New surgical technique allows doctors to add more organs to the donor pool

Two types of light-based therapies can sterilize donor organs prior to transplantation

New surgical technique allows doctors to add more organs to the donor pool

A new technique co-developed by U of T researchers uses light-based therapy to kill viruses in organs meant for transplantation. The method lets physicians treat human donor lungs infected with Hepatitis C, preventing viral transmission to the organ recipient.

The co-authors of the procedure, published in Nature, are hopeful that it could vastly increase the number of organs eligible for transplantation in North America.

The new surgical technique is based on existing methods

This technique uses an existing procedure known as ex-vivo lung perfusion. Here, after retrieval by practitioners, the lungs are placed in a chamber with a circuit and specific liquids flow through the organs’ vasculature.

During this circuit the solution passes through the lungs, washing out a lot of viruses. The newly developed technique uses a machine with two light-based therapies — namely, ultraviolet C irradiation and photodynamic therapy — to eventually sterilize the organs before the transplantation.

The research team developed a customized illumination device which is attached to the machine where perfused liquid passes through, irradiating the virus and therefore inactivating it with light.

The researchers aim to further develop the technique by treating the lungs themselves with light, not just the liquid that passes through them. To achieve this, more research is needed on the optical properties of the lungs to engineer new technology to illuminate them.

Adding organs to the donor pool

Co-author Dr. Marcos Galasso, a U of T thoracic surgeon and ex-vivo lung perfusion specialist, stressed the importance of this new technique in an interview with The Varsity.

“There is a great need for donor organs,” he said, “[which has led] to some people dying on the waiting list for transplantation.”

Galasso added that treating Hepatitis C-infected donor lungs alone could make a huge impact on the donor pool due to the opioid crisis gripping North America. He noted that most patients who die from drug overdoses test positive for the virus.

According to Galasso, if health care practitioners could add volunteers infected with Hepatitis C to the donor pool, there could between 1000 to 2000 new lung donors eligible per year in North America.

“We could actually have a massive impact in the organ donation environment in North America [with this surgical technique].”

Where computers and clinics intersect

Raw Talk Podcast hosts expert panel discussions about AI’s role in healthcare

Where computers and clinics intersect

Experts in medicine, academia, and industry explored the promises and perils of the applications of artificial intelligence (AI) in health care during panel discussions with the Raw Talk Podcast on May 7. The event was organized by graduate students of U of T’s Institute of Medical Science.

The two panels, collectively named “Medicine Meets Machine: The Emerging Role of AI in Healthcare,” aimed to demystify sensationalism and clarify misconceptions about the growing field of study.

“On one hand, it seems like everyone has heard about [AI],” said Co-executive Producer Grace Jacobs. “But on the other hand, it seems like there’s a lot of misunderstanding and misconceptions that are quite common.”

How AI is used in health care

While discussing the reality of AI, several panelists emphasized that it should be viewed and treated as a tool. “It is statistics where you don’t have to predefine your model exactly,” said Dr. Jason Lerch of the University of Oxford.

Other speakers agreed that AI is an expansion of — or a replacement for — traditional statistics, image processing, and risk scores, as it can provide doctors with more robust and accurate information. However, final health care recommendations and decisions remain in the hands of doctors and patients.

“You always need a pilot,” said Dr. Marzyeh Ghassemi, a U of T assistant professor of computer science and medicine.

But what advantages can this tool provide? Ghassemi thinks it can assimilate clues from a wider range of patients’ conditions to predict treatment outcomes, replacing the experience-based intuition that doctors currently rely on.

Speaking on her time in the Intensive Care Unit as an MIT PhD student, Ghassemi said, “A patient would come in, and I swear they would look to me exactly the same as prior patients, and the… senior doctors would call it. They would say, ‘oh, this one’s not going to make it. They’re going to die.’ And I would say, ‘Okay… why?’ And they said, ‘I’m not sure. I have a sense.’”

“They used different words — gestalt, sense — but they all essentially said the same thing. ‘I just — I have a sense.'”

Doctors develop this sense by seeing many cases during their training, but they can intuit only the cases that they had personally experienced; AI algorithms can potentially understand many more cases using a wider dataset.

Accessing those cases requires access to patient data, and access to data requires conversations about consent and privacy. Ghassemi and Dr. Sunit Das, a neurosurgeon at St. Michael’s Hospital and Scientist at the Keenan Research Centre for Biomedical Science, said that “de-identification” — the removal of information that can be traced back to individual identities — protects privacy.

Large de-identified datasets from the United States and the United Kingdom are available for AI research, but generally, Canada lags behind these countries in making health data available for this purpose.

Dr. Alison Paprica, Vice-President of Health Strategy and Partnerships at the Vector Institute, agreed that data should be used for research, but argued that de-identification alone does not eliminate risk.

“You’re not just giving a dataset to anybody,” she said. “You’re giving a dataset to people who are extremely skilled at finding relationships and patterns and maybe piecing together information in ways that most people couldn’t. So I think there’s going to be heightened sensitivity around re-identification risk.”

Society must manage this risk and balance it against the benefits. “How do we balance that?” Paprica asked. She suggested that consulting all involved stakeholders could help strike that equilibrium.

Advice for scientists aiming to use AI in their research

So what advice did the panelists have for scientists hoping to harness the power of AI in their own research?

Ghassemi stressed the importance of knowing what you’re doing: researchers have created many tools that make AI research easy to implement, but conscientious scientists need to know the statistical and training principles behind the methods.

“If you’re not aware of how these things are trained,” she said, “it’s really easy to misuse them. Like, shockingly easy to misuse them.”

Other panelists advised users to take care when choosing data to train the algorithms. “A learning algorithm can’t overcome bad data that goes in, or can’t completely overcome it,” said Lerch.

Moderator Dr. Shreejoy Tripathy summed up a key takeaway on applying AI to health care: “Understand your data… And understand your algorithms.”

In conversation with Professor Cynthia Goh

Chemistry professor bridges passions for research and entrepreneurship

In conversation with Professor Cynthia Goh

Professor Cynthia Goh balances many responsibilities. She is a professor in the Department of Chemistry, the Department of Materials Science and Engineering, the Institute of Medical Science, and the Munk School of Global Affairs.

She is the director and founder of the Impact Centre, which strives to bring “science to society” through entrepreneurship, and also the academic director of University of Toronto Entrepreneurship.

Goh describes herself as “a STEM student through and through.” Explaining her interest in STEM, she says, “I think if you know the rules that govern the world you can make a better world.”

Goh’s research interests lie in nanoscience — specifically, the properties, structures, conformations, and interactions of molecules such as polymers and biomolecules, and how these molecules can be used to improve areas such as health care and disease treatment.

After receiving tenure, she shifted her focus to entrepreneurship. “I was making impact in my discipline, I would write a paper and people would quote it and write papers about it. But, I really wanted to see how to make a difference in people’s lives and I learned, basically, that’s about bringing this nice research result to creating a product that somebody can use.” This is how the Impact Centre was created.

The Impact Centre was recognized by the university in 2013, but it has been in operation for years prior to that. Goh describes the centre’s mission as striving to connect the research being done in institutions to a service or a product to create positive impact.

In its beginning stages, Goh had designed an extracurricular entrepreneurial skills training program for students who believed that the skills would be of value to them.

But according to Goh, there was a disconnect between research and application. The change in direction was a challenge. However, Goh views challenges as opportunities to overcome obstacles and forge paths to new areas.

In fact, when Goh began working at U of T, she was the only woman in the Department of Chemistry, and this continued for eight years.

“When I had my kid, nobody knew what the maternity leave rules were because nobody has asked for maternity leave before me,” says Goh. She recounts that she would carry her child at work and would, at times, receive strange looks.

But instead of “carrying a chip on [her] shoulder,” she explains, “I’ve always had the attitude that if people maybe may sound like they’re not on your side, it’s probably because they just don’t have the experience.”

From the small sample of children Goh has worked with, she says that despite the generalization that boys seem to have more outward confidence than girls, “confidence comes from having done your homework.”

The nature of STEM subjects, she says, allows for checking if an answer is correct. “In math, you can tell what the correct answer is, so I can build a lot of confidence knowing I’m right.”