WATCHMAN FLX™ Pro M635WU60350Recalls & reported problems

Summary

The FDA's MAUDE database contains 250 adverse event reports that list this exact device (DI 00191506004620), received between Dec 20, 2023 and Sep 30, 2026 — classified as 29 deaths, 212 injuries, 9 malfunctions.

The most frequently reported specific device problem is “Migration” (60 reports).

2 other recalls cover devices cleared under the same FDA submission (P130013); they may or may not involve this specific model.

Reports come from manufacturers, hospitals and patients and are not verified by the FDA. A report does not prove the device caused the event, and counts can't be used to compare devices or estimate failure rates. What reports can and can't tell you · How this data works · Data updated Oct 18, 2026.

Most reported problems

Recent adverse event reports

The 25 most recent of 250 reports, in the reporter's own words as published by the FDA.

• DeathSep 30, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a stroke and patient death occurred. A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted. Immediately following the procedure, the patient exhibited right-sided weakness, inability to awaken, absence of speech attempts, inability to follow commands, and dysconjugate gaze. The patient was subsequently diagnosed with a stroke and was admitted to the hospital. In response to the stroke, thrombectomy was performed in Interventional Radiology to remove the clot and mechanical ventilation were performed. Four days following the index procedure, the patient died. The reported cause of death was thrombosis of the left middle cerebral artery (MCA) with a large left MCA infarct and significant cerebral edema resulting in a 1.8 cm left-to-right midline shift. The physician believed that a combination of preexisting comorbidities and the concomitant procedure led to the stroke.

  Patient problems: Loss of consciousness; Muscle Weakness/Atrophy; Speech Disorder; Stroke/CVA; Thromboembolism; Visual Disturbances

  MAUDE report 50945914 ↗
• InjurySep 28, 2026Migration; Failure to Seal

  It was reported migration and a device leak occurred. A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on(b)(6) 2026. The patient was subsequently discharged. At the routine 45-day follow-up, transesophageal echocardiography (TEE) revealed the device had a 2.9mm leak. A computed tomography (CT) scan was also completed which showed that the Closure Device had shifted and the leak was measured at 3.2mm. The device position was distal and slightly tucked under the anterior ridge with the leak on the inferior/posterior side. There is no intervention planned. The patient remains on oral anticoagulation (OAC) medication.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50915301 ↗
• InjurySep 21, 2026Failure to Seal

  It was reported an implant did not seal. A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was deployed. A 3 mm posterior/lateral peri-device leak at 0 degrees and a 2.5 mm posterior peri-device leak at 135 degrees were considered acceptable, and the device was released. The patient was discharged following the procedure. At a routine follow up, Transesophageal Echocardiography (TEE) was performed, and it was noted the posterior peri-device leak had increased to 3.74 mm. As a result, the patient is unable to discontinue their prescribed blood thinner medication.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50846219 ↗
• DeathSep 18, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that death occurred.This was a concomitant atrial fibrillation ablation procedure with Farapulse, and a left atrial appendage (LAA) closure procedure that was performed, a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. During the procedure heparin was administered. It was reported by the research coordinator that post procedure the patient experienced a stroke, which resulted in death, the patient passed away on (b)(6) 2026. The mechanism of the stroke was hemorrhagic. The research coordinator believed the cause of death on certificate was stroke.It was further reported that the patient had multiple comorbidities including severe right atrium (RA) enlargement and severe left ventricle (LV) dysfunction. The physician believes that these comorbidities along with large transseptal puncture and left atrial intra cardiac echocardiography (ICE) could have contributed to clot formation. The stroke was thrombotic in nature and a thrombectomy was performed on the patient. The thrombus was not cardiac. During the procedure heparin was administered before transseptal, the first activated clotting time (ACT) was five (5) minutes after heparin.

  Patient problems: Facial Paralysis; Stroke/CVA; Thrombosis/Thrombus

  MAUDE report 50825382 ↗
• InjurySep 16, 2026Migration

  It was reported implant movement/shift and stroke occurred. A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2025. The patient was subsequently discharged. In (b)(6) 2026, while traveling in Miami, Florida, the patient presented to an emergency department where it was reported that the patient had experienced a stroke with symptoms of dizziness, aphasia, and right sided weakness while on a flight. A transesophageal echocardiography (TEE) examination was performed and revealed that the Closure Device was positioned outside of the left atrial appendage and appeared to be engaged only with a portion of the coumadin ridge. Additionally, it was noted that there was no evidence of endothelialization. No thrombus was noted on the Closure Device. There was no intervention performed. The imaging confirmed an acute ischemic stroke; left anterior corona radiata with two punctate subacute/late subacute lacunar infarcts. The treating physician at the hospital stated that the patient had undergone a follow-up TEE approximately six months after the implant procedure with the implanting physician and was advised at th

  Patient problems: Dizziness; Muscle Weakness/Atrophy; Speech Disorder; Stroke/CVA

  MAUDE report 50787713 ↗
• InjurySep 15, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that cerebral vascular accident occurred.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. Heparin was administrated after transeptal puncture, and the activated clotting time (ACT) was 385 seconds. During the procedure, the closure device met Position, Anchor, Size and Seal (PASS) criteria. During the post-operative care, the patient had a stroke and ended up having to go to Neurology before being discharged on the same day as implantation. Per the physician, the patient had some residual effects from the stroke. The patient was placed on antithrombotic medication.

  Patient problems: Stroke/CVA

  MAUDE report 50778651 ↗
• InjurySep 15, 2026Adverse Event Without Identified Device or Use Problem; Migration

  It was reported that device shift occurred.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. During the procedure there were no complications, there was only one (1) partial recapture, and the closure device met the Position, Anchor, Size and Seal (PASS) criteria and was released. The patient was discharged. On (b)(6) 2026, the patient had been admitted for blurry vision, and upon further examination a transesophageal echocardiography (TEE) was performed, and the location of the closure device was noted as proximal when compared to the implant images. A computed tomography (CT) scan was requested by the physician. Once the scan is assessed the physician will determine if it needs to be explanted or not.

  Patient problems: Blurred Vision; No Clinical Signs, Symptoms or Conditions

  MAUDE report 50778300 ↗
• InjurySep 15, 2026Device Dislodged or Dislocated

  It was reported that device embolization occurred.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was selected to be used. This was a concomitant procedure. After ablation was completed, the physician began with the closure device procedure. The ablation sheath was exchanged for transeptal. The pigtail catheter was advanced into the LAA and a contrast picture was taken. The left atrium pressure was ten (10). The rhythm at the time of the implant of the closure device was normal sinus. A 35mm closure device was prepped and deployed. Initially the closure device was too proximal and multiple recaptures were performed. After last deployment, the position appears acceptable and the Position, Anchor, Size and Seal (PASS) criteria were met. Post release it was noted a proximal shift in the closure device, attempts were made to rescrew the closure device but were unsuccessful. The decision was made to attempt retrieval, during this time, the closure device had shifted even more. As the physician gathered retrieval equipment, safari wire and amplatz super stiff were inserted into the left atrium to exchange for a non-Boston Scientif

  Patient problems: Unspecified Tissue Injury

  MAUDE report 50777877 ↗
• InjurySep 15, 2026Migration; Failure to Seal

  It was reported that device shift and device leak occurred.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged. During the procedure there were no recaptures performed. The patient had a routine follow up computed tomography (CT) and imaging identified that the closure device shifted proximally. The closure device position was proximal with a leak under the fabric cap, according to the implant team it was under compressed. The patient was cardioverted within 30 days of implant. The patient was asymptomatic and stable at this time. The closure device was successfully removed on (b)(6) 2026 by a cardiothoracic (CT) surgeon via surgical retrieval, the appendage was ligated at the time of the closure device removal and the patient is recovering.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50774829 ↗
• InjurySep 11, 2026Adverse Event Without Identified Device or Use Problem

  It was reported thrombosis occurred.A left atrial appendage (LAA) closure procedure was being performed, and a 35mm WATCHMAN FLX Pro LAA Closure Device was implanted (b)(6) 2025. The patient was discharged. During a Computed Tomography Angiography (CTA) coronary scan a year and a half later, a device related thrombus (DRT) on the WATCHMAN device was an incidental finding. There were no further complications reported.It was further reported that post implant at 45-days, the patient was on Eliquis and Aspirin, then at 6 months, Aspirin and Plavix and afterwards on Aspirin only. The thrombus was not mobile and noted on the face of the Closure Device.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50740307 ↗
• MalfunctionSep 10, 2026Difficult to Remove; Deformation Due to Compressive Stress

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50723131 ↗
• InjurySep 8, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA (b)(6).It was reported that the patient has to remain on medication.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2024. The patient was discharged. During the procedure, one closure device was used with no recapture or repositioning. There was no leak during Position, Anchor, Size and Seal (PASS) evaluation and the closure device compression ranged from 22 to 26 percent. At an unknown time, it was reported that the patient's closure device was not working. The patient recently had a cardioversion procedure because atrial fibrillation had returned. Before the cardioversion, a magnetic resonance imaging (MRI) scan was performed and the physician who performed the MRI said that the patient's closure device was not working. When the patient went back to the regular cardiologist, the physician confirmed that the closure device was not working. It was stated that the physician did not give the reason but told the patient that the only option was to have the closure device removed with open heart surgery. The patient did not want to do that so the physician placed the patient back on blood thi

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50669824 ↗
• InjurySep 4, 2026Migration

  It was reported that device migration and a stroke occurred. A concomitant procedure consisting of pulse field ablation and left atrial appendage closure (LAAC) was performed. Following completion of the ablation procedure, a WATCHMAN TruSeal Access System (WAS) and a 35mm WATCHMAN FLX Pro Left Atrial Appendage (LAA) Closure Device and Delivery System (WDS) were selected for the LAAC procedure. The WDS was advanced into the LAA and deployed. Prior to release, the device position and compression were assessed and deemed acceptable. Following release, the Closure Device appeared to shift to a more proximal position compared with its pre-release location. Although the device remained within the LAA, it was noted to be seated relatively proximally. The patient remained under observation following implantation. Subsequently, the patient developed symptoms for a stroke. Magnetic resonance imaging (MRI) was performed as part of the post-procedural evaluation.

  Patient problems: Air Embolism; Stroke/CVA

  MAUDE report 50601428 ↗
• InjurySep 4, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a pericardial effusion occurred.A left atrial appendage closure (LAAC) procedure was being performed. It was noted that the patient had a trace baseline pericardial effusion prior to the procedure. A WATCHMAN Access System (WAS) and a 35mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was selected for use. The transseptal puncture (TSP) site was identified on intracardiac echocardiography (ICE) as being in a mid and slightly posterior location. The physician encountered difficulty advancing the ICE catheter from the right side to the left side of the heart. As a result, the ICE catheter was positioned on the right side of the heart, and the procedure was continued under transesophageal echocardiography (TEE) guidance. The left atrial appendage (LAA) was engaged using a pigtail catheter, and the 35mm WDS was advanced, deployed, and released without any recaptures. Prior to removal of the TEE probe, an effusion sweep was performed. The trace pericardial effusion was observed and considered unchanged from baseline. After the procedure was completed and the physician had left the sterile field and entered the control room, the anesthesiologist noted a de

  Patient problems: Low Blood Pressure/ Hypotension; Pericardial Effusion

  MAUDE report 50601424 ↗
• InjurySep 3, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50600088 ↗
• InjurySep 3, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Pericardial Effusion

  MAUDE report 50600009 ↗
• InjurySep 3, 2026Migration; Failure to Seal

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50599999 ↗
• InjuryAug 24, 2026Failure to Seal

  It was reported a leak occurred.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. During the patient's routine follow-up, computed tomography (CT) imaging noted a device leak. On (b)(6) 2026, the physician attempted to close the leak unsuccessfully. The patient will return for another attempt of leak closure at a later date. There is no further information at this time.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50415979 ↗
• InjuryAug 17, 2026Device Dislodged or Dislocated

  It was reported that device embolization occurred.A left atrial appendage (LAA) closure procedure was being performed, and a 35mm WATCHMAN FLX Pro Closure Device was selected to be used. The patient shape of the appendage was chicken wing. During the procedure, after attempting several closure devices, the third device met Position, Anchor, Size and Seal (PASS) criteria. The specific compression was 20-26 percent; the left atrium mean pressure was two (2) and the patient received an IV fluid bolus. The physician released the closure device, and it immediately embolized. The physician unsuccessfully attempted to snare the closure device from the left atrium. The closure device traveled to the left ventricle and then into the ascending aorta. Vascular surgery performed a cutdown on the left femoral artery and the closure device was successful snared and removed from the ascending aorta. The physician suggested the volume status was the reason for smaller pre-ostium measurements. The physician used three (3) closure devices during this implant and was confident by the time the third closure device was used, the patient's volume should have stabilized. There is no plan to retry implant

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50274596 ↗
• InjuryAug 13, 2026Device Dislodged or Dislocated

  REPORTED VIA CLINICAL STUDY.It was reported that device embolization occurred.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2025. The patient was discharged. During the 12 month follow up computed tomography, imaging showed device embolization. There were no corrective actions or diagnostic tests associated with the finding.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50236036 ↗
• InjuryAug 12, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50223122 ↗
• InjuryAug 7, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that thrombosis occurred. A left atrial appendage closure (LAAC) procedure was performed and a 35 mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was implanted on (b)(6) 2026. The patient was discharged on a post implant medication regimen of 75 mg of Plavix and 81 mg of Aspirin. At a routine 45-day follow up appointment on (b)(6) 2026 transesophageal echocardiography (TEE) imaging showed device related thrombus. The patient was switched to 20mg of Xarelto daily and will have a follow up TEE in two months.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50174131 ↗
• InjuryAug 6, 2026Failure to Seal

  It was reported the device did not seal. A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. Post implant a device leak measuring approximately 5mm was noted. The physician had attempted to use a 40mm Closure Device; however, due to the patient's large anatomy, the device could not be positioned with adequate depth. The patient was discharged following the procedure. At the routine 45-day follow-up, transesophageal echocardiography (TEE) imaging confirmed the 5mm leak was still present. As a result, the patient remained on oral anticoagulation (OAC) medication. At a subsequent follow-up visit, computed tomography (CT) imaging showed that the 5mm leak remained unchanged. The patient has elected to have the leak coiled with an Interventional Cardiologist at a later date.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50165647 ↗
• InjuryAug 3, 2026Failure to Seal

  It was reported that cerebral vascular accident occurred.A left atrial appendage (LAA) closure procedure was performed, and a 35mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6)2025-. The patient was discharged. It was reported that the patient experienced a stroke within the two months preceding (b)(6)2026, the reporter was unable to provide the exact date of event. Following the closure device implant, the patient received a post 45-day computed tomography (CT) scan on (b)(6)2025 that showed a 4mm peri device leak. Subsequently, a transesophageal echocardiogram (TEE) performed on (b)(6)2026, revealed a 3.5mm gap on the superior access, a small lobe uncovered, and a 2mm posterior device leak. The reporter was unable to provide information regarding the post-procedure medication regimen initiated after the December CT scan or whether any interventions were performed in response to the CT findings. The reporter was also unaware of any medication changes or interventions following the June TEE findings.

  Patient problems: Stroke/CVA

  MAUDE report 50114156 ↗
• InjuryJul 31, 2026Migration

  It was reported that device shift and explant occurred. A concomitant ablation and left atrial appendage closure procedure was being performed. WATCHMAN sizing was determined prior to ablation; the workup suggested a 35-40mm sized WATCHMAN FLX Pro Closure Device. Intracardiac echocardiogram (ICE) imaging measured 22-28mm. The ablation was performed successfully with a non-Boston Scientific (BSC) pulse field ablation device. Afterwards, the sheath was exchanged for a WATCHMAN TruSteer Access System. The physician selected a 35mm WATCHMAN FLX Pro Closure Device. After two partial re-captures, the Closure Device was successfully implanted. Release criteria were met with 25-31% compression, the tug test was stable, and the position was acceptable at the level of the ostium. After full release, the Closure Device shifted. The physician deemed explant necessary. A 22Fr non-BSC sheath was inserted along with non-BSC biopsy forceps for removal of the Closure Device from the appendage. The patient remained stable with no adverse events. The physician felt re-implant was not appropriate at this time.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50100610 ↗

Recalls under the same FDA submission

These recalls involve devices cleared under P130013. One submission often covers many models, so check the product and lot details in each record.

• Z-2765-2015 · Aug 25, 2015 · Terminated
  Boston Scientific, WATCHMAN Left Atrial Appendage Closure Device with Delivery System, 21mm x 12F ( M635WU21060, WU21060, 24mm x 12F(M635WU24060, WU2406) , 27mm x 12F(M635WU27060,
• Z-2766-2015 · Aug 25, 2015 · Terminated
  Boston Scientific, WATCHMAN Access System Access Sheath with Dilator, 14F Single curve( M635TU10060, TU1006) , 14F Double curve (M635TU20060, TU2006) , & 14F Anterior curve (M635