Abstract 2985: Mid-term Off-pump Implantation of Axial Flow Pumps (LVAD) in a Preclinical Chronic Ischemic Heart Failure Model
BACKGROUND: Successful off-pump implantation of left ventricular assist devices (LVADs) with axial flow in patients with low ejection fraction (EF) would be of great clinical relevance. Prior to clinical application, new devices and implantation techniques are usually tested in healthy animals as chronic heart failure models for LVAD-therapy are not available. Aim of our study was the establishment of a new technique with off-pump axial flow-LVAD in a chronic ischemic heart failure model.
METHODS AND RESULTS: 9 sheep underwent intracoronary microsphere injection into the circumflex artery in order to create chronic ischemic heart failure. Reduced EF was assessed using echocardiography (TEE). All animals underwent off-pump implantation of a new mini axial flow pump by an extraperitoneal, sub-costal surgical approach with the final goal of postoperative survival. Our technique allows easy exposure of the diaphragmatic surface of the heart and the descending aorta. 9 animals (65–78 kg) underwent off-pump implantation 30 (25–33) days after intracoronary sphere injecetion. All animals had a significantly reduced EF (15–30%). 8 animals survived the surgical procedure (12 hours-33 days). The average 12-hour blood loss was 435 ml. The procedure time was not extended by any adverse events (60–145 min).
CONCLUSIONS: The extraperitoneal, sub-costal surgical approach is less invasive than a median sternotomy and allows axial flow pumps to be implanted quickly and without cardiopulmonary bypass (CPB) in animals with severely decreased LV-function. Our model can be used for additional surgical or medical studies involving LVAD therapy.