WATCHMAN FLX™ Pro M635WU60310Recalls & reported problems

Summary

The FDA's MAUDE database contains 452 adverse event reports that list this exact device (DI 00191506004613), received between Oct 20, 2023 and Sep 29, 2026 — classified as 46 deaths, 389 injuries, 17 malfunctions.

The most frequently reported specific device problem is “Migration” (70 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 452 reports, in the reporter's own words as published by the FDA.

• InjurySep 29, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Abdominal Pain; Speech Disorder; Unspecified Respiratory Problem

  MAUDE report 50937080 ↗
• InjurySep 29, 2026Failure to Seal

  REPORTED VIA CLINICAL STUDYIt was reported that the device did not seal. A left atrial appendage (LAA) closure procedure was performed as part of a clinical study, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2025. The patient was discharged. The patient had a routine 12 month follow up, and computed tomography (CT) imaging showed a 7mm leak was present. No intervention or treatment was performed or planned.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50934465 ↗
• InjurySep 25, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that thrombosis occurred.A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2024. The patient was discharged. The patient had a follow up computed tomography (CT) scan performed on (b)(6) 2026, to evaluate a non-mobile thrombus located towards the limbus side that was previously discovered on a computed tomography (CT) performed on (b)(6) 2025, and to evaluate the contrast patency of the closure device as well. The WATCHMAN Clinical evaluated the CT that was done on (b)(6) 2026 and asked to also see the CT from on (b)(6) 2025, to be able to compare previous CT with the current CT. Based on what the WATCHMAN Clinical had seen, both of the CTs were sent to the Therapy Operations team for additional evaluation as well. The WATCHMAN Clinical has not heard back from the Therapy Operations team yet to get their impression of the CT. During the procedure, the closure device met all of Position, Anchor, Size and Seal (PASS) criteria the day of implant. After evaluating the CTs, the closure device still meets all of PASS criteria. Before implant, the patient was on Eliquis and Aspirin (ASA). Now t

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50896846 ↗
• InjurySep 24, 2026Migration; Failure to Seal

  It was reported that peri-device leak (PDL) occurred.The patient previously underwent a left atrial appendage (LAA) closure procedure and a 31mm WATCHMAN FLX Pro Closure Device was implanted.At a follow up appointment on an unknown date, transesophageal echocardiogram (TEE) visualized a PDL around the Closure Device and confirmed there was movement/shift of the device since the implant procedure. The patient subsequently returned for a leak closure procedure. The peri-device leak was successfully closed using two non-Boston Scientific (BSC) Amplatzer Vascular Plug (AVP) devices. The patient was reported to be stable with no additional complications.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50888958 ↗
• InjurySep 22, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that cardiac perforation, pericardial effusion and cardiac tamponade occurred.The patient underwent a concomitant pulse field ablation (PFA) and a left atrial appendage (LAA) closure procedure. The physician gained venous access and proceeded with the concomitant procedure. The ablation procedure was successfully completed. A WATCHMAN Access System (WAS) and a 31mm WATCHMAN FLX Pro LAA Closure Device & Delivery System (WDS) were selected to be used. The physician positioned the WAS in the LAA of the patient and then inserted the WDS. The closure device was deployed in the patient but was proximal so the closure device was recaptured. The closure device was redeployed and positioned in the LAA when it was noted that the device had perforated the LAA. Angiogram imaging confirmed the perforation. The closure device was recaptured and redeployed in an ideal position. Transesophageal Echocardiogram (TEE) imaging showed a large pericardial effusion with cardiac tamponade. The physician performed a pericardiocentesis and drained the effusion, but the effusion did not dissipate. The patient underwent open heart surgery to repair the perforation. There were no other complica

  Patient problems: Cardiac Perforation; Cardiac Tamponade; Pericardial Effusion

  MAUDE report 50857637 ↗
• InjurySep 21, 2026Failure to Seal

  It was reported that peri-device leak (PDL) occurred. The patient previously underwent a left atrial appendage (LAA) closure procedure, and a 31 mm WATCHMAN FLX Pro Closure Device was implanted under intracardiac echocardiography (ICE) guidance. A 4 mm PDL was identified and documented at the 45-day follow-up. Upon retrospective review of the implant images, the leak may have been present at the time of implant. 427 days post index procedure, the patient underwent a revision procedure using a non-Boston Scientific (BSC) device to close the peri-device leak. Following the intervention, the leak appeared sealed.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50840377 ↗
• InjurySep 17, 2026Failure to Seal

  It was reported that thrombosis and device leak occurred.A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged. On (b)(6) 2026, the patient had a routine follow up transesophageal echocardiography (TEE) and imaging showed a thrombus. On (b)(6) 2026, it was noted that the patient also had a 4mm leak. Post treatment follow-up echocardiography noted that the thrombus was resolved. The physician is expecting to close the leak by coils; however, no date is set for this.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50809851 ↗
• InjurySep 17, 2026Migration

  It was reported that device migration occurred. A left atrial appendage closure (LAAC) procedure was performed on (b)(6) 2026, and a 31mm WATCHMAN FLX Pro LAA Closure Device was implanted as part of a concomitant ablation procedure. Despite having challenging anatomy, only one deployment was needed. There were no full or partial recaptures. The patient was discharged. The patient went in for an emergent follow up with episodes of double vision and loss of balance on (b)(6) 2026, and echocardiography imaging was performed. The device was discovered to have shifted and had partially embolized out of the LAA. A decision was made to explant the device. The patient was adamant that a new Closure Device be implanted. The canted device was successfully percutaneously explanted, and a new device was implanted. The patient was reported to be in stable condition following the procedure.

  Patient problems: Balance Problems; Diplopia/Double Vision

  MAUDE report 50803049 ↗
• InjurySep 17, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion (PE) and cardiac tamponade occurred.A left atrial appendage (LAA) closure procedure was performed under transesophageal echocardiography (TEE) and intracardiac echocardiography (ICE) guidance. Baseline imaging demonstrated no PE. Transseptal puncture was performed using a VersaCross system with a fixed curve sheath. The patient had very challenging LAA anatomy with shallow usable depth and both posterior and anterior lobes. Multiple recaptures and repositioning attempts were performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted.Approximately two hours after the procedure, while in the post-anesthesia care unit (PACU), the patient became hypotensive. Imaging identified a PE with cardiac tamponade. Pericardiocentesis was performed, and approximately 250 mL of fluid was removed and transfused back to the patient. The patient remained hospitalized beyond the standard of care.

  Patient problems: Cardiac Tamponade; Low Blood Pressure/ Hypotension; Pericardial Effusion

  MAUDE report 50802473 ↗
• InjurySep 16, 2026Adverse Event Without Identified Device or Use Problem

  It was reported thrombosis occurred.A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN Access System (WAS) and a 31mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was selected for use. The WDS was advanced and deployed in the LAA. After the fourth deployment, the transesophageal echocardiography (TEE) imaging angles were being reviewed for positioning, and it was noticed that a thrombus was swirling in the distal end of the device/appendage. The physician was notified of the finding immediately, just as the notified certified registered nurse anesthetist (CRNA) reported electrocardiogram (EKG) changes (ST elevation). The physician quickly got arterial access on the left femoral artery and wanted to immediately take the device out of the appendage. It was suggested that the device not be removed before we could confirm where the clot was. The thrombus was reported to have resolved approximately 12 minutes after the thrombus was first seen. The physician cancelled the procedure and decided to recapture the Closure Device and completely remove the devices out of the body. The patient woke with no cognitive deficits or movement issues. The

  Patient problems: Non specific EKG/ECG Changes; Thrombosis/Thrombus

  MAUDE report 50793323 ↗
• InjurySep 16, 2026Migration

  It was reported device migration occurred. A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged. At the routine 45 day follow up, it was found that the Closure Device had migrated in the LAA with more than half of the Closure Device proximal of the ostium. The patient did not have any symptoms present. The physician was able to use a snare to remove the device and a new 31m Closure Device was implanted. There were no patient complications and the patient was discharged.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50788570 ↗
• InjurySep 16, 2026Failure to Seal

  It was reported that the device did not seal and thrombosis occurred.A left atrial appendage (LAA) closure procedure was being performed. A WATCHMAN Access System (WAS) and a 31mm WATCHMAN FLX Pro 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. There were no patient complications that were reported to have occurred.Sixteen (16) months later the patient had a follow up Computed Tomography (CT) procedure. The CT imaging showed that there was a 6mm leak and a thrombus in the left atrium. The physician continued the patient on anticoagulation medication in response to the thrombus event. The physician decided not to address the leak. There were no other complications that were reported to have occurred.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50786874 ↗
• InjurySep 15, 2026Migration

  It was reported that device shift occurred.A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2025. The patient was discharged. On (b)(6) 2026, the patient was scheduled for an atrial fibrillation (AF) ablation to be performed by an Electrophysiology (EP) cardiologist in the EP laboratory. The patient underwent general anesthesia for this procedure. The EP cardiologist performed transesophageal echocardiography (TEE) to rule out clot for the AF ablation, and it was discovered that the closure device was under compressed, had shifted and was not in the position of release. The EP cardiologist consulted the physician who performed the closure device procedure and had the physician observe the closure device on TEE. The physician noted that the closure device was not completely in the appendage and appeared to have been shifted from the time of implant. Both physicians discussed to have the patient wake up from general anesthesia and to not have the AF ablation performed that day and discuss further options of the closure device. The physician asked the Watchman Team to evaluate the computed tomography (CT)

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50773281 ↗
• InjurySep 11, 2026Failure to Seal

  REPORTED VIA PATIENT CALL CENTERIt was reported the device did not seal.A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6)-2025. The patient was discharged. The patient called in to the WATCHMAN Call Center reporting that he has had two follow ups where transesophageal echocardiography (TEE) has shown that the Closure Device did not fit perfectly creating a small leak. The patient reported the physician kept him on Eliquis mediation to reduce the risk of a stroke. No further information was available or provided.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50736549 ↗
• DeathSep 11, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a patient death occurred.A concomitant Farapulse and left atrial appendage (LAA) closure procedure was performed. Both cases went as planned and a 31mm WATCHMAN FLX Pro Closure Device was implanted. The patient stayed overnight and X-ray and echocardiogram showed the closure device in place and no pericardial effusion. The patient discharged home the following day. Six days later the patient was found deceased at their home. There is no further information at this time.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50732821 ↗
• InjurySep 9, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that a transient ischemic attack occurred.A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged on Plavix 75 mg and ASA 81 mg. As a Plavix non-responder, the patient was switched to Brilinta 90 mg twice a day while inpatient. On (b)(6) 2026, the patient was admitted with cerebral vascular accident (CVA) symptoms, the patient had left sided weakness, left facial droop, slurred speech and decreased sensation. On (b)(6) 2026, a head computed tomography (CT) was performed and imaging showed no acute findings. Carotid imaging demonstrated no flow-limiting stenosis. A magnetic resonance imaging (MRI) could not be performed due to an incompatible pacemaker (PM). During the procedure a complete seal was noted and there were no changes to the seal of the closure device. The patient symptoms resolved within 24 hours, and the patient fully recovered. The patient was discharged home on Brilinta 90mg twice a day.

  Patient problems: Facial Paralysis; Muscle Weakness/Atrophy; Numbness; Speech Disorder; Transient Ischemic Attack

  MAUDE report 50692788 ↗
• MalfunctionSep 8, 2026Activation Failure

  It was reported a procedure was cancelled. Patient was scheduled for concomitant procedure for a WATCHMAN implant and an ablation. A left atrial appendage (LAA) closure procedure was being performed. A WATCHMAN Access System (WAS) and a 31mm WATCHMAN FLX Pro LAA Closure Device & Delivery System (WDS) were selected for use. It was noted the patient had prominent pectinate muscles. Immediately following deployment of the Closure Device, the tip did not fully expand, and tug test noted one half protrusion. In the mitral axis, device expansion was acceptable despite one half protrusion. Physician attempted to deploy the Closure Device four additional times, and the protrusion did not resolve. A decrease in closure device size was suggested; however, since the ablation procedure was successful, the physician elected to cancel the procedure. There were no further complications reported.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50671606 ↗
• InjurySep 4, 2026Device Dislodged or Dislocated

  It was reported device embolization occurred.A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN Access System (WAS) and a 31mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was selected for use. The WDS was advanced, deployed and the Closure Device was implanted in the LAA. As the patient was being moved over to the bed, they complained of arm pain and their blood pressure dropped. It was found that the 31mm Closure Device had embolized out of the appendage into the mitral valve. A non-Boston Scientific (BSC) grasping device was used to retrieve the device, and a new 27mm Closure Device was implanted. There were no further complications, and the patient has been discharged home.

  Patient problems: Low Blood Pressure/ Hypotension; Pain

  MAUDE report 50600725 ↗
• InjurySep 4, 2026Failure to Seal

  Patient problems: No Clinical Signs, Symptoms or Conditions; Thrombosis/Thrombus

  MAUDE report 50600107 ↗
• InjurySep 3, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Pericardial Effusion

  MAUDE report 50600007 ↗
• InjuryAug 28, 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 31mm WATCHMAN FLX Pro LAA Closure Device was implanted. The patient was discharged. At the patients routine 45-day follow-up transesophageal echocardiography (TEE), a pedunculated, mobile, device related thrombus (DRT) was observed on the WATCHMAN FLX Pro Closure Device. As a result, the patient remains on their oral anticoagulant medication.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50508443 ↗
• InjuryAug 21, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50383804 ↗
• InjuryAug 21, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50380876 ↗
• DeathAug 21, 2026Adverse Event Without Identified Device or Use Problem

  It was reported hypotension, bradycardia, cardiac arrest and death occurred. A concomitant procedure (ablation/left atrial appendage closure (LAAC)) was being performed. A WATCHMAN TruSteer Access System (WAS) and a 31mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was selected for use. After the ablation portion of the procedure, the LAAC procedure was completed without any reported complications. Electrocardiogram (EKG) monitoring showed no ST-segment elevation or evidence of any lethal arrhythmias. At the conclusion of the procedure, the physician was in the process of closing the groin access site, and protamine was administered to reverse the effects of heparin anticoagulation. The anesthesia physician observed a sudden decline in the patient's blood pressure along with bradycardia. Cardiopulmonary resuscitation (CPR) was initiated. A transesophageal echocardiogram (TEE) was performed to evaluate for a potential pericardial effusion or cardiac tamponade as a cause of the hemodynamic instability. No pericardial effusion was identified on TEE. Despite resuscitative efforts, the patient remained unstable and experienced recurrent episodes of ventricular tachycard

  Patient problems: Bradycardia; Cardiac Arrest; Low Blood Pressure/ Hypotension; Tachycardia; Ventricular Fibrillation

  MAUDE report 50378996 ↗
• InjuryAug 20, 2026Migration; Failure to Seal

  REPORTED VIA PATIENT CALL CENTERIt was reported the device did not seal. A left atrial appendage (LAA) closure procedure was performed, and a 31mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged. The patient called into the WATCHMAN Patient Call Center stating that computed tomography (CT) imaging was completed and the results showed that the left side of the Closure Device did not seal.A good faith effort was made to the Boston Scientific (BSC) Senior Clinical Specialist. The BSC Senior Clinical Specialist reported that the patient had routine 90 day computed tomography (CT) imaging on (b)(6) 2026. The imaging physician believed the Closure Device looked good. A second opinion was obtained and the Cardiologist believed there was a leak and possible thrombus present. There was no intervention required at this time. The patient was kept on Eliquis medication (5mg BID).

  Patient problems: No Clinical Signs, Symptoms or Conditions; Thrombosis/Thrombus

  MAUDE report 50349161 ↗

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