California researchers have developed a technique to grow artificial blood vessels from a patient's own skin cells -- a technique that could quickly find application in kidney-failure victims undergoing dialysis.
The technique has been tested in 10 patients, and preliminary results published Thursday in the journal Lancet suggest that the blood vessels can remain viable for long periods.
"This technology is very, very promising," Dr. Vladimir Mironov of the Medical University of South Carolina wrote in an editorial accompanying the report.
About half of kidney-dialysis patients require a permanently implanted tube to connect their circulatory system to a dialysis machine because they have no suitable blood vessels that can be harvested. But these plastic tubes leave patients susceptible to infections and inflammation.
Researchers at Cytograft Tissue Engineering in Novato take skin cells from the back of a patient's hand and extract two types of cells -- fibroblasts that provide the structural framework of the vessels and endothelial cells that provide the lining. The cells are grown in flat sheets in the laboratory, then formed into a tube. The process takes about six months.
The shunts have been tested in 10 high-risk kidney patients in Buenos Aires and Katowice, Poland, Todd McAllister of Cytograft reported in Lancet. Three of the patients suffered a failure during the first three months of the trial -- a not-unexpected result considering the patients' risk factors, McAllister said. Another withdrew from the study and a fifth died of unrelated causes. The rest of the grafts have functioned for as long as 20 months.
The chief drawback of the new vessels is likely to be cost, Mironov said. They are expected to cost $15,000 to $20,000, compared with about $3,000 for the plastic tube.