WATCHMAN FLX™ Pro M635WU60270Recalls & reported problems

Summary

The FDA's MAUDE database contains 596 adverse event reports that list this exact device (DI 00191506004606), received between Oct 26, 2023 and Sep 30, 2026 — classified as 57 deaths, 524 injuries, 15 malfunctions.

The most frequently reported specific device problem is “Migration” (65 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 596 reports, 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 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 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 ↗
• InjurySep 23, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that there was a pericardial effusion.A left atrial appendage (LAA) closure procedure was being performed. A WATCHMAN Access System (WAS) and a 27mm 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.Six (6) days post procedure the presented to the emergency department experiencing a pericardial effusion. The physician performed a pericardiocentesis and drained 800cc of blood from the patient. There were no other complications that were reported to have occurred as result of this event.

  Patient problems: Pericardial Effusion

  MAUDE report 50869816 ↗
• InjurySep 17, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion occurred. A left atrial appendage closure procedure was being performed. Transseptal puncture was performed with a VersaCross Connect and a WATCHMAN FXD Double Curve Access System. Difficulty was noted in obtaining transseptal puncture. A 27mm WATCHMAN FLX Pro Closure Device was implanted. Post-implant, a pericardial effusion was noted around the ventricle during the final sweep. Additional protamine was administered and the patient was monitored on the table with physician present. The patient was still intubated, and transesophageal echocardiography was still in place. Transthoracic echocardiogram was performed as well. After some time, the physician determined the pericardial effusion was not large enough for additional treatment and the patient was sent to the recovery unit. A few hours later, a pericardiocentesis was performed. A drain was placed and the patient was kept overnight for observation. The next day, the patient was confirmed to be doing well and was discharged. The physician believed the pericardial effusion had been caused during transseptal puncture.

  Patient problems: Pericardial Effusion

  MAUDE report 50810128 ↗
• InjurySep 17, 2026Migration; Failure to Seal

  It was reported that device migration occurred and the implant did not seal. A 27mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was implanted on (b)(6) 2026. At a routine six month follow up appointment on (b)(6) 2026 transesophageal echocardiography (TEE) showed the device had shifted sideways and proximally in the appendage. The device was no longer meeting all of the criteria for position, anchor, size and seal (PASS) and was no longer therapeutic. There also appeared to be under fabric flow into the LAA. The physician plans to attempt to snare the device out of the appendage. There were no additional complications reported.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50809444 ↗
• InjurySep 17, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that ischemic stroke and peri-device leak (PDL) occurred.The patient previously underwent a concomitant atrial fibrillation ablation and left atrial appendage (LAA) closure procedure on (b)(6) 2026, under transesophageal echocardiography (TEE) guidance. A 27mm WATCHMAN FLX Pro Closure Device was implanted with no leak noted at the completion of the procedure. At the 45-day follow-up, TEE demonstrated the Closure Device in appropriate position with an approximately 2 mm peri-device leak and no evidence of device-related thrombus. The patient remained compliant with dual antiplatelet therapy consisting of aspirin and clopidogrel for approximately six months following implant.The patient subsequently presented to the hospital and brain magnetic resonance imaging (MRI) demonstrated an acute/subacute occipital ischemic infarct. The event was diagnosed as an ischemic stroke. No device-related thrombus had been identified on the prior 45-day TEE.

  Patient problems: Paresthesia; Stroke/CVA; Visual Disturbances

  MAUDE report 50805553 ↗
• InjurySep 16, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Cardiac Perforation; Chest Pain; Pericardial Effusion; Tachycardia

  MAUDE report 50796460 ↗
• InjurySep 16, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a pericardial effusion and cardiac perforation occurred. A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN Access System (WAS) and a 27mm WATCHMAN FLX Pro LAA Closure Device & Delivery System (WDS) were selected for use. While the physician attempted to recapture the closure device, an effusion was noted. While examining Transesophageal Echocardiography (TEE) images, it was observed the sheath tip was now in the transverse sinus, noting fluid was accumulating. It was noted there was a perforation of the posterior wall. The physician elected to discontinue the implant procedure as a result of procedure complications. Fluids were given to the patient, but no further intervention was required to manage the pericardial effusion.

  Patient problems: Cardiac Perforation; Pericardial Effusion

  MAUDE report 50789769 ↗
• InjurySep 15, 2026Migration; Failure to Seal

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50780047 ↗
• InjurySep 15, 2026Migration

  It was reported that device shift occurred.A left atrial appendage (LAA) closure procedure was performed, and a 27mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged. On the routine 45 day follow up transesophageal echocardiography (TEE) the closure device was found to be less compressed than it was after the procedure. The physician said that it was measuring 5 to 7 percent in two views. The closure device is still in a good position and has a complete seal per the physician. The current plans are to leave the closure device in its current position.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50778299 ↗
• InjurySep 14, 2026Migration; Failure to Seal

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50764989 ↗
• InjurySep 14, 2026Failure to Seal

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50764866 ↗
• InjurySep 11, 2026Migration; Failure to Seal

  REPORTED VIA PATIENT CALL CENTERIt was reported that device migration occurred and the implant did not seal. A left atrial appendage closure (LAAC) procedure was performed, and a 27mm WATCHMAN FLX Pro LAA Closure Device was implanted on (b)(6)-2024. The patient called the WATCHMAN patient call center and reported the device had become unrooted and rotated, creating a large crevice in the roof of the appendage. The patient was in for transesophageal echocardiography (TEE) imaging prior to a pulmonary vein isolation (PVI) procedure when the suspected leak was discovered. The patient reports imaging at the first follow up was normal. Imaging at the one year follow up showed a small leak. Computed tomography (CT) imaging has been scheduled for 14-Sep-2026, and a follow up physician visit on (b)(6)-2026.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50736615 ↗
• InjurySep 11, 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 27mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was implanted on (b)(6) 2026. The WDS was deployed and protruded approximately one half at the 135-degree angle in the posterior. The device was recaptured. The device was deployed from deep within the anterior on the second deployment. The protrusion in the posterior was approximately one third at the 135-degree angle. The compression rate was 16.7% to 21.5% and there was no leak noted around the device. An accessory left atrial appendage was identified. The physician determined that it could not be sealed with a single WATCHMAN implant and decided to release the device. The patient was discharged. At a routine follow up on (b)(6) 2026, a pericardial effusion was identified and a drain was performed. There was no additional information provided.

  Patient problems: Dyspnea; Pericardial Effusion

  MAUDE report 50736220 ↗
• InjurySep 10, 2026Device-Device Incompatibility; Device Dislodged or Dislocated; Migration

  It was reported that device embolization occurred. The patient required surgical removal. A left atrial appendage (LAA) closure procedure was being performed under transesophageal echocardiography (TEE) guidance. Pre-procedure imaging demonstrated challenging LAA anatomy. Transseptal puncture was performed using a fixed VersaCross Transseptal System. A 27mm WATCHMAN FLX Pro Delivery System and Closure Device (WDS) was initially attempted but was displaced proximally due to the appendage anatomy. A 24mm WDS was then attempted but did not achieve adequate compression. The physician subsequently returned to a 27mm WDS using a WATCHMAN TruSteer Access System (WAS).After several positioning attempts, the 27mm WDS met release criteria and was released. Following release, the Closure Device appeared to have shifted. The physician elected to retrieve the Closure Device and abort the procedure. After recrossing the septum and advancing a biotome for retrieval, the sheath contacted the Closure Device, causing it to dislodge and embolize into the left ventricular outflow tract (LVOT). Percutaneous retrieval from the LVOT was attempted but was unsuccessful. Cardiovascular surgery was consulted

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50723732 ↗
• InjurySep 10, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50721834 ↗
• MalfunctionSep 10, 2026Material Deformation

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50717779 ↗
• InjurySep 9, 2026Adverse Event Without Identified Device or Use Problem

  REPORTED VIA CLINICAL STUDY.It was reported that hypo attenuated thickening occurred.A left atrial appendage (LAA) closure procedure was performed, and a 27mm WATCHMAN FLX Pro Closure Device was successfully implanted on (b)(6) 2025. The patient was discharged. During a routine 12 month follow up computed tomography (CT), it was noted that the patient presented grade three (3) hypo attenuated thickening (HAT). There were no corrective actions or diagnostic tests associated with the finding.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50693421 ↗
• InjurySep 9, 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 27mm WATCHMAN FLX Pro Closure Device was implanted on (b)(6) 2026. The patient was discharged. On (b)(6) 2026, the patient presented for a routine follow-up transesophageal echocardiography (TEE), during which it was noted that the closure device had shifted, although it appeared stable. To further evaluate the finding, a computed tomography (CT) scan was obtained on (b)(6) 2026, which confirmed proximal closure device migration. Upon retrospective review of the follow-up TEE, color Doppler imaging demonstrated a leak on the ridge side, with no remaining fabric coverage. Following discussion with the physician, the decision was made to proceed with closure device explantation. The patient will resume anticoagulation therapy until the procedure. The planned retrieval strategy includes the use of a non-Boston Scientific (BSC) retrieval device, a grasping device, and a WATCHMAN TruSteer Access System (WAS) sheath. If the patient remains clinically stable and anatomy is suitable, a replacement closure device will be implanted during the same procedure, with th

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50692009 ↗
• InjurySep 8, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that thrombosis occurred.A left atrial appendage (LAA) closure procedure was being performed, and a 27mm WATCHMAN FLX Pro Closure Device was selected to be used. During the procedure, after deployment of the closure device, a mobile thrombus was noted inside the closure device but seemed to be biased towards the mitral annulus or posterior side of the appendage. The closure device was proximal, but safe to leave, so was evaluated for Position, Anchor, Size and Seal (PASS) criteria which was met and was released. The patient's activated clotting time (ACT) was greater than 400 during the procedure and was taken five (5) minutes after the second dose of heparin. Half of the heparin was administrated prior to transseptal and the other half after transeptal.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50670555 ↗
• InjurySep 4, 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 27mm WATCHMAN FLX Pro LAA Closure and Delivery System (WDS) was implanted on (b)(6)2023. The patient was admitted to the hospital for unrelated necrotic wounds on (b)(6)2026. Transesophageal echocardiography (TEE) imaging was done and incidentally showed a large mobile thrombus on the face of the WATCHMAN device. A thrombectomy was completed using an Angiovac system on (b)(6)2026. The procedure improved the thrombus significantly. The patient remained in the hospital to recover.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50602474 ↗
• InjurySep 4, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that esophageal perforation occurred.A left atrial appendage (LAA) closure procedure was performed, and a 27mm WATCHMAN FLX Pro Closure Device and a WATCHMAN TruSteer Access System (WAS) were selected to be used. During the procedure there were no issues with transseptal puncture or advancement of the VersaCross wire and there were no concerns relayed by the physician. There was a proximal amount of pectination but the physician was able to cover it with the closure device on the first attempt. The patient remained stable throughout the procedure, and no symptoms were observed until post-procedure. An echocardiogram was performed to evaluate for pericardial effusion and assess potential causes of hypotension. The patient was later found to have sustained an esophageal tear, which resulted in a decrease in hemoglobin levels to 6g/dL and required further medical intervention. The following day, a decrease in hemoglobin levels and the presence of coffee-ground stool were noted. On (b)(6)2026, the patient was admitted to the intensive care unit (ICU), needed multiple units of blood and platelets. The esophageal tear was managed with the placement of four hemoclips.

  Patient problems: Anemia; Hemorrhage/Blood Loss/Bleeding; Low Blood Pressure/ Hypotension; Perforation of Esophagus

  MAUDE report 50602154 ↗
• InjurySep 4, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion (PE) and cardiac tamponade occurred.The patient was on Eliquis at the time of the event. A concomitant procedure consisting of pulsed field ablation and left atrial appendage (LAA) closure was performed under transesophageal echocardiography (TEE), intracardiac echocardiography (ICE), and fluoroscopic guidance. A trace PE was noted at baseline near the ventricular apex. Transseptal puncture was performed using VersaCross Connect along with a WATCHMAN Access System (WAS). A 31mm WATCHMAN FLX Pro Delivery System and Closure Device (WDS) was inserted and deployed on the first attempt without recapture or repositioning. Following Closure Device release, WAS removal, and groin closure, a post-procedure TEE sweep demonstrated an increased PE. The patient developed hypotension with cardiac compression. Pericardiocentesis was performed and approximately 180cc of dull-colored fluid was removed. No perforation site was visualized. The patient also required additional blood transfusion.

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

  MAUDE report 50602043 ↗
• InjurySep 4, 2026Failure to Seal

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50600134 ↗

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-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
• 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,