COMPLIANCE CHAMBER PERFORMANCE IN THE FIRST CLINICAL APPLICATION OF THE Arrow LionHeart??? LVAS

Abstract

The Arrow LionHeart™ Left Ventricular Assist System (LVAS) is a completely implanted system that employs a compliance chamber implanted in the pleural space. The chamber compensates for displaced blood stroke volume and atmospheric pressure changes. The segmented polyurethane chamber is discoid-shaped (5 in. dia., 0.5 in. thick). The system has been implanted in 29 patients in Europe and 10 patients in the U.S. The longest surviving patient is alive more than 1100 days post implantation. All Lhambers performed satisfactorily, allowing normal pump output over a wide range of conditions. Fourteen compliance measurements were collected from 10 patients. The working range was found to be −50 to + 14 cc (84 cc volume change) over a pressure of −20 to + 5 mmHg 125 mmHg range). Six compliance measurements were made within the first 2 postop months, and eight were made between 7 months and 2 years. Overall compliance was 3.39 cc/mmHg (95% CI: 2.7, 4.06). Repeated assessments showed no significant changes in compliance over time. Refill intervals were typically monthly, but ranged from 2- 6 weeks. The gas loss rate was estimated to be 2–3 day with the system filled with room air. Gas loss rates measured during pre-clinical animal testing were not significantly different, averaging 2 cc/day (95% CI: 1.2, 2.8). The compliance chamber allows for an intact-skin system that may contribute to improved quality of life for long term LVAS patients.