French Team Implants First Long-Term Artificial Heart 106
Posted
by
timothy
from the bunch-of-greedy-capitalist-heart-makers dept.
from the bunch-of-greedy-capitalist-heart-makers dept.
TrueSatan writes "Physicians at the Georges Pompidou European Hospital in Paris have inserted a heart made by the French Carmat company. The heart features bovine tissue components used to reduce the clot forming tendencies of fully artificial units and is intended to allow greater freedom of movement to the patient than previous, short-term use, units permitted. It is powered by external, wearable, lithium-ion batteries and is approximately three times heavier than a typical (European) human heart, though the manufacturer intends to reduce the weight and size of the unit so as to allow use by smaller recipients — in particular most women and men from areas of the world where average body size is less than white/Caucasian averages."
Pulsatile vs Pulse-less Designs (Score:5, Informative)
In modern times, Artificial Heart designs have been diverging into two camps. This one belongs to the old-school cardiac mimics -- complex multi-chamber pumps designed to mimic the pulsatile flow of a natural heart. The bovine pericardium lining is a clever idea -- we already make bio-prosthetic valves (mostly from pig heart valves). As the material is non-living connective tissue, it doesn't raise the same acute rejection problems that living xeno-grafts have. And, while most patients with such valves still require permanent treatment with drugs to prevent clots, the required degree of anti-coagulation is much less than those required with mechanical valves.
The other school consists of the pulse-less turbine-type devices. Instead of mimicking a natural heart, these devices use a high-speed rotating impeller to drive fluid flow. It was once thought that the shearing forces of an impeller would result in too much damage to red blood cells, and that pulsatile flow of blood was a necessary feature physiological feature, but non-pulsatile later-generation Ventricular Assistive Devices have demonstrated this is not the case. Currently, all such devices are only used as adjuncts to a failing natural heart, and there are no such devices approved as complete replacements -- yet. Compared with their more complex cousins, these devices are smaller and lighter, and mechanically more robust. However, they suffer from issues with clots and damage to leukocytes, due to the artificial materials used.
In either case, it will be interesting to see how the devices performs out in the field. The expected Five-year lifespan of a unit doesn't sound like much, but keep in mind many patients will be elderly, and your goal may simply be to give them improved quality-of-life, until in a few years something else kills them instead.