician deployed the device, but it landed proximally.A full recapture was completed.Upon repositioning the device, fluid was noted behind the appendage.Transesophageal echocardiography (tee) was used to sweep for effusion.An effusion appeared close to the right side of the heart and was dark in appearance.The device was fully recaptured.Another angiography was completed of the laa and no perforation was observed.The laac procedure was discontinued.The wds was withdrawn and a pericardiocentesis was performed.Around 300cc of fluid was removed.The patient was admitted to the intensive care unit (icu) and was discharged the next day.

• 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: 50931466
• Report Number: 2124215-2026-51631
• Device Sequence Number: 9597848
• Product Code: NGV
• UDI-Device Identifier: 00191506004590
• Combination Product (Y/N): N
• Initial Reporter State: FL
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• 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): 09/29/2026

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: M635WU60240
• Device Catalogue Number: M635WU60240
• Device Lot Number: 0038922574
• 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: 09/21/2026
• Initial Report FDA Received Date: 09/29/2026
• Date Device Manufactured: 03/25/2026
• 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