An implantable left atrial pressure sensor lead designed for percutaneous extraction using standard techniques.

BACKGROUND: An implantable left atrial pressure (LAP) monitoring system for guiding the management of patients with advanced heart failure has the potential to require extraction, particularly in the setting of infection. The LAP sensor lead was designed to be suitable for ease of percutaneous extraction using standard techniques for extracting pacemaker and defibrillator leads. The clinical experience, to date, with percutaneous extraction of the LAP sensor lead is presented. METHODS: A total of 82 patients underwent successful implantation of the LAP sensor lead using transseptal catheterization. Five patients of the 82 patients during a cumulative follow-up period of 267 patient-years (median of 2.9 years/patient) underwent percutaneous extraction using manual traction with a locking stylet and/or an excimer laser sheath to bore through adhesions. The distal fixation anchors of the LAP sensor lead are designed to fold forward during extraction so that the sensor module can easily separate from the interatrial septum. RESULTS: Percutaneous extraction of the LAP sensor lead was accomplished successfully in all five patients with no embolic events, vascular tears, perforations, or other complications requiring surgical intervention. Manual traction alone was sufficient to detach the LAP sensor lead from the interatrial septum in all cases. Use of the excimer laser sheath was needed in selected cases to bore through scar tissue within the venous insertion site, but not within the heart. CONCLUSIONS: The extraction of the LAP sensor lead was accomplished safely using standard techniques and equipment for percutaneously extracting pacemaker and defibrillator leads.

Comparative pathology of an implantable left atrial pressure sensor.

A left atrial pressure (LAP) monitoring system was developed for guiding the management of patients with heart failure. The LAP sensor is implanted into the left atrium via transseptal catheterization and affixed to the interatrial septum by nitinol anchors. The long-term safety of permanent implantation of the LAP sensor in patients was evaluated based on the comparative pathology in animals. Tissue specimens of the LAP sensor from 7 patients, 49 canines, and 14 ovine were examined for thrombosis and tissue overgrowth. Implant duration ranged from 22 to 1,686 days. Gross examination showed minimal-to-moderate tissue overgrowth with no evidence of migration, erosion, or perforation. There was no excessive host-to-device reaction or active thrombogenesis in any of the subjects that followed the antithrombotic therapy protocol. Micro-computed tomography scanning confirmed the structural integrity of the device. Low vacuum scanning electron microscopy and histology showed neoendocardial tissue overgrowth with no inflammation or fibrin. The pathology of both animal models was found to closely approximate the pathology in humans and favorably supports the long-term safety of the device.