Echocardiographic assessment of a novel blood-guiding accessory for left ventricular assist devices in swine.

Abstract

Objectives: Left ventricular assist devices are part of the foundations of mechanical circulatory support. As such devices evolve in technology, so does their implantation techniques, becoming less invasive. We developed a novel blood-guiding accessory for less invasive implantation, redirecting the blood intracardially into the ascending aorta through a transaortic outflow.

Methods: Ten healthy female swine (German Landrace, 104.4 ± 13.0 kg) underwent epicardial echocardiography before and after left ventricular assist device implantation. Cardiac geometry, aortic valve function and outflow positioning, were assessed before and after implantation.

Results: Epicardial echocardiography revealed sufficient biventricular unloading after device implantation. The end-diastolic and end-systolic left ventricular diameters decreased by 16% and 20%, respectively. Retrograde unloading was displayed by smaller diameters in left and right atria at 22% and 25%, respectively. At baseline, one animal presented mild aortic regurgitation, unchanged under mechanical support, whereas one developed mild de novo insufficiency. The outflow graft was either well centered within the aortic valve (n = 3) or between two cusps.

Conclusions: A left ventricular assist device with the accessory allowed sufficient ventricular unloading, preserving biventricular function. Although the outflow graft was well centered within the aortic valve in only 30% of the cases, no relevant aortic regurgitation was found in the acute setting. Chronic testing in larger samples is required to analyze results in long term.