Reliability of cardiac implantable electronic device leads

Abstract

This editorial refers to ‘Failure of a novel silicone–polyurethane copolymer (Optim™) to prevent implantable cardioverter-defibrillator lead insulation abrasions’ by R.G. Hauser et al. , on page 278–283 Leads are unquestionably the weak link in cardiac implantable electronic device (CIED) treatment, the insulation material in particular. Since the first fully implantable pacemaker employing epicardial leads in 1958, there has been an ongoing struggle to find the perfect insulation material. Various forms of silicone and polyurethane have been the main alternatives in addition to ethylenetetrafluoroethylene and polytetrafluoroethylene for internal electrical insulation. Silicone and polyurethane have their advantages and disadvantages and have been associated with considerable problems over the years; many will remember the shortcomings of the promising, at the time, 80 Da polyurethane. The development of lead insulation material is associated with several intrinsic problems; in vivo failures often show after considerable dwelling time. Even the best bench and animal tests have a problem imitating the challenging mechanical, chemical, and thermal environment of leads, especially reproducing long-term use in vivo . In addition to resisting these challenges, lead insulation materials need to provide sound electrical insulation. The fact that both manufacturers and physicians encourage the speedy development of thinner leads presents an additional challenge to lead reliability. Finally, the previous lack of strict regulatory rules when introducing new leads has been a shortcoming. It should be acknowledged that manufacturers have tried hard to provide better products and have improved their lead development processes in many ways, not least by better bench testing, extended …