WATCHMAN FLX ProRecalls & reported problems across all models

We found 6 models of WATCHMAN FLX Pro by Boston Scientific Corporation in the FDA's device registry (GUDID). Together they are named in 1,978 adverse event reports in the FDA's MAUDE database, received between Oct 20, 2023 and Sep 30, 2026 — classified as 200 deaths, 1,725 injuries, 53 malfunctions.

The most frequently reported specific device problem is “Migration” (252 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 Pro problems

WATCHMAN FLX Pro models

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

• WATCHMAN FLX™ Pro M635WU60270

  System, appendage closure, left atrial
  57 deaths596 reports
• WATCHMAN FLX™ Pro M635WU60310

  System, appendage closure, left atrial
  46 deaths452 reports
• WATCHMAN FLX™ Pro M635WU60240

  System, appendage closure, left atrial
  48 deaths429 reports
• WATCHMAN FLX™ Pro M635WU60350

  System, appendage closure, left atrial
  29 deaths250 reports
• WATCHMAN FLX™ Pro M635WU60200

  System, appendage closure, left atrial
  10 deaths147 reports
• WATCHMAN FLX™ Pro M635WU60400

  System, appendage closure, left atrial
  10 deaths104 reports

Recent WATCHMAN FLX Pro adverse event reports

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

• InjurySep 30, 2026Difficult to Remove

  Patient problems: Cardiac Perforation; Pericardial Effusion; Unspecified Tissue Injury

  MAUDE report 50951307 ↗
• InjurySep 30, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a pericardial effusion and cardiac tamponade occurred.A left atrial appendage closure (LAAC) procedure was performed, and a 20mm WATCHMAN FLX Pro LAA Closure Device was successfully implanted. Approximately five hours post procedure, the patient was experiencing unknown symptoms. A pericardial effusion with tamponade was noted. A pericardiocentesis was performed, removing an unknown amount of fluid from the patient.

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

  MAUDE report 50950744 ↗
• 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 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 29, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion occurred. A left atrial appendage closure (LAAC) procedure was performed. A 20mm WATCHMAN FLX Pro LAA Closure Device was successfully implanted on (b)(6) 2026. The patient was noted to have a small appendage, but the physician was able proceeded with the procedure. There were no recaptures or repositions performed and there were no issues reported with the transeptal puncture. The patient was discharged. The patient was seen in the emergency department on (b)(6) 2026, due to shortness of breath and general weakness. Pericardial effusion was reported and the patient was hospitalized. Pericardiocentesis was completed on (b)(6) 2026, and 500cc of red fluid was drained. The patient was stable following the procedure and discharged the next day.

  Patient problems: Dyspnea; Muscle Weakness/Atrophy; Pericardial Effusion

  MAUDE report 50934193 ↗
• InjurySep 29, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion occurred. A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN TruSteer Access System (WAS) and a 24mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) were selected for use. During the transeptal puncture (TSP) the landing zone was low and posterior. The physician did not cross at that position. The physician then came to a mid/mid location and crossed the septum there. The pigtail wire did not advance in its normal shape. The wire was retracted back into the dilator, and the wire was readvanced into the LA where it then took its normal curl. The TruSteer sheath was then advanced into the LA and an angiography was completed to compare preprocedural measurements. The 24mm device was prepped and advanced in the WDS. The physician deployed the device, but it landed proximally. A full recapture was completed. Upon repositioning the device, fluid was noted behind the appendage. Transesophageal echocardiography (TEE) was used to sweep for effusion. An effusion appeared close to the right side of the heart and was dark in appearance. The device was fully recaptured. Another angiography was completed of the

  Patient problems: Pericardial Effusion

  MAUDE report 50931466 ↗
• InjurySep 28, 2026Adverse Event Without Identified Device or Use Problem

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

  MAUDE report 50924318 ↗
• InjurySep 28, 2026Premature Separation

  It was reported that premature core wire detachment occurred. A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN Access System (WAS) and a 24mm WATCHMAN FLX Pro LAA Closure (LAAC) Device and Delivery System was selected for use. The device appeared attached when going up the sheath, but when the tug test was done it was noted that the device had become unscrewed from the core wire. The device was left in place as it met all of the position, anchor, size and seal (PASS) criteria. The patient was reported to be in stable condition and has since been released.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50915809 ↗
• 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 28, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that device thrombosis occurred.A left atrial appendage (LAA) closure procedure was performed, and a 27mm WATCHMAN FLX Pro Closure Device was implanted. The patient was discharged. At the one-year follow-up computed tomography (CT), findings of a device related thrombus (DRT) extending beyond the fabric portion of the closure device were observed. The DRT was layered from the screw portion toward the coumadin ridge side. Anticoagulant therapy had been discontinued three (3) months after the procedure, and the patient was currently taking antiplatelet medication. No infarction-like symptoms had been observed to date. After the CT findings were confirmed, anticoagulant therapy was resumed, and a follow-up CT was planned for 3 to 6 months later.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50915102 ↗
• 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 24, 2026Migration

  It was reported that device migration occurred.A left atrial appendage (LAA) closure procedure was performed under transesophageal echocardiography (TEE) guidance. A 20mm WATCHMAN FLX Pro Delivery System and Closure Device (WDS) was positioned in the available deployment location due to limited appendage depth. Prior to release, the WDS met PASS criteria with approximately 10% to 15% compression, a successful tug test, no leak, and approximately one-third shoulder.Following release, the Closure Device shifted proximally and a larger shoulder was noted, most prominently in the 90 degree TEE view, causing it to no longer meet release criteria. Subsequent TEE assessment demonstrated no further movement of the Closure Device. No intervention was performed, and the plan is to reassess device position at the 45 day follow up.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50886890 ↗
• InjurySep 24, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that an air embolism occurred. A left atrial appendage closure (LAAC) procedure was being performed and a WATCHMAN Access System (WAS) and a 27mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) were selected for use. The device was implanted. During withdrawal and closure the anesthesiologist noted air in the right upper pulmonary vein (RUPV). A non-Boston Scientific sheath was used to access the RUPV and aspirate the air bubbles. There were no additional patient complications reported.

  Patient problems: Air Embolism

  MAUDE report 50883177 ↗

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