Sunnybrook Magazine - Spring 2018

New surgical navigation system may help improve use of life-like facial prosthetics

Brenda Coulter with her prosthetic eye

Brenda Coulter is grateful she’s alive. Brenda was driving along Highway 403 in June 2014 when a piece of metal boomeranged through her windshield and sheared off most of her face. Miraculously, she managed to stop the car safely.

After she was stabilized at a local hospital, Brenda was airlifted to Sunnybrook. There, trauma surgeons performed a 15-hour life-saving surgery to rebuild her skull and much of her face, using her driver’s license photo as reference.

“Since then, I’ve had 12 surgeries to reconstruct my face, which is now about three-quarters titanium,” says Brenda, who is now 58 years old. “My right eye has extreme damage to the cornea and optic nerve, but the team saved the eye, so I have a little bit of vision. I lost my left eye.”

Brenda’s orbital cavity, where her left eye used to be, is smoothed over with skin taken from other parts of her body. She has an adhesive prosthetic eye socket and eye, which she can glue into place.

“Affixing my prosthetic is a real challenge because I’m partially sighted, so I can’t see to put it on correctly,” Brenda notes. To attach an adhesive prosthetic, the wearer must smear glue onto the back of the prosthetic, use a blow dryer to help it dry and then manually determine where to place it.

Behind-the-scenes: How facial prosthetics are made using 3-D printing

“And if I get it wrong and there’s a big gap or it’s crooked, my husband says, ‘Brenda, something’s not quite right with your eye,’ and I have to remove it and start again, often three times,” she says. “I actually just stopped wearing it and either go out without it or decide to stay home.”

Late last year, Brenda got word that new funding is available for surgical implants for craniofacial prosthetics. Surgical implants are two or more screws that hold magnets to allow the wearer to just snap a customized prosthetic into place. For Brenda, the magnetic points to attach her prosthetic will make a world of difference.

“Having this surgery will simplify my life,” she said before her surgery in early January. “It’s called an elective surgery. But to me, it’s not that at all. After an injury like mine, it’s not just the bleeding that requires attention. There’s so much more. This new prosthetic – and the magnets to stick it on – will make a huge difference in my life. When I go out, I get stared at. It will be nice to feel normal again.”

Brenda holding her prosthetic eye

Brenda’s 13th surgery

Brenda’s latest experience felt similar to the 12 surgeries before. She was anaesthetized and fast asleep. But for the surgical team, it was a whole new ball game.

Brenda was the first patient at Sunnybrook – and in the world – where surgeons used a state-of-the-art navigation system to help guide the placement of two 3-millimetre screws.

As a prosthodontic resident (a dentist who specializes in the replacement of teeth) and a master’s student at the University of Toronto, Dr. Eszter Somogyi-Ganss participated in the creation and evaluation of a new navigational system that allows surgeons to connect a previous CT image to the patient’s anatomy in real time and then easily navigate the implants to the bone on the patient’s face. Designed for use in dentistry, the system is currently being modified and tweaked for use in other facial surgeries.

Now a maxillofacial prosthodontist in Sunnybrook’s Craniofacial Prosthetics Unit in the Department of Dentistry, Dr. Somogyi-Ganss works with surgeons to examine CT images and plan where best to place the surgical screws. The team then loads up the plan into the navigation system and it guides their hands and drill to the right spot.

“To place surgical implants, the surgeon may have to drill up or down or sideways,” she explains. “This computer-guided system tells the surgeon: ‘Drill here. Drill this deep. Drill on this angle.’”

And it all happens in real time.

“This system is like a glide path in an aircraft,” says  Dr. Kevin Higgins, one of the head and neck surgeons at Sunnybrook who performed Brenda’s surgery. “You have your flight path, and if there’s any deviation, you get an alert. It tells you to stop. This surgical system guides exactly how you are holding the drill – the pitch, the yaw and the roll – so you get optimal placement. It’s taking precision placement to the next level.”

Typically for surgeries like this, a pre-operative image is used to plan the screw placement, and a guide mask is made out of plastic and placed over the patient’s face. Surgeons then drill into the premade holes in the template, keeping an eye on the previously completed image. But imaging isn’t always 100 per cent accurate and the masks rely on being placed in the exact same spot. The masks also don’t allow the surgeons to make adjustments in the moment.

“With the navigation system, if you’ve figured out that the bone isn’t good enough and you want to move three millimetres to the right, you can change the position of the implant on the computer and it will navigate you three millimetres to the right,” Dr. Somogyi-Ganss says. “It’s very flexible.”

A difference of even just a few millimetres can make or break a surgical implant, according to Dr. Higgins. “Some of these patients don’t have a lot of bone left or they’ve had radiation therapy, and so, the bone is less reliable and is thin,” he explains. “And you can’t put the implant in air – like an eggshell of bone with air underneath it – because it won’t take. It won’t stay or it will just get infected. It’s like hanging a picture on a thin wall. It won’t work; you need an anchor point.”

He hopes the new navigational system will take an already accurate surgical procedure and make it even more precise, while also making the pre-operative experience easier on patients by eliminating an extra CT scan and the need for a mask.

Click on the photos below to view gallery

All of this lays a solid foundation for the next step in the process.

“The real essence of the program is the prosthetic. If the anchor points are stable, the anaplastologists can make the rest happen,” says Dr. Higgins, referring to the specialists who make prosthetics. “That’s where the artistry is.”

Dr. Somogyi-Ganss notes that the Craniofacial Prosthetics Unit team is like a village. “It takes the whole team to plan, make the prosthetic, execute the surgical implant and then place the prosthetic properly. It’s not a quick fix,” she says. “But if you make and fit an implant-retained prosthetic for a patient who has trouble wearing a glue-on one, that’s a major victory for all of us.”

Dr. Higgins agrees. “If you can imagine someone who’d otherwise be covered in a mask or not going outside [and] completely socially withdrawn, to now be able to go out into public and be treated like any other human being, to re-enter the workplace, to have a social life – that is quality of life, which is immeasurable. As we advance our ways of treating traumas and cancers, we must advance the ways we provide quality of life, too.”

After the surgery

Brenda continues to adjust to life with a visual impairment. A hair colourist and technician before her injury, she can no longer work in that field. She has, however, found joy in other things – acrylic painting in bold colours, attending Blue Jays games with her husband, Michael, and travelling down south each year.

As her implants stabilize over the coming months, Brenda is waiting patiently until she can start the next step of her magnetic prosthetic – the modelling, painting and fitting.

“This one wasn’t life-saving surgery, but it was life-changing surgery. I’m so excited for my new prosthetic,” Brenda says. “People have always been kind since my injury, but it’s always about my face. I get lots of questions. It’ll be nice to be in the world and it won’t always be about that.”

Inside Sunnybrook’s Craniofacial Prosthetics Unit

Sunnybrook’s Craniofacial Prosthetics Unit (CPU) is the only multidisciplinary clinic in Ontario where surgeons, dentists and anaplastologists work as a team. The only other unit like it in Canada is in Edmonton.

Sunnybrook’s CPU team is made up of two anaplastologists (specialists trained in the art and science of creating custom prosthetic devices), two head and neck surgeons, a coordinator and a maxillofacial prosthodontist (a highly specialized dentist who is an expert in the prosthetic rehabilitation of patients with facial differences due to trauma, cancer or congenital malformation).

The team makes and fits about 50 prostheses per year – for a mix of new patients and existing patients. Prostheses last about two years before they start to wear out and undergo colour changes.

Patients come from all over Ontario and some from other provinces and even beyond. Prostheses for Ontario residents are partially funded by the Assistive Devices Program of the Ministry of Health and Long-Term Care – 75 per cent, with the balance being the patient’s responsibility.

This is the first year that surgical implants will be 100 per cent funded by the Ministry of Health and Long-Term Care for Ontario residents. Sunnybrook’s team will do about 15 surgical implants this year.

Reasons for requiring a facial prosthesis:

  • 44 per cent: cancer
  • 37 per cent: congenital
  • 14 per cent: trauma
  • 5 per cent: other

All photography by Kevin Van Paassen

About the author

Alexis Dobranowski

Alexis Dobranowski is a Communications Advisor at Sunnybrook.