Dog’s Muscle Grafted to Boost Its Heart

In a revolutionary approach to aiding a deteriorating heart, surgeons in Philadelphia have created an auxiliary heart booster out of a dog’s back muscle and then implanted it in the dog.

If such a blood pump were constructed of a human patient’s own muscles, it would eliminate the rejection problem that now endangers heart transplant patients, the long waits for available donor hearts and the need for awkward external power sources for mechanical blood pumps.

Despite advances in drug treatment, heart transplants and the artificial heart, thousands of people die annually with irreversible heart failure.

The auxiliary muscle blood pump was formed by Drs. Larry Stephenson, Michael Acker and colleagues at the University of Pennsylvania Hospital and connected to the dog’s circulatory system Nov. 11. The mixed-breed dog, Bruno, was reported “healthy, happy and active.”

Stephenson reported the development at a National Heart, Lung and Blood Institute conference last week in Bethesda, Md., saying it is the first such system to work independently in an animal.

The muscle from the dog’s back was rolled into a multilayered spiral with a cavity in the middle. It then was connected to the animal’s blood vessels and nerves. Three weeks later the dog’s aorta, it’s largest artery, was redirected so that it fed in and out of the muscle cavity.

A battery-powered pacemaker synchronized to the beat of the dog’s heart was connected to a nerve leading to the displaced muscle to stimulate it into contracting at the proper rate.

Stephenson and Acker plan more dog tests before trying the technique in humans, but they said they see no reason why the same process would not work in humans. Stephenson acknowledged that such an operation probably is at least two years away.