WATCHMAN TruSteer™ Access System M635TU90050Recalls & reported problems

Summary

The FDA's MAUDE database contains 302 adverse event reports that list this exact device (DI 00191506022310), received between May 20, 2024 and Sep 28, 2026 — classified as 28 deaths, 250 injuries, 24 malfunctions.

The most frequently reported specific device problem is “Material Deformation” (12 reports).

1 FDA recall record name this device's identifier, 1 still open.

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.

Recalls naming this device

1. Jul 29, 2025Class IOpen, Classified

   Boston Scientific has identified a higher likelihood of air embolism events when procedures are performed without positive pressure-controlled ventilation. According to published literature and clinical data, in percutaneous procedures requiring transseptal access to the left atrium when conscious or deep sedation is used, patients have an approximately three-times higher risk (U.S. study) of negative left atrium pressure and air ingress. This risk is especially prevalent in patients with pre-existing low left atrial pressure, hypovolemia, and partial upper airway collapse.

   Z-2436-2025 · Root cause: Under Investigation by firm · Recall details · FDA record ↗

Most reported problems

Recent adverse event reports

The 25 most recent of 302 reports, in the reporter's own words as published by the FDA.

• MalfunctionSep 28, 2026Deformation Due to Compressive Stress

  It was reported that device damage occurred.During a left atrial appendage (LAA) closure procedure using transesophageal echocardiography (TEE) guidance, a 35mm WATCHMAN FLX Pro Delivery System and Closure Device (WDS) and WATCHMAN TruSteer Access System (WAS) were used. The procedure was performed without incident, and the Closure Device was successfully released. Following release, the physician attempted to advance a wire through the WAS; however, the wire would not advance. The WAS was removed, and a kink was observed in the access sheath. It was reported that the sheath had been maintained in the neutral position while withdrawing to the right side of the heart and that no excessive force was used during the procedure. The WAS was removed, and the groin access site was closed. The procedure was completed as planned, and the patient remained stable with no additional problems reported.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50915803 ↗
• InjurySep 18, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a circumferential pericardial effusion, cardiac tamponade and cardiac perforation occurred. A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN TruSteer Access System (WAS) was selected for use. A small baseline effusion was noted in the transverse sinus adjacent and deep to the LAA just before the procedure. The initial transeptal puncture (TSP) was performed. The physician inserted the TruSteer sheath and parked it inside the LAA. Using Transesophageal Echocardiography (TEE), a small amount of fluid in the transverse sinus and in the LAA was noted. The physician inserted the pigtail catheter. Using fluoroscopy, it was noted the pigtail catheter jumped outside of the sheath. Using TEE, it was noted contrast filling in the transverse sinus/pericardium. At this time, the patient's vitals were noted, and the patient became hypotensive and tachycardic. The physician performed pericardiocentesis, draining approximately 1300mL of dull red colored blood from the pericardium, transfusing it back to the patient. The patient went into ventricular tachycardia and cardioversion was implemented. A pericardial drain was inserted, and the patient was

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

  MAUDE report 50818291 ↗
• InjurySep 17, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a thrombosis occurred. A left atrial appendage closure (LAAC) procedure was being performed, and a WATCHMAN TruSteer Access System (WAS) was selected for use. The initial transseptal puncture (TSP) was performed, and the pigtail catheter was inserted and advanced into the Left Atrial Appendage (LAA). The WATCHMAN TruSteer sheath was at the ostium of the LAA. Transesophageal echocardiography (TEE) imaging noted a thrombus on the pigtail catheter. The physician aspirated from the TruSteer sheath and removed the pigtail catheter from the appendage. The thrombus resolved. The WATCHMAN Closure Device (WDS) was successfully implanted in the LAA. As a result, the patient remains on their oral anticoagulant (OAC) medication.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50809988 ↗
• InjurySep 17, 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 WATCHMAN TruSteer Access System (WAS) and a WATCHMAN FLX Pro Closure Device and Delivery System were selected to be used. During the procedure, the activated clotting time (ACT) was 368 seconds. Half of the heparin dose was administered prior to transseptal puncture, with the remaining half administered afterward. There were no partial or full recaptures performed, and the closure device was successfully deployed on the first attempt. An echogenicity was noted on the TruSteer Access System as the closure device was deployed. While removing the Delivery System and TruSteer sheath out, the physician aspirated. The Delivery System was removed from the left side, and the echogenicity was not seen on left side. The scrub technician was able to flush the WAS sheath once it was out of the body and observed thrombotic material outside of the WAS sheath on distal tip. Per the physician, no thrombus was noted prior to transesophageal echocardiography (TEE) removal.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50804100 ↗
• InjurySep 17, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that the patient experienced an ST segment elevation.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 TruSteer Access System (WAS) and a WATCHMAN FLX Pro LAA Closure Device & Delivery System (WDS) were selected to be used. The physician inserted the WAS and imaging showed that the WAS was on the mitral valve. The physician then advanced the WAS into the LAA, and it was noted that the patient was experiencing an ST segment elevation. No air was seen in the patient or any device. The procedure was continued and the closure device was successfully implanted in the LAA of the patient. After the device was implanted it was noted that the patients vitals were getting better. Another physician came in to do a heart catheterization and those images were clean. The physician believes that they may have minorly injured the circumflex artery when they flipped the WAS from the mitral valve into the LAA and that the minor injury was already settling down by the time the pr

  Patient problems: Non specific EKG/ECG Changes; Perforation of Vessels

  MAUDE report 50802181 ↗
• InjurySep 16, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a thrombus occurred. A left atrial appendage (LAA) closure procedure was being performed. A WATCHMAN TruSteer Access System (WAS) and a WATCHMAN LAA Closure Device & Delivery System (WDS) were selected for use. The physician advanced the TruSteer sheath and pigtail catheter into the appendage. An Activated Clotting Time (ACT) measurement of 139 seconds was obtained. The physician paused to check ACT, this time measuring 143 seconds, and another 10,000 units of Heparin was administered. The pigtail was removed from the TruSteer sheath. As the pigtail catheter was removed from the patient's body, clots were noted on the pigtail catheter. The physician replaced the old TruSteer for a new one. ACT was measured and it was over 400 seconds. Physician proceeded with the implant procedure and a Closure Device was successfully implanted in the LAA.

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50791024 ↗
• InjurySep 16, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50790388 ↗
• InjurySep 16, 2026Air/Gas in Device

  It was reported that thrombosis occurred.A left atrial appendage (LAA) closure procedure was being performed under transesophageal echocardiography (TEE) guidance. Anticoagulation had been held for two days prior to the procedure. Following right femoral venous access and an 18 french non-Boston Scientific (BSC) sheath insertion, a WATCHMAN TruSteer Access System (WAS) and VersaCross system were advanced for transseptal puncture. Heparin was ordered prior to transseptal access; however, the non-BSC sheath stopcock was noted to be closed to the patient, and the initial bolus was not delivered. Heparin was subsequently administered within approximately one minute after transseptal puncture. The activated clotting time (ACT) was 213 seconds. A diagnostic pigtail catheter was advanced into the LAA and the WAS was positioned at the ostium. Air was then noted within the manifold and subsequently visualized within the WAS under fluoroscopy. The physician immediately stopped the procedure, aspirated the system, and withdrew the WAS to the right side of the heart. TEE then identified thrombus attached near the transseptal puncture site and extending into the left atrium with movement within

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50789763 ↗
• MalfunctionSep 16, 2026Use of Device Problem; Deformation Due to Compressive Stress

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50789351 ↗
• MalfunctionSep 16, 2026Air/Gas in Device

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50787310 ↗
• InjurySep 15, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50780305 ↗
• InjurySep 11, 2026Adverse Event Without Identified Device or Use Problem

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

  MAUDE report 50740300 ↗
• InjurySep 9, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that thrombosis occurred.A left atrial appendage (LAA) closure procedure was being performed under transesophageal echocardiography (TEE) guidance. The patient was not on anticoagulation prior to the procedure, and the LAA was confirmed to be free of thrombus before venous access was obtained. Following access, 11,000 units of heparin were administered. A WATCHMAN TruSteer Access System (WAS) was advanced into the left atrium following transseptal puncture, and a pigtail catheter was placed in the LAA. An activated clotting time (ACT) obtained approximately five minutes after the initial heparin administration was 121 seconds and was considered subtherapeutic. An additional 11,000 units of heparin were administered. When the pigtail catheter was removed, thrombus was visualized on the pigtail catheter while it was outside of the patient. A subsequent ACT was 280 seconds, and after further imaging assessment, the physicians elected to proceed. The pigtail catheter was reintroduced, and LAA angiography was performed. A 27mm WATCHMAN FLX Pro Delivery System and Closure Device (WDS) was then advanced. While the WDS was being unsheathed to the flex-ball configuration, a

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50695048 ↗
• InjurySep 8, 2026Adverse Event Without Identified Device or Use Problem

  It was reported a pericardial effusion occurred. A left atrial appendage (LAA) closure procedure was being performed. A WATCHMAN TruSteer Access System (WAS) was selected for use. The initial transeptal puncture (TSP) was difficult to perform as there was no visualization of the septum or the sheath via transesophageal echocardiography (TEE). The patient's blood pressure dropped, and a small effusion was noted. No intervention was performed and the physician elected to cancel the procedure. The patient was monitored overnight in the intensive care unit (ICU). No further complications were noted.

  Patient problems: Low Blood Pressure/ Hypotension; Pericardial Effusion

  MAUDE report 50668891 ↗
• InjurySep 4, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that cardiac perforation and pericardial effusion occurred. A left atrial appendage closure (LAAC) was being performed. A WATCHMAN TruSteer Access System (WAS) and a WATCHMAN FLX Pro LAA Closure Device and Delivery System were selected for use. The patient had a history of triple bypass surgery and a significantly rotated heart. A VersaCross Connect was used to complete the transeptal puncture (TSP). The TruSteer sheath perforated the aorta upon TSP. There was a small effusion underneath both right and left ventricles on transesophageal echocardiography (TEE). It was measured at 4mm and did not change. The patient was brought into the operating room for surgical intervention. There were no additional details provided.

  Patient problems: Cardiac Perforation; Pericardial Effusion

  MAUDE report 50612701 ↗
• InjurySep 4, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that thrombosis occurred. A left atrial appendage closure (LAAC) procedure was being performed. A WATCHMAN TruSteer Access System (WAS) was used with a VersaCross Connect to enter the superior vena cava (SVC). A full dose of Heparin was given and access was gained to the LA. Transesophageal echocardiography (TEE) imaging confirmed the wire position and also showed a clot was forming on the wire. The dilator was removed and the sheath was advanced closed to the wire, so an attempt could be made to aspirate the clot through the sheath. Part of the clot was pulled into the sheath, but it occluded the sheath so aspiration could not continue. A non-BSC device was attempted, but as it was exchanged out the wire was accidentally pulled into the sheath and sheared off the clot. The clot could not be located in any cardiac chambers, so it was assumed the clot embolized to the arterial or cerebral system. The patient remained stable. The procedure was discontinued and the patient was brought to the intensive care unit (ICU). The patient was woken up and given a neurological assessment. The patient status was unchanged compared to prior to the procedure. There were no signs of

  Patient problems: Thrombosis/Thrombus

  MAUDE report 50602426 ↗
• InjurySep 4, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion, chest pain, hypotension and thrombosis occurred. A left atrial appendage closure (LAAC) procedure was being performed. Prior to the procedure, the patient was known to have a patent foramen ovale (PFO), an extremely aneurysmal septum and difficult anatomy with a rotated heart. A WATCHMAN TruSteer Access System (WAS) was selected for use. It was decided to cross the septum above the PFO, rather than through. When attempting to advance VersaCross looped wire up the superior vena cava (SVC), the wire and sheath kept advancing through the PFO rather than up the SVC. Suboptimal imaging was a concern throughout the case. The physician was unable to visualize the sheath, wire and appendage on transesophageal echocardiography (TEE). A sweep was attempted to find the sheath and the wire. The sheath had crossed above the PFO. The sheath was riding parallel alongside the top of the aorta, but the end of the sheath and wire could not be seen on TEE. There was concern that the pericardial space had been crossed. Pericardial fluid was aspirated and the pigtail was withdrawn slightly. Blood was aspirated from the pigtail. Vitals were monitored while an e

  Patient problems: Chest Pain; Low Blood Pressure/ Hypotension; Pericardial Effusion; Thrombosis/Thrombus

  MAUDE report 50602403 ↗
• InjurySep 4, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Cardiac Perforation; Cardiac Tamponade; Perforation; Pericardial Effusion

  MAUDE report 50600345 ↗
• InjurySep 3, 2026Adverse Event Without Identified Device or Use Problem

  Patient problems: Asystole; Cardiac Arrest; Hypoxia; Low Blood Pressure/ Hypotension

  MAUDE report 50600003 ↗
• InjuryAug 24, 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 (0.8mm) baseline pericardial effusion prior to the procedure at the right ventricle. A WATCHMAN TruSteer Access System (WAS) and a 24mm WATCHMAN FLX Pro LAA Closure Device and Delivery System (WDS) was selected for use. Heparin was administered to achieve an activated clotting time (ACT) greater than 300 seconds. The WAS sheath was introduced, and transseptal puncture (TSP) was successfully performed. A guidewire was advanced into the left atrium (LA), and the sheath was advanced across the septum into the LA. A pigtail catheter was inserted, and an angiogram of the left atrial appendage was performed. The 24mm WDS was prepared for deployment. The pigtail catheter was removed, and the WDS was advanced through the WAS sheath. The Closure Device was unsheathed to flex ball, and an angiogram was obtained at that time. During assessment, an increase in the size of the pericardial effusion was observed. A transesophageal echocardiography (TEE) sweep was performed, which confirmed that the effusion had enlarged from its baseline m

  Patient problems: Low Blood Pressure/ Hypotension; Pericardial Effusion

  MAUDE report 50420744 ↗
• MalfunctionAug 24, 2026Deformation Due to Compressive Stress

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50420737 ↗
• InjuryAug 21, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion, cardiac tamponade and cardiac perforation occurred.A left atrial appendage (LAA) closure procedure was being performed, and a WATCHMAN TruSteer Access System (WAS) was selected to be used. During the procedure, while exchanging for a larger closure device, the exchange was performed without using a pigtail catheter. The clinical suggested re-advancing a pigtail catheter to facilitate safe sheath positioning. During the pigtail loading with the wire, the wire appeared to be in the pericardium. An effusion sweep was performed during the loading of the 24mm closure device, and a pericardial effusion was noted. The 24mm closure device was deployed safely, and met Position, Anchor, Size and Seal (PASS) criteria. Before releasing the closure device, a contrast shot was performed, raising concern for a perforation on the ridge side. The closure device was subsequently released, equipment was moved to the left side, and protamine was administered. The physician attempted to performed pericardiocentesis but was unsuccessful. A pericardial window procedure was then performed and additional blood was required. The patient was stable when transferred

  Patient problems: Cardiac Perforation; Cardiac Tamponade; Pericardial Effusion

  MAUDE report 50376439 ↗
• InjuryAug 21, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that cardiac perforation and pericardial effusion occurred.A left atrial appendage closure (LAAC) procedure was being performed concomitantly with an ablation procedure. After the ablation was completed, the sheath was smoothly exchanged for a WATCHMAN TruSteer Access System (WAS). The physician inserted a pigtail catheter into the LAA and advanced using fluoroscopy due to not having visualization on intracardiac echo (ICE). The WAS continued to be advanced up to the ostium. An appendagram was taken, but visualization was difficult, so the physician completed another contrast shot. The result was the same. The patient's blood pressure began to drop into the middle 70s systolic over 60 diastolic. An effusion check was completed, and an effusion was noted in the LAA. The patient remained stable and the electrocardiogram (EKG) remained the same. The physician spent additional time repositioning the WAS before discontinuing the procedure and addressing the effusion. The physician performed a pericardiocentesis and removed 400cc of bright red blood. An unknown amount of blood was re-transfused back into the patient. The bleeding continued and the physician realized the a

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

  MAUDE report 50372479 ↗
• InjuryAug 20, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that pericardial effusion occurred.A left atrial appendage (LAA) closure procedure was being performed, and a WATCHMAN TruSteer Access System (WAS) was selected to be used. The patient had a windsock anatomy with posterior bend. During the procedure the physician performed transseptal puncture with the WAS and a pigtail catheter. The pigtail catheter was advanced into the appendage and removed for closure device insertion. During transesophageal echocardiography (TEE) monitoring the physician noted more fluid being present around the appendage and was concerned for a pericardial effusion. The implanting physician placed the procedure on hold and had imaging physician sweep for size of effusion present. The effusion was seen around the left ventricle (LV) measuring one (1) cm in diameter, the patient was in atrial fibrillation (AF) with heart rate elevated to about 100 bpm for the entire case, and the blood pressure (BP) was elevated to about 170/80. The physician determined to abort procedure due to uncertainty of post-operation care. The patient was monitored with TEE for 20 minutes where vitals stabilized, the patient went into sinus rhythm, and the effusion never

  Patient problems: Atrial Fibrillation; High Blood Pressure/ Hypertension; Pericardial Effusion

  MAUDE report 50349135 ↗
• InjuryAug 19, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that a vessel perforation 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 concomitant procedure was successfully completed. A WATCHMAN TruSteer Access System (WAS) and a WATCHMAN FLX Pro LAA Closure Device & Delivery System (WDS) were selected to be used. The physician inserted the WAS in the patient, and the right femoral vein was perforated. The procedure was continued and the closure device was successfully implanted. The patients' blood pressure dropped after removing the WAS from the patient. The patient had a stent placed to repair the artery that was perforated. There was no other treatment or intervention performed for the patient. No other complications were reported to have occurred as a result of this event. The patient is expected to make a full recovery.

  Patient problems: Low Blood Pressure/ Hypotension; Perforation of Vessels

  MAUDE report 50329780 ↗