Engineering Vessels for Bypass Surgery, Grafts
WEDNESDAY, Oct. 22 (HealthDayNews) -- Tiny blood vessels taken from laboratory rats and re-engineered for implantation in other animals show promise for bypass surgery and grafts in humans.

This technique, developed by surgeons at the University of Michigan Health System, may in future benefit people who've already had vascular bypass surgery and need new blood vessels for subsequent procedures.

Here's how it works. The surgeons remove hair-width arterial grafts from the rats. Using a detergent solution, they remove all living cells from the rest of the tissue and insert vascular cells from the new host. The graft is then reimplanted. Using the new host's own cells reduces the chance of rejection.

"Small blood vessels are needed all the time for grafts to use in heart bypass surgery, lower extremity bypasses and tissue transfer," lead researcher Dr. David L. Brown, assistant professor, division of plastic surgery, says in a prepared statement.

"The biggest problem is finding a source for these vessels. A typical source is some other blood vessel in the patient's body. To be able to have something that we can manufacture ahead of time or be able to take off the shelf would be advantageous to many patients," Brown says.

Similar techniques using larger blood vessels have been tested in previous research. This is the first time that scientists have used such small blood vessels.

"You'd expect that the smaller the vessel is, the greater the chance that it would clot. But in our study, the blood vessels stayed open, despite being only 1 millimeter in diameter," co-author Dr. Gregory Borschel says in a prepared statement.

The research was presented Oct. 22 at the American College of Surgeons annual clinical congress in Chicago.

--Robert Preidt

SOURCE: University of Michigan Health System, news release, Oct. 22, 2003

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