Stanford University Chief of Pediatric Surgery James Dunn, MD, is applying to the U.S. Food and Drug Administration (FDA) to start human trials on his distraction enterogenesis-inducing endoluminal coils.

“The idea of applying force to the intestine is based on many other things that we do in surgery: tissue expanders that are applied for breast reconstruction and distraction osteogenesis for making bone,” said Dr. Dunn. “When I heard that one time in a lecture hall I said to myself ‘we must be able to do that for an intestine.’”

Dr. Dunn’s springs are intended to treat children with short bowel syndrome, a condition that affects 3,000 children in the U.S. every year and that for which there is no definitive cure.

“Short bowel syndrome is a devastating disease with few viable treatments that meaningfully restore quality of life for children affected with this disease,” said Department of Surgery Chair Dr. Mary Hawn. “A device solution, such as the one developed by Dr. Dunn will expand the capacity of the native gut. This is truly innovative, will drastically improve the outcomes and—quite simply—will save lives.”

As the disease affects fewer than 200,000 people in the United States, Dr. Dunn is applying for a Humanitarian Device Exemption (HDE) from the U.S. Food and Drug Administration (FDA).

“Normally when you want to test a new device you have you go through very complicated, expensive process of clinical trials,” said Dr. Dunn. “With an HDE, we can go through a shortened phase of clinical testing.”

Dr. Dunn’s original coil design had a smooth surface, but he and his team had trouble getting the spring to stick.

“It worked with a segment of the intestine that was separated from the main gastrointestinal tract, but it didn’t work within the main,” said Dr. Dunn. “The intestine is designed to move things out.”

Progress came to a halt. Until inspiration hit one evening when Dr. Dunn took his dog out for a walk.

“My dog wanted to go one way, and I wanted to go another. He dug his paws in at an angle,” said Dr. Dunn. “We tried adding spokes to the surface of the coil in one direction, and then the other direction. But the intestine goes back and forth, it’s not unidirectional, so we decided to try both.“

The bi-directional spokes allow the coil to anchor itself in the intestine.

“We don’t want it to stay in there forever though, so we’re making [the coil] biodegradable so it will break down after a couple of weeks,” said Dr. Dunn.

Dr. Dunn used a 3D printer with funds from the Stanford-Coulter Translation Research Grant he was awarded this year.

“Dr. Dunn’s Coulter application had a number of attractive aspects we look for as we assess the ‘translational potential’ for a grant: compelling preclinical data that addressed some of the major questions around both the safety and efficacy of the technology, an elegant but simple device design, a clear plan to refine the design and test in a larger animal model, and issued and pending patents all combined to make this a strong application,” said Gordon Saul, Executive Director of the Stanford Biodesign Program and Coulter Program Director. “What helped the project stand out, however, was a clear and compelling clinical need—both in terms of the clinical impact on patient’s suffering from short bowel syndrome, but also the downstream economic impact on the healthcare system.”

Dr. Dunn’s proposal was unanimously approved with “strong support” by the review team.

“The 3D printer has been extremely useful while we’ve been testing out different designs. It’s great for rapid prototyping,” said Dr. Dunn. “In the future, if we are approved for human trials, we will be able to use it to easily customize the size of each coil depending on the patient.”

Even if Dr. Dunn is approved for the HDE, the shorted clinical trial consisting of 5-10 patients will cost approximately $2 million.

“Because the market is small, big companies don’t want to take it on,” said Dr. Dunn. “In these cases, we rely on philanthropic donations, people who are willing to donate money for the good of the patients.”