If at first you don’t succeed, switch and try again

This advertorial is sponsored by Medtronic.

Despite the popularity that aspiration-first stroke thrombectomy has gained in recent years, the approach has its limitations—and, on occasions where it proves unsuccessful, neurointerventional physicians should be prepared to pivot towards a different strategy as early as possible in order to maximise their chances of achieving a positive outcome. This is a key message imparted by Manuel Moreu (Hospital Clínico San Carlos, Madrid, Spain), who recently spoke to NeuroNews about the vital role for ‘early technique switches’ following a failed first attempt at recanalisation.

While Moreu and many other neurointerventionists are in agreement that a direct aspiration first pass technique (ADAPT) is appropriate in certain cases, the current literature shows that the approach does not always prove to be sufficient, often leading to stent retriever (SR) deployment being required in order to achieve adequate clot removal. Findings from multiple studies—including the randomised ASTER trial and global ASSIST registry—indicate that approximately 33% of aspiration-first cases will be unsuccessful, thus requiring a rescue or ‘bailout’ strategy in order to boost the likelihood of recanalisation being achieved.^1–3

“I am not an ‘aspiration-first guy’ but, if I believe I’m going to be able to remove the clot with aspiration as a first approach, I will use it,” Moreu explains. “It is faster and more straightforward [than other approaches].”

“The question right now,” he continues, “is when to change the technique, and why. We know that, the more passes you perform, the lower the [chance of successful] recanalisation⁸ and the lower the probability of a good clinical outcome.^7,8 The problem is that all of these papers showing this relate to SR passes. We don’t really know what happens with aspiration; we believe it’s similar, but we don’t have the same amount of information as with an SR-first approach.”

Challenges facing aspiration

According to Moreu, there are two major challenges that face aspiration-first thrombectomy approaches: navigating the catheter smoothly past the ophthalmic segment⁴ and through the neurovasculature to the location of the clot, and maximising the area of contact and optimising the angulation between the clot⁵ and the catheter’s distal tip.

As such, clots located in more distal locations or in curved segments of the patient’s neurovasculature are among those generally considered less amenable to aspiration alone.⁵ An aspiration-only strategy may also be less likely to achieve success in cases presenting with a high clot burden.¹¹

Moreu notes that an SR can be deployed to act as an ‘anchor’ in some of these cases, overcoming two of the main drivers of aspiration-first failure by facilitating smoother, safer navigation of the catheter and getting closer to the thrombus interface.^4,5

“If you are not able to ascend the aspiration catheter, then anchoring is more than just helpful—it is the only option. It’s what needs to be done to get the catheter high enough,” Moreu avers. “People don’t always count these instances as a failure of aspiration, because there has not been an actual attempt with aspiration alone. But, I do think we should count them as failures, and as rescue techniques, as the aspiration catheter was not able to get to the clot. The most important part is the idea you had from the beginning, so that—if you randomise this in a clinical trial—it counts as an aspiration-first technique with a combined approach as the rescue strategy.”

What do the data suggest?

Regardless of whether this anchoring strategy is universally considered as a bailout or not, the latest evidence suggests that a shift from aspiration alone to a ‘traditional’ combined approach following a failed first pass is beneficial. A US study that analysed almost 3,000 patients and was published within the last year indicates that switching between the two leads to second-pass thrombolysis in cerebral infarction (TICI) 2c–3 recanalisation being three times more likely, with a similar trend observed upon switching between the second and third passes.⁶

“We need to understand that changing the technique may be something we have to do, and it may be something that’s going to be good for the patient,” Moreu says. “ADAPT is a really good technique but, if it has not worked, we need to start to think about changing the technique to try to improve their TICI score. And, it seems [based on the aforementioned study] that, the faster you change from aspiration to a combined technique, the better the results will be after the procedure itself.”

The direct relevance of first-pass success with thrombectomy treatments was initially outlined by Osama Zaidat (Toledo, USA) et al in a 2018 paper⁷, and subsequent studies have produced similar findings—not only in terms of clinical outcomes like modified Rankin scale (mRS) scores⁸, but also from a healthcare economics perspective.^9,10

The cost savings enabled by the first-pass effect (FPE) were elucidated in a 2022 paper from Eva González Diaz (Barakaldo, Spain) et al, with researchers demonstrating that successful first-pass recanalisation (modified TICI 0–3) can reduce a patient’s stroke-related lifetime costs by €44,289 compared to those who do not achieve a final modified TICI score of 0–3. The study also shows that a clinical outcome of mRS 2 can save healthcare systems in Spain approximately €63,000, €50,000, and €30,000 in annual long-term costs per patient, as compared to mRS scores of 5, 4 and 3, respectively.⁹

“The greater the number of passes you do, the lower the recanalisation rate of each pass, and the lower the rate of good clinical outcomes,” Moreu elaborates. “Several publications have all agreed that [there is a reduction of benefit after each pass],⁸ so a good clinical outcome is rare, and you also increase the chance of a symptomatic intracranial haemorrhage [sICH]. You are decreasing the benefits and increasing the risks.”

However, while the first-pass effect is widely accepted as optimal, Moreu believes it is also important to recognise the fact that success at the first attempt is not always possible—hence the need for an appropriate bailout strategy.

“If you start with aspiration and are unable to remove the clot at the first pass, I believe we need to push to change the technique in order to improve the ‘second-pass effect’,” he quips.

A shift in mindset

A notable reason why neurointerventionists might be reluctant to switch away from aspiration alone pertains to speed and efficiency—as the mantra goes, ‘time is brain’, and ascending an SR will take more time while multiple aspiration attempts can be performed within a relatively short period.

On the flipside, ASTER trial data suggest comparable sICH rates between aspiration and combined-approach thrombectomy, potentially allaying concerns over the latter’s safety.² And, given the established reasons to target successful recanalisation within the smallest possible number of passes, Moreu’s view is that switching between these approaches—from aspiration alone or, indeed, an SR alone, to combination thrombectomy—should be considered an option at the outset of any case.

“The first-pass technique needs to be the one you are more comfortable with,” he explains. “So, if you’re an aspiration guy [or girl], that’s perfect—COMPASS and ASTER have shown that it is not inferior, so what you are doing is okay. It’s also important to note that we sometimes do a first pass that was not a perfect attempt and we know the technique has not reached its full potential. However, if you believe that the first pass was done perfectly, then changing the technique will improve the recanalisation results, and that will improve clinical outcomes.”

Medtronic’s neurovascular portfolio provides physicians with options across the multiple different approaches to stroke thrombectomy; recent INSPIRE-S registry data from 802 patients demonstrated excellent real-world safety and efficacy outcomes using the company’s Solitaire^TM revascularisation device and React^TM aspiration catheter.¹² The registry is core lab- and clinical events committee-adjudicated, and endorsed by the European Society of Minimally Invasive Neurological Therapy (ESMINT). Combined results from all treatment groups included 55.1% mRS 0–2 at 90 days, 46.5% first-pass expanded TICI ≥2c, 73.5% final successful revascularisation (expanded TICI ≥2c), and 1.5% sICH.

References:

1. Diana F, Vinci S L, Ruggiero M et al. Comparison of aspiration versus combined technique as first-line approach in terminal internal carotid artery occlusion: a multicenter experience. J Neurointerv Surg. 2022; 14(7): 666–71.
2. Lapergue B, Blanc R, Gory B et al. Effect of endovascular contact aspiration vs stent retriever on revascularization in patients with acute ischemic stroke and large vessel occlusion: the ASTER randomized clinical trial. JAMA. 2017; 318(5): 443–52.
3. Gupta R, Miralbés S, Bonilla A C et al. Technique and impact on first pass effect primary results of the ASSIST global registry. J Neurointerv Surg. 2025; 17(2): 128–38.
4. Li J, Tomasello A, Requena M et al. Trackability of distal access catheters: an in vitro quantitative evaluation of navigation strategies. J Neurointerv Surg. 2023; 15(5): 496–501.
5. Bernava G, Rosi A, Machi P et al. Direct thromboaspiration efficacy for mechanical thrombectomy is related to the angle of interaction between the aspiration catheter and the clot. J Neurointerv Surg. 2020; 12(4): 396–400.
6. Martins P N, Nogueira R G, Tarek M A et al. Early technique switch following failed passes during mechanical thrombectomy for ischemic stroke: should the approach change and when? J Neurointerv Surg. 2025; 17(3): 236–41.
7. Zaidat O O, Castonguay A C, Linfante I et al. First pass effect: a new measure for stroke thrombectomy devices. Stroke. 2018; 49(3): 660–6.
8. García-Tornel Á, Requena M, Rubiera M et al. When to stop: the detrimental effect of device-passes in acute ischemic stroke secondary to large vessel occlusion. Stroke. 2019; 50(7): 1781–8.
9. Diaz E G, Rodríguez-Paz C, Fernandez-Prieto A et al. Economic impact of the first pass effect in mechanical thrombectomy for acute ischaemic stroke treatment in Spain: a cost-effectiveness analysis from the national health system perspective. BMJ Open. 2022; 12(9): e054816.
10. Zaidat O O, Ribo M, Andersson T et al. Health economic impact of first-pass success among patients with acute ischemic stroke treated with mechanical thrombectomy: a United States and European perspective. J Neurointerv Surg. 2021; 13: 1117–23.
11. Mascitelli J R, Kellner C P, Oravec C S et al. Factors associated with successful revascularization using the aspiration component of ADAPT in the treatment of acute ischemic stroke. J Neurointerv Surg. 2017; 9(7): 636–40.
12. Data on file: 2024 09 19 NTF_INSPIRE S EMEA Primary Results Data Release.

DISCLAIMER: The data and content included in this article express only the clinical perspective of the presenter. They are completely independent and do not necessarily reflect the opinions of Medtronic.