WATCHMAN FLXRecalls & reported problems across all models

We found 5 models of WATCHMAN FLX by Boston Scientific Corporation in the FDA's device registry (GUDID). Together they are named in 2,280 adverse event reports in the FDA's MAUDE database, received between Sep 14, 2020 and Sep 30, 2026 — classified as 153 deaths, 2,031 injuries, 96 malfunctions.

The most frequently reported specific device problem is “Migration” (212 reports).

Reports come from manufacturers, hospitals and patients and are not verified by the FDA. A report does not prove the device caused the event. Widely used products collect more reports, so totals can't be used to compare products or estimate failure rates. Only reports that name a model's exact device identifier are counted. What reports can and can't tell you · How this data works

Most reported WATCHMAN FLX problems

WATCHMAN FLX models

5 models, most reported first. Each model has its own page with its reports, recalls and device details.

• WATCHMAN FLX™ M635WU50270

  System, appendage closure, left atrial
  43 deaths731 reports
• WATCHMAN FLX™ M635WU50240

  System, appendage closure, left atrial
  51 deaths606 reports
• WATCHMAN FLX™ M635WU50310

  System, appendage closure, left atrial
  29 deaths458 reports
• WATCHMAN FLX™ M635WU50200

  System, appendage closure, left atrial
  18 deaths254 reports
• WATCHMAN FLX™ M635WU50350

  System, appendage closure, left atrial
  12 deaths231 reports

Recent WATCHMAN FLX adverse event reports

The 15 most recent reports across all models, in the reporter's own words as published by the FDA.

• DeathSep 30, 2026Device Dislodged or Dislocated

  REPORTED VIA LITERATURE ARTICLEIt was reported that death occurred.A 67-year-old man underwent successful transfemoral left atrial appendage occlusion (LAAO) with a 31mm WATCHMAN FLX Closure Device with transesophageal echocardiography (TEE) guidance. Multiple angles were used to evaluate the left atrial appendage (LAA) dimensions, with the widest ostium measured at 22 mm. The implant satisfied manufacturer Position, Anchor, Size, and Seal (PASS) criteria. Immediate post implant TEE confirmed appropriate closure device position, stable anchoring, adequate seal, and closure device compression of 19 to 29 percent with no peri device leak on color Doppler assessment. No procedural complications occurred, and the patient was observed overnight, as per institutional protocol. The patient was discharged on dual antiplatelet therapy and instructed to avoid strenuous activity for two (2) weeks. Eighteen days later, while shoveling snow, the patient developed sudden-onset chest and back pain followed by bilateral lower extremity paralysis. Computed tomography (CT) revealed complete mid abdominal aortic occlusion from embolization of the LAAO closure device. Using a non-Boston Scientific (BS

  Patient problems: Abdominal Pain; Back pain; Chest Pain; Dizziness; Encephalopathy; Hematoma; High Blood Pressure/ Hypertension; Ischemia; Low Blood Pressure/ Hypotension; Mitral Valve Insufficiency/ Regurgitation; Muscle Weakness/Atrophy; Numbness; Paralysis; Renal Failure; Spinal Cord Injury; Thrombosis/Thrombus

  MAUDE report 50951585 ↗
• DeathSep 29, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA CLINICAL STUDY.It was reported that death occurred.A left atrial appendage (LAA) closure procedure was performed, and a 27mm WATCHMAN FLX Closure Device was implanted on (b)(6) 2021. The patient was discharged. On (b)(6) 2026, the patient passed away due to ongoing issues with malignancy. Per investigator, the causality to the study device is noted as not related. However, per sponsor, the causality of the study device has been assessed as possible as per the conventions. It was further reported that the cause of death is unknown.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50932951 ↗
• InjurySep 29, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Muscle Weakness/Atrophy; Speech Disorder; Stroke/CVA; Unspecified Mental, Emotional or Behavioral Problem

  MAUDE report 50932546 ↗
• InjurySep 21, 2026Migration

  It was reported that thrombosis and device migration occurred.The patient previously underwent a left atrial appendage (LAA) closure procedure in 2023, and a 27mm WATCHMAN FLX Closure Device was implanted.Approximately two years post implant, the patient was scheduled to undergo an ablation procedure. Prior to the procedure, thrombus was identified within the LAA and the ablation was cancelled. The patient was also informed that the Closure Device had shifted distally within the appendage.The patient was subsequently treated with anticoagulation and was advised that long-term blood thinner therapy would be required. At the time of reporting, the thrombus had resolved.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50843400 ↗
• InjurySep 17, 2026Failure to Seal

  It was reported that a stroke occurred.A left atrial appendage closure (LAAC) procedure was performed, and a 20mm WATCHMAN FLX LAA Closure Device was implanted on (b)(6) 2024. The patient was discharged on a regimen of Aspirin and 75mg of Plavix. Computed tomography angiography (CTA) was completed at the routine 45 day follow up. A 4mm leak was noted. Plavix was discontinued. The patient had magnetic resonance imaging (MRI) done on the brain on (b)(6) 2026 and was diagnosed with a stroke. The patient was not taking any antithrombotic medication at the time of the stroke.

  Patient problems: Stroke/CVA

  MAUDE report 50802942 ↗
• InjurySep 15, 2026Adverse Event Without Identified Device or Use Problem; Failure to Seal

  Patient problems: Fall; Stroke/CVA

  MAUDE report 50780271 ↗
• InjurySep 11, 2026Adverse Event Without Identified Device or Use Problem

  Reported via Clinical StudyIt was reported that the patient experienced a transient ischemic attack.A left atrial appendage (LAA) closure procedure was being performed. A WATCHMAN Access System (WAS) and a 24mm WATCHMAN FLX LAA Closure Device & Delivery System (WDS) were selected to be used. The procedure was successfully completed with the closure device implanted in the LAA of the patient with a complete LAA seal and deployed device diameter of 18.6 mm. There were no patient complications that were reported to have occurred. The patient was discharged on aspirin (81mg/day) and ticagrelor (180mg/day).Five (5) years post procedure, the patient presented to an outside hospital with a complaint of left-sided extremity weakness. The patient was hospitalized for further evaluation. X-ray and labs were performed in response to the event. At the time of the event, the patient was on aspirin (81 mg/day). The patient was diagnosed with experiencing a transient ischemic attack. The event is ongoing. There have been no other complications that have been reported to have occurred.

  Patient problems: Muscle Weakness/Atrophy; No Clinical Signs, Symptoms or Conditions; Transient Ischemic Attack

  MAUDE report 50735306 ↗
• InjurySep 10, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Chest Pain; Thrombosis/Thrombus

  MAUDE report 50722735 ↗
• InjurySep 4, 2026Nonstandard Device; Failure to Seal

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50600711 ↗
• InjurySep 1, 2026Failure to Seal

  REPORTED VIA CLINICAL STUDY.It was reported an implant did not seal.A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX LAA Closure Device was implanted on (b)(6) 2022. The patient was discharged. On June 9, 2026, during the patient follow-up surveillance computed tomography angiography (CTA) for dilated aortic root imaging, a 5.5mm peri device leak was suspected. Follow-up Transesophageal Echocardiography (TEE) imaging confirmed a 3mm leak. As a result, the patient remains on their oral anticoagulant medication.

  Patient problems: Fall; No Clinical Signs, Symptoms or Conditions; Transient Ischemic Attack

  MAUDE report 50548861 ↗
• InjuryAug 18, 2026Adverse Event Without Identified Device or Use Problem

  It was reported thrombosis occurred. A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Closure Device was implanted on (b)(6) 2024. The patient was subsequently discharged. A physician later reported to a Boston Scientific (BSC) Clinical Specialist that the patient presented to a different hospital from the implanting facility on (b)(6) 2026, with an altered mental status. A transesophageal echocardiogram (TEE) was performed and revealed the presence of a thrombus on the WATCHMAN FLX Closure Device. The patient was placed on a stroke protocol for further evaluation and management. The patient underwent a computed tomography angiography (CTA) of the head and neck, magnetic resonance imaging (MRI) of the brain, and a transesophageal echocardiogram (TEE) as part of the stroke evaluation. Findings were consistent with a Percheron artery stroke and hypertensive urgency. An MRI of the brain and brainstem without contrast performed on (b)(6) 2026, showed bilateral restricted diffusion within the thalami. The MRI also noted prior infarctions involving the cerebellum and both cerebral hemispheres. The patient had not been compliant with keeping follow up

  Patient problems: Cognitive Changes; High Blood Pressure/ Hypertension; Stroke/CVA; Thrombosis/Thrombus

  MAUDE report 50310189 ↗
• InjuryAug 13, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA CLINICAL STUDY. It was reported that a stroke occurred. A left atrial appendage closure (LAAC) procedure was performed. A 24mm WATCHMAN FLX LAA Closure was implanted on (b)(6) 2022. On (b)(6) 2026, the patient presented acutely confused. The physician initially considered the symptoms related to a recent extubation, medical comorbidities and likely sundowning. The symptoms continued the next day, so computed tomography (CT) imaging of the patient head was ordered. The CT showed concerns for right posterior cerebral artery (PCA) infarct. The patient was experiencing hallucinations, which worsened in the evening hours. The National Institutes of Health (NIH) stroke score was 4. The patient was not given Tenecteplase (TNK) but was on Bival. There was suspicion of embolic etiology due to Impella placement. Computed tomography angiography (CTA) of the head and neck was negative on (b)(6) 2026. By (b)(6) 2026, the patient symptoms improved and no additional stroke work up was completed.

  Patient problems: Cognitive Changes; Confusion/ Disorientation; Stroke/CVA

  MAUDE report 50244655 ↗
• DeathAug 13, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA CLINICAL STUDY:It was reported that patient death occurred. A left atrial appendage closure (LAAC) procedure was performed and a 31mm WATCHMAN FLX LAA Closure Device and Delivery System (WDS) was successfully implanted on (b)(6) 2022. The patient is reported to have passed away at home on (b)(6) 2026. A review of the obituary provided no additional information and no official cause of death was provided.It was further reported that the physician has assessed the relationship of the death and the implant as not related.It was further reported that the patient experienced cardiac arrest due to worsening acute kidney failure.It was further reported that as per the Sponsor, the causality of the study device WATCHMAN FLX LAA Closure Device has been downgraded to Not related as per the conventions. The complaint has been withdrawn.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50240105 ↗
• DeathAug 6, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA CLINICAL STUDY:It was reported that death occurred.A left atrial appendage (LAA) closure procedure was performed. The patient was on apixaban (10 mg/day) therapy prior to enrollment into the study. On (b)(6) 2023 implant transesophageal echocardiography (TEE) assessment revealed 2 LAA lobes with an ostium diameter of 23.3 mm and length of 39.1mm. On (b)(6) 2023, the patient got crossover and successful placement of 27mm WATCHMAN FLX device with complete LAA seal and deployed device diameter of 22.7mm. Prior to the implant procedure aspirin was administered. The patient was discharged on the same day on apixaban (10 mg/day) and aspirin (81 mg/day). On (b)(6) 2026,1039 days post index procedure, the patient passed away and the cause of death is unknown. At the time of death, the patient was not on any anticoagulant/ antiplatelet medication. No action taken and diagnostics was performed in response to the event. No further information available at this time.It was further reported that the sponsor device causality assessment is not related, the complaint will be close as not a complaint.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50165898 ↗
• InjuryJul 29, 2026Migration

  It was reported device migration occurred. A left atrial appendage (LAA) closure procedure was performed, and a 27mm WATCHMAN FLX Closure Device was implanted on (b)(6)-2023. The patient was discharged. At a routine follow up, it was found that the Closure Device had shifted very proximal in the appendage and was only attached by a few of the bottom row anchors. The physician removed the Closure Device using a percutaneous snare and implanted a new 27mm WATCHMAN FLX Pro Closure Device without complications.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50074526 ↗

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