MONDAY, March 7 (HealthDay News) -- In a potential advance in
the field of tissue engineering, researchers report that they've
been able to repair injured urinary systems in boys by using
bladder cells grown in a laboratory.
Currently, physicians use pieces of skin to repair the urethras
of boys whose groins were injured in car accidents or other
traumas, but the procedure often fails. In the new cases, surgeons
tried a different approach, reconnecting the severed urethras with
tube-like structures created with bladder cells. The boys, who had
the procedures several years ago, are said to be doing fine
now.
The study shows that "tissues can be engineered using the
patients' own cells, and they last long term," said Dr. Anthony
Atala, director of the Wake Forest Institute for Regenerative
Medicine and a co-author of the study.
There are caveats about the findings, however. The injuries
sustained by the boys are rare, and the study included just five
boys. The procedure needs more testing, and it's not known if it
would work in adults. And, creating body parts from cells -- the
crux of tissue engineering's potential -- remains an immense
challenge.
Still, "we are definitely a step further in demonstrating that
the results that have been reported in animals can be translated to
clinic," said Dr. Karl-Dietrich Sievert, professor of urology at
the University of Tuebingen in Germany, who wrote a commentary
accompanying the study, which was published online March 8 in
The Lancet and was funded by the U.S. National Institutes of
Health.
The boys who underwent the procedures at a hospital in Mexico
City were 10 to 14 years old. They had sustained injuries that had
severed their urethras, making it impossible for them to urinate
properly and requiring them to use catheters.
Car injuries and falls are common causes of such injuries, Atala
said.
The researchers took bits of tissue -- about half the size of a
postage stamp -- from the boys' bladders and then grew the bladder
cells into urethra-like tubes. Surgeons then reconnected the
severed urethras with the tubes.
The boys have been doing well for as long as six years,
according to the study. The results show "that these are actually
able to work in the long term, and that they're able to grow with
the patient," Atala said.
He said it costs about $5,000 to create a replacement urethra.
He didn't know the cost of the surgery but said the procedure would
save money over time because these types of procedures would not
need to be redone, unlike the method currently used.
In the big picture, Atala said, the findings could pave the way
for the creation of other tube-like structures in the body, such as
replacement arteries.
For now, however, products of tissue engineering are rarely used
in medicine outside of skin grafts, said Nenad Bursac, associate
professor of biomedical engineering at Duke University. One hurdle
is cost, he said.
However, Bursac said, research is continuing and scientists are
in the early stages of testing products for the repair of
cartilage, the cornea and the heart.
More information
Cornell University has more about
tissue engineering.