After determining that functional integration of the skeletal and smooth muscle was feasible, dogs were used to study this technique in the lower esophageal sphincter. Before injection, the dog's baseline sphincter pressure and esophageal acidity were monitored. Four billion muscle cells were injected into the lower esophageal sphincter of each of the three dogs. When assayed again after three weeks, the sphincter pressure had doubled. They also noticed no abnormal features about the esophagus, confirming that the cells had successfully integrated into the sphincter.
Of the three dogs tested, one displayed signs of reflux disease; before the procedure, its esophagus was excessively acidic 26.5 percent of the time. After the injection, this dropped to 1.5 percent of the time, which could mean that the procedure strengthened the sphincter enough to reduce the animal's reflux.
"The concept of culturing your own tissue and then re-implanting it to patch up some weak spots really represents thinking outside the box," said Peter Kahrilas, MD, professor of gastroenterology at Northwestern University, who was not involved in the study. Still, he added, "Many hurdles remain to be traversed before that demonstration of feasibility translates into a viable durable therapy."
Pasricha said he hopes to soon begin trials of the therapy in humans suffering from fecal incontinence. Pasricha's co-authors are Ron Jankowski, Ph
|Contact: Tracie White|
Stanford University Medical Center