FDA Issues Safety Alert on Boston Scientific’s Watchman Access Systems — Procedural Risks Under Review

On August 5, 2025, the U.S. Food and Drug Administration (FDA) released an early safety alert for Boston Scientific’s Watchman Access Systems, which are used in implanting the Watchman left atrial appendage occlusion (LAAO) device.

The alert follows reports of 120 serious injuries and 17 patient deaths as of July 30, 2025, primarily due to air embolisms occurring during device implantation. While the implanted Watchman devices themselves are unaffected, the agency warns that the access systems used in their placement can create procedural hazards under certain conditions—particularly in cases performed under conscious or deep sedation without positive-pressure controlled ventilation.

This development has significant implications for cardiology surgical teams, hospital supply chain management, and procedural training programs.

Background on the Watchman Device

The Watchman device, first approved by the FDA in 2015, is designed for patients with non-valvular atrial fibrillation who require stroke prevention but are unable to take long-term oral anticoagulants. The implant closes off the left atrial appendage, where blood clots commonly form.

Implantation is performed via a transseptal catheter approach, using an Access System that introduces the Watchman implant into the left atrium. The FDA’s current concerns are not with the implant itself, but with the delivery system used during the procedure.

According to the FDA and Boston Scientific’s updated Instructions for Use (IFU), the primary hazard identified is air embolism—the entry of air into the circulatory system during device exchanges or catheter manipulation. This can result in:

• Arrhythmia

• Stroke

• Circulatory collapse

• End-organ damage

The FDA’s early alert notes that risk factors include:

• Performing procedures without positive-pressure controlled ventilation

• Hypovolemia during sedation

• Keeping the access system’s valve above the level of the patient’s heart

• Exchanging components during phases of patient inhalation

In coordination with the FDA, Boston Scientific has:

1. Revised IFU Guidance

o Keep access valve below heart level during exchanges

o Maintain positive-pressure ventilation when possible

o Avoid exchanges during inhalation; instead, time them during exhalation

o Ensure patient is not hypovolemic

2. Distributed Urgent Field Safety Notices to all U.S. hospitals using the Watchman system

3. Updated Training Protocols for physicians and support staff in interventional cardiology and cardiac electrophysiology departments

Procedural Risk Mitigation

Hospitals must integrate the updated IFU guidance into their standard operating procedures (SOPs) immediately. Air embolism events are rare but catastrophic, and prevention depends on precise control over patient ventilation and device handling.

Staff Training and Competency

Interventional cardiology teams—especially those working in outpatient or hybrid OR settings—need rapid re-training. The revised recommendations may require anesthesia presence for cases that previously used only conscious sedation.

cheduling and Resource Allocation

Facilities may face short-term procedural slowdowns as teams adapt to the updated protocols, potentially impacting elective Watchman implantation volumes.

Regulatory Compliance

Failure to follow updated IFU recommendations could increase liability risk in the event of an adverse outcome, especially since the FDA’s alert is now public record.

Inventory Considerations

• Boston Scientific’s update does not require product recalls but does require that updated IFUs be distributed with all stocked Access Systems.

• Supply managers should verify that any on-site inventory includes the revised documentation and that staff are trained before next use.

Procurement Implications

• No alternative suppliers for Watchman implants exist; however, some facilities may explore alternative LAAO devices (e.g., Abbott’s Amplatzer Amulet) for select patients if procedural risk perceptions shift.

Cost Factors

• Additional anesthesia requirements or extended procedural times could increase the per-case cost of Watchman implantation.

This event underscores the importance of post-market surveillance—identifying safety concerns not during device approval, but during widespread use in real-world settings. The Watchman’s base technology remains valuable, but its delivery method now requires tighter procedural control.

The surgical market takeaway:

• Continuous vigilance post-approval is essential

• Rapid protocol dissemination can prevent future harm

• Cross-team coordination (surgery, anesthesia, nursing, procurement) is critical for fast adoption of safety updates

“This is a classic example of how procedural environment—not the device itself—can create risk. The Watchman remains a key technology for stroke prevention in atrial fibrillation, but the access method demands absolute adherence to new safety protocols. Hospitals that act quickly to retrain and adjust workflows will protect both patients and procedural volumes.”

— Surgical Market Watcher Team

Immediate Training: Conduct targeted briefings for all physicians, anesthesiologists, and cath lab nurses involved in Watchman implants.

Protocol Update: Incorporate revised IFU steps into institutional SOPs and checklists.

• Audit Inventory: Ensure all stored Access Systems have updated instructions attached.

• Monitor Adverse Event Reports: Track FDA’s MAUDE database for emerging incident patterns.

• Reassess Case Selection: Review which patients may require general anesthesia for optimal safety.