ASTER2 Trial: Combined Aspiration + Stent Retriever vs Stent Retriever Alone
In patients with anterior circulation LVO treated within 8 hours, does combined first-pass contact aspiration plus stent retriever achieve higher near-total reperfusion (eTICI 2c-3) than stent retriever alone?
Lapergue et al. (JAMA 2021) · doi:10.1001/jama.2021.13827 · 408 patients
Population
Included
- Age 18 years or older
- Acute ischemic stroke with anterior circulation large vessel occlusion (ICA, M1, or M2)
- Groin puncture initiable within 8 hours of symptom onset
- No minimum NIHSS score was required
- Prestroke mRS 3 or less (mRS greater than 3 was an exclusion)
- Age 18 and older (i.e., candidates must have had their 18th birthday)
- Groin puncture carried out within 8 hours of first symptoms
- Neuroimaging demonstrates large vessel proximal occlusion (distal ICA through MCA bifurcation, M1 or M2)
- Consenting requirements met according to French laws
- With or without intravenous thrombolysis
Excluded
- Posterior circulation occlusion
- Pre-existing functional disability
- Contraindication to anesthesia or contrast
- Tandem cervical lesion requiring stenting
- Severe or fatal comorbidity likely to prevent improvement, follow-up, or benefit from the procedure
- Absence of large vessel occlusion on non-invasive imaging
- Known or suspected pre-existing (chronic) large vessel occlusion in the symptomatic territory
- Suspected pregnancy; if a woman is of childbearing potential, a urine or serum beta human chorionic gonadotropin (betaHCG) test is positive
- Severe contrast medium allergy or absolute contraindication to iodinated agents
- Patient comorbidities likely preventing improvement, follow-up, or benefit from the procedure
- Acute ischemic stroke involving posterior circulation (vertebrobasilar occlusion)
- Angiographic evidence of carotid dissection or tandem cervical occlusion or stenosis requiring treatment
- Patients benefiting from a legal protection
- Non-membership of a national insurance scheme
- Opposition of the patient or (in case of inclusion as a matter of urgency) of the trustworthy person
Source: ClinicalTrials.gov NCT03290885· Retrieved 2026-06-08
Primary Outcome: Near-Total Reperfusion (eTICI 2c-3)
Procedural endpoint, not a clinical outcome measure
Procedural endpoint, not clinical outcome
The chart shows end-of-procedure eTICI 2c-3 reperfusion rates. mRS 0-2 at 90 days was 38.0% (combined) vs 41.9% (stent retriever alone); no significant clinical difference. Procedure time did not differ (median 42 vs 44 minutes).
Difference not statistically significant (p = 0.17); no difference band is drawn.
eTICI 2c-3 Reperfusion
Study Arms
- Agent
- Combined first-pass technique: contact aspiration and stent retriever used simultaneously
- Route
- Endovascular (transfemoral)
- Co-interventions
- IV thrombolysis if eligible (within 8 h of onset, or within 4.5 h on DWI/FLAIR-mismatch imaging) then rapid transfer; balloon-guide catheter mandatory in both groups; distal two-thirds of stent retriever deployed (proximal third in clot) combined with contact aspiration; pull-out after temporary balloon-guide inflation; GA/conscious sedation/local per practice; ≥3 attempts before rescue crossover.
Combined (experimental) arm, n=205 randomized/203 primary. Lapergue JAMA 2021 Methods p.1159,1161.
- Agent
- Stent retriever alone (CE-marked devices)
- Route
- Endovascular (transfemoral)
- Co-interventions
- IV thrombolysis if eligible (within 8 h, or within 4.5 h on mismatch imaging) then rapid transfer; balloon-guide catheter mandatory; distal two-thirds of stent retriever deployed; pull-out after temporary balloon-guide inflation; GA/conscious sedation/local; ≥3 attempts before rescue crossover.
Stent-retriever-alone (control) arm, n=203 randomized/202 primary. Lapergue JAMA 2021 Methods p.1159,1161.
Trial Design
Type
- Multicenter randomized open-label, blinded-endpoint trial
- Combined contact aspiration plus stent retriever vs stent retriever alone
- Anterior circulation LVO within 8 hours
- Conducted in 11 French comprehensive stroke centers
Timeline
Enrolled 2017-2018 with 12-month follow-up
N
408
Enrollment
French multicenter randomized open-label blinded-endpoint trial enrolling 408 patients at 11 comprehensive stroke centers between 2017 and 2018 (Lapergue JAMA 2021).
ClinicalTrials.gov
NCT03290885Bedside Pearl
ASTER2 did not show that routine first-pass combined aspiration plus stent retriever improves reperfusion or clinical outcome over stent retriever alone. The 6.6 pp numerical advantage in eTICI 2c-3 came with added device burden and no shortening of the procedure (median puncture to reperfusion 42 vs 44 minutes). Reserve combined technique for rescue or operator-specific indications.
See also