Perianal Fistulas Curable with Adult Stem Cell Treatment

MedPage Today, May 22, 2007

Spanish researchers say that a cure for perianal fistula can be found in a patient's fat. The stem cells in the fat to be more precise.

According to Damian García-Olmo, Ph.D., of La Paz Hospital in Madrid, patients saw a 71% cure rate in their fistulas when they were treated with a combination of stem cells derived from their own adipose tissue and fibrin glue. These results were observed in a phase II clinical trial.

During Digestive Disease Week sessions, Dr. García-Olmo said that the typical protocol which is fibrin glue treatment by itself, resulted in only a 16% cure rate in contrast.

"We defined a cure as complete rehabilitation" of the region of the fistula, both internally and externally, he said.

Although they occur in other conditions as well, perianal fistulas are common in those suffering from Crohn's disease. Researchers enrolled 49 patients diagnosed with Crohn's or cryptoglandular disease, and suffering from fistulas into the study.

Stem cells that were expanded in a lab after being extracted from liposuctioned from their own fat were re-injected three months later into the patients in the stem cell group.

Fibrin glue alone was administered to those patients in the control group, where into the internal opening of the fistula, researchers injected fibrin glue and 20 million stem cells into the non-control group.

Dr. García-Olmo said that the treatment group got more glue plus another 40 millions stem cells and the control patients were given a second dose of fibrin glue if the fistula was not healed at the eight week mark.

The difference between the stem cell and control group was significant at P=0.0001. For both non-Crohn's and Crohn's afflicted patients, the stem cell treatment was effective.

A low quality of life results from the internal opening which exposes the contents of the bowel during the healing process said Dr. García-Olmo.

"We need a new treatment for these patients, because we have a low rate of healing and high rate of recurrence," he said.

There are "two reasons why this is special," said Maria Abreu, M.D., of Mount Sinai in New York, who moderated the press conference during which the Spanish study was discussed.

"One is the morbidity of fistulas and how conventional medicine has not been effective and surgery can leave a defect in the anus that leaves a person incontinent," said Dr. Abreu, who was not involved in the research.

"And the second is that it uses stem cells."

"The glue alone is only slightly better than doing nothing at all," she said. "What is not clear is whether you need the stem cells plus the glue to get this great effect."

Dr. García-Olmo and his team set a very high bar said Abreu. The team used an endpoint -- complete response -- despite the phase II nature of the trial.

She said that a complete response is defined as no drainage from any fistula where a partial response is defined as having less than half of a patient's fistulas draining to the outside.