Does Mom get a side of bacon with her new heart valve?

There's a farmer joke about a pig with a wooden leg.

When a traveling salesman asks how the pig lost his leg, the farmer launches into a series of heroic tales about how the pig once bolted through the flames of their burning house to drag his unconscious wife to safety, risked its life to rescue their baby from a pack of wolves, saved their daughter from drowning in the creek, and even managed to use its snout to call 9-1-1 on a cell phone after the farmer's heart attack.

Amazed, the salesman still can't understand how the pig lost his leg.

"Well," the farmer explains. "A pig that good, you can't eat all at once."

My 81-year-old mom, who should go home from the hospital in a few days, owes her life to the common pig.

Of course, Mom's cardiologist (and my old fraternity brother) R. Jeffrey Snell, surgeon Robert J. March and the team at Rush University Medical Center deserve credit for making it all happen flawlessly. But, as farm people who know a thing or two about pigs, Mom and I are curious about her new aortic valve that was made from a combination of heart valves from two pigs.

While it was the subject of jokes back in the 1970s when actor John Wayne got a pig valve, the procedure is commonplace today.

"Valve replacement surgery has been around for decades," says Hinsdale veterinarian Taylor Bennett, a University of Illinois at Chicago researcher and senior scientific adviser for the National Association for Biomedical Research. "We live in a fast-changing world. It's hard to keep up. But we're still using pig valves."

Just as Homer Simpson marveled in disbelief at this "wonderful, magical animal" that gives us pork chops, ribs, ham, sausage, chitlins and bacon, Mom and I wonder about the pigs that gave her a new heart valve.

"They come from the slaughterhouse as far as I know," Bennett says. "Pigs are not bred and raised and slaughtered for the valves."

So pigs that provided Mom's new heart valve might also have contributed to her breakfast plate? And their intestines might have been used to make the blood thinner she took after surgery?

"Most porcine heart valves come from pigs born of a sow bred for good mothering capabilities and large, healthy litters," says Joe McGrath, a spokesman for the cardiovascular unit of Medtronic Inc., an international medical technology company that is one of the leaders in heart valve products.

Pigs are monitored, vaccinated and given government-approved care.

"All tissue for Medtronic heart valves come from either USDA-approved processing plants in the United States or approved processing plants in Western Europe and Australia," McGrath says.

When the pigs go to slaughterhouses, onsite veterinarians or inspectors harvest the hearts, pack them in temperature-controlled containers and ship them within 24 hours to facilities where they are hand-sewn into heart valves for humans. To meet the demands of patients from children to large adults, the pigs vary in size from 12 pounds to 350 pounds, McGrath says.

While Mom has a soft spot for the majestic Chester White pigs once raised by her brother, their valves are no different than those found on a Hampshire, Yorkshire, Berkshire, Duroc or other breeds. When it comes to heart valves or bacon, pigs are pretty consistent.

And Mom is doing great.

"Good," says Bennett. "It's really kind of amazing what they can do."

I'm not sure if he was talking about all the medical personal or those amazing pigs.