Pig Intestinal Tissue Helps Human Injury

L O S   A N G E L E S, April 17, 2001 -- Doctors are getting help from pigs to repair human shoulder injuries.

Orthopedic surgeons can now use tough tissue patches from pigs' intestines to restore ripped tendons in the shoulder called the rotator cuff.

About 20 percent to 40 percent of Americans each year get a torn rotator cuff, either due to a sports injury or aging, degenerative tissue.

Rotator cuff injuries can be debilitating.

"You have to kind of baby it all the time and you couldn't really put in certain directions or else my arm would come out of joint, which was painful," says Tom Archibald, a rotator cuff patient.

Pig Intestinal Fortitude

While some doctors told him surgery might hurt more than help, University of Southern California orthopedic surgeon Dr. John Itamura offered him a unique alternative — patching up his torn tendon with a piece of pig tissue.

The challenge in Archibald's case was that his tendon was so damaged it was difficult for doctors to stitch it together.

"It's like trying to suture together two pieces of wet toilet paper, which would be quite difficult to do," says Itamura.

The pig tissue, which is actually a 2 ½½-inch wide circle made from 10 layers of pig's intestines, gives the surgeon something to sew into, like a tissue bridge.

In December, the Food and Drug Administration gave DePuy OrthoTech, a division of Johnson & Johnson, approval to use this patch-like device, called Restore Orthobiologic Soft Tissue Implant, for repair of rotator cuff tears.

In 1998, the company, based in Warsaw, Ind., had received approval to use the device for other musculoskeletal injuries.

To date, U.S. doctors have implanted approximately 1,000 of these scaffolds for either soft tissue or rotator cuff repairs.

Pig Tissue Gets Absorbed

What surgeons do is sew the pig tissue into the torn tendon. Over time, the body creates new tissue around the area to fix the tendon. The tissue patch, which is made mostly of collagen, somehow stimulates the body to grow the new tendon tissue, also mostly collagen. The body also absorbs the remaining pig tissue.

Researchers at Purdue University and DePuy Orthopedics, both in Indiana, found that a certain layer of cells, called the submucosa, from the pig's intestines could act as this scaffold, after testing it and other tissues for such an effect.

The company takes the pigs' intestines, isolates the submucosal tissue and disinfects, sterilizes and processes it for use in human beings.

"As soon as I had the operation the thing I noticed most was the tightness that I had in my back and my shoulder again, which I hadn't had for 30 years," Archibald says.

"[I'm] looking forward to a second half of life with more than I was able to do in the last 30 years."

ABCNEWS' Denise Dador and ABCNEWS.com's Robin Eisner contributed to this report.