A Canadian first: New device helps to tackle challenging deep vein thrombosis cases


When Crystal Ellis arrived at the hospital in July, her left leg had swollen to nearly twice its size.

“The pain was from my foot to my stomach,” she describes. “My stomach was swollen and I could barely walk.”

This wasn’t her first experience with these symptoms. Ellis had a blood clot in one of the main veins that went from her left leg into her abdomen in 2014. The condition – called deep vein thrombosis or DVT – happens when the main veins from the legs or arms are blocked, stopping blood from going back to the heart to be re-oxygenated and recirculated.

An estimated 45,000 Canadians are impacted by DVT each year. The common symptoms are swelling and pain, as well as redness and warmth in the impacted area. DVTs are typically treated with anti-coagulant medications – commonly known as blood thinners.

One of the risks of a DVT is that the blood clots can travel to other parts of the body. In 2014, Ellis also experienced a pulmonary embolism, where a blood clot travelled to her right lung. She ultimately spent over a month in hospital for care and recovery.

At that time, Ellis had a stent put into the vein in her left leg as part of her DVT treatment. A stent is a small mesh tube that is placed in the vein to hold it open. This past July – when Ellis was experiencing significant swelling and pain – it was because blood clots had formed and hardened inside the stent, blocking it completely. She was transferred by ambulance to St. Michael’s Hospital where the Interventional Radiology team did their best to clean out the stent and open it up.

The Hematology team at St. Michael’s continued to follow Ellis and – while the procedure at St. Michael’s had helped – she was still experiencing swelling and pain in her left leg.

“I can’t run like I used to. I have a seven-year-old child and I can’t play with him at the park,” says Ellis, when describing the impact of the DVT on her day-to-day life. “Walking up and down stairs is a challenge for me. The building I live in has 25 floors. We have three elevators but a lot of the time the elevators don’t work.”

Around this time, the Interventional Radiology team was discussing bringing in a new device called a RevCore Thrombectomy Catheter. The new device has an adjustable metal coring element that shaves off and clears out blood clots that have formed and hardened within a stent.

Ellis is the first patient in Canada to receive treatment with this device.

“Without these new types of tools, our ability to treat the blocked stent is limited,” says Dr. Andrew Brown, an interventional radiologist at St. Michael’s. “Essentially, these patients were left to manage as best they can with their pain and reduced mobility.”

Interventional radiology is a specialty of medicine where physicians use imaging tools – like ultrasounds, CT scans and X-rays – to provide image-guided, minimally-invasive treatment and care.

New innovations like this compliment ongoing efforts to create a multidisciplinary approach to DVT care that has set St. Michael’s Hospital apart among its peers.

During the procedure, which took place in late November, Brown placed the device through a vein behind Ellis’ knee. Once the device arrived at the stent, he increased the diameter of the coring element and rotated it by hand to carve away at the blockage in the stent. Throughout the procedure, he and his team used X-rays and ultrasounds to help guide them.

Ellis returned home the same day as the procedure and has regular check-ins with the Interventional Radiology team.

For Brown, using the new device accomplished exactly what he had hoped. 

“I was extremely happy with the results. Now we have to let the medicine do its work,” says Brown, referring to the blood thinners Ellis will continue to take.

“Immediately after the procedure, the area where we shaved off the blood clots becomes prothrombotic – essentially looking for platelets and coagulation factors to grab onto and form more blood clots,” Brown describes. “After a period of time, it becomes dormant and patients can come off the medication.”

“Monitoring is the big key,” says Brown. “Sometimes it’s just peace of mind for the patients and sometimes it actually is incredibly important because we do begin to see that there’s a portion of the stent that looks like it’s narrowing again.”

In the months following the procedure, Ellis has noticed significant improvements.

“Before, even just walking to another room my leg would balloon and I would have a lot of pain,” says Ellis. “Now I still have some swelling but I don’t have much pain unless I walk a longer distance.”

Addressing gaps in deep vein thrombosis care

Adding this new device to their toolbox is an exciting development for Brown and the Interventional Radiology team at St. Michael’s.

“The majority of the people that I see are in their 20s, 30s and early 40s,” says Brown. “For them to not be able to exercise, not to be able to walk up a set of stairs without pain or shortness of breath – that is a significant impediment. It doesn’t feel good to have to say to a patient that we did the best we could but there’s nothing left to offer you.”

It also helps to address a gap that Brown knows has long existed for his patients. He recounts one patient in particular from the hospital he worked at before coming to St. Michael’s. She had a DVT blocking the big vein in her abdomen, causing swelling and inflammation in both of her legs. He and a colleague did all that they could to help her but the tools and options available at the time weren’t enough.

“Even today, I think about her a lot because she ultimately died of her disease,” recounts Brown. “The opportunity to bring something new to St. Michael’s that potentially could help patients like her – when I couldn’t help her at that time – is very important to me.”

New innovations like this compliment ongoing efforts to create a multidisciplinary approach to DVT care that has set St. Michael’s Hospital apart among its peers.

“To my knowledge, it really is the only place in the province where folks from Hematology, Vascular Surgery, Interventional Radiology and Emergency Medicine are bringing their resources and expertise to bear on DVT patients,” explains Brown. “Some cases can be very complicated, so to do this well requires a team effort.”

By Robyn Cox


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