Clearing Pathways: Imaging and Reimagining Open New DVT Treatment Doors
With confident strides and quick pace, Laura Resnansky takes the steps of the famously-steep Lyon Street stairs in San Francisco, in training for a half marathon. She's not showing any signs of being winded, and it's a 288-stair climb.
Eighteen months ago, Resnansky would not have attempted the demanding workout. Then, deep inside a vein in her left leg was a blood clot that first appeared a few months earlier when she was 20 weeks pregnant. With blood flow blocked by the clot, her leg swelled to twice its size. She was in constant pain. Her doctor prescribed medication to thin Resnansky's blood and, as another precaution, advised Resnansky to spend the last half of the pregnancy on bed rest to keep her leg elevated.
The pain in her leg lessened, but a few months after her daughter was born and Resnansky stopped taking the blood thinning medication, her leg swelled again and the pain returned.
This time, Resnansky went to see Lawrence "Rusty" Hofmann, MD, at Stanford Hospital & Clinics. Hofmann is a radiologist, a physician focused on the art of seeing inside the body. But, more importantly to Resnansky, Hofmann is an interventional radiologist, someone who is focused on creatively combining radiology's precise vision with medical devices revamped to very small scale to offer proactive treatment of blocked veins.
Seeing more clearly
What Hofmann discovered, with a CT scan of Resnansky's leg, was that, despite the blood thinners, the original clot was still there. And, it had grown to block most of the flow out of her vein. To help Resnansky, Hofmann used an innovative treatment approach designed to treat both recent and older clots, once thought untreatable, in the millions of people whose veins become blocked by blood clots. The clotting phenomenon is known as deep vein thrombosis, commonly referred to as DVT. The condition's most lethal possibility is that a clot will break lose and travel to the lung, heart or brain.
More than 15 million Americans suffer from some form of the disease. Each year sees another 600,000 cases of DVT. An estimated 100,000 die annually from complications related to the disease.
We knew we could treat chronic DVT if we had better devices.
Clots appear for several reasons; many form after a traumatic injury to the body followed by long periods of low-activity recovery. DVT can also appear in women taking oral contraceptives, or, like Resnansky, when they are pregnant. Other clots form and remain to cause chronic pain and loss of mobility or function. Until now, that on-going, chronic DVT has been considered untreatable.
For many years, the standard treatment for all clots was to thin the blood, said Hofmann, who is also chief of the Hospital's Division of Interventional Radiology. That approach, he said, "was the equivalent of someone coming in and saying, "I'm not feeling well,' and the doctor saying, 'You have cancer. Here's a pill.' What we can do now is stage a clot, look at it, and understand that it's a combination of biology and anatomy."
Using advanced CT scans to locate each clot in the geography of each patient's body now makes it possible to do much more than prescribe blood thinners, Hofmann said. He discovered that Resnansky's clot was May-Thurner Syndrome, the result of a physical anomaly in the veins of the abdomen and leg. One vein compresses another, which slows blood flow and raises the odds of repeated blood clots.
Putting Resnansky on blood thinners for the rest of her life was not what Hofmann wanted to do. Instead, he placed her under conscious sedation, found the appropriate vein at the back of her left leg and made an incision small enough to be covered after surgery with a band-aid. In went a catheter that would carry the wire Hofmann would use to break through the old clot. Later, the catheter would also carry a stent, a mesh tube that Hofmann would leave in the place where Resnansky's vein had been blocked and narrowed by compression. The stent would not only strengthen the vein but also help prevent future clots.
I feel like I don't have the limitations or the concerns I had. If it does happen again, I know how they would treat it.
Throughout the entire procedure, Hofmann would be able to track, with real time x-rays, the progress of the catheter and the wire.
Resnansky went home the same day. Breaking up her clot was relatively easy. For others, whose clots have been in place for years and for whom no treatment was believed possible, Hofmann has offered hope. "These older clots were obstacles no one could get through, where the clot had completely occluded the vein and the vein almost disappeared," Hofmann said, "or, you'd see some small tiny veins where big ones used to be. The difficulty was getting through this blockage." He joked about interventional radiologists being "the MacGyvers of medicine," recalling a 1980's television character who saved every episode by ingeniously transforming a highly original combination of objects into something completely different.
Catheters have been used to enter many parts of the body. Wires have been used for other medical procedures. Balloon angioplasty has long been part of cardiovascular care. CT scans were used for a variety of imaging purposes. Stents have been important repair components. "We've been able to take things used in one part of the body and use them with DVT," Hofmann said. "We knew we could treat chronic DVT if we had better devices."
Other innovations lower the odds of possible long-term effects. The new CT scans reduce the amount of radiation a patient receives. For recently formed clots, Stanford physicians now use a kind of soaker hose delivery of blood thinners that keeps the chemistry focused on the clot. "We can give the patient the drug right where it needs to be," Hofmann said. "And if we remove the clot quickly the vein doesn't become completely blocked."
Some of Hofmann's chronic DVT patients have flown in from outside the U.S. to take advantage of these new techniques and the special equipment, available at Stanford and only a handful of other medical facilities.
Resnansky is doing great, she said. "I feel like I don't have the limitations or the concerns I had. I'm healthy and I'm taking care of myself. I try not to worry about it." Hofmann has told her the stent will probably last about 10 years. She'll see him once a year for a special look at the vein. "It could have been something far worse," she said. "If it does happen again, I know it is treatable and that gives me peace of mind."
She's an active mother. Her son, Hayden, 5, is constantly curious. Margaret, almost 2, still likes to sit on a parental hip. Resnansky is also associate director of clinical program management at a Bay Area biotechnology company. And she's training for that half-marathon.
She thinks, too, about others with DVT, those who might be treated with these newer techniques. "It's a shame more people don't know about this," she said. "It changes the quality of life significantly."
About Stanford Hospital & Clinics
Stanford Hospital & Clinics, located in Palo Alto, California with multiple facilities throughout the region, is internationally renowned for leading edge and coordinated care in cancer, neurosciences, cardiovascular medicine, surgery, organ transplant, medicine specialties and primary care. Stanford Hospital & Clinics is part of Stanford Medicine, which includes Lucile Packard Children's Hospital Stanford and the Stanford University School of Medicine. Throughout its history, Stanford has been at the forefront of discovery and innovation, as researchers and clinicians work together to improve health, alleviate suffering, and translate medical breakthroughs into better ways to deliver patient care. Stanford Hospital & Clinics: Healing humanity through science and compassion, one patient at a time. For more information, visit: StanfordHospital.org.