PDF: Penumbra Separator 3D
(2017)Objective
To evaluate whether the use of the Penumbra 3D Revascularization Device in conjunction with aspiration thrombectomy improves angiographic and clinical outcomes compared to aspiration thrombectomy alone in patients with acute ischemic stroke.
Study Summary
Intervention
Randomized controlled trial comparing aspiration thrombectomy alone vs. aspiration thrombectomy plus the Penumbra Separator 3D device in patients with anterior circulation large-vessel occlusion stroke within 8 hours of symptom onset.
Inclusion Criteria
Patients with acute ischemic stroke due to anterior circulation large-vessel occlusion (ICA or M1), NIHSS ≥ 8, ASPECTS ≥ 6, and within 8 hours of symptom onset.
Study Design
Arms: Aspiration thrombectomy alone vs. aspiration thrombectomy + Penumbra Separator 3D device.
Patients per Arm: 3D Device: 81, Aspiration alone: 83
Outcome
Bottom Line
In patients with acute ischemic stroke, mechanical thrombectomy using the 3-D stent retriever with aspiration was noninferior to aspiration alone in achieving successful revascularization. Rates of device- and procedure-related serious adverse events and 90-day functional outcomes were similar between the two groups.
Major Points
- This was a randomized, noninferiority clinical trial comparing a combination of a 3-D stent retriever with aspiration versus aspiration alone for mechanical thrombectomy in large-vessel occlusion stroke.
- The primary effectiveness endpoint of successful revascularization (mTICI grade 2-3) was achieved in 87.2% of the combination therapy group versus 82.3% of the aspiration-alone group, meeting the criteria for noninferiority (difference, 4.9%; 90% CI, -3.6% to 13.5%).
- Rates of device-related serious adverse events (4.1% vs 5.0%) and procedure-related serious adverse events (10.2% vs 14.0%) were not significantly different between the combination and aspiration-alone groups, respectively.
- There was no significant difference in the rate of good functional outcome (mRS 0-2) at 90 days (45.3% vs. 45.8%).
- The trial provides Class 1 evidence for the noninferiority of the 3-D stent retriever with aspiration compared to aspiration alone.
Study Design
- Study Type
- Prospective, randomized, single-blinded, active controlled, noninferiority, multicenter trial.
- Randomization
- Yes
- Blinding
- Adjudicators of the primary end points and imaging core laboratory were masked to treatment allocation; treating investigators were not masked.
- Sample Size
- 198
- Follow-up
- 90 days.
- Centers
- 25
- Countries
- United States
Primary Outcome
Definition: The primary effectiveness endpoint was the rate of successful angiographic revascularization of the occluded target vessel, defined as a modified Thrombolysis in Cerebral Infarction (mTICI) grade of 2 to 3.
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| 82.3% (79/96) | 87.2% (82/94) | - | Non-inferiority met (lower bound of 90% CI > -15%) |
Limitations & Criticisms
- Investigators were not masked to the treatment arm, although the primary trial endpoints were adjudicated by masked core laboratory staff.
- The primary efficacy endpoint of mTICI 2-3 was less stringent than the current standard of mTICI 2b-3, though a post hoc analysis suggested the noninferiority requirements would have still been met with the stricter definition.
- The results are specific to the 3-D stent retriever and should not be extrapolated to other stent retriever devices.
- The noninferiority margin of 15% may have been too wide, as such a difference in reperfusion could potentially lead to different clinical outcomes.
Citation
JAMA Neurol. 2018;75(3):304-311. doi:10.1001/jamaneurol.2017.3967