Medical 3D printing is 'future of surgery'

Detroit — One day in the not-too-distant future, your surgeon might be able to give you new bones, joints, even soft-tissue organs that were "printed" in-house.

It sounds like something out of "Westworld," the HBO sci-fi series where humanoid robots are 3D-printed. But hospitals are working on the cutting edge of medical innovation to make it a reality.

At the University of Michigan in Ann Arbor, Mich., doctors and researchers led by otolaryngologist Glenn Green, M.D., are working on nearly 30 medical 3D projects that are customized to help individual patients.

UM's most successful implantable 3D procedure is a medical 3D-created biodegradable splint device to treat a rare life-threatening airway disorder that mostly occurs in babies called tracheobronchomalacia. The disorder causes the windpipe to periodically collapse and prevents normal breathing.

The manufactured splint device using one of UM's 30 3D printers is sewn around a floppy airway area in the neck to provide support and protection during airway growth. Over three years, the splint is absorbed by the body. UM has treated a total of 15 patients from the ages of three months up to 70, said Green, who practices at UM's C.S. Mott Children's Hospital.

"We think [medical 3D printing] is the next great revolution in surgery," said Green. "It is still in the early stage where we are trying to work everything out. There isn't reimbursement for most of it. It is a key problem we are working on."

UM is not the only hospital in the region working to bring 3-D medical printing into the operating room. Henry Ford Hospital in Detroit and Beaumont Hospital in Royal Oak are also working on their own applications for this transformational technology.

Hospitals are already using medical 3D printing technology. Most often, an FDA-approved machine is used to create precise replicas of skulls, jaws, hearts and valves, knee and hip implants, fibulas and even sports shoe inserts and hearing aids.

The 3D printed models help doctors plan and practice complex heart, orthopedic, facial and pulmonary procedures. The models are also used for patient and family education. Prices vary, but most models cost between $300 and $10,000 and are made out of plastic, ceramic, titanium or compressible metal mesh, in the case of aortic or mitral valve replacement parts.

But medical 3D printing technologies may one day be used to manufacture artificial veins, muscles, limbs, cells, tissues, skin and other organs. Researchers are experimenting with printing human tissue and organs by layering living cells instead of plastic or titanium, a process called bioprinting. Regenerative medicine researchers at Wake Forest University in Winston-Salem, N.C., are already using human cells instead of polymers to print organs using an advanced Integrated Tissue and Organ Printing System.

The ability to print human tissue could have a huge impact on such things as pharmaceutical research, organ transplants, surgical operations and reconstructive surgery.

Bioprinting could allow hospitals to become "manufacturing centers" of living tissues, said Eric Myers, a product designer at the Henry Ford Innovation Institute in Detroit. "They will be able to make a sheet of skin for a burn patient or full ears made out of cartilage."

"Another future application is new drugs," Myers said. "Instead of taking a generic pill, a pharmacist makes one using a 3D print to match a patient's specific needs that has a time release function," he said.

Researchers believe practical use of these advances could be 10 to 20 years away. But the future might get here quickly.

Bryan Crutchfield, general manager of Materialise North America in Plymouth, Mich., a medical 3D implant and model manufacturer, said the technology is rapidly advancing as researchers seek answers for difficult patient care problems.

Printing speeds for the sophisticated machines are doubling and tripling each year, enabling doctors to move surgery schedules ahead. And the types of polymers and biocompatible powders than can be used as raw material to create the models are multiplying.

Materialise operates more than a dozen medical 3D printers — ranging in cost from $100,000 to $800,000 — and creates orthopedic models for more than 500 hospital and medical customers in the U.S., including more than a dozen in Michigan.

"We take CT and MRI images, which are slices of the body, [and] we can recreate 3D models of a patient's anatomy and then allow clinicians to take those models and use in approaches to treatment," Crutchfield said. "Doctors can pre-plan those surgeries using software. It helps improve patient education [and] patient outcomes because it takes less time in surgery and you can plan ahead to execute it."

Researchers at UM, Beaumont Hospital in Royal Oak, Mich., and Henry Ford Hospital in Detroit, as well as many other hospitals nationally, are developing a variety of heart, orthopedic and pulmonary 3D clinical projects in collaboration with Materialise and seeking FDA review to use them in medical settings.

Henry Ford owns three 3D printers, costing from $5,000 to $50,000, that produce about 70 percent of the hundreds of models they have created for patients and doctors.

The Henry Ford Innovation Institute houses the 3D printers from Stratasys, Formlabs and MakerBot. So far, more than 700 patients in eight different departments have been treated using the 3D models the team has made in the past three years.

"Doctors have given us hundreds of ideas, from surgical instruments to devices" for tracheas, hearts and catheters, Myers said.

About 95 percent of the 3D models are of the heart, but they also are made for doctors in orthopedics, oncology and otolaryngology.

The printing process works like this: After Myers receives the CT scan on the body part, he carefully separates everything out of the image except the body part he will print. Depending on the size of the print and complexity, the printer will take six to 24 hours to create the thin layers that make up the object.

"We use [the model] for patient education. That is huge. It is much easier to explain to patient and family how (the surgery) would affect them, as opposed to pointing at 2D drawings. They see a 3D image they can hold and patient comprehension goes through the roof."

Myers will usually have the model ready for the physician by the next day. "At first, we didn't know how to use it," he said. "It took us the first six months to boil it down to the process to use on patient care."

A growing number of Beaumont surgeons also are using the Royal Oak's 3D medical printing laboratory to educate patients and their families about their procedures, said Ken Richey, Beaumont's 3D medical lab manager. Beaumont contracts with Materialise and two other companies to print out the structural materials used for the demonstrations.

Besides patient education, doctors at Beaumont and Henry Ford use medical 3D printing technology to help doctors plan out medical procedures and surgeries.

Using 3D models reduces OR time and "saves $180 a minute in OR costs," Myers said. "You are choosing the correct device more often, the correct catheter and it helps reduce length of stay."

And 3D printing makes it easier to customize parts for patients.

"You no longer have to fit the patient to the part," Myers said. "You fit the part to the patient."

For example, Myers said most hip and knee implants are generic devices. "Using 3D printing you can custom fit each one," he said.

UM has been researching medical 3D printing since 1996 under biomedical engineer Scott Hollister, but it wasn't until 2012 that Green and Hollister joined forces to develop the implantable airway splint.

"I had been looking for a solution for some time. There is a severe problem with a lot of kids dying around the country of tracheobronchomalacia," Green said. "We have done 15 procedures so far ... 13 have done very well. One died of cardiac disease; another child passed away because of lung problems.

UM has more than 30 printers in operation, with half in the otolaryngology department, and has printed out hundreds of models and implants, Green said. The most expensive is a $100,000 EOS 3D printer, which is used to make the implantable airway splints.

"We are working on more than a dozen devices in my area, ranging from surgical models for students and residents to practice on to implantable devices," said Green, noting that the medical education value of 3D will show dividends in the future.

Implanting the splints requires a special FDA emergency exemption, but Green said UM is working with the FDA to get approval for a clinical trial that would prove the airway splint's effectiveness. Success in clinical trials is a proven method to convince private and government payers to reimburse treatments, he said.

"If we were supported through reimbursement, it would make a gigantic difference," said Green, adding that many more patients could be helped using 3D. "All our initial work was supported by federal grants. A lot was self-supported through donors. We are starting to see some corporate involvement, device manufacturers putting money into it."

Green at UM said inserting the 3D airway splint in a child can save $1 million in future medical costs. But each time UM wants to operate on a patient it must get insurance approval that Green says takes up to 10 hours of staff time.

Beaumont pediatric plastic surgeon Kongkrit Chaiyasate, M.D, conducts about 50 craniofacial, or skull reshaping, surgeries each year on babies and young children under age one.

Known as the "champion" of 3D printing at Beaumont, the Thailand-born Chaiyasate said in his six years at Beaumont he has worked on cases ranging from faces mangled by a raccoon to gunshot wounds to children with deformed cleft palates.

"We see babies [a day or two old and up to a year] who have craniums that are not growing. In the old days, surgeons would eyeball it and then do cuts. Now we do a CT scan for diagnosis and then plan it out and use the plating guide" created using the 3D printer, Chaiyasate said. "It is a two-hour surgery with about four to six weeks for recovery."

Chaiyasate said surgeries are performed on babies who are born with joints between the parts of the skull that have fused prematurely, which can put pressure on the brain.

The CT imaging gives Chaiyasate information on where to expand the skull. It usually takes two weeks to get back the plating guides from Materialise or two other 3D printing companies that Beaumont uses.

While the costs are about $5,000 more for the 3D procedure, Chaiyasate said families are not billed extra. "The procedure saves money because of less time in the OR. Insurance gives you one payment for the hospital, and we fold the costs into the bill," he said. "There is no net financial [charge] for the procedure. We have higher quality and better outcomes for patients."

Chaiyasate's first case was Ramon Aguilar Jr. in 2012. Ramon was born with a craniofacial condition known as Goldenhar syndrome. "Ramon had a congenital defect. One side of his face was not the same as the other," he said.

The goal of the surgery was to reconstruct the right side of Ramon's face and his jaw to allow him to eat solid food. Ramon completed the surgery and at age 21 graduated from high school.

Chaiyasate also does about three surgeries per month — aided by medical 3D printing — to rebuild faces for patients who have cancers of the jaw. The four-hour surgery starts by cutting into the calf bone to get a replacement bone for the jaw.

"We use 3D [printing] to create a guide, a piece of plastic to snap the segment on, for the fibula and the jaw," Chaiyasate said. "It was an 18-hour surgery, but we do it now in four hours because of the planning."

Looking to the future, Chaiyasate said Beaumont doesn't yet place materials like 3D printed bones or joints in the body. "Skin grafts are the future. We have a long way to go to get there, but it's going to happen," he said. "The difficulty now is controlling the cells. They cannot be replicated in mass volumes."

Richey, who has been with Beaumont since 1998, said he recognizes the value of using specialized software and digital images to illustrate in color and in three dimensions patients' medical problems for surgeons.

"The surgeons love it. When you think about how much it costs in the OR — $250 per minute — the surgeons can sit at my desk in the lab and plan [their] surgeries," said Richey, adding that surgery time can be cut nearly in half.

A growing number of Beaumont doctors, including neurologists, pediatric surgeons, orthopedic surgeons, cancer surgeons and interventional radiologists, are using the 3D medical printing software that was developed by Materialise to plan out their procedures.

In her office at Henry Ford Hospital, cardiologist Dee Dee Wang has more than 100 3D models of hearts on a bookshelf. Each heart is custom-made for patients based on CT scans of their hearts. She calls them her clinical heart library.

"Our patients are too frail and not candidates for open heart surgery, and their remaining option is getting readmitted to the hospital, or hospice. They have less six months to live, so they are very sick and have run out of options," said Wang, who is head of structural imaging and medical director of 3D printing at Henry Ford Innovation Institute.

Nearly five years ago, cardiologist William O'Neill, M.D., Henry Ford's medical director of the Center for Structural Heart Disease, began doing transcatheter mitral valve replacement procedures using medical 3-D procedures under an FDA humanitarian exemption. The mitral valve connects the left upper (atrium) and lower (ventricle) chambers of the heart.

However, this heart procedure is one of the most technically challenging because the mitral valve is one of the most complex structures in the heart. Incorrect valve sizing can cause the valve to embolize, creating blockages. An embolism could block blood flow to the rest of the body and cause harm.

Using 3D imaging, planning and printing, O'Neill and fellow cardiologist Adam Greenbaum, M.D., created new techniques using a wire guided up through the femoral vein in the leg to the heart to open more blood flow to the rest of the body. This allows safe implantation of these valves into patients and could potentially help thousands of patients, Wang said.

More than 13 percent of patients over age 75, or approximately 5 million people, have some degree of aortic or mitral valve disease. So far, Henry Ford has successfully performed more than 200 of the procedures, including placing a valve in the mitral position more than 50 times, the hospital said. The FDA gave approval for the mitral valve in valve implantation last fall.

"Dr. O'Neill is working on a problem where the patient has no or low blood flow. We can't do surgery in those instances," Wang said. "For many patients, we think we have fixed the problem and now these patients are candidates for mitral valve replacement."

3D printing is also helping cardiologists improve a more common procedure called the "left atrial appendage closure," Wang said. This procedure is for patients with irregular heartbeat conditions, called atrial fibrillation, who are not able to take blood thinners. The danger of a clogged atrial appendage pouch is that a blood clot could form, break away and cause a fatal stroke. Henry Ford has conducted more than 1,000 of the atrial procedures.

Two years ago, the FDA approved a device called the Watchman for use in this type of procedure. But imaging planning for the procedure was lacking.

By printing out the exact replica of the heart, Wang said, cardiologists could get a better view of the blockage and devise a better surgery plan.

"Before, there was a 16 percent complication rate," said Wang. "By innovating 3D imaging and 3D printing customized case plans for our patients, we demonstrated that in our first 100 patients we had zero complications."

Wang said the use of the 3D model for atrial appendage procedures "helps us to choose the right size of the catheter" inserted into the patient's body to place mesh devices. She added that the 3D model also gives doctors a better idea of how large the Watchman self-expanding device needs to be to open the atrial appendage.

Wang said manufacturers make five sizes, but many more are needed because each patient's heart, valves and appendages are different sizes.

"Before, you had to guess the right sizes," Wang said. "Now we have a better idea what ones to use." Data shows before 3D was used, doctors used an average of 1.8 devices per patient; that number has dropped to 1.2, she said.

For the left atrial appendage Watchman procedure, Wang said the use of 3D printing also cut surgery time to about 45 minutes from 80 minutes, reducing costs and improving outcomes.

Medical 3D printing was the subject of jokes five or six years ago in some circles of medicine. Now, Wang said, 3D has proven itself, because lives have been saved.

"People can't blow it off now. In the next 10 years, all hospitals will have in-house printers and all patients will have access to them," said Wang, adding that the future is limitless for 3D applications in health care. "Bench research 10 to 15 years down the road will enable transplants and see early stem cells for organs."

Like many hospitals, payment for 3D printing is a challenge. Henry Ford funds its 3D program through Ford Motor Foundation grants.

"We are early adopters. We get phone calls from physicians in other hospitals in the U.S. and in other countries, France and Germany," Wang said. "We get questions how we do it and get lots of referrals — they fly in — if they can't do it locally."