Posterior Fossa Stroke - Ep.1/2 - SLICE Worldwide 2022

Delphi Consensus

Posterior circulation stroke thrombectomy – a mortality-reducing procedure

Introduction:

The year 2022 brought two positive trials for posterior circulation stroke, both performed in China. The experience with previous basilar trials has made it possible to limit cross-over rates, focus on an adequate population, and choose the right primary outcome measure. These combined factors were responsible for the positive results of these basilar occlusion trials, which showed not just improvement in disability but also mortality. The scope of this short review is not to go through the trials but to provide the practitioner with the relevant details for the minimal work-up needed to treat a basilar thrombosis in the clinical practice rapidly.

Key points of the literature evidence:

BAOCHE trial(1):

Included patients between 6 and 24 hours (so late time window trial)
PC-ASPECTS > 5 (on CTA source imaging/MRI) and excluded patients older than 80 years.
69% of patients were selected based on NC-CT and CTA, thus validating the idea that MR-imaging is unnecessary for posterior circulation stroke.
Solitaire – AB was used as an initial device.

ATTENTION(2):

Included patients from between 0 and 12 hours.
PC – ASPECTS > 5 (on CTA source imaging/MRI) and more than >8 in patients older than 80. NIHSS > 10.
70% of patients were selected based on NC-CT and CTA, thus validating the idea that MR-imaging is not necessary for posterior circulation stroke;
No device restriction.

CLINICAL RELEVANCE AND EXTERNAL VALIDITY OF THE TWO TRIALS:

Both trials are performed in Asian populations, but they are large enough to offer insights into the population of patients that has no ICAD.
ICAD populations in the Basic trial and MR-CLEAN registry are much more frequent than in the anterior circulation stroke.
Cardiovascular risk factors were the same between the two trials and prior western populations.
If anything, the high percentage of ICAD should prove that ICAD management is feasible and safe and is associated with a significant treatment effect.

Conclusion

Available data supports thrombectomy for basilar occlusions. MRI imaging seems not to be of significant use for the clinical selection of these patients in early or late time windows. All local protocols should focus on obtaining rapid, simple – imaging selection for patients with basilar artery occlusion.

1. Jovin TG, Li C, Wu L, Wu C, Chen J, Jiang C, et al. Trial of Thrombectomy 6 to 24 Hours after Stroke Due to Basilar-Artery Occlusion. New England Journal of Medicine. 2022 Oct 13;387(15):1373–84.

2. Tao C, Nogueira RG, Zhu Y, Sun J, Han H, Yuan G, et al. Trial of Endovascular Treatment of Acute Basilar-Artery Occlusion. New England Journal of Medicine 2022 Oct 13 387(15):1361–72.