FDA elevates Boston Scientific cryoablation correction effort following four deaths

The FDA is elevating a recall from Boston Scientific covering its cryoablation balloon catheters for the treatment of atrial fibrillation.

No hardware is being removed from use—instead, the company’s effort focuses on updating the instructions for the POLARx procedure, following a higher-than-anticipated number of reports detailing damage to the esophagus, including seven injuries and four deaths. The agency said it has classified the recall in its most serious category.

Boston Scientific first alerted healthcare providers of the potential risks in mid-October, specifically of the rare chances of developing an atrial-esophageal fistula—a possibly fatal complication, where thermal energy from the catheter causes a connection between the heart’s atrium and the esophagus.

Leaks between the two organs can cause gastrointestinal bleeding, as well as salvia and air bubbles within the bloodstream that block the flow of oxygen, in addition to the risk of septic infections.

The company urged providers to monitor the location of the balloon during the procedure and its proximity to the esophagus and to avoid performing cryoablation directly on the posterior wall of the left atrium. It also recommended maintaining the balloon’s temperature, and to not perform immediately repeated ablations within the same area.

A probe may also be placed in the esophagus to check its temperature, and freezing should be paused if it drops below 20° C, according to Boston Scientific.

The safety communication from the FDA follows one from earlier this week regarding a subset of Boston Scientific’s pacemakers. Among certain models manufactured before September 2018, certain battery production techniques could lead to the implants being underpowered in specific circumstances, potentially causing them to enter a safety mode with limited functionality.