Expanding the scope of carotid pathologies
Treatments seek to bring better outcomes in existing and rare conditions.
Carotid pathologies — including carotid stenosis, carotid webs, carotid dissection and intraluminal thrombosis — are complex conditions requiring critical expertise. Understanding the latest in imaging advances, delicate decisions on care and more are the focus of a session on Thursday, “Hot Topics on Hot Carotids.”
For decades, the key measurement for determining the risk of cerebrovascular events by atherosclerotic carotid disease has been based on the degree of stenosis. But that’s just one part of a bigger, evolving picture.
Luca Saba, MD, dean of the School of Medicine at the University of Cagliari in Italy, said the “degree of stenosis” approach originated from landmark trials like NASCET and ECST that were conducted beginning more than 40 years ago when the only method for assessing carotid arteries was angiography.
“Since angiography could only measure the degree of stenosis, this became the main parameter of interest,” Saba said. “The enormous impact of those trials, with high levels of evidence, effectively transformed this measure into dogma. However, in the past 40 years, significant advances have been made.”
Saba, who is also a professor of radiology and chair of his university’s radiology department, will address those advances in his presentation, “Degree of Stenosis Isn’t Everything.”
“The introduction of CT, MRI and ultrasound allows us to visualize not just the degree of stenosis, but also the underlying cause — the carotid plaque,” he said. “Over the last 20 years, it has become clear that certain morphological and structural characteristics of plaque are linked to increased vulnerability, higher risk of rupture and greater potential for risks.
“Today, thanks to advancements in imaging technology, we have the ability to better characterize the plaque itself and more accurately stratify cerebrovascular risk.”
Saba said degree of stenosis is an indirect parameter, and there is a growing capability of including other measurements and diagnostic tools.
“The goal is to shift the focus from stenosis alone to the concept of plaque vulnerability,” he said, including demonstrating the role of different imaging techniques in identifying features that make plaque vulnerable.
Intraluminal thrombus in carotid arteries is a highly dangerous condition in which a thrombus is stuck to the wall but weakly attached, meaning it could detach from the vessel at any moment, causing the patient to have a stroke. Johanna Ospel, MD, PhD, will discuss the best methods for treating these patients in her presentation, “The Intraluminal Thrombus of Damocles.”
“This is a pretty precarious situation, since any mechanical manipulation that we perform during interventions could also dislodge the thrombus,” said Ospel, neuroradiology fellow and stroke researcher at the University of Calgary in Alberta. “There is a high risk of doing nothing and a high risk when intervening,” she said.
“Patients with intraluminal thrombi must be watched very closely because they can have a stroke at any minute. If that happens, rapid treatment is necessary, so every minute counts.”
Ospel said it is the condition’s rarity that makes it particularly challenging because it’s unlikely there will ever be enough patients to do a randomized controlled trial to fully study it.
“Therefore, multicenter, retrospective pooling data is absolutely critical to gather large enough datasets to make any evidence-based treatment decisions,” she said. “This is a main difference compared to more common causes of stroke, such as carotid stenosis or atrial fibrillation, where randomized trials are feasible and have been done or are underway.”
Two other presentations will be included in the session Thursday: “Caught in the (Carotid) Webs” by Shadi Yaghi, MD, FAHA, associate professor of neurology at Brown University, and “Occluded Carotid: A Fait Accompli” by Edgar A. Samaniego, MD, MS, clinical professor of neurology at the University of Iowa.
