Abstract 13966: Chronic ICD Lead Removal From the Substernal Space is Feasible Without Complication

Abstract

Introduction: The transvenous ICD is the device standard for treatment of ventricular arrhythmias, but ICD lead extraction from the heart and vasculature has morbidity and mortality concerns. The extravascular ICD (EV ICD) with lead placement in the anterior mediastinum (substernal space) is in development as an alternative to transvenous ICD. Described is the first reported substernal lead removal experience from humans. Hypothesis: The anterior mediastinum, a soft tissue space absent major vascular elements, provides a suitable environment for chronic lead removal without complication. Methods: The first-in-human EV ICD pilot study was a prospective study conducted at 4 sites in Australia and New Zealand. Subjects with a class I or IIa indication for single-chamber ICD were implanted via minimally invasive technique, with the distal end of the lead placed substernally via an incision near the xiphoid, and the proximal end tunneled subcutaneously to a left midaxillary device. Results: A total of 21 patients underwent the EV ICD procedure, and 17 entered chronic follow-up after successful implant and testing. Among these 17 patients, 3 were electively explanted at 85, 114 and 310 days post-implant. Respectively, the first patient experienced a lead tip displacement resulting in P-wave oversensing and inappropriate shock; the second underwent elective chronic defibrillation testing 3 months post-implant, where a 10-Joule safety margin was not established; and the third experienced recurrent VT and intolerance to ATP due to high pacing threshold. Lead removals were conducted per HRS guidelines. The proximal end of the lead was removed from the device pocket to the xiphoid incision, with minor resistance noted in pulling the lead connector through the subcutaneous tunnel. Light traction was sufficient to remove the distal end of the lead from the substernal space, with minor tissue adhesions observed near the lead incision site. All leads were removed intact, and there were no adverse events associated with system removal. Conclusions: ICD lead removal from the substernal space is feasible through 310 days without adverse events. Further understanding from a larger patient population with greater implant duration will help verify these early results.