Blood Vessels Grown in a Lab Safely Used in Dialysis Patients in Trial
Blood vessels grown in a laboratory were safely implanted in three kidney disease patients, enabling them to have regular dialysis without relying on traditional shunts that caused complications and failed, researchers said.
The foot-long vessels were engineered from donor skin cells, grown on sheets and rolled around temporary supports to form a cylindrical shape, according to the report released by the American Heart Association. The “off-the-shelf” vessels, which connected an artery to a vein in the arm, gave doctors access to the patients’ blood so they could perform dialysis.
The artificial vessels may one day benefit millions of people, including those who need heart bypass operations, surgery to circumvent diseased arteries in the legs or repair of congenital birth defects, said Todd McAllister, chief executive officer of Cytograft Tissue Engineering Inc., the closely held company based in Novato, California, that devised the grafts.
The technology “is clearly very new science,” McAllister said today on a conference call with reporters. “We certainly hope this is something that will be clinically available to a widespread number of patients within the next 24 months.”
The three patients, all from Poland, had such serious vein problems previously that they needed a catheter in the groin to get access for the dialysis, the researchers said. After eight months and numerous punctures starting at seven weeks, there was only one complication, caused when a needle fell out during dialysis. The resulting blood clot was removed and the patient is still getting treatment through the engineered graft.
Seeking Alternative
The high failure rates of synthetic grafts or a patient’s own vessels stitched together to create access for dialysis, “is a huge public health problem that has both clinical and economic complications,” said Robert Harrington, director of Duke University’s Clinical Research Institute in Durham, North Carolina. “If the work as demonstrated thus far continues in such a positive way, this is big news,” said Harrington, who wasn’t involved in the study.
The company is planning a large study abroad involving 40 patients who will get the engineered blood vessels compared with 20 patients getting traditional treatment. It will probably have to repeat the test in the U.S. to get Food and Drug Administration approval for the graft, which is expected to cost $6,000 to $10,000, McAllister said.
Storage Life
The engineered vessels had about a two-month storage life before they were implanted in the patients, he said. They have held up in mechanical and animal tests when used more than a year after they were made, he said. The grafts don’t appear to trigger a response from the patients’ immune systems, eliminating the need for powerful immune suppressing drugs and tests to match the cells used in the graft to the patients’ tissue type, he said.
The small diameter of the vessels, 4.8 millimeters, made dialysis difficult, though the procedure was completed successfully during the study, the researchers said. While the failure rate and the need for interventions were low, the risk is expected to increase with time, they said.
Other companies, including closely held Humacyte Inc. of Durham, North Carolina, are working on similar technology.
A previous study using tissue-engineered grafts made from the patient’s own cells found almost one in three failed to mature. Of those that matured, the usable vessels lasted as long as three years and reduced complications and graft failures 2.4- fold compared with shunts using the patient’s natural blood vessels or synthetic materials.
The new approach allows researchers to keep the engineered vessels on hand, eliminating the time needed to craft them and cutting down on the cost, once estimated to reach $20,000.
“Our approach could allow hundreds of thousands of patients to be treated from one master cell line,’ McAllister said.
To contact the reporter on this story: Michelle Fay Cortez in Minneapolis at mcortez@bloomberg.net
To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net
Rate this Page