Boston Scientific Watchman Access System Air Embolism Lawsuit Lawyers

Boston Scientific Issues Urgent Safety Update Over Increased Risk of Air Embolism During Watchman Implant Procedures

The Watchman Access System, developed by Boston Scientific, is a medical device intended to help prevent strokes in patients with atrial fibrillation. It is part of a minimally invasive procedure where the device is inserted into the heart to close off the left atrial appendage, reducing the risk of dangerous blood clots.

Recently, the U.S. Food and Drug Administration (FDA) and Boston Scientific issued an urgent safety alert for specific Watchman Access System models. This alert stems from troubling data showing that patients undergoing implantation without positive pressure-controlled ventilation face a three-times higher risk of serious complications, including stroke, organ damage, or death.

As of July 30, 2025, the manufacturer reported 120 serious injuries and 17 deaths linked to these risks. This warning is part of the FDA’s pilot program to improve the speed and transparency of medical device safety updates. For individuals who may have been harmed during a Watchman procedure, the alert raises significant legal and medical questions.

What is the Watchman Access System and How Does It Work?

The Watchman Access System is designed to be used during a left atrial appendage closure (LAAC) procedure. This procedure is performed on patients with atrial fibrillation not caused by a heart valve problem who are at risk for stroke but may not be ideal candidates for long-term blood thinner use.

During the procedure, a catheter-based sheath is inserted through a vein in the leg, advanced to the heart, and passed through the septum to access the left atrium. The Watchman device is then deployed to permanently seal off the left atrial appendage.

While the Watchman device itself has been used successfully for many patients, the new safety alert focuses on the specific Access System equipment used during the implantation — particularly in cases where the patient is not placed under positive pressure-controlled ventilation during the procedure.

Details of the FDA and Boston Scientific Warning

The July 30, 2025, warning letter issued by Boston Scientific highlights a critical risk of air embolism — a potentially fatal event where air enters the bloodstream and disrupts circulation. The letter explains that without positive pressure ventilation, certain patients are at significantly greater risk of:

• Negative left atrial pressure, which can draw air into the heart.
• Air ingress through the sheath during device insertion or exchange.
• Resulting complications such as arrhythmias, hemodynamic collapse, stroke, or organ failure due to ischemia.

The warning specifies that the risk is three times higher for patients not under positive pressure-controlled ventilation and is particularly elevated in those with:

• Pre-existing low left atrial pressure.
• Hypovolemia (low blood volume).
• Partial upper airway collapse during sedation.

These findings are not speculative — they are based on real-world outcomes. Boston Scientific disclosed 120 serious injuries and 17 deaths connected to this issue.

What Causes the Risk of Air Embolism in Watchman Procedures?

Air embolism occurs when air bubbles enter the bloodstream and travel to the brain, heart, or other organs. In the context of the Watchman Access System, this can happen if the pressure in the left atrium drops below the surrounding air pressure during insertion or device exchanges.

Without positive pressure ventilation, patients may inhale and exhale in a way that creates intermittent drops in left atrial pressure. These pressure drops can allow small amounts of air to be drawn into the heart via the sheath, especially if it is positioned above the level of the heart or if device exchanges occur too quickly.

The consequences can be severe:

• Neurological Damage: Stroke or brain injury from air bubbles blocking cerebral arteries.
• Cardiac Collapse: Arrhythmias or complete loss of circulation due to impaired heart function.
• Organ Failure: Ischemic injury to kidneys, liver, or other critical organs.

The warning also emphasizes that these complications can occur even if the device is implanted correctly, meaning the risk is tied directly to procedural factors.

Safety Recommendations and Procedural Changes

To reduce the risk of air embolism, Boston Scientific and the FDA have updated procedural instructions for all clinicians using the affected Access Systems. The new recommendations include:

1. Ensure patients are not hypovolemic before the procedure, especially if positive pressure ventilation is not used.
2. Maintain the sheath valve below the heart level and/or submerged in fluid during insertion to minimize air entry.
3. Select the appropriate anesthesia method based on the patient’s physical and medical profile, with consideration of using positive pressure ventilation for higher-risk individuals.
4. Perform device exchanges under fluid and below heart level, withdrawing devices slowly to limit the chance of air being drawn into the system.

Boston Scientific also announced that updated instructions will be added to Watchman physician training programs to prevent further incidents.

Who May Be Affected by This Warning?

The current safety alert applies only to patients undergoing a Watchman implantation procedure. Patients who already have the Watchman device in place are not at risk from this specific issue and do not need additional testing or removal of the device.

The greatest potential impact is on:

• Patients who experienced unexpected complications during the implantation procedure.
• Families of individuals who suffered a stroke, heart failure, or death during or shortly after the procedure.
• Individuals whose medical records indicate air embolism or other ischemic events during implantation.

Potential Legal Claims for Watchman Access System Injuries

When medical devices cause harm due to inadequate instructions, design flaws, or procedural hazards that were not properly disclosed, patients may have grounds for legal action. Possible claims related to Watchman Access System injuries could include:

• Product Liability: Alleging the device or its instructions were defective or failed to include adequate warnings.
• Medical Malpractice: Claiming procedural negligence by the medical team during implantation.
• Wrongful Death: For families of patients who died due to procedural complications linked to the device.

Given the reported number of serious injuries and fatalities, there may be a substantial number of individuals and families eligible to pursue claims for compensation covering medical costs, lost income, long-term care, and emotional distress.

Watchman Access System Lawsuit FAQs

What is the Watchman Access System?
It is a medical device used to close off the left atrial appendage in patients with atrial fibrillation to prevent strokes without long-term blood thinners. The Access System is the specialized catheter equipment used to implant the Watchman device.

Why is there a safety warning?
The FDA and Boston Scientific issued the warning after identifying a three-times higher risk of serious complications, including air embolism, stroke, and death, during procedures without positive pressure-controlled ventilation.

How many injuries and deaths have been reported?
As of July 30, 2025, there have been 120 serious injuries and 17 deaths linked to this procedural risk.

Does this affect patients who already have the Watchman device?
No. The warning applies only to the implantation process. Patients who already have the device and did not experience complications during surgery are not affected.

Can I sue if I was injured during a Watchman procedure?
You may have grounds for a product liability or medical malpractice claim, depending on the circumstances. Consulting with a law firm experienced in medical device litigation is crucial to determine eligibility.

What compensation could I receive?
Possible damages include medical expenses, lost income, long-term care costs, and compensation for pain, suffering, or loss of a loved one.

Contact Parker Waichman LLP For A Free Case Review

If you or a loved one suffered complications during a Watchman implantation procedure, you may be entitled to significant compensation. Parker Waichman LLP is a national law firm dedicated to protecting the rights of medical device injury victims. Our attorneys are currently investigating claims related to the Watchman Access System and the recent FDA safety alert.

Call 1-800-YOUR-LAWYER (1-800-968-7529) today for a free claim consultation. We will review your case, explain your legal options, and fight to hold those responsible accountable. Regardless of your location or where your injury occurred, our nationwide product injury law firm is ready to explain your legal rights.