Sunnybrook Magazine Sunnybrook Magazine - Spring 2020

Leading-edge stent technology for aneurysms gives Sunnybrook patient a second chance at life

Neurosurgeon and senior scientist Dr. Victor Yang holding a stent.

 (Photography by Kevin Van Paassen)


About 18 hours after an ambulance rushed his wife to Sunnybrook, Dean Kirkhus faced a decision that he knew could spell the difference between life and death for his partner of more than 33 years.

Tracy Kirkhus had a ruptured aneurysm, which meant that a ballooning blood vessel in her brain had burst and was leaking blood into the space around her brain. The 56-year-old was unconscious and unresponsive by the time Dr. Victor Yang, a neurosurgeon and senior scientist at Sunnybrook, took her into the operating room.

“She was in a deep, deep coma,” Dr. Yang says. “Because of the location of her aneurysm and her deteriorating condition, by the time I saw her, the options available to her were limited.”

The initial line of treatment for a brain aneurysm is endovascular coiling, which involves pushing a platinum coil through a catheter to induce clotting and prevent blood from getting through the aneurysm.

In Tracy’s case, the aneurysm occurred right against the brain stem, with a shape that makes it difficult to receive the coil at the rupture point. Though Dr. Yang tried the endovascular coiling procedure, it failed to fully repair the aneurysm, he says.

The next option was a stent, but this would require blood thinner medications because the metal in conventional stents can cause blood clots. For Tracy, who had hemorrhaged badly, blood thinners were not advisable.

“After the [initial] surgery, Dr. Yang came to me and told me it didn’t work out,” says Dean. “Then, he said he had another idea.”

Dr. Yang’s idea was to implant a flexible stent with a special polymer surface designed to mimic the natural properties of blood cells. At that time, the stent – called a Pipeline Flex Embolization Device with Shield Technology – was not approved for clinical use, so Dr. Yang needed Health Canada’s permission to use the device on a compassionate basis.

“And of course, they needed our consent,” Dean says. “I didn’t think twice. I knew we had little choice but to go ahead with this other method and I felt that we could trust Dr. Yang.”

He waited anxiously to see whether Dr. Yang’s creative manoeuvre would be successful.

A harrowing journey

The events leading up to Tracy’s surgery at Sunnybrook started in February 2019, just two days before Valentine’s Day.

She was in Toronto with Dean, an Air Canada pilot who was attending a work training course. (Tracy, a manager at an air traffic control centre, first met Dean back in the ’80s when he was a bush pilot). After taking in a movie with her daughter, who lives in Toronto, Tracy headed to her home near Minden, Ont., located about 2.5 hours northeast of the city. She was hoping to dodge a snowstorm expected to hit Toronto that night.

As Tracy drove north on Highway 400, the headache that had been bothering her all day went from tolerable to excruciating. She stopped at a roadside service centre just off the highway and went to the washroom.

She was in a stall when her aneurysm ruptured.

“It felt like the top of my head exploded and I hit the floor,” Tracy recalls. She managed to get herself up and out of the washroom, but then she fell again.

“That’s when I noticed people were looking at me strangely – they probably thought I was drunk,” Tracy says. “I went to the counter and bought myself a pop and some chips, somehow thinking that if I did that, everything would be fine.” Tracy went to her car and then began vomiting.

Dean had texted his wife earlier to check that she had made it home safely. She responded after midnight, but her text came through as jumbled letters. When Dean called her, she told him she was at a service centre along the 400, but could not tell him which one. He immediately got in his car and went from service station to service station, searching for his wife.

“When I found her, I thought she was having a stroke, so I drove her to the nearest urgent care clinic,” he says. The doctor who saw Tracy ordered a CT scan of her brain. At around 4:30 a.m., she was taken by ambulance to Sunnybrook.

Tracy Kirkus.

Tracy Kirkhus and her husband, Dean, at their home near Minden, Ont. (Photography by Kevin Van Paassen)

‛Cutting-edge approaches’ that save lives

The Pipeline flex shield stent is made with a synthetic version of an organic compound found in the outer membrane of red blood cells. This mesh-like biomaterial prevents blood cells from reacting to the stent implant. Once implanted, the Pipeline flex shield stent acts as a scaffold and helps rebuild the damaged blood vessel.

To get the Pipeline flex shield stent to Tracy’s brain, Dr. Yang used a flexible catheter, inserted into an artery in the groin region and sent up through the body. He also employed innovative imaging technology called Doppler Optical Coherence Tomography (OCT), which uses infrared light waves to create images of tissue, cells and molecules.

With OCT to guide him, Dr. Yang was able to see and accurately position the stent in the damaged blood vessel.

“My research lab was the first in Canada to do OCT research 20 years ago, and at Sunnybrook we are still the only group in the world capable of doing Doppler OCT in neurovascular patients,” says Dr. Yang.

Sunnybrook was also the first in Canada to implant the Pipeline flex shield stent, which is now Health Canada approved. To date, says Dr. Yang, Sunnybrook is one of the leading hospitals in the country for treating complex ruptured aneurysms using this technology.

“As part of the hospital’s mandate to innovate and stay at the forefront of treatment technology, Sunnybrook has led research in brain sciences with cutting-edge approaches to treating neurovascular diseases,” Dr. Yang says. “At the same time, Sunnybrook has also advanced its application of image-guided, minimally invasive therapies.”

By combining these two strategic directions, doctors at Sunnybrook have been able to treat more and more patients who would have previously been quite difficult to treat, he adds.

For Tracy Kirkhus, Sunnybrook’s innovations in neurovascular treatment have meant a second chance at life.

After spending 25 days in intensive care at Sunnybrook, Tracy spent another five months in hospital, both in Toronto and in Lindsay, Ont. By August 2019, she was able to return home, where she continued to receive physiotherapy and occupational rehabilitation. Now, she is able to walk and goes to rehab sessions twice a week.

Tracy says her vision is still impaired, and sometimes she forgets things. Talking at length can take a toll on her.

“But I’m alive, and I’m home,” Tracy says. “Dr. Yang and all the great people at Sunnybrook are my heroes.”

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Marjo Johne