Aspiration as good as stent retriever for stroke
Removal of a clot by aspiration is as good as removal by a stent retriever in stroke patients in the COMPASS* study, a result that is expected to shift practice patterns.
Aspiration uses a large bore-cathether, stent retriever a cylindrical self-expanding device that pushes the thrombus against the artery wall. Both approaches are meant to re-establish blood flow to the brain.
“There is now level I evidence that primary aspiration and stent retrievers have equivalent clinical outcomes in emergent large vessel occlusion,” said study author Dr J. Mocco from the Mount Sinai Hospital in New York City, New York, US. “Now that we have this evidence for aspiration, I think many more practitioners will start trying this technique. It’s a little faster to do aspiration compared with stent retriever, but it’s a personal choice.”
Initial data utilizing an aspiration approach suggested similar functional outcomes with superior technical results, while lowering procedure time and device costs vs traditional stent retriever as a first line approach. [J Neurointerv Surg 2014;6:260-264; J Neurointerv Surg 2014;6:231-237]
In the COMPASS study, Mocco and team sought to compare a direct aspiration first pass technique (ADAPT) with stent retrieval as first line (SRFL) in 270 adult acute ischaemic stroke patients treated within 6 hours of symptom onset. Patients had a National Institutes of Health Stroke Scale score of >5 at the time of imaging, a large-vessel proximal occlusion (distal internal carotid artery through middle cerebral artery bifurcation), and a pre-event modified Rankin Scale (mRS) score of 0–1. [ISC 2018, LB abstract 4]
Both approaches yielded comparable functional outcomes; time and quality of perfusion were similar as well. The percentage of patients achieving success (thrombolysis in cerebral infarction [TICI] grade ≥2b) with the primary modality was 83.2 percent with aspiration vs 81.3 percent with stent retrieval. The primary endpoint of functional outcome (mRS score 0–2) at 90 days was achieved in 49 percent of patients treated with stent retriever and 52 percent in those treated with aspiration (p=0.0014 for non-inferiority).
There was a similar shift in overall mRS distribution between groups at 90 days (odds ratio [OR], 0.98, 95 percent confidence interval, 0.64–1.51). The rate of TICI grade ≥2c within 45 minutes of groin puncture was 50 percent with aspiration vs 44 percent with stent retriever (p=0.2998). TICI grade ≥3 within 45 minutes of puncture was 34 and 23 percent with aspiration and stent retriever, respectively (p=0.0486). Time from groin puncture to TICI grade ≥2b was 22 and 33 minutes, respectively (p= 0.0194), or 11 minutes faster for the aspiration approach.
The safety endpoints of all-cause mortality at 90 days and intracranial haemorrhage within 24 hours were similar between groups (22 percent and 3 percent each for both). Cost data are still pending as of this writing.
Which approach is better for removing certain clots? Mocco said large studies are warranted to determine which clots are more conducive for removal through which approach and the type of patients to benefit from either approach.