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	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	10/26/2025
Type of Reportable Event	Serious Injury
Event or Problem Description
Reported via literature article.It was reported that a device leak occurred.A left atrial appendage (laac) closure procedure was performed in 234 patients using previous-generation watchman flx (wmf) between may-21 and 14-feb-24, and in 134 patients using wmf-pro between 21-feb-24, and mar-2025.The background, procedural and short-term outcomes of consecutive 46 patients who underwent laac using large wmf-pro devices (35mm) and compared 35mm (33) with 40mm (13) was evaluated.This study was approved by the kurashiki central hospital irb and adhered to the declaration of helsinki.Device position, anchoring, seal, size, and release were confirmed by transesophageal echocardiography (tee) and fluoroscopy.Successful laac was defined as correct device placement with residual flow less than or equal to 5mm.Successful laac was achieved in 97 percent of wmf cases and 100 percent of wmf-pro cases.Follow-up tee or cardiac contrast (cct) was performed three (3) months post procedure.The imaging follow-up at 3 months were performed.There was no difference in the peri device leak (pdl) or patency at three (3) months were observed between the two groups, and no device related thrombus (drt) at 3 months was diagnosed in either group.However, pdl or gap was more frequently diagnosed in the wmf-pro 40mm group and significant pdl or gap greater than three to five millimeters was significantly more frequently diagnosed in this group.Significant pdls at 3 months persisted on the posterior-side.Among patients with significant pdl at 3 months, cases 1 and 3 had prominent pectinate muscles.No ischemic stroke events occurred in either group at 3 months.Previous study reported change in significant pdl greater than three to five millimeters between 45 days and one (1) year increased in one patient, unchanged in 42, and improved in 81 patients.In this report, two out of three pdls in the 40mm group were apparently associated with large pectinate muscles rather than with large ostial size itself.Therefore, such pdls are not logically linked to the larger device diameter.The transition from wmf to wmf-pro showed a similar proportion of large device usage.The 40mm device allowed closure of larger laas and demonstrated comparable procedural safety.However, use of 40mm device is technically more challenging and may be associated with residual pdl.
Additional Manufacturer Narrative
B3: estimated as 26/10/25 as the published date for the article is noted as october 26, 2025.D4 unique identifier (udi) #: detailed product information was not provided to bsc.Based on the nature of the information provided to bsc, it is not possible to perform a good faith effort to obtain the information.Because the product is unknown at this time, we are unable to provide the complete unique identifier (udi) # and other product specific information.If additional details become available, a supplemental report will be submitted.Literature citation: r.Chatani., h.Harata., m.Fujita., nishiura, n., mushiake, k., ono, s., tasaka, h., maruo, t., kadota, k., kubo, s.(2025).Potential of a novel large left atrial appendage closure device: short-term outcomes of the watchman flx pro 40-mm versus 35-mm.Catheterization and cardiovascular interventions 106 (2025): 3959-3962.Https://doi.Org/10.1002/ccd.70282.

• 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: 23877063
• Report Number: 2124215-2025-92605
• Device Sequence Number: 20026518
• Product Code: NGV
• UDI-Device Identifier: 00191506004637
• UDI-Public: (01)00191506004637
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Other,Foreign,Literature,Health Professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial
• Report Date (Section B): 12/23/2025

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
• 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: 12/07/2025
• Initial Report FDA Received Date: 12/23/2025
• 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 Sex: Unknown