Mike Wright's new esophagus continues to work like "a newborn
baby's" -- his way of describing the organ he came within weeks of
losing in 2010.
The 56-year-old Columbus, Ohio, man -- the world's second to
undergo experimental esophagus-replacement surgery in Pittsburgh,
his occurring in January 2010 -- remains the biggest cheerleader for
the still-experimental surgery soon to be tested in a human clinical
Blair Jobe, a West Penn Allegheny Health Systems surgeon formerly
with the University of Pittsburgh Medical Center, is scheduling the
clinical trial to begin in September and involving as many as 40
patients who have Barrett's disease with dysplasia (abnormal cell
growth) or early-stage esophageal cancer.
The trial will test whether regrowth of the esophagus lining, as
occurred with Mr. Wright, produces better results than the current
practice of removing the entire esophagus to treat esophageal
cancer, then creating a makeshift esophagus with a portion of the
stomach. This highly invasive procedure, known as esophagectomy, is
the mainstay of therapy for the majority of esophageal cancers and
results in a 50-percent complication rate and a long-term quality of
life issue, Dr. Jobe said.
Dr. Jobe's success in treating six patients to date without
failure represents the latest advance in pioneering tissue-
engineering research done at the University of Pittsburgh and UPMC's
McGowan Institute for Regenerative Medicine. The current line of
research began with the development of two-dimensional tissue
replacement, including tubes or tracts and skin, with efforts now
under way to replace tendons. The research is progressing to
creating whole human organs.
Dr. Jobe said the replacement of esophageal linings in six
patients represents "proof of principle for this approach, and we
must now validate the results in a clinical trial in order to
responsibly introduce this technique into clinical practice." He
said there is still a problem of strictures, or a narrowing of the
"food tube," in places after the lining restores itself. "But the
strictures were stretched open with an outpatient procedure."
It's an issue to be addressed in the clinical trial.
The efforts of Dr. Jobe and the McGowan Institute reflect a
worldwide trend in using tissue engineering to treat disease and
repair damage. To date, 10 successful procedures to generate
functional new tissue to repair tracheas have been reported, while
eight patients have received new tissue-engineered bladders. Doctors
still must study the patient outcomes, particularly if the
procedures were done on a large scale, Dr. Jobe said.
Stephen Badylak, deputy director of the McGowan Institute and
noted worldwide for his research in tissue engineering, developed
the esophagus-replacement strategy and led research in removing
cells from pig tissue to create a scaffolding that can regenerate
damaged tissue. The scaffolding material, now available
commercially, has been used 3 million times worldwide to repair
linings, wounds and skin, with efforts under way to repair tendons.
It's the basis of the esophagus-replacement process. With six
successes to date, Dr. Badylak said, "We're batting a thousand, but
the numbers are still very low and further studies are definitely
warranted." The scaffolding is a key element in research to create
new human organs.
Evolution did the hard work of tissue engineering with its method
of signalling stem cells to create the needed tissue, Dr. Badylak
said. "We have realized the ideal scaffolding during 100 million
years of evolution. The hardest part was done by Mother Nature."
The scaffolding is "extracellular matrix," or ECM -- a matrix or
tissue framework developed from pig tissue from which all the pig's
cells have been removed. The ECM naturally contains growth factors
and proteins among other molecules that appear to signal the
recipient's adult stem cells, and possibly other cells, to transform
themselves into site-specific cells needed at that particular
location of the body. …