NeuroVoices: Yasha Kayan, MD, on Stroke, Devices, and Emerging Therapies for Neurointervention

Neurointerventional surgery has undergone a significant transformation over the past decade, evolving from a niche, procedure-driven specialty into a cornerstone of modern neurologic care. Advances in device technology, imaging, and clinical trial evidence have reshaped how clinicians approach acute ischemic stroke, aneurysms, and a growing number of cerebrovascular and neurovascular conditions, with endovascular therapies now widely considered standard of care in many settings.

In acute stroke management specifically, the shift from rigid time-based treatment paradigms to more individualized, tissue-based decision-making has expanded treatment eligibility and improved patient outcomes. At the same time, improvements in thrombectomy devices, workflow optimization, and system-level coordination have helped reduce time to reperfusion, a critical determinant of neurologic recovery.

In a new iteration of NeuroVoices, Yasha Kayan, MD, medical director of neurointerventional surgery at Abbott Northwestern Hospital, part of Allina Health, discussed the evolution of the field, key considerations in patient selection, workflow optimization strategies, and emerging areas that are poised to further expand the scope of neurointerventional care.

Transcript edited for clarity. Click here for more NeuroVoices.

NeurologyLive: How has neurointerventional surgery evolved in recent years, particularly in the management of acute ischemic stroke?

Yasha Kayan, MD: The primary way that our field has evolved is going from one where we did most of the things that we do based on expert opinion to truly an evidence-based field driven by robust clinical trial data. So particularly in the area of ischemic stroke, acute stroke, we've transitioned, for example, from strictly time-based selection criteria to tissue-based criteria.

We also have a lot of improved devices, like large reperfusion catheters that can get more distal than we ever thought possible. And we also have better data supporting thrombectomy for basilar occlusion. So there are a variety of advancements that have been made in this particular disease, but others as well.

And what we've really witnessed over a very short period of time is the transition of a field from a novelty or a niche into really a standard of care. Particularly with acute ischemic stroke, it’s one with a very low number needed to treat in order to see a real clinical benefit for our patients.

How do patient selection factors guide endovascular intervention, especially in extended time windows?

So there are a lot of factors that guide us, and I'll touch on a few. One that comes up time and again, particularly in this population, is age. Even though intervention has been found to be beneficial in older age groups, it doesn't mean we abandon common sense.

It’s also true that older folks are less likely to do as well as younger folks, and not everyone ages in the same way. There are 90-year-old runners and there are 60-year-old folks who are bedbound. So decisions to treat really need to be more nuanced than just based on a number. You’d be surprised how often people don’t ask how a patient was doing before their stroke.

Another very important factor is technical complexity, and this is very underrated. Not every stroke intervention is the same in terms of complexity. There are what we call “simple” procedures, where you're performing an embolectomy of a clot that came from the heart in a younger patient with normal blood vessels. Those are sort of the “one-and-done” procedures, where the rate of first-pass success is very high.

Then there are more complex cases, like tandem occlusions in elderly patients with extreme tortuosity, or distal occlusions that are difficult to safely navigate unless you have the patient completely still under general anesthesia. Or re-occlusions due to in situ plaque and intracranial atherosclerotic disease. So there are a variety of technical factors that can make a procedure much more challenging.

It’s not just that it’s challenging for the operator. It’s that you have to perform higher-risk maneuvers to achieve recanalization, and sometimes those maneuvers can change the risk-benefit analysis in a way that isn’t fully accounted for if you just do a cursory interpretation of clinical trial data.

Another factor would be the volume of dead brain. Yes, there is data showing benefit to intervention in patients with low ASPECTS scores, meaning more brain has already been lost. But that doesn’t mean we rush in for all of these cases. We need to use common sense, especially with late presenters.

These are the patients who can end up bleeding. One example is a moderate severity, non-dominant hemisphere stroke that could rehab reasonably well, but if you intervene too aggressively, you might convert it into an unsurvivable hemorrhage. So these are just a few of the factors we are constantly weighing when making a decision to treat.

How do you approach complex or borderline cases where imaging and clinical presentation don’t fully align?

For me, the best way to approach these difficult cases is to really put yourself in the family’s shoes and think, what would you do if this was your mother, your father, your grandmother, your grandfather—what have you.

That mental exercise is something we should probably do more often as physicians. Looking through that lens has a way of grounding you and enables you to see around potential blind spots that we all have. So that’s sort of my go-to approach for tough decisions.

What are the most important workflow considerations for optimizing door-to-reperfusion times?

I do think AI is having an increasingly important role in workflow optimization. But going back to the basics, doing things the same way every time is extremely important.

That means reaching consensus with your partners and colleagues on how you do things—the imaging you rely on, the devices you use—so that you’re not reinventing the wheel with every case.

It’s also important to review your processes and go through everything line by line, eliminating the things that don’t matter. You’d be surprised how many things we do just because that’s how we’ve always done them, versus doing the things that actually drive patient care forward.

We do a lot of important preoperative steps for patient safety, and that makes sense in less urgent situations. But in the case of an emergent large vessel occlusion, the safety equation changes. The most unsafe thing is the clot in someone’s brain, not whether we checked every box we normally would.

The last thing I would say is relationships. Because we are streamlining workflows, relationships become even more important. At my home hospital, I try to maintain a positive rapport with my staff so they feel comfortable raising safety concerns.

We’ve also transitioned to taking system calls, which means working in hospitals we may not be familiar with. Just recently, I performed a thrombectomy at a hospital I had never worked at before, with a team I had never met. Taking a moment at the start to break the ice and establish communication can go a long way in improving procedural safety.

What technologies or devices are currently advancing the field?

One of the things I mentioned earlier is large-bore catheters that are extremely navigable. These devices shave minutes off procedure time and allow for distal access to clot in a non-traumatic way. So you’re giving more patients the benefit of revascularization without exposing them to the risks we had with earlier devices.

But it’s not just stroke. Aneurysm treatment has also evolved significantly. People still say we coil aneurysms, but it’s not really just coiling anymore. That was very much a 90s-era approach.

In our practice today, less than 10% of aneurysms are treated primarily with coils. A large portion are treated with intravascular or intrasaccular flow diversion. You’d be hard-pressed to find an aneurysm today that doesn’t have an endovascular solution.

This has changed the risk-benefit analysis. Aneurysm treatment is much safer and more effective now than it was even five or ten years ago. That changes who you treat and who you offer procedures to.

And even the cases we consider challenging are often just as difficult for open surgical colleagues. So the most important thing is that these cases are managed in a multidisciplinary environment by specialists.

What emerging areas should neurologists be paying closer attention to?

The field is not just becoming more mature—it’s rapidly expanding. We’re treating diseases that we weren’t even close to addressing just a few years ago.

One area is idiopathic intracranial hypertension. Venous sinus stenting has become a very important part of management, and we’re noticing that the subset of patients who may benefit is likely larger than previously thought. Related to that is pulsatile tinnitus, which can also be treated effectively with venous sinus stenting and can be quite debilitating for patients.

Another area is spontaneous CSF leaks and intracranial hypotension. We’re doing more advanced myelographic workups and offering treatments like targeted epidural blood patches and venous embolization. Chronic subdural hematoma is another major area, with minimally invasive approaches proving to be safe and effective, especially in elderly patients or those on anticoagulation.

Finally, carotid stenting is seeing renewed expansion. The latest data suggest that more patients with carotid disease may benefit from stenting than previously thought. So these are the areas that are likely to see the most growth and provide meaningful benefit for patients.