While implantable ventricular assist devices (VADs) have been keeping adults with heart failure alive for a number of years now, they haven’t been made small and effective enough for use in young children. The pumps have to remain outside the body and so present a host of side effects that require careful management by the clinical team.
This week at the American Association for Thoracic Surgery Annual Meeting, researchers are presenting a VAD that’s small enough to fit into a child down to 11 pounds (5 Kg) and that has proven itself in an initial study on live sheep.
The Infant Jarvik 2015, as the name implies, involved the legendary Robert Jarvik of the Jarvik Heart in the design. It’s capable of moving three liters of blood per minute, compared to around five for the currently available adult models. This should allow the device to serve children of different sizes and different cardiac assistance needs.
The pump’s performance in the pre-clinical study will be passed to the FDA for review in preparation for its initial use in severely ill kids, which the researchers hope will initiate later this year.
From the American Association for Thoracic Surgery:
In the current report, researchers implanted the pump in ten sheep through the apex of the left ventricle. The outflow graft was attached to the proximal descending aorta. Eight of the ten sheep completed the study and remained in good health, as indicated by appropriate weight gain, over a period of one to two months. The remaining two animals did not complete the study due to complications that were not directly related to the pump.
The most significant finding was very minimal hemolysis (premature destruction of red blood cells) despite high pump speed (the pump rotor spins up to 18,000 times per minutes). In six animals, there were small kidney infarcts, which is often seen in this type of animal studies in part due to inability to fully anticoagulate these animals. The entire VAD flow pathway was clean, without thrombi or fibrin deposits except in one.