This advertorial is sponsored by Penumbra.
The proliferation of new thrombectomy devices coupled with a deepened understanding of these procedures has led to strategies like ADAPT (a direct aspiration first-pass technique) becoming one of the hottest topics in the neurointerventional space. With this in mind, Alex Solich (Karolinska University Hospital, Stockholm, Sweden) sat down with NeuroNews to take a closer look at the concept of Science-Based Aspiration Thrombectomy (S-BAT).
“Aspiration has become mainstream over the past couple of years—but it was more marginalised during the dawn of aspiration technology,” Solich comments, highlighting the evolution endovascular stroke treatment has undergone since its safety and effectiveness was fully established in 2015. “Even the best catheters we had were challenging to navigate, especially in anatomically demanding cases. Catheter technologies have taken big leaps forward in recent years, and [newer, more advanced] catheters can be navigated to the occlusion site without any major problems. This has enabled us to use aspiration in an increasing number of patients.”
Through a sprawling portfolio of ischaemic stroke products—including its ENGINE system, RED reperfusion catheters and BMX access catheters—Penumbra has played a leading role in these technological advancements. Now, the company has established a concept within which these newer, more effective tools can be utilised with even greater efficiency—and through which the science underlying aspiration thrombectomy can be better understood.
A scientific basis
S-BAT, Solich explains, is comprised of four key pillars: physics, vessel sizing, flow control, and time.
“If you want to get aspiration right, first of all, you need to look at physics and how the aspiration works,” he says. “We need to understand that we’re not sucking the thrombus inside the catheter—it is actually pushed inside the catheter by the pressure differential we are creating between the catheter and the [vessel] when we aspirate. This is a critical point to understand.”
Solich also emphasises the importance of appropriate sizing, warning his peers of the potential pitfalls in selecting a larger-diameter or even ‘super-bore’ aspiration catheters that will occupy the entire lumen of the target vessel, as this reduces the pressure differential between thrombus and vacuum source—a pressure differential that is believed to support effective clot removal.
“Flow around the outside of the catheter helps push the thrombus inside the catheter, which means you don’t always want to oversize your [device] compared to the vessel,” he adds. “Our experiences and understanding of this have changed how we perform aspiration. We’re looking at the size1 and angulation of the vessel, and trying to anticipate the contact point with the thrombus itself, and then choosing our catheters according to these details.”
If you want to get aspiration right, first of all, you need to look at physics and how the aspiration works
The core principles of aspiration physics and vessel sizing also tie into the third pillar of S-BAT. According to Solich, ensuring flow around the catheter helps to maintain the supply of blood to the patient’s collateral vessels, which can have a direct impact on their chances of surviving and recovering post-stroke.
“We need to think about how important the collaterals [and protective flow around the catheter] are in keeping the parenchyma alive,” he says. “Patients who are arriving for thrombectomy in the late window, for example, often have very good collaterals; their brain has potentially survived for more than six hours. By putting these patients on the table, and inserting larger-bore catheters or balloon guide catheters, you are creating an environment with diminished flow—the collateral system may then collapse and, if recanalisation cannot be achieved quickly enough, we are likely to see worse outcomes.”
Lastly, the ‘Time is brain’ adage continues to be bolstered by evidence indicating that reducing the duration of a thrombectomy procedure can have a tangible impact on patient outcomes. Solich sites recent data suggesting that completing a thrombectomy within 30 minutes appears to be just as vital as achieving the often-lauded first-pass effect in terms of optimising clinical results, with patients undergoing multiple passes to reach successful recanalisation inside 30 minutes demonstrating comparable outcomes to those only requiring a single pass.2
“In order to achieve this,” Solich adds, “you need to prepare yourself for the thrombectomy so you know what you’ll be facing. Make sure you have the best available techniques and tools that you have the most experience with, and aim for a groin-to-groin time of 30–35 minutes.”
Improving outcomes
Over the past 15 years, granular data from the national EVAS registry—which incorporates roughly 99% of stroke thrombectomies in Sweden—have provided the country’s neurointerventionists with a great deal of insight on ischaemic stroke treatments. In Solich’s view, these types of large-scale registries can enable the timing, technique and outcomes of thrombectomies to be evaluated in the real world.
“What we have seen in EVAS is that—in the last 4–5 years—aspiration has started to take over and is generating very good results,” he relays. “When we compare aspiration-first approaches with any other strategy, the procedures are faster and are yielding better outcomes. The next question is, if we compare aspiration strategies—and compare sites or operators that are applying the principles of S-BAT to ones that are not—will there be some dichotomy in the data?”
For Solich, the future of stroke thrombectomy will see S-BAT play a pivotal role alongside greater focus on granular anatomical information gleaned from preprocedural computed tomography angiography (CTA) imaging and key insights on clot radiomics, potentially enabling individualised treatments, enhancing patient selection, and supporting physicians in choosing the most appropriate devices and techniques ahead of a procedure.
“Thrombectomy is a technical sport and should be treated as such; you need to review your cases and learn from your mistakes,” he concludes. “Also, all good masters of the trade need the right tools, and treating the whole portfolio of devices as your toolbox is the way to go. It’s important to size your catheter to the vessel—one size doesn’t fit all.3 We are also talking more and more about distal aspiration, and you really need the whole toolbox to reach those more distally located clots.”
References:
- Saber H, Froehler M, Zaidat O et al. Variation in Vessel Size and Angiographic Outcomes Following Stent‐Retriever Thrombectomy in Acute Ischemic Stroke: STRATIS Registry. S:VIN. 2024; 4(3): e000978.
- Koo A, Reeves B, Renedo D et al. Impact of Procedure Time on First Pass Effect in Mechanical Thrombectomy for Anterior Circulation Acute Ischemic Stroke. Neurosurgery. 2024; 95(1): 128–36.
- Charbonnier G, Primikiris P, Desmarets M et al. Defining the optimal size of an aspiration catheter in relation to the arterial diameter during mechanical thrombectomy for stroke. J Neuroradiol. 2024; 51(1): 47–51.
DISCLAIMER: Procedural techniques and considerations are illustrative examples from representative experience. Physicians’ treatment and techniques will vary on their medical judgement.
