The FDA has classified Bolton Medical’s recall of its RelayPro Thoracic Stent-Graft System as Class I, the agency’s most serious category, reserved for problems that may cause serious injury or death. The escalation follows the manufacturer’s report of three patient deaths tied to a defect that can trap the graft inside the aorta during implantation.

The failure mode leaves little margin. According to the FDA’s notice, the device’s proximal clasp can disconnect from the outer control tube, leaving the graft unable to unclasp from the delivery system. A surgeon may notice “a lack of resistance felt when sliding the apex holder back accompanied by a failure to release the proximal stent.” Once that happens the implant cannot be recaptured, and, the FDA adds, “this failure mode is not able to be recognized until it occurs during the procedure.”

There is no device-level rescue. The agency states plainly that “no device-based bailout method has been identified for this specific scenario.” When the techniques in the instructions for use fail, clinicians are told that “clinical judgment should guide timely decision-making, including consideration of conversion to open surgery” — a high-risk fallback in patients undergoing what is meant to be minimally invasive thoracic aortic repair.

What the deaths involved

As of April 23, 2026, Bolton Medical, a subsidiary of Terumo Aortic, had reported three deaths associated with the issue. One patient died of an aortic perforation; two others died of stroke after the procedure was converted to open surgery.

“This failure mode can occur without prior warning and no device-based bailout method has been identified for this specific scenario.” — FDA recall notice

The recall (FDA number Z-2160-2026) covers all lots of the RelayPro N4 non-bare-stent configuration, 32 mm and above, spanning 49 reference numbers. The devices were distributed worldwide, including Puerto Rico, Argentina, Chile, Canada, Colombia, Mexico and the United Kingdom. The FDA logs the action as a labeling correction rather than a physical removal, and Bolton is directing customers to consider alternative stent-grafts until mitigation measures are in place.

The company initiated the action on April 22, sent customer letters on April 23, and the FDA issued an Early Alert on April 28 before classifying the recall as Class I on May 20. The root cause remains “under investigation by firm.” The RelayPro is used to repair aneurysms, dissections and tears of the thoracic aorta.