Three shunts failed during the safety phase of the study, which is a normal failure rate seen in these high-risk patients, the researchers noted. In addition, one patient withdrew from the trial and one patient died of causes unrelated to the shunt.
Of the five remaining patients, the grafts were used for dialysis for six to 20 months. Only one patient needed surgical correction to keep the shunt open. In all, seven patients used the shunt for one month, and five used the shunt for six months. That's close to the standard performance of all shunts, the researchers noted.
The average life expectancy for a patient on dialysis is about six years, McAllister said. These patients go through one to two vein grafts made from their own veins, and after that they will need to have plastic tubes implanted. Plastic tubes fail on average every 12 months, he said.
In contrast, the new tissue-engineered graft should last from one to five years, McAllister said. In addition, since the patient's cells are banked, another graft can be grown and implanted as needed, he said.
This process of creating grafts is expensive, McAllister noted. However, he expects the process to become cost-effective given the amount of time the graft lasts, and further cost reductions should emerge as the process is streamlined and becomes more common.
This therapy won't be available to patients for three to four years, McAllister predicted. The company is also working on creating other vessels to repair heart and other vascular damage, he said.
Dr. Vladimir Mironov, director of the Shared Tissue Engineering Lab at the Medical University of South Carolina and author of an accompanying editorial in the journal, called the technique a milestone in tissue engineering.
"We have the first commercial clinic
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