New brain surgery innovation: Practice on a 3-D model

There's a fair chance that Teresa Flint is alive today and around for her three kids because her doctors failed to fix her brain aneurysm the first few times they took a crack at it.

That's because those initial attempts by Flint's surgeons were made on a 3-D printed replica of her complex, potentially fatal aneurysm instead of actually inside the head of the 49-year-old Buffalo, New York-area resident.

The dry runs on Flint's tangled aneurysm were done on a model printed by an "Eden 260V," an $87,000 3-D printer made by Stratasys Ltd.

"It feels like the real thing," said lead surgeon Dr. Adnan Siddiqui of the model, which is multicolored, made from different materials that replicate the feel of tangled vessels, and has blood flowing through it during the practice sessions.

Siddiqui said the practice attempts on the replica helped him realize that his initial game plan for inserting a tiny metal "basket" into the aneurysm wouldn't work, and neither would several other approaches he tried after that.

The virtual trial and error took place over several hours this year, and helped Siddiqui figure out the right strategy for attacking the aneurysm.

He replicated that strategy — with success — the next day when he did the real surgery on Flint.

Without those practice attempts, "It would have been three to four hours in her head" before doctors would have arrived at the correct approach, said Siddiqui, who is chief medical officer at the Jacobs Institute in Buffalo and vice chair of neurosurgery at the Jacobs School of Medicine.

Doing the actual surgery took just 45 minutes or less following practice on the 3-D replica. The amount of time that was saved, he said, could also have saved Flint.

"There was less chance of her suffering some form of stroke or dying from that procedure," Siddiqui said. He said that normally, there is a 5 to 10 percent chance of brain aneurysm surgery patients suffering such a result from the operation.

"When I found out I had an aneurysm, at first I was a little nervous. It was very scary to be in the position of not knowing, wondering if life would go on as normal," Flint said. "I think it's wonderful to be able to practice to know what you're doing beforehand."

If Siddiqui is right, a lot more doctors will be doing such practice in the future on 3-D models of complex brain aneurysms, cardiac conditions, and other tricky medical issues. Siddiqui said that the similarity of the blood vessels printed by the devices to the real thing is a major improvement on silicone models that have been used to train doctors, and a great improvement on animal subjects whose vessels don't correspond to those of humans.

"This is going to change the way we train physicians," Siddiqui said of 3-D replicas. "I think this is going to impact every aspect of medical care."

He said that the Jacobs Institute originally used the Stratasys 3D Printer it purchased several years ago to print out models to train physicians on procedures, and to test devices used in those procedures. Such training and testing represented a step up in terms of real-world feel from the computer simulations that the institutes had been relying upon, and which it still uses to introduce surgeons to procedures.

But it was only a year or so ago that doctors at the institute started to think about using the printer for something beyond general training.

"We said, 'Why can't we print out brain aneurysms on these models?' " Siddiqui said.

"I would say that for the last year, we have three or four cases" in which the printer produced exact replicas of a patient's aneurysm so that surgeons could practice on them before doing the actual surgery, he said.

The Jacobs Institute's printer also has been used to replicate actual complex aneurysms of patients elsewhere when their own surgeons have requested them, he said.

Michael Gaisford, director of medical solutions at Stratasys, said the company also offers that service to medical centers that don't own a 3-D medical printer made by the company.

He said that more than 100 hospitals and research centers own the same kind of Stratasys printer that was used to print Flint's aneurysm, primarily "larger research institutions that have larger resources."

"We're starting to see more and more in community hospitals," Gaisford said.

But Gaisford said that as of yet, "I'm not aware of any other hospital that is using this for aneurysms in particular," other than the Jacobs Institute.

And he said most of the printers' uses to date have been for research purposes as opposed to printing out replicas specific to a certain patient.

Gaisford also said that to date, 3-D printers have been more frequently used to model rigid body parts, such as bones. It was only in the past two years or so that the Eden 260 printer has been used to print out blood vessels.

A recent use of another 3-D printer platform made by Stratasys was at Boston's Children's Hospital, where doctors used a printed replica of the skull of a young girl with a severe facial deformity to plot out a nine-hour surgery they performed on her.

Stratasys also has partnered with a company that originally spun off from the University of Malaya in Malaysia, which is using the company's printer to create a neurosurgery training model of a brain, which includes skin that can be pulled back and bone that can be drilled into, replicating the feel of actual brain surgery.

"They can train those skills in, again, a no-risk environment," Gaisford said.