title: Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?
abstract: Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation ("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter,prospectiveregistries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Elia
authors.initials: E
authors.lastname: De Maria
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Ambra
authors.initials: A
authors.lastname: Borghi
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bonetti
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Fontana
authors.affiliation: Elia De Maria, Ambra Borghi, Lorenzo Bonetti, Pier Luigi Fontana, Stefano Cappelli, Cardiology Unit, Ramazzini Hospital, 41012 Carpi (Modena), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Cappelli
keywords: Biotronik implantable cardioverter defibrillator lead; Externalized conductors; Implantable cardioverter defibrillator; Insulation failure