WATCHMAN FLX™ Pro M635WU60240Recalls & reported problems

Summary

The FDA's MAUDE database contains 429 adverse event reports that list this exact device (DI 00191506004590), received between Nov 21, 2023 and Sep 29, 2026 — classified as 48 deaths, 373 injuries, 8 malfunctions.

The most frequently reported specific device problem is “Migration” (32 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 429 reports, in the reporter's own words as published by the FDA.

• 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 The wire was retracted back into the dilator, and the wire was readvanced into the LA where it then took its normal curl.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, 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 24, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion occurred. A left atrial appendage closure (LAAC) procedure was performed, and a 24mm WATCHMAN FLX Pro Closure Device was implanted. Approximately 8 months post implant the patient was scheduled to undergo atrial fibrillation ablation with a non-Boston Scientific ablation system. Baseline intracardiac echocardiogram was performed which noted a pericardial effusion that had not previously been seen in any of the post-LAAC transthoracic or transesophageal echocardiograms from post-procedure or 45-day follow-up. The ablation procedure was performed. No intervention was performed for the pericardial effusion. The treating physician commented that it was not large enough to perform pericardiocentesis. Computed tomography was ordered which the radiologist read as a trace effusion and noted the Closure Device looked fine. The treating physician was unsure why every other modality did not see the pericardial effusion and commented that the pericardial effusion was "definitely there". The treating physician is concerned the effusion was caused by erosion from the implanted Closure Device. The patient was asymptomatic and stable.

  Patient problems: Pericardial Effusion

  MAUDE report 50882216 ↗
• InjurySep 22, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion occurred. A left atrial appendage closure (LAAC) procedure was performed and a 24mm WATCHMAN FLX Pro LAA Closure Device and Delivery System was implanted. Transesophageal Echocardiography (TEE) was used throughout the procedure and noted a physiological effusion prior to the procedure. The patient was noted to have an anterior chicken wing anatomy. The transeptal puncture (TSP) was completed and after one recapture the device was implanted. A post operative echo showed the effusion had grown. The patient blood pressure declined. A pericardiocentesis was performed and 200cc of red fluid was removed. The blood that was drained was transfused back into the patient. The patient has since been discharged home.

  Patient problems: Low Blood Pressure/ Hypotension; Pericardial Effusion

  MAUDE report 50859027 ↗
• InjurySep 21, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Pericardial Effusion

  MAUDE report 50847347 ↗
• InjurySep 21, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that ST segment elevation occurred.A left atrial appendage (LAA) closure procedure was being performed under transesophageal echocardiography (TEE) guidance and general anesthesia. A WATCHMAN FXD Double Curve Access System (WAS) was used with VersaCross Connect for transseptal puncture then a WATCHMAN TruSteer Access System was inserted. A 24mm WATCHMAN FLX Pro Delivery System and Closure Device (WDS) was initially deployed. Following deployment, ST segment elevation was noted on the EKG along with hypotension, and it did not immediately resolve. The physician performed a right coronary angiogram. No coronary spasm was identified, and no air was visualized within the patient. Following angiography, the ST segments returned to baseline and the patient remained hemodynamically stable. In the physicians opinion, the event was related to air introduction into the WDS. A 20mm WDS was subsequently prepared, inserted, deployed, and released without further issue. The patient remained stable with no additional reported complications, and was discharged home.

  Patient problems: Low Blood Pressure/ Hypotension; Non specific EKG/ECG Changes

  MAUDE report 50842879 ↗
• InjurySep 18, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Pericardial Effusion; Unspecified Tissue Injury

  MAUDE report 50828756 ↗
• InjurySep 17, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Pericardial Effusion

  MAUDE report 50810713 ↗
• InjurySep 17, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA PATIENT CALL CENTERIt was reported that cerebral vascular accident occurred.A left atrial appendage (LAA) closure procedure was performed, and a 24mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2025. The patient was discharged. The patient stated they suffered a stroke in (b)(6) 2026 and was subsequently hospitalized for several days. During hospitalization, the patient noted the cardiologist advised that, the Closure Device was implanted as intended and they could not explain the cause of the stroke. The patient noted that they had been diagnosed with atrial fibrillation (AF) for about twelve years. Prior to the Closure Device implant, the patient was taking warfarin. The patient's cardiologist wanted the patient off warfarin and suggested the Closure Device implant as an alternative. Post Closure Device implant, the patient was prescribed Eliquis. The patient noted that on (b)(6) 2025, they had a follow up with the surgeon's nurse practitioner. The patient had another follow up visit with the surgeon's nurse practitioner on (b)(6) 2025, and at that time they were directed to stop taking Eliquis blood thinner medication and to start taking 81mg of Aspirin

  Patient problems: Fall; Paralysis; Speech Disorder; Stroke/CVA

  MAUDE report 50809238 ↗
• InjurySep 16, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Cardiac Arrest; Urinary Incontinence

  MAUDE report 50796459 ↗
• InjurySep 15, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that the patient experienced chest pain. A left atrial appendage closure (LAAC) procedure was performed and a 24mm WATCHMAN FLX Pro LAA Closure Device was implanted. Post procedure, the patient developed chest discomfort with ST segment depression. Transesophageal Echocardiography (TEE) showed no effusion. The patient was to be brought back for a left heart catheterization (LHC) procedure.

  Patient problems: Chest Pain; Non specific EKG/ECG Changes

  MAUDE report 50775561 ↗
• InjurySep 15, 2026Migration; Failure to Seal

  It was reported that the device did not seal. A left atrial appendage closure (LAAC) procedure was performed on (b)(6) 2026 and a 24mm WATCHMAN FLX Pro LAA Closure and Delivery System (WDS) was implanted. On (b)(6) 2026 the patient had post WATCHMAN implant computed tomography (CT) completed to evaluate the device. The nurse practitioner notified the WATCHMAN team on (b)(6) 2026 about the completed CT. The CT was received by the WATCHMAN team and sent it to the Therapy Ops team for additional evaluation. The Therapy Ops team reported that it appeared there was an uncovered lobe. Depending on where it was measured there was a gap of 3-10mm. There was no evidence of thrombus, but the device appeared to have shifted. The patient did not experience any symptoms. The report was sent to the nurse practitioner to share with the implanting physician the information about the gap in the device and the leak. There was no additional information provided.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50772974 ↗
• InjurySep 15, 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 24mm WATCHMAN FLX Pro LAA Closure Device was implanted. The patient was discharged. At patients routine computed tomography (CT) imaging, a 4.5mm limbus hypo attenuated thickening (HAT) was observed on the WATCHMAN Closure Device. There was no intervention required.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50772659 ↗
• InjurySep 11, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50739870 ↗
• InjurySep 11, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that air embolism occurred. A left atrial appendage closure procedure was being performed. Approximately 5 minutes after the 24mm WATCHMAN FLX Pro Closure Device and Delivery System were inserted into the anatomy, the patient experienced ST segment elevation. Approximately 5 minutes later, while examining transesophageal echocardiogram (TEE), air was visualized first in the appendage, and then later in the apex of the left ventricle. Contrast of the coronary arteries was performed which identified no blockage. The ST segment elevation continued but headed back towards baseline and eventually resolved, resuming normal sinus rhythm. The implanting physician determined it was safe to resume the procedure, and a 20mm WATCHMAN FLX Pro Closure Device was implanted. The patient was kept overnight for observation.

  Patient problems: Air Embolism; Non specific EKG/ECG Changes

  MAUDE report 50736613 ↗
• InjurySep 11, 2026Failure to Seal

  It was reported that device leak occurred.A left atrial appendage (LAA) closure procedure was performed, and a 24mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. During the procedure, there were multiple recaptures and repositions, the patient had a difficult anatomy and was a challenging procedure. The patient was discharged. During a routine follow up computed tomography (CT) scan, a 7mm leak was noted. The CT was sent to the Therapy Operations team for evaluation. Per the Therapy Operations report it stated that the distal portion of the appendage showed no signs of contrast nor contrast going around the closure device but that a proximal lobe was left uncovered. After discussion with the physician, there is no plan for intervention. The patient was on Eliquis and Aspirin medication.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50734763 ↗
• InjurySep 11, 2026Premature Separation

  It was reported a device prematurely detached from the core wire.A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN Access System (WAS) and a 24mm WATCHMAN FLX Pro LAA Closure Device & Delivery System (WDS) were selected for use. The Closure Device was positioned in the appendage and as the physician pulled the sheath back to perform the tug test, the Closure Device prematurely released from the core wire releasing the Closure Device in the appendage. The physician noted that the device was deployed in the appendage at a good position, meeting Position, Anchor, Size and Seal (PASS) criteria. The Closure Device was left in position. There were no patient complications reported.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50733903 ↗
• InjurySep 4, 2026Migration

  It was reported that device migration occurred. A left atrial appendage closure (LAAC) procedure was being performed. A 24mm WATCHMAN FLX Pro LAA Closure Device and Delivery System was deployed. An xray with contrast and intracardiac echo confirmed all position, anchor, size and seal (PASS) criteria were met and the device was released. While completing a sweeping check for effusion, the implanter noticed the device had shifted. The device continued to turn sideways. A decision was made the snare the device because of the risk of embolization and because it would not heal in that position. An interventional cardiologist assisted on the retrieval. The patient was intubated and the physician switched to transesophageal echocardiography (TEE) imaging. The forceps were visualized on the face of the device. The device was pulled all the way into the WATCHMAN TruSteer Access System. It was engaged on the posterior limbus side. It was about the same amount of pressure as normal to recapture a device. When the device was removed it appeared to be in perfect condition. All of the hooks were intact, and the tines were in the correct positions. A larger device was then selected to be implante

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50614442 ↗
• InjurySep 4, 2026Device Dislodged or Dislocated

  It was reported a device embolization occurred.A left atrial appendage (LAA) closure procedure was performed, and a 24mm WATCHMAN FLX Pro Closure Device was successfully implanted. The patient was discharged. During patient's routine 45-day transesophageal echocardiogram (TEE) imaging, it was noted the closure device was not in the LAA. Radiograph (X-ray) imaging located the closure device in the patient's aorta. The patient was scheduled for device retrieval. The embolized closure device was percutaneously retrieved via 16 F Cook DrySeal Sheath and Rescue Alligator grasping forceps without any incident. There are no current plans for reimplantation. There were no further complications and the patient remained in the hospital for approximately three days post procedure before being discharged.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50602448 ↗
• InjurySep 4, 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 24mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged on Eliquis 5mg twice a day. During the routine 3-month follow-up transesophageal echocardiography (TEE) performed on (b)(6) 2026, there was a small thrombus attached to the threaded insert of the closure device between the inset and limbus. The patient was instructed to stay on Eliquis. On (b)(6) 2026, upon follow-up, the same thrombus was still present. The patient was told to remain on Eliquis for another 3 months and return for TEE imaging.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50602163 ↗
• InjurySep 4, 2026Use of Device Problem; Device Dislodged or Dislocated

  Patient problems: Dyspnea

  MAUDE report 50600206 ↗
• InjurySep 4, 2026Migration; Failure to Seal

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50600138 ↗
• InjurySep 1, 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. A 24mm WATCHMAN FLX Pro LAA Closure Device & Delivery System (WDS) were selected for use. Transesophageal Echocardiography (TEE) imaging noted a trace effusion prior to the procedure. The initial transeptal puncture (TSP) was difficult to perform due to a sharp posterior-inferior bend in the patient anatomy. The physician attempted to cross the septum several times using the VersaCross Connect wire, adding two different sheath/dilator bends for greater reach. After physician deployed the Closure Device, and completed a sweep, TEE imaging showed no change in effusion. Approximately thirty minutes post deployment, the patient's blood pressure dropped. TEE imaging noted the effusion near the apex of the left ventricle. Physician performed a pericardiocentesis to treat the effusion, draining an unknown amount of dull colored fluid. Patient was stabilized and was admitted to intensive care unit. There were no further complications and approximately three days post procedure, the patient was discharged.

  Patient problems: Low Blood Pressure/ Hypotension; Pericardial Effusion

  MAUDE report 50548865 ↗
• InjuryAug 21, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA PATIENT CALL CENTER, it was reported fluid accumulation in the lungs occurred post procedure. A left atrial appendage (LAA) closure procedure was performed, and a 24mmmm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was subsequently discharged. The patient's daughter contacted the WATCHMAN Call Center to report that her father has experienced ongoing fluid accumulation in his lungs since undergoing the WATCHMAN procedure. According to the patient's daughter, the patient began experiencing shortness of breath approximately 3 to 4 days after the procedure. He returned to his physician and was prescribed cortisone; however, the medication did not appear to improve his symptoms. Approximately three weeks later, the patient was taken to the hospital, where he was found to have fluid in his lungs. The patient was subsequently started on Lasix. However, each time attempts have been made to taper or discontinue the medication, fluid reaccumulates. The patient's daughter believes the symptoms are directly related to the WATCHMAN procedure, as the patient had never experienced this issue previously. She further reported that the patient has been evalu

  Patient problems: Dyspnea; Pulmonary Edema

  MAUDE report 50379357 ↗
• InjuryAug 21, 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 24mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged. The LAA anatomy of the patient was a bifurcated windsock with limited depth. During the procedure there were eight (8) recaptures. The physician was reviewing a routine follow up computed tomography (CT) scan and imaging showed the closure device shifted distally resulting in a 2mm to 4.5mm sub-fabric leak. No further information was provided.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50372499 ↗

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