The McGowan Institute’s teams of researchers—led by William Wagner, PhD, Michael Sacks, PhD, and David Vorp, PhD—are getting closer to technologies which will someday repair damaged hearts and veins.
From the labs of Drs. Wagner and Sacks it was recently reported a patch designed to help damaged cardiac tissue recover from a heart attack has been successful in early animal testing and is moving toward potential human use. In a trial with rats that had induced heart attacks, the patch was implanted directly on the damaged part of the heart wall. The wall was thicker, “with abundant smooth muscle bundles,” and healthier, mature heart cells. This biodegradable heart patch may one day prevent the long-term cardiac damage that so many suffer after a heart attack. A next step toward human use has started in an animal trial with pigs—a larger animal with responses more similar to those of people.
In patients with clogged arteries, bypasses usually fail because the replacement veins, which are often nonessential veins taken from another part of the body, aren’t up to the job. Veins are used to low blood pressure and low flow, and they don’t feel the pulsations of the heart. Arteries, on the other hand, have higher blood flow, higher shear stresses, and they pulsate because of their proximity to the heart. So when veins from the leg are plugged into the arterial environment, they tend to panic. When a vein is implanted into the arterial environment it assumes that it is injured and immediately tries to counteract the problem by thickening. As it thickens, the canal also begins to narrow, and you’re right back where you started from…a clogged artery. Researchers in the lab of Dr. Vorp hope to rectify this situation by making implanted veins stronger by first wrapping them in a biodegradable polymer material like the one developed for the Wagner and Sacks’ cardiac patch. It is proposed that once wrapped, the vein may not thicken as much upon exposure to its new, harsher environment. After a few days, the wrap—the vein girdle—degrades allowing the vein to slowly adapt to its new role.
PittMed (Summer 2007)
Abstract, Journal of the American College of Cardiology 2007;49:2292–300
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