Kennesaw, GA - A human valve for pulmonary-valve replacement that has been stripped of its cells by a proprietary process and so may be less immunogenic than conventional allograft valves has been approved by the FDA [1]. The decellularization process that the manufacturer, CryoLife, uses on its CryoValve SynerGraft (SG) pulmonary valve leaves behind "a scaffold of connective tissue that still functions like a human heart valve, potentially lowering the risk of an immune response and subsequent tissue rejection," the agency said in a February 7 statement.

The CryoValve SG pulmonary human heart valve is "indicated for the replacement of diseased, damaged, malformed, or malfunctioning native pulmonary valves," according to a CryoLife press release [2]. "The valve can be used in conjunction with right ventricular outflow tract reconstruction procedures, commonly performed in children with congenital heart defects."

In a study of 342 SynerGraft valves implanted from 2000 to 2004, the FDA said, the company's decellularized valve "performed at least as well" as 1246 "traditional" CryoLife allograft valves with respect to structural deterioration, endocarditis, and thrombosis and "device-related operations" and patient mortality.

The company says it is planning a postmarket study "to seek evidence for the potential and implied long-term benefits of the SynerGraft process. Data to be collected are expected to include long-term safety and hemodynamic function, immune response, and explant analysis. CryoLife believes that this information may help it ascertain whether the SynerGraft process reduces the immunogenicity of the transplanted heart valve and recellularizes with the recipient's own cells."