Endovascular Therapy Effective in Posterior Circulation Vessel Occlusion

A team of researchers investigated whether mechanical thrombectomy for ischemic stroke due to primary distal occlusion of the posterior cerebral artery was safe, feasible, and beneficial compared with standard medical treatment.

Endovascular therapy is safe, feasible, and effective among patients with stroke attributed to primary distal occlusion of the posterior cerebral artery (PCA) of the P2 or P3 segment, according to study results published in JAMA Neurology.

Because only limited data exist about the benefit of endovascular treatment for posterior circulation distal, medium vessel occlusion, the objective of the current study was to determine the safety of mechanical thrombectomy for primary distal posterior cerebral artery occlusion stroke. Additionally, study researchers sought to compare the outcomes of mechanical thrombectomy for isolated posterior circulation stroke of the PCA P2 and P3 segments with the outcomes of standard medical treatment with or without intravenous thrombolysis.

This case-control study included patients treated for primary distal occlusion of the PCA of the P2 or P3 segment, who received mechanical thrombectomy or standard medical treatment between January 1, 2010, and June 30, 2020.

The primary outcome was the improvement of National Institutes of Health Stroke Scale (NIHSS) scores at discharge from baseline. Symptomatic intracranial hemorrhage and hemorrhagic complications were the safety outcomes.

The study sample included 184 patients (median age, 74 years; 48.4% men), of whom 149 patients (81.0%) had posterior circulation distal, medium vessel occlusion located in the P2 segment of PCA, and 35 patients (19.0%) had occlusion located in the P3 segment.

The mean NIHSS scores decreased from baseline to discharge by -2.4 points (95% CI, -3.2 to -1.6) in the standard medical treatment group and by -3.9 points (95% CI, -5.4 to -2.5) in the endovascular treatment group (P =.06). Among patients with baseline NIHSS of 10 points or greater at baseline, and for those ineligible for intravenous thrombolysis, the mean differences in NIHSS score decrease were significantly higher in the endovascular treatment vs standard medical treatment group (P =.04 and P =.005, respectively).

Safety analysis indicated the rate of symptomatic intracerebral hemorrhage was 4.3% in both cohorts. The overall in-hospital mortality rate was 4.9% (9 of 183 patients), the 90-day mortality rate was 13.4% (18 of 134 patients), and mortality rates did not differ significantly between the treatment groups.

The study had several limitations, including the retrospective and nonrandomized design, missing data, and lack of data on the exact extent and location of infarct tissue and specific symptoms of distal occlusion of posterior circulation.

“In this case-control study, mechanical thrombectomy for primary posterior circulation [distal, medium vessel occlusion] appeared to be reasonable, safe, and technically feasible for therapeutic management of occlusions of the P2 or P3 segment compared with standard medical treatment, especially if patients were not eligible for [intravenous thrombolysis] or presented with high NIHSS scores (≥10 points),” concluded the study researchers.

Disclosure: Several study authors declared affiliations with pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Meyer L, Stracke CP, Jungi N, et al. Thrombectomy for primary distal posterior cerebral artery occlusion stroke: the TOPMOST study. JAMA Neurol. Published online April 1, 2021. doi:10.1001/jamaneurol.2021.0001