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

Model Number	M635WU60400
Medical Device Problem Code	Failure to Seal (4070)
Health Effect - Clinical Code	Pain (1994)
Date of Event	02/04/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
Reported via patient call center.It was reported that a device leak occurred.A left atrial appendage (laa) closure procedure was performed, and a 40mm watchman flx pro closure device was implanted on (b)(6) 2025.Prior to release of the closure device, the position, anchor, size and seal (pass) criteria was met with a note of a 1.5mm leak on the seal.There was no noted shift but a possible missed posterior lobe.The patient had very difficult anatomy with challenging imaging with a large anterior chicken wing with heavy pectinate.The baseline ostium measured 31mm wide but upon doing an angiogram it was noted it appeared much wider and it was realized there was an entire lobe missing that the physician was having a difficult time imaging on tee.When re-measuring the physician realized the ostium was closer to 34mm wide.A 40mm closure device was used and it appeared to be sitting at the ostium with a 1.5mm leak.It was determined that this was a suitable position.Tee imaging was extremely challenging throughout the case and relied on fluoroscopy imaging for a majority of the procedure.The patient was discharged.The patient stated that during the six (6) weeks follow up computed tomography (ct) scan, a 10mm leak was noted around the closure device.The patient went back to the hospital on (b)(6) 2026 and a transesophageal echocardiography (tee) was performed, the patient stated that it is still bleeding one centimeter.The patient also stated that both legs were sore and was unable to walk since the procedure was performed.The patient continues to take warfarin and has continued to have problems with the legs being sore.
Additional Manufacturer Narrative
B5 describe event or problem: updated with additional information received.
Event or Problem Description
Reported via patient call center.It was reported that a device leak occurred.A left atrial appendage (laa) closure procedure was performed, and a 40mm watchman flx pro closure device was implanted on (b)(6) 2025.Prior to release of the closure device, the position, anchor, size and seal (pass) criteria was met with a note of a 1.5mm leak on the seal.There was no noted shift but a possible missed posterior lobe.The patient had very difficult anatomy with challenging imaging with a large anterior chicken wing with heavy pectinate.The baseline ostium measured 31mm wide but upon doing an angiogram it was noted it appeared much wider and it was realized there was an entire lobe missing that the physician was having a difficult time imaging on tee.When re-measuring the physician realized the ostium was closer to 34mm wide.A 40mm closure device was used and it appeared to be sitting at the ostium with a 1.5mm leak.It was determined that this was a suitable position.Tee imaging was extremely challenging throughout the case and relied on fluoroscopy imaging for a majority of the procedure.The patient was discharged.The patient stated that during the six (6) weeks follow up computed tomography (ct) scan, a 10mm leak was noted around the closure device.The patient went back to the hospital on (b)(6) 2026 and a transesophageal echocardiography (tee) was performed, the patient stated that it is still bleeding one centimeter.The patient also stated that both legs were sore and was unable to walk since the procedure was performed.The patient continues to take warfarin and has continued to have problems with the legs being sore.It was further reported that the leg pain was believed to be caused by the closure device used perclose, only the right groin was accessed and there were no issues with the groin access reported.A follow-up phone call was performed at one (1) week, and no further issues were reported.
Additional Manufacturer Narrative
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 a review was completed of the device history records (dhr) for the watchman flx? pro, part # (b)(4) batch # 0035588459.The device was processed through all normal operational conditions and passed all acceptance activities.The dhr review did not identify any deviations or non-conformances that could have contributed to the event.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 implant did not seal and pain (medication and imaging required).Risk review a risk review was completed and confirmed that the events of implant did not seal and pain 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.
Event or Problem Description
Reported via patient call center it was reported that a device leak occurred.A left atrial appendage (laa) closure procedure was performed, and a 40mm watchman flx pro closure device was implanted on (b)(6) 2025.Prior to release of the closure device, the position, anchor, size and seal (pass) criteria was met with a note of a 1.5mm leak on the seal.There was no noted shift but a possible missed posterior lobe.The patient had very difficult anatomy with challenging imaging with a large anterior chicken wing with heavy pectinate.The baseline ostium measured 31mm wide but upon doing an angiogram it was noted it appeared much wider and it was realized there was an entire lobe missing that the physician was having a difficult time imaging on tee.When re-measuring the physician realized the ostium was closer to 34mm wide.A 40mm closure device was used and it appeared to be sitting at the ostium with a 1.5mm leak.It was determined that this was a suitable position.Tee imaging was extremely challenging throughout the case and relied on fluoroscopy imaging for a majority of the procedure.The patient was discharged.The patient stated that during the six (6) weeks follow up computed tomography (ct) scan, a 10mm leak was noted around the closure device.The patient went back to the hospital on (b)(6) 2026 and a transesophageal echocardiography (tee) was performed, the patient stated that it is still bleeding one centimeter.The patient also stated that both legs were sore and was unable to walk since the procedure was performed.The patient continues to take warfarin and has continued to have problems with the legs being sore.It was further reported that the leg pain was believed to be caused by the closure device used perclose, only the right groin was accessed and there were no issues with the groin access reported.A follow-up phone call was performed at one (1) week, and no further issues were reported.

• 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: 24391915
• Report Number: 2124215-2026-09370
• Device Sequence Number: 18797104
• Product Code: NGV
• UDI-Device Identifier: 00191506004637
• UDI-Public: (01)00191506004637(17)280109(10)35588459
• Combination Product (Y/N): N
• Initial Reporter State: IA
• 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: Consumer,Health Professional,Company Representative
• Initial Reporter Occupation: Other
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 04/16/2026

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: M635WU60400
• Device Catalogue Number: M635WU60400
• Device Lot Number: 0035588459
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 02/06/2026
• Supplement Date Received by Manufacturer: 03/24/2026; 04/13/2026
• Initial Report FDA Received Date: 02/19/2026
• Supplement Report FDA Received Date: 03/26/2026; 04/16/2026
• Date Device Manufactured: 01/09/2025
• 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 Age: 72 YR
• Patient Sex: Male