Multicenter investigation of technical and clinical outcomes after thrombectomy for Proximal Medium Vessel Occlusion (pMeVO) by frontline technique

Clinical and radiographic outcomes after mechanical thrombectomy in medium-vessel posterior cerebral artery occlusions: Subgroup analysis from STAR

BACKGROUND

Whereas mechanical thrombectomy (MT) has become standard-of-care treatment for patients with salvageable brain tissue after acute stroke caused by large-vessel occlusions, the results of MT in patients with medium-vessel occlusions (MEVOs), particularly in the posterior cerebral artery (PCA), are not well known.

METHODS

Using data from the international Stroke Thrombectomy and Aneurysm Registry (STAR), we assessed presenting characteristics and clinical outcomes for patients who underwent MT for primary occlusions in the P2 PCA segment. As a subanalysis, we compared the PCA MeVO outcomes with STAR's anterior circulation MeVO outcomes, namely middle cerebral artery (MCA) M2 and M3 segments.

RESULTS

Of the 9812 patients in STAR, 43 underwent MT for isolated PCA MeVOs. The patients' median age was 69 years (interquartile range 61-79), and 48.8% were female. The median NIH Stroke Scale score was 9 (range 6-17). After recanalization, 67.4% of patients achieved successful recanalization (modified treatment in cerebral infarction score [mTICI] ≥ 2b), with a first-pass success rate of 44.2%, and 39.6% achieved a modified Rankin score of 0-2 at 90 days. Nine patients (20.9%) had died by the 90-day follow-up. In comparison with M2 and M3 MeVOs, there were no differences in presenting characteristics among the three groups. Patients with PCA MeVOs were less likely to undergo intra-arterial thrombolysis (4.7% PCA vs. 10.1% M2 vs. 16.2% M3, p = 0.046) or to achieve successful recanalization (mTICI ≥ 2b, 67.4%, 86.7%, 82.3%, respectively, p < 0.001); however, there were no differences in the rates of successful first-pass recanalization (44.2%, 49.8%, 52.3%, respectively, p = 0.65).

CONCLUSIONS

We describe the STAR experience performing MT in patients with PCA MeVOs. Our analysis supports that successful first-pass recanalization can be achieved in PCA MEVOs at a rate similar to that in MCA MeVOs, although further study and possible innovation may be necessary to improve successful PCA MeVO recanalization rates.

Reliability assessment of distal occlusion eTICI scoring

BACKGROUND

The eThrombolysis in Cerebral Infarction (eTICI) score has been validated in proximal large artery occlusion (pLAOs). Despite the growing number of distal medium vessel occlusions (DMVOs) mechanical thrombectomies (MT) and the widespread utilization of the eTICI scoring system, its reliability and standardization for more distal occlusions have not been validated. We aim to evaluate the interrater reliability of eTICI scores in primary DMVOs.

METHODS

This was a retrospective analysis of a prospectively maintained database for consecutive patients with pLAO and DMVO MT at a single comprehensive stroke center from 2015 to 2022. Two fellowship-trained neurointerventionalists blindly/independently assessed digital subtraction angiograms for final eTICI, followed by consensus reads for discrepancies.

RESULTS

59 DMVO of 2248 thrombectomies [M3:29(50%)/M4:1(2%)/A1:3(5%)/A2:12(22%)/A3: 5(9%)/P1:7(12%)/P2:1(2%)] and 124 pLAOs of 308 thrombectomies [i-ICA:13(11%)/MCA-M1: 111(90%)] were included. The distribution of final eTICI scores was comparable between pLAO vs DMVOs (p = 0.82). The pLAO final eTICI score assessment between two readers demonstrated moderate reliability with a kappa0.77 (95%CI: 0.67-0.88), while the DMVO eTICI score assessment exhibited almost-perfect agreement with kappa 0.94 (95%CI: 0.90-0.99). The agreement between the consensus read and the original report in DMVOs was 0.86 (95% CI: 0.71-1.00) while for pLAO it was 0.83(95% CI: 0.76-0.90). The performance of eTICI was comparable amongst different DMVO territories as well as for distal vs. very distal occlusions.

CONCLUSION

eTICI score exhibited comparable performance for DMVO as compared to pLAO strokes. Further studies investigating DMVO eTICI grading and clinical outcomes are warranted.

Comprehensive analysis of the impact of procedure time and the 'golden hour' in subpopulations of stroke thrombectomy patients

OBJECTIVE

To evaluate the effect of procedure time on thrombectomy outcomes in different subpopulations of patients undergoing endovascular thrombectomy (EVT), given the recently expanded indications for EVT.

METHODS

This multicenter study included patients undergoing EVT for acute ischemic stroke at 35 centers globally. Procedure time was defined as time from groin puncture to successful recanalization (Thrombolysis in Cerebral Infarction score ≥2b) or abortion of procedure. Patients were stratified based on stroke location, use of IV tissue plasminogen activator (tPA), Alberta Stroke Program Early CT score, age group, and onset-to-groin time. Primary outcome was the 90-day modified Rankin Scale (mRS) score, with scores 0-2 designating good outcome. Secondary outcome was postprocedural symptomatic intracranial hemorrhage (sICH). Multivariate analyses were performed using generalized linear models to study the impact of procedure time on outcomes in each subpopulation.

RESULTS

Among 8961 patients included in the study, a longer procedure time was associated with higher odds of poor outcome (mRS score 3-6), with 10% increase in odds for each 10 min increment. When procedure time exceeded the 'golden hour', poor outcome was twice as likely. The golden hour effect was consistent in patients with anterior and posterior circulation strokes, proximal or distal occlusions, in patients with large core infarcts, with or without IV tPA treatment, and across age groups. Procedures exceeding 1 hour were associated with a 40% higher sICH rate. Posterior circulation strokes, delayed presentation, and old age were the variables most sensitive to procedure time.

CONCLUSIONS

In this work we demonstrate the universality of the golden hour effect, in which procedures lasting more than 1 hour are associated with worse clinical outcomes and higher rates of sICH across different subpopulations of patients undergoing EVT.