MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION WATCHMAN FLX? PRO; SYSTEM, APPENDAGE CLOSURE, LEFT ATRIAL

Model Number	M635WU60200
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Codes	Chest Pain (1776); Dyspnea (1816); Paralysis (1997); Pericardial Effusion (3271); Pericarditis (4448)
Date of Event	01/27/2026
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Detailed product information was not provided to bsc.Because the product is unknown at this time, we are unable to provide the complete udi and other product specific information.If additional details become available, a supplemental report will be submitted.
Event or Problem Description
It was reported that pericardial effusion, pericarditis and hemidiaphragm paralysis occurred.A left atrial appendage (laa) closure procedure was performed, and a 20mm watchman flx pro closure device was implanted on (b)(6) 2025.Post procedure the patient developed some chest pain.At first follow up after discharge, the patient was determined to have pericarditis, and some fluid was noted in the pericardial space.The fluid was not drained, and the pericarditis was treated with medication, but the patient did continue to experience pain and dyspnea during the treatment.In the time following the closure device implant a non-boston scientific (bsc) lynx device was implanted in the distal esophagus.On (b)(6) 2026, the patient reported for a follow up and the patient has left hemidiaphragm paralysis.The physician reached out to share the complaint and asked if this is something that has been reported after a closure device procedure.The physician was also questioning if it is a consequence of the pericarditis.The physician followed up a few hours later to report that a pulmonologist reported the left hemidiaphragm was mildly elevated pre closure device procedure.The non-bsc lynx device has also been reported as a potential cause for phrenic nerve injury.
Event or Problem Description
It was reported that pericardial effusion, pericarditis and hemidiaphragm paralysis occurred.A left atrial appendage (laa) closure procedure was performed, and a 20mm watchman flx pro closure device was implanted on (b)(6) 2025.Post procedure the patient developed some chest pain.At first follow up after discharge, the patient was determined to have pericarditis, and some fluid was noted in the pericardial space.The fluid was not drained, and the pericarditis was treated with medication, but the patient did continue to experience pain and dyspnea during the treatment.In the time following the closure device implant a non-boston scientific (bsc) lynx device was implanted in the distal esophagus.On (b)(6) 2026, the patient reported for a follow up and the patient has left hemidiaphragm paralysis.The physician reached out to share the complaint and asked if this is something that has been reported after a closure device procedure.The physician was also questioning if it is a consequence of the pericarditis.The physician followed up a few hours later to report that a pulmonologist reported the left hemidiaphragm was mildly elevated pre closure device procedure.The non-bsc lynx device has also been reported as a potential cause for phrenic nerve injury.
Additional Manufacturer Narrative
Detailed product information was not provided to bsc.Because the product is unknown at this time, we are unable to provide the complete udi and other product specific information.If additional details become available, a supplemental report will be submitted.With all the available information, boston scientific (bsc) concludes: device technical analysis: the watchman flx? pro remains implanted; therefore, returned device analysis could not be completed.Device history record review: the batch number for the watchman flx? pro, part # m635wu60200 was not provided.A ship history was performed to identify the last three most recently shipped batches to the customer and no batches were identified.Boston scientific's manufacturing processes include extensive inspections to ensure that all finished devices meet specification, and there is no evidence that this product did not meet specification prior to distribution.Labeling review: there was no evidence to suggest that the device was used in a manner inconsistent with the labeling.Watchman flx? pro instructions for use (ifu) lists potential complications, risks and adverse events that may be associated with the use of this device which include pericardial effusion and chest pain (pericarditis, dyspnea, paralysis) (medication required, hospitalization).Risk review: a risk review was completed and confirmed that the events of pericardial effusion and chest pain (pericarditis, dyspnea, paralysis) were defined in the risk documentation.These event types have been accounted for during product risk analysis to support acceptable risk benefit for the product.Investigation conclusion: based on a thorough review of the reported complaint, boston scientific has assigned an investigation conclusion code of known inherent risk of device.

• 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 ; EI
• Manufacturer Contact: rachel shields ; 4100 hamline ave n; arden hills, MN 55112 ; 6512422111
• MDR Report Key: 24292512
• Report Number: 2124215-2026-07128
• Device Sequence Number: 10165692
• Product Code: NGV
• UDI-Device Identifier: 00191506004583
• UDI-Public: (01)00191506004583
• Combination Product (Y/N): N
• Initial Reporter State: CO
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 03/24/2026

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: M635WU60200
• Device Catalogue Number: M635WU60200
• 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: 01/27/2026
• Supplement Date Received by Manufacturer: 03/23/2026
• Initial Report FDA Received Date: 02/09/2026
• Supplement Report FDA Received Date: 03/24/2026
• 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: Other
• Patient Sex: Female
• Patient Race: White