Muscle progenitor cells restore urinary sphincter function

March 1, 2008

Autologous muscle progenitor cells are able to restore otherwise irreversibly damaged sphincter function.

Conducted under the direction of Anthony Atala, MD, lead scientist Daniel Eberli, MD, PhD, evaluated a novel treatment modality, muscle cell therapy, that addresses the underlying cause of urethral sphincter insufficiency. Researchers used a model of urinary sphincter insufficiency created by microsurgically excising approximately 80% of the sphincter muscle in 26 dogs.

Urodynamic studies, functional organ bath studies, and ultrasound and histologic examinations were performed, and sphincter function observed over the following 6 months, with the markers demonstrating the developing muscle fibers.

Sphincter function restored

Treated animals recovered sphincter pressure to approximately 80% of normal, while pressures in the control animals dropped and remained at 20% of normal. In addition, nerve stimulation in the treated animals produced contraction in the normal range by 2 months post-procedure. Fluoroscopic and CT imaging of the treated sphincter and controls also revealed differences of reconstitution.

"Injected cells were able to survive and to form mature tissue within the damaged sphincter," Dr. Tillman pointed out. "This study demonstrates the feasibility of using autologous muscle precursor cells for the functional restoration of urinary sphincter muscle in patients with sphincter insufficiency."

Response to the presentation was strong.

"This is a beautiful study that exemplifies exciting work," said Howard M. Snyder, III, MD, professor of urology in surgery at the University of Pennsylvania School of Medicine, Philadelphia. "The functional reconstitution of damaged tissue is the Holy Grail."

Dr. Snyder noted that muscle function is influenced by a vast number of different factors that must be kept in mind when conducting experiments such as this, and he emphasized that the cells not only be reconstituted, but also functional.