A team of University doctors held Conan Thompson’s head, trying to decide whether or not he would need drastic surgery to allow him to breathe. This was no normal consultation, however, because Conan was no normal patient: He was a 30-week-old fetus still inside his mother’s womb.

In the doctors’ hands were 3D-printed models of Conan’s head, the first 3D-printed models of a fetal head used to inform a surgical decision. With the accurate physical model, the doctors were able to see that their patient could be born through a Caesarian section instead of a riskier surgical procedure.

Conan’s mother, Megan Thompson, had been referred to C.S. Mott Children’s Hospital after an ultrasound showed a potentially dangerous lump on Conan’s face.

“What we worried was that when he was born, the lump would cover his nose and mouth and prevent him from being able to breathe,” said Kyle VanKoevering, a resident in the University Hospital’s Department of Otolaryngology.

When they first saw Conan’s case, doctors worried they might have to perform an ex utero intrapartum treatment procedure, or EXIT, a complicated procedure that involves operating on the baby after it has been delivered but before the umbilical cord is cut. This process is more dangerous and more expensive than traditional births.

The doctors were concerned about the lump, but couldn’t tell from the fuzzy ultrasound whether or not it warranted an EXIT procedure. The team decided to try an MRI scan, since it would give them a clearer picture than the ultrasound. MRI machines take many images of a subject in “slices” about two millimeters apart. However, VanKoevering said, even an MRI wasn’t enough in this case.

“When you look at an MRI, you look at a stack of two-dimensional pictures,” VanKoevering said. “And your brain basically compiles that stack into a three-dimensional profile where each picture is separated by a millimeter or three millimeters. But it’s hard to envision the detailed anatomy of a tiny infant when the MRI isn’t too clear.”

Normally, doctors would prepare what was necessary for an EXIT procedure at this point. But Glenn Green, associate professor of otolaryngology, had another idea.

“And so Dr. Green called me one night and said, ‘Kyle, do you think we could take a special MRI scan and make a 3D model from it?’ ” VanKoevering said. “And I said, ‘Well, I don’t know that it’s ever been done in a fetus before like this…Let’s try it.’ ”

VanKoevering, who graduated with a biomedical engineering degree from the University in 2007, used computer programs to construct a 3D digital model of Conan’s head based on MRI images. He explained that, after the modeling, the printing was easy.

“We called a 3D printer in Ann Arbor — a local company called Thingsmiths — and we asked if they would be willing to print these models. Of course, we had a very short timeframe because the kid’s delivery was coming up very soon and we were really not clear yet on what we wanted to do. So we called them and they said, ‘Yeah, we can get these on the printers tonight and they’ll be ready tomorrow night.’ It was less than a 24-hour turnaround. These things can literally be printed overnight.”

The doctors soon had multiple models of Conan’s head in their hands. Some were opaque to show details about the lump, while others were clear to show information about the bones and deeper structural aspects of Conan’s face. With this new information, they were able to see that the lump would not pose a grave risk.

VanKoevering said this is just one example of 3D printing’s increasing impact on medicine. Similar techniques could be used for other complex surgeries such as removing large tumors and intricate heart procedures.

“3D printing is certainly a rapidly evolving field in medicine because it allows such versatility in designing models and potentially implants to reflect the unique anatomy that each patient has,” he said. “So I think this is an area of medicine that will continue to evolve rapidly over the next five years, and I’m excited to see how it goes.”

This is not the first time University doctors have used 3D printing as a medical tool. In 2013, two members of the team — Green and Scott Hollister, professor of biochemical and mechanical engineering — were honored by Popular Mechanics for 3D printing a biodegradable splint used to save the life of a two-year-old with breathing problems.

The results of Conan’s surgery were published Oct. 5 under in the journal Pediatrics.

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