Bladder Repair Technique Called Promising
Harvard University researchers have for the first time repaired congenital defects in animal bladders and other organs using tissues harvested from the fetus before birth.
A small piece of bladder tissue, extracted from prenatal sheep using video-guided surgery, for example, was cultured in the laboratory to produce a much larger segment of bladder tissue. That tissue, in turn, was used to rebuild the defective bladder after the lamb was born, Dr. Dario Fauza of Harvard reports today at a meeting of the British Assn. of Paediatric Surgeons in Istanbul, Turkey.
Fauza and his colleague, Dr. Anthony Atala, hope to begin testing the procedure in human infants “within a few months” if they can get permission from the Food and Drug Administration.
“This is potentially a big deal because it will allow the [newborn], which otherwise would have a very constricted bladder, to have normal bladder capacity,” said Dr. Russell Jennings of UC San Francisco. There is no good way to treat these “exstrophied” bladders now, he said. “This will be a fabulous option if it works” in humans.
In an exstrophied bladder, much of the organ is missing at birth. Such exstrophies are rare, but they are difficult to treat. Surgeons now simply sew what tissue is present into a ball, making a very small bladder, or supplement the bladder tissue with tissue from the stomach, colon or small intestine--each of which creates problems of its own.
The advantage of the new technique is that bioengineers are creating actual bladder tissue in the lab. Since the original tissue is from the eventual recipient, furthermore, there is no problem with rejection.
“This can save lives,” Fauza said.
The team has also produced skin, bone, cartilage for a trachea and “a very rudimentary kidney,” Atala said. Each has been successfully tested in sheep--a total of 24 so far--but the bladder tissue is closest to being used in humans, he added.
The newly reported research is part of a larger project at Harvard and the Massachusetts Institute of Technology to produce laboratory-grown organs for adults. Dr. Joseph Vacanti and his colleagues had earlier reported success in growing organs for animals, but they have not yet tried the procedure in humans.
