Is polyurethane lead insulation still controversial?

A controversy arose some 10 years ago over the reliability of polyurethane lead insulation. On the basis of one of the longest standing and largest databanks worldwide, the authors compare the cumulative survival of several thousand polyurethane, standard silastic, and high-performance silastic electrodes as it pertains to the failure criterion described as insulation degradation. With the possible exception of the Medtronic 6972 (Medtronic, Inc.) electrode, polyurethane electrodes have a 100% reliability at 84 months, which is similar to silastic electrodes.