SPRINGFIELD -- Greg Gagnon thought Baystate Medical Center's purchase of a 3D printer some 36 months ago would mean he could save the institution money by printing replacement parts for equipment or modified existing equipment to be more user friendly.
Little did the Baystate clinical engineering service representative specialist know it would shortly embark him on a second career -- and his employer on a pioneering path -- in the production of patient-specific anatomical models created in-house to serve a variety of educational and medical needs.
"Three-and-a-half years ago clinical engineering bought this printer for $1,400 to reproduce parts for equipment," said Gagnon, seated before two computers wedged between two 3D printers in a room of equipment that speaks to his first specialty - fixing life support machines, like ventilators.
"Within six months, one of our surgeons - Dr. Andy Doben - who does rib fixation surgery came up and said I heard you have this 3D printer, can you print out some ribs for me?"
Gagnon said his reply was, "I have no idea," as his concentration in biomedical engineering at New Haven's Gateway Community College was before the era of 3D printers. Yet, for the Chicopee Comprehensive High graduate who grew up with a "love of fixing things to make them faster, bigger, better," the challenge was on for the possible. He found the software programs needed through Google and YouTube videos on how to print 3D plastic anatomical models to the scale required and thus began the process of self-education.
Fast forward to now, and the 33-year-old self-described "jack of all trades" has created such models from what is known in the profession as "Digital Imaging and Communications in Medicine" (DICOM) files, in this case CT scans and MRIs, to help surgeons and other physicians better repair traumatic injuries to a patient's face, see that a tumor is within centimeters of an organ, and ensure metal plates are bent exactly in advance of surgery to fix a difficult-to-repair rib cage.
"On this CT scan you can see the jaw is broken in two places," said Gagnon, pointing to a scan imported onto his computer that begins the anatomical modeling process and holding the 3D printed model in his hand.
"I take the CT scan and a digital representation of that to scale and then I have other software where I can realign everything and this is printed out. Then, the surgeon takes metal plates and bends them to this model knowing this is the exact size and shape it is supposed to be. This saves time during the surgery because they can use these pre-bent plates and know they are they right shape. They sterilize them and bring them into the surgery already prepared."
Radiation oncologist Michael J. Yunes, Baystate Health's chief of radiology, calls Gagnon's 3D printed anatomical modeling a "game changer" for both patients and providers.
"For patients and for interdisciplinary discussions it is a unique opportunity and allows us to do something no one else is doing in such a broad fashion. It is a real game changer," Yunes said.
"For many specialties it is a change in how to prepare for procedures, as well as how we think about education and discuss treatment with family. Patients are now better able to understand because they have something they can hold in their hand and look at from many different angles."
Yunes said a patient can look at the model and see why they may experience side effects from treatment, like radiation, when they observer how close their tumor is "near critical structures."
"It is definitely a leap forward. I can show someone a CT scan and even a 3-D model, but that is a far cry from being able to hand them their brain," said Yunes of the model.
Yunes has had Gagnon do 3D printed anatomical models for a patient with a tumor in the ear canal, as well as for a patient with a tumor in an area where they had previous spinal surgery.
"It is really a way to not only educate the patient but educate other specialties about what we are trying to do and the physicality of it," said Yunes, who will have a patient specific model made for himself as well as one for the patient to keep.
He added, "I am certainly willing to try new things, but I will not recommend it if it is a waste of money and time."
"This is saving money, improving quality of care and patient satisfaction. It is a win/win," Yunes said.
Gagnon has done anatomical modeling for a number of others at Baystate including thoracic surgeon Rose Ganim and pediatric surgeon Kevin Moriarty, as well as Dr. Michael Spink, a specialist in oral and maxillofacial surgery affiliated with Baystate.
He appreciates the feedback he gets from them and what they tell him of the feedback from patients.
"The doctors who use it say it is invaluable. They say the feedback from the patients is amazing in that sometimes they will take it home and show the families," Gagnon said.
"I did a mediastinum with a tumor near the heart for Dr. Moriarty. I did two different pieces. He took pictures in the surgery and he said it looked just like the model."
Gagnon likes the challenge of never having the exact request twice, and of coaxing Baystate's two modest 3D printers into maximum performance. He is limited in how large a model he can print - 9 inches by 6 inches by 6 inches - but can segment out parts of the anatomy to print if needed and them reassemble. He has built a special nozzle for one of the printers so the resin model does not shrink as it cools.
"The software has all sort of tools. I have this tumor, how thick do I want to make the walls when I make it. Do I want it to be a solid object. You could print solid plastic. Or, you could say I want the wall thickness to be two millimeters thick and I want the outside dimension to be accurate," said Gagnon of what is involved in the modeling process.
"It would take the outside edge and go in two millimeters and that way there the outside is accurate. If you want the inside accurate, you do the exact opposite. So, there are multiple steps in taking it from the pretty three-D imagine on the screen that can spin around to something that is physically printable."
He said software allows for mirror imaging where "you can take an object and cut it in half" as well as segment.
"I can export this whole thing, and then using other software can cut it into pieces," said Gagnon of an image on his computer screen.
"I would say the bone is one object, the lung is another object so that way there you can print them separately, do different things. One, the inside is accurate, the other the outside is accurate you can change everything. That is the art behind the scenes."
Gagnon said the 3D printer lasers the image into liquid resin as the model is built.
"This metal plate up here goes down into the resin, and then there is a laser that goes around and whatever that laser hits, it cures," said Gagnon, pointing to the newer model printer with the red cover that sits to the right of his computers.
"It does that layer by layer and that built platform slowly raises up. It is actually so accurate when it prints you can't even see the layer lines. You can with the older printer see how it builds up the layers one at a time, but with the newer printer the layers are so tiny you can't really see them. The layer height is thinner than on the CT scans so whatever you can get on the CT's you can print just as well or better on the printer. The technology has come a long way."
The models print in white, and Gagnon will sometimes highlight areas in different colors or clear coat the model.
He did this with the tumor near the ear canal, painting it red against the surrounding structures.
This is the acoustic neuroma," said Gagnon, pointing to the small, but clearly visible shape.
"They can see it is close to the ear canal. It is better than a black and grey image on the screen. Most people won't know what that is, but when you give someone a model like this, it is very clear and it is patient specific."
The doctor can say to the patient, "This is you. This is why we need to give you treatment."
Gagnon added "trial and error" over the last three years has helped him "get good at this."
"Say, the surgeon says I need all the ribs from the back - 12 inches or more -- and this prints six inches at a time," Gagnon said.
"I can take these ribs and cut them all and then put a pin in one and a hole in the other and separate them and it prints and you piece it together. I have done some things where they just want the bone and the tumor and you put locating pins so you can be sure this is exactly where tumor is in the patient."
While he has "gotten better and better learning how to work with CT scans" to create the models, Gagnon said, "If I look at this and I need confirmation as to where the tumor is, I have people right down one floor in radiology who will come up and look at this and make sure it is right."
"I will ask before I print, did I get the whole tumor?" Gagnon said.
The process of printing can be time consuming - sometimes up to 20 hours - and if a printer stops mid-way, printing has to start from the beginning.
"There can be a lot of pressure," Gagnon said.
"Sometimes you come back at night or a weekend and start a second print because you need both done by the morning. It is a learning curve for everyone. I always tell any doctor, surgeon if I don't know what we can do until we try. Worse case scenario I will say we couldn't do it. I don't know if I have ever done the same thing twice. It is always something different. One of the coolest things about a 3D printer is that if you can think it up, for the most part you can make it."
Gagnon said one of his most challenging models involved using mirror imaging for a surgeon repairing widespread injuries to half a patient's face using metal plates.
"This is severe trauma," said Gagnon, pointing to a 3D color imagine on his computer screen.
"Mirror imaging the patient's right side of their face to the left allowed me to print out a model of pretty much the missing bone structure in the actual size and shape that it was supposed to be. So the surgeon takes that repaired half of the face and pre-bends all the metal plates to that exact shape."
Gagnon added, "No surgeon is going to take one of these models and go 'I am just going to start cutting.' No one is going to rely on it like that but now they can take that model and scroll through the CT scan and go this is here, that is there, OK, that is what it actually looks like," Gagnon said.
"If not, they are trying to do the modeling in their head. They are hoping what they put together in their head is what is there when they actually do the surgery - this kind of reassures them that what they think is there is there."
He called the half face "the most complicated as far as mirror imaging and making sure everything in step two was lined up."
"As far as segmenting bone in this software it is really easy as bone is the most dense - the white here is the bone - it is clearly different from everything else, but once you start to get into a muscle layer and the tumor that can be more difficult," Gagnon said.
"I did a model of a right lung tumor but it was right next to the heart and there was vascular all around it and that is what they wanted to know - 'Can we cut this out. How much room do we have?'"
Gagnon said for that modeling, "the segmentation was the hardest because you had to make sure that everything you are saying, 'this is this, this is this vessel,' is accurate and correct."
"You have airways that are very close to the tumor. You have to make sure all that is right, that was definitely the case where I asked one of the radiologist to come up here and I told him you can change any of this very easily and just make sure it is OK. He said it is all good. He did not want to change anything. He said, 'No it is all set.'"
Another modeling he did was for a brain aneurysm.
"In lifesize, those can be very small, but I can take that and blow it up by 300 percent and have a large model that normally would have very tiny vessels going around it. The surgeon actually showed the staff in the ER, this is what we are doing. We are going to go in and cut here, we are going to cut this off here. We can scale the model to different sizes if it is a visual thing and does not need to be life-sized. We can blow things up or shrink them down. It really depends."
Gagnon added modeling is not something you do "for every surgery."
"Our surgeon who does rib fixations where a rib is broken and he puts one metal plate on it, he has done that thousands and thousands of times and doesn't need to waste time with a plastic model. It is really the complex surgeries where this technology really shines. It helps them with better planning, better repair work."