Thrombectomy and Thrombolysis of Isolated Posterior Cerebral Artery Occlusion

Predictors of poor outcome in acute stroke patients with posterior cerebral artery occlusion and medical management

BACKGROUND AND AIMS

The clinical evolution of acute ischemic stroke patients with isolated proximal posterior cerebral artery (PCA) occlusion treated with medical management alone has been poorly described. We aimed to determine the clinical and radiological factors associated with poor functional outcome in this population.

METHODS

We conducted a multicenter international retrospective study of consecutive stroke patients with isolated occlusion of the first (P1) or second (P2) segment of PCA admitted within 6 h from symptoms onset in 26 stroke centers in France, Switzerland, and the United States, treated with the best medical management alone. Poor functional outcome was defined as a modified Rankin scale (mRS) ⩾2 at 3 months or no return to pre-stroke mRS. The associations between pretreatment variables and poor outcome were studied in univariable and then multivariable analyses, as well as the association between poor outcome and key follow-up radiological variables.

RESULTS

Overall, 585 patients were included. The median age was 74 years (interquartile range (IQR) = 63-83), median National Institutes of Health Stroke Scale (NIHSS) was 6 (3-10), 80% received intravenous thrombolysis (IVT), and 22% and 78% had P1 and P2 occlusions, respectively. Poor outcome occurred in 56% of patients. In multivariable analysis focusing on pretreatment variables, age (adjusted odds ratio (OR) = 1.12 per 5-year increase [95% confidence interval (CI) = 1.05-1.20]; p = 0.001), NIHSS score (aOR = 1.12 per each point increase [1.08-1.18]; p < 0.001), infarct volume (aOR = 1.16 per 5 mL increase [1.07-1.25]; p < 0.001), and the lack of IVT use (aOR = 1.79 [1.10-2.94], p = 0.020) were independently associated with poor outcome. Regarding 24-h follow-up radiological variables, complete recanalization (defined as no clot in the vascular tree at or beyond the primary occlusive lesion, aOR = 0.37 [95% CI = 0.21-0.65], p < 0.001) and parenchymal hematoma occurrence (aOR = 2.37 [95% CI = 1.01-5.56], p = 0.048) were independently associated with poor 3-month outcome.

CONCLUSIONS

Poor outcome occurred in more than half of medically treated PCA-related acute stroke patients. Facilitating IVT use may improve functional outcome. Therapeutic approaches aimed at enhancing recanalization and reducing hemorrhagic transformation need to be studied in clinical trials.

Efficacy and safety outcomes of endovascular versus best medical treatment in posterior cerebral artery occlusion stroke

BACKGROUND

The management of acute ischemic stroke due to isolated posterior cerebral artery occlusion (iPCAO) remains a topic of debate. This study investigates the efficacy and safety of endovascular treatment (EVT) versus best medical treatment (BMT) in patients with iPCAO.

METHODS

A systematic search was conducted across electronic databases including PubMed, Embase, and the Cochrane Library. Controlled studies comparing EVT and BMT in patients with iPCAO were selected. The primary efficacy outcome assessed was excellent outcome, defined as a modified Rankin Scale (mRS) score of 0-1. The primary safety outcome was symptomatic intracranial hemorrhage (sICH). Secondary outcomes included functional independence (mRS 0-2), early neurological improvement (ENI), and mortality rates. Statistical analyses were conducted using random effects models.

RESULTS

Eleven retrospective cohort studies involving 1811 patients with EVT and 2871 patients with BMT were analyzed. Compared with BMT, EVT was associated with a higher likelihood of an excellent outcome (adjusted OR (aOR) 1.33, 95% CI 1.14 to 1.54) and ENI (aOR 1.66, 95% CI 1.39 to 1.98), but no significant difference in functional independence (aOR 1.02, 95% CI 0.88 to 1.18). Compared with BMT, EVT may not be associated with an increased risk of sICH in patients with iPCAO (aOR 1.34, 95% CI 0.60 to 3.02) or mortality (aOR 1.31, 95% CI 0.83 to 2.08), although heterogeneity was high.

CONCLUSIONS

EVT may improve the likelihood of an excellent outcome and ENI in patients with iPCAO. However, the potential risks of sICH and mortality warrant consideration. Randomized trials are required to establish the definitive efficacy and safety of EVT in this patient population.

Intravenous thrombolysis therapy and dementia risk in acute ischemic stroke patients: A retrospective cohort study in Taiwan

Background

Intravenous thrombolysis (IVT) is the standard treatment for acute ischemic stroke (AIS) to improve functional outcomes. Furthermore, AIS is an important risk factor for dementia. Limited evidence has shown the long-term benefit of IVT on dementia in Western countries.

Objective

We aim to investigate the association between IVT and the risk of dementia in acute ischemic stroke patients in Asian population.

Methods

A retrospective cohort study using medical records from a medical center in Taiwan between 2017 and 2022 was conducted. We included acute ischemic stroke patients aged over 55 years old who had not previously been diagnosed with dementia. The primary outcome was incident dementia ascertained through dementia diagnosis in medical records. The inverse probability of treatment-weighted Cox proportional hazard models were used to estimate the association between IVT and incident dementia.

Results

A total of 1471 patients with AIS were included. 939 (63.8%) were male, and the mean age was 70.7± 9.6 years. Among them, 19.1% of patients (n = 281) received IVT. The mean follow-up time was 2.6± 1.7 years. Although not statistically significant, the IVT was associated with a decreased risk of dementia (HR: 0.88 [95%CI 0.54-1.41)]).

Conclusions

The IVT was associated with lower risk of dementia, although not statistically significant, in reducing the incidence of dementia in Asian patients with ischemic stroke. Studies with larger sample sizes will be needed in the future.

Perfusion imaging predicts short-term clinical outcome in isolated posterior cerebral artery occlusion stroke

BACKGROUND AND PURPOSE

Ischemic strokes due to isolated posterior cerebral artery (PCA) occlusions represent 5% of all strokes but have significant impacts on patients' quality of life, primarily due to visual deficits and thalamic involvement. Current guidelines for acute PCA occlusion management are sparse, and the prognostic value of perfusion imaging parameters remains underexplored.

METHODS

We conducted a retrospective analysis of 32 patients with isolated PCA occlusions treated at Johns Hopkins Medical Institutions between January 2017 and March 2023. Patients underwent pretreatment perfusion imaging, with perfusion parameters analyzed using RAPID software. The primary outcome was short-term clinical outcome as measured by the National Institutes of Health Stroke Scale (NIHSS) at discharge.

RESULTS

The median age of the cohort was 70 years, with 34% female and 66% male. Significant correlations were found between NIHSS at discharge and various perfusion parameters, including time-to-maximum (Tmax) >6 seconds (ρ = .55, p = .004), Tmax >8 seconds (ρ = .59, p = .002), Tmax >10 seconds (ρ = .6, p = .001), mismatch volume (ρ = .51, p = .008), and cerebral blood volume (CBV) < 34% (ρ = .59, p = .002).

CONCLUSIONS

Tmax and CBV volumes significantly correlated with discharge NIHSS with marginal superiority of Tmax >10 seconds and CBV <42% volumes. These findings suggest that CT and MR perfusion imaging can play a crucial role in the acute management of PCA strokes, though larger, standardized studies are needed to validate these results and refine imaging thresholds specific to posterior circulation infarcts.

Endovascular therapy versus medical management in isolated posterior cerebral artery acute ischemic stroke: A multinational multicenter propensity score-weighted study

BACKGROUND

Despite the proven effectiveness of endovascular therapy (EVT) in acute ischemic strokes (AIS) involving anterior circulation large vessel occlusions, isolated posterior cerebral artery (PCA) occlusions (iPCAo) remain underexplored in clinical trials. This study investigates the comparative effectiveness and safety of EVT against medical management (MM) in patients with iPCAo.

METHODS

This multinational, multicenter propensity score-weighted study analyzed data from the Multicenter Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy (MAD-MT) registry, involving 37 centers across North America, Asia, and Europe. We included iPCAo patients treated with either EVT or MM. The primary outcome was the modified Rankin Scale (mRS) at 90 days, with secondary outcomes including functional independence, mortality, and safety profiles such as hemorrhagic complications.

RESULTS

A total of 177 patients were analyzed (88 MM and 89 EVT). EVT showed a statistically significant improvement in 90-day mRS scores (OR = 0.55, 95% CI = 0.30-1.00, p = 0.048), functional independence (OR = 2.52, 95% CI = 1.02-6.20, p = 0.045), and a reduction in 90-day mortality (OR = 0.12, 95% CI = 0.03-0.54, p = 0.006) compared to MM. Hemorrhagic complications were not significantly different between the groups.

CONCLUSION

EVT for iPCAo is associated with better neurological outcomes and lower mortality compared to MM, without an increased risk of hemorrhagic complications. Nevertheless, these results should be interpreted with caution due to the study's observational design. The findings are hypothesis-generating and highlight the need for future randomized controlled trials to confirm these observations and establish definitive treatment guidelines for this patient population.

Mechanical Thrombectomy Versus Intravenous Thrombolysis in Distal Medium Vessel Acute Ischemic Stroke: A Multinational Multicenter Propensity Score-Matched Study

BACKGROUND AND PURPOSE

The management of acute ischemic stroke (AIS) due to distal medium vessel occlusion (DMVO) remains uncertain, particularly in comparing the effectiveness of intravenous thrombolysis (IVT) plus mechanical thrombectomy (MT) versus IVT alone. This study aimed to evaluate the safety and efficacy in DMVO patients treated with either MT-IVT or IVT alone.

METHODS

This multinational study analyzed data from 37 centers across North America, Asia, and Europe. Patients with AIS due to DMVO were included, with data collected from September 2017 to July 2023. The primary outcome was functional independence, with secondary outcomes including mortality and safety measures such as types of intracerebral hemorrhage.

RESULTS

The study involved 1,057 patients before matching, and 640 patients post-matching. Functional outcomes at 90 days showed no significant difference between groups in achieving good functional recovery (modified Rankin Scale 0-1 and 0-2), with adjusted odds ratios (OR) of 1.21 (95% confidence interval [CI] 0.81 to 1.79; P=0.35) and 1.00 (95% CI 0.66 to 1.51; P>0.99), respectively. Mortality rates at 90 days were similar between the two groups (OR 0.75, 95% CI 0.44 to 1.29; P=0.30). The incidence of symptomatic intracerebral hemorrhage was comparable, but any type of intracranial hemorrhage was significantly higher in the MT-IVT group (OR 0.43, 95% CI 0.29 to 0.63; P<0.001).

CONCLUSION

The results of this study indicate that while MT-IVT and IVT alone show similar functional and mortality outcomes in DMVO patients, MT-IVT presents a higher risk of hemorrhagic complications, thus MT-IVT may not routinely offer additional benefits over IVT alone for all DMVO stroke patients. Further prospective randomized trials are needed to identify patient subgroups most likely to benefit from MT-IVT treatment in DMVO.

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.

Meta-analysis of clinical and safety profiles after reperfusion therapy in acute posterior circulation strokes: insights and implications

BACKGROUND

Posterior circulation stroke (PCS) accounts for approximately 20% of all acute ischemic strokes. The optimal reperfusion therapy for PCS management remains uncertain.

PURPOSE

To evaluate the prevalence and outcomes of intravenous thrombolysis (IVT), endovascular thrombectomy (EVT), and bridging therapy in PCS patients.

MATERIAL AND METHODS

We conducted a meta-analysis of 19 studies examining reperfusion therapy outcomes in PCS patients, including 9765 individuals. We pooled prevalence data and assessed associations between reperfusion therapies and clinical, safety, and recanalization outcomes using random-effects models.

RESULTS

The pooled prevalence of reperfusion therapies post-acute PCS was 39% for IVT, 54% for EVT, and 48% for bridging therapy. EVT was associated with significantly higher odds of favorable functional outcomes (modified Rankin Score [mRS] 0-3) at 90 days compared to standard medical therapy (odds ratio [OR] = 5.68; 95% confidence interval [CI]=2.07-15.59; P = 0.001). Conversely, bridging therapy was linked to reduced odds of favorable functional outcomes at 90 days compared to EVT (OR = 0.35; 95% CI=0.26-0.47; P < 0.001). Bridging therapy was also significantly associated with lower odds of good functional outcomes (mRS 0-2) (OR = 0.25; 95% CI=0.11-0.54; P < 0.001), reduced risk of symptomatic intracranial hemorrhage (OR = 0.26; 95% CI=0.07-0.68; P = 0.009), lower mortality (OR = 0.13; 95% CI=0.04-0.44; P = 0.001), and less successful recanalization (OR = 0.35; 95% CI=0.13-0.94; P = 0.038) relative to EVT.

CONCLUSION

Our meta-analysis underscores the favorable outcomes associated with EVT in PCS cases. With notable reperfusion rates, understanding factors influencing PCS outcomes can inform patient selection and prognostic considerations.

Symptomatic intracerebral hemorrhage in proximal and distal medium middle cerebral artery occlusion patients treated with mechanical thrombectomy

BACKGROUND

Acute ischemic stroke (AIS) caused by distal medium vessel occlusions (DMVOs) represents a significant proportion of overall stroke cases. While intravenous thrombolysis (IVT) has been a primary treatment, advancements in endovascular procedures have led to increased use of mechanical thrombectomy (MT) in DMVO stroke patients. However, symptomatic intracerebral hemorrhage (sICH) remains a critical complication of AIS, particularly after undergoing intervention. This study aims to identify factors associated with sICH in DMVO stroke patients undergoing MT.

METHODS

This retrospective analysis utilized data from the Multicenter Analysis of Distal Medium Vessel Occlusions: Effect of Mechanical Thrombectomy (MAD-MT) registry, involving 37 centers across North America, Asia, and Europe. Middle cerebral artery (MCA) DMVO stroke patients were included. The primary outcome measured was sICH, as defined per the Heidelberg Bleeding Classification. Univariable and multivariable logistic regression were used to identify factors independently associated with sICH.

RESULTS

Among 1708 DMVO stroke patients, 148 (8.7%) developed sICH. Factors associated with sICH in DMVO patients treated with MT included older age (adjusted odds ratio (aOR) 1.01, 95% confidence interval (95% CI) 1.00 to 1.03, P=0.048), distal occlusion site (M3, M4) compared with medium occlusions (M2) (aOR 1.71, 95% CI 1.07 to 2.74, P=0.026), prior use of antiplatelet drugs (aOR 2.06, 95% CI 1.41 to 2.99, P<0.001), lower Alberta Stroke Program Early CT Scores (ASPECTS) (aOR 0.75, 95% CI 0.66 to 0.84, P<0.001), higher preoperative blood glucose level (aOR 1.00, 95% CI 1.00 to 1.01, P=0.012), number of passes (aOR 1.27, 95% CI 1.15 to 1.39, P<0.001), and successful recanalization (Thrombolysis In Cerebral Infarction (TICI) 2b-3) (aOR 0.43, 95% CI 0.28 to 0.66, P<0.001).

CONCLUSION

This study provides novel insight into factors associated with sICH in patients undergoing MT for DMVO, emphasizing the importance of age, distal occlusion site, prior use of antiplatelet drugs, lower ASPECTS, higher preoperative blood glucose level, and procedural factors such as the number of passes and successful recanalization. Pending confirmation, consideration of these factors may improve personalized treatment strategies.

Endovascular therapy versus best medical management in distal medium middle cerebral artery acute ischaemic stroke: a multinational multicentre propensity score-matched study

BACKGROUND

The efficacy of endovascular treatment (EVT) in acute ischaemic stroke due to distal medium vessel occlusion (DMVO) remains uncertain. Our study aimed to evaluate the safety and efficacy of EVT compared with the best medical management (BMM) in DMVO.

METHODS

In this prospectively collected, retrospectively reviewed, multicentre cohort study, we analysed data from the Multicentre Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy registry. Patients with acute ischaemic stroke due to DMVO in the M2, M3 and M4 segments who underwent EVT or received BMM were included. Primary outcome measures comprised 10 co-primary endpoints, including functional independence (mRS 0-2), excellent outcome (mRS 0-1), mortality (mRS 6) and haemorrhagic complications. Propensity score matching was employed to balance the cohorts.

RESULTS

Among 2125 patients included in the primary analysis, 1713 received EVT and 412 received BMM. After propensity score matching, each group comprised 391 patients. At 90 days, no significant difference was observed in achieving mRS 0-2 between EVT and BMM (adjusted OR 1.00, 95% CI 0.67 to 1.50, p>0.99). However, EVT was associated with higher rates of symptomatic intracerebral haemorrhage (8.4% vs 3.0%, adjusted OR 3.56, 95% CI 1.69 to 7.48, p<0.001) and any intracranial haemorrhage (37% vs 19%, adjusted OR 2.61, 95% CI 1.81 to 3.78, p<0.001). Mortality rates were similar between groups (13% in both, adjusted OR 1.48, 95% CI 0.87 to 2.51, p=0.15).

CONCLUSION

Our findings suggest that while EVT does not significantly improve functional outcomes compared with BMM in DMVO, it is associated with higher risks of haemorrhagic complications. These results support a cautious approach to the use of EVT in DMVO and highlight the need for further prospective randomised trials to refine treatment strategies.

Endovascular Versus Medical Therapy in Posterior Cerebral Artery Stroke: Role of Baseline NIHSS Score and Occlusion Site

BACKGROUND

Acute ischemic stroke with isolated posterior cerebral artery occlusion (iPCAO) lacks management evidence from randomized trials. We aimed to evaluate whether the association between endovascular treatment (EVT) and outcomes in iPCAO acute ischemic stroke is modified by initial stroke severity (baseline National Institutes of Health Stroke Scale [NIHSS]) and arterial occlusion site.

METHODS

Based on the multicenter, retrospective, case-control study of consecutive iPCAO acute ischemic stroke patients (PLATO study [Posterior Cerebral Artery Occlusion Stroke]), we assessed the heterogeneity of EVT outcomes compared with medical management (MM) for iPCAO, according to baseline NIHSS score (≤6 versus >6) and occlusion site (P1 versus P2), using multivariable regression modeling with interaction terms. The primary outcome was the favorable shift of 3-month modified Rankin Scale (mRS). Secondary outcomes included excellent outcome (mRS score 0-1), functional independence (mRS score 0-2), symptomatic intracranial hemorrhage, and mortality.

RESULTS

From 1344 patients assessed for eligibility, 1059 were included (median age, 74 years; 43.7% women; 41.3% had intravenous thrombolysis): 364 receiving EVT and 695 receiving MM. Baseline stroke severity did not modify the association of EVT with 3-month mRS distribution (Pinteraction=0.312) but did with functional independence (Pinteraction=0.010), with a similar trend on excellent outcome (Pinteraction=0.069). EVT was associated with more favorable outcomes than MM in patients with baseline NIHSS score >6 (mRS score 0-1, 30.6% versus 17.7%; adjusted odds ratio [aOR], 2.01 [95% CI, 1.22-3.31]; mRS score 0 to 2, 46.1% versus 31.9%; aOR, 1.64 [95% CI, 1.08-2.51]) but not in those with NIHSS score ≤6 (mRS score 0-1, 43.8% versus 46.3%; aOR, 0.90 [95% CI, 0.49-1.64]; mRS score 0-2, 65.3% versus 74.3%; aOR, 0.55 [95% CI, 0.30-1.0]). EVT was associated with more symptomatic intracranial hemorrhage regardless of baseline NIHSS score (Pinteraction=0.467), while the mortality increase was more pronounced in patients with NIHSS score ≤6 (Pinteraction=0.044; NIHSS score ≤6: aOR, 7.95 [95% CI, 3.11-20.28]; NIHSS score >6: aOR, 1.98 [95% CI, 1.08-3.65]). Arterial occlusion site did not modify the association of EVT with outcomes compared with MM.

CONCLUSIONS

Baseline clinical stroke severity, rather than the occlusion site, may be an important modifier of the association between EVT and outcomes in iPCAO. Only severely affected patients with iPCAO (NIHSS score >6) had more favorable disability outcomes with EVT than MM, despite increased mortality and symptomatic intracranial hemorrhage.

Follow-up infarct volume on fluid attenuated inversion recovery (FLAIR) imaging in distal medium vessel occlusions: the role of cerebral blood volume index

BACKGROUND

Distal medium vessel occlusions (DMVOs) contribute substantially to the incidence of acute ischemic strokes (AIS) and pose distinct challenges in clinical management and prognosis. Neuroimaging techniques, such as Fluid Attenuation Inversion Recovery (FLAIR) imaging and cerebral blood volume (CBV) index derived from perfusion imaging, have significantly improved our ability to assess the impact of strokes and predict their outcomes. The primary objective of this study was to investigate relationship between follow-up infarct volume (FIV) as assessed by FLAIR imaging in patients with DMVOs.

METHODS

This prospectively collected, retrospective reviewed cohort study included patients from two comprehensive stroke centers within the Johns Hopkins Medical Enterprise, spanning August 2018-October 2022. The cohort consisted of adults with AIS attributable to DMVO. Detailed imaging analyses were conducted, encompassing non-contrast CT, CT angiography (CTA), CT perfusion (CTP), and FLAIR imaging. Univariable and multivariable linear regression models were employed to assess the association between different factors and FIV.

RESULTS

The study included 79 patients with DMVO stroke with a median age of 69 years (IQR, 62-77 years), and 57% (n = 45) were female. There was a negative correlation between the CBV index and FIV in a univariable linear regression analysis (Beta =  - 16; 95% CI,  - 23 to  - 8.3; p < 0.001) and a multivariable linear regression model (Beta =  - 9.1 per 0.1 change; 95% CI,  - 15 to  - 2.7; p = 0.006). Diabetes was independently associated with larger FIV (Beta = 46; 95% CI, 16 to 75; p = 0.003). Additionally, a higher baseline ASPECTS was associated with lower FIV (Beta =  - 30; 95% CI,  - 41 to  - 20; p < 0.001).

CONCLUSION

Our findings underscore the CBV index as an independent association with FIV in DMVOs, which highlights the critical role of collateral circulation in determining stroke outcomes in this patient population. In addition, our study confirms a negative association of ASPECTS with FLAIR FIV and identifies diabetes as independent factor associated with larger FIV. These insights pave the way for further large-scale, prospective studies to corroborate these findings, thereby refining the strategies for stroke prognostication and management.

Endovascular therapy for posterior cerebral artery occlusion: systematic review with meta-analysis

Endovascular therapy (EVT) is a highly effective stroke treatment, but trials validating this intervention did not include patients with posterior cerebral artery (PCA) occlusion. The aim of this systematic review with meta-analysis was to assess the efficacy and safety of EVT for acute PCA occlusion. PubMed, Scopus, ISI, and CENTRAL were searched for studies assessing EVT in adult patients with PCA occlusion. Outcomes of interest were recanalization, symptomatic intracerebral haemorrhage (sICH), mortality, functional independence, and excellent functional outcome at 90 days. Frequencies and odds ratios (ORs) were pooled using random effect models and heterogeneity was measured using the I2 statistic and explored by means of meta-regression. Fifteen studies were included, all observational. Recanalization rates were high [81%, 95% CI (73-88%)] and sICH rates low [2%, 95% CI (1-4%)]. Heterogeneity was high for recanalization (I2 = 80%) but not for sICH, and not accounted for by any of the moderators tested. Compared to best medical treatment, EVT was associated with higher chances of sICH [OR = 2.04, 95% CI (1.12-3.71)] and no effect in functional independence [OR = 0.98, 95% CI (0.63-1.54)], with a tendency to higher chances of excellent functional outcome [OR = 1.29, 95% CI (0.90-1.86)] and mortality [OR = 1.56, 95% CI (0.84-2.90)]. EVT for acute PCA occlusion is technically feasible but associated with higher chance of sICH. There is no evidence to support this treatment to achieve higher rates of functional independence, but other gains that can impact patients' quality of life cannot be excluded. More studies are required with robust design, better patient selection, and comprehensive outcome evaluation.

Thrombectomy vs Medical Management for Posterior Cerebral Artery Stroke: Systematic Review, Meta-Analysis, and Real-World Data

BACKGROUND AND OBJECTIVES

There is a paucity of high-level evidence for endovascular thrombectomy (EVT) in posterior cerebral artery (PCA) strokes.

METHODS

The MEDLINE, Embase, and Web of Science databases were queried for well-conducted cohort studies comparing EVT vs medical management (MM) for PCA strokes. Outcomes of interest included 90-day functional outcomes, symptomatic intracranial hemorrhage (sICH), and death. The level of evidence was determined per the Oxford Centre for Evidence-Based Medicine criteria. We also conducted a propensity score matched (PSM) analysis of the 2016-2020 National Inpatient Sample (NIS) to provide support for our findings with real-world data.

RESULTS

A total of 2,095 patients (685 EVT and 1,410 MM) were identified across 5 well-conducted cohort studies. EVT was significantly associated with higher odds of no disability at 90 days (odds ratio [OR] 1.25, 95% CI 1.04-1.50, p = 0.015) but not functional independence (OR 0.87, 95% CI 0.72-1.07, p = 0.18). EVT was also associated with higher odds of sICH (OR 2.48, 95% CI 1.55-3.97, p < 0.001) and numerically higher odds of death (OR 1.32, 95% CI 0.73-2.38; p = 0.35). PSM analysis of 95,585 PCA stroke patients in the NIS showed that EVT (n = 1,540) was associated with lower rates of good discharge outcomes (24.4% vs 30.7%, p = 0.037), higher rates of in-hospital mortality (8.8% vs 4.9%, p = 0.021), higher rates of ICH (18.2% and 11.7%, p = 0.008), and higher rates of subarachnoid hemorrhage (3.9% vs 0.6%, p < 0.001). Among patients with moderate to severe strokes (NIH Stroke Scale 5 or greater), EVT was associated with significantly higher rates of good outcomes (21.7% vs 13.8%, p = 0.023) with similar rates of mortality (7.6% vs 6.6%, p = 0.67) and ICH (17.8% vs, 13.1%, p = 0.18).

DISCUSSION

Our meta-analysis revealed that while EVT may be effective in alleviating disabling deficits due to PCA strokes, it is not associated with different odds of functional independence and may be associated with higher odds of sICH. These findings were corroborated by our large propensity score matched analysis of real-world data in the United States. Thus, the decision to pursue PCA thrombectomies should be carefully individualized for each patient. Future randomized trials are needed to further explore the efficacy and safety of EVT for the treatment of PCA strokes.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that in patients with acute PCA ischemic stroke, treatment with EVT compared with MM alone was associated with higher odds of no disabling deficit at 90 days and higher odds of sICH.

Endovascular Thrombectomy Versus Intravenous Thrombolysis of Posterior Cerebral Artery Occlusion Stroke

BACKGROUND AND PURPOSE

Posterior cerebral artery occlusion (PCAo) can cause long-term disability, yet randomized controlled trials to guide optimal reperfusion strategy are lacking. We compared the outcomes of PCAo patients treated with endovascular thrombectomy (EVT) with or without intravenous thrombolysis (IVT) to patients treated with IVT alone.

METHODS

From the multicenter retrospective Posterior cerebraL ArTery Occlusion (PLATO) registry, we included patients with isolated PCAo treated with reperfusion therapy within 24 hours of onset between January 2015 and August 2022. The primary outcome was the distribution of the modified Rankin Scale (mRS) at 3 months. Other outcomes comprised 3-month excellent (mRS 0-1) and independent outcome (mRS 0-2), early neurological improvement (ENI), mortality, and symptomatic intracranial hemorrhage (sICH). The treatments were compared using inverse probability weighted regression adjustment.

RESULTS

Among 724 patients, 400 received EVT+/-IVT and 324 IVT alone (median age 74 years, 57.7% men). The median National Institutes of Health Stroke Scale score on admission was 7, and the occluded segment was P1 (43.9%), P2 (48.3%), P3-P4 (6.1%), bilateral (1.0%), or fetal posterior cerebral artery (0.7%). Compared to IVT alone, EVT+/-IVT was not associated with improved functional outcome (adjusted common odds ratio [OR] 1.07, 95% confidence interval [CI] 0.79-1.43). EVT increased the odds for ENI (adjusted OR [aOR] 1.49, 95% CI 1.05-2.12), sICH (aOR 2.87, 95% CI 1.23-6.72), and mortality (aOR 1.77, 95% CI 1.07-2.95).

CONCLUSION

Despite higher odds for early improvement, EVT+/-IVT did not affect functional outcome compared to IVT alone after PCAo. This may be driven by the increased risk of sICH and mortality after EVT.

Endovascular thrombectomy for treatment of isolated posterior cerebral artery occlusion: a real-world analysis of hospitalizations in the United States

BACKGROUND

Despite renewed interest and recently demonstrated efficacy for endovascular thrombectomy (EVT) for treatment of acute ischemic stroke (AIS) of the posterior circulation, to date, no randomized clinical trials have been conducted to evaluate EVT for isolated occlusions of the posterior cerebral artery (IPCA).

METHODS

Hospitalizations for adult patients with primary admission diagnoses of IPCA occlusion were identified in the National Inpatient Sample registry during the period of 2016-2020. The study exposure was treatment with EVT, and primary clinical endpoints included favorable functional outcome (defined as discharge disposition to home without services, previously shown to have high concordance with modified Rankin scale scores 0-2), in-hospital mortality, and any intracranial hemorrhage (ICH). Inverse probability of treatment weighting (IPTW) was performed to balance baseline clinical characteristics between those receiving EVT or medical management (MM).

RESULTS

This analysis identified 34,880 IPCA occlusion hospitalizations, 730 (2.1%) of which documented treatment with EVT. Following IPTW adjustment, EVT was associated with favorable outcome in IPCA patients presenting with mild deficits (M-D) (NIHSS < 6) [adjusted odds ratio (aOR) 2.36, 95% confidence interval (CI) 2.27, 2.45; p < 0.001] and in those presenting with moderate-to-severe deficits (M-S-D) (NIHSS 6-42) (aOR 2.00, 95% CI 1.86, 2.15; p < 0.001). Mortality rates did not differ among those with M-S-D [EVT 4.8% vs. MM 4.7%, p = 0.742], while ICH rates were lower.

CONCLUSION

Retrospective analysis of a large administrative registry in the Unites States demonstrates an association of EVT with favorable outcomes following IPCA occlusion, without concomitant risk of hemorrhagic transformation or mortality.

Optimizing remote and rural prehospital resources using air transport of thrombectomy candidates

BACKGROUND

In Finland, the yearly number of mechanical thrombectomies for acute stroke is increasing and more patients are transported over 100 km to the comprehensive stroke centre (CSC) for definitive care. This leaves the rural townships without immediate emergency medical services (EMS) for hours. In this study we compare the EMS' estimated return times to own station after the handover of a thrombectomy candidate between two transport methods: (1) using ground transportation with an ambulance to the CSC or (2) using a hydrid strategy starting the transportation with an ambulance and continuing by air with a helicopter emergency medical services unit (HEMS).

METHODS

We reviewed retrospectively all thrombectomy candidates' transportations from the hospital district of South Ostrobothnia to definitive care at the nearest CSC, Tampere University Hospital from June 2020 to October 2022. The dispatch protocol stated that a thrombectomy candidate's transport begins immediately with an ambulance and if the local HEMS unit is available the patient is handed over to them at a rendezvous. If not, the patient is transported to the CSC by ground. Transport times and locations of the patient handovers were reviewed from the CSC's EMS database and the driving time back to ambulance station was estimated using Google maps. The HEMS unit's pilot's log was reviewed to assess their mission engagement time.

RESULTS

The median distance from the CSC to the ambulances' stations was 188 km (IQR 149-204 km) and from the rendezvous with the HEMS unit 70 km (IQR 51-91 km, p < 0.001). The estimated median driving time back to station after the patient handover at the CSC was 145 min (IQR 117-153 min) compared to the patient handover to the HEMS unit 53 min (IQR 38-68 min, p < 0.001). The HEMS unit was occupied in thrombectomy candidate's transport mission for a median of 136 min (IQR 127-148 min).

CONCLUSION

A hybrid strategy to transport thrombectomy candidates with an ambulance and a helicopter reallocates the EMS resources markedly faster back to their own district.

Acute ischemic stroke outcomes in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Although patients with COVID-19 have a higher risk of acute ischemic stroke (AIS), the impact on stroke outcomes remains uncertain.

AIMS

To determine the clinical outcomes of patients with AIS and COVID-19 (AIS-COVID+).

METHODS

We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Our protocol was registered with the International Prospective Register of Systematic Reviews (CRD42020211977). Systematic searches were last performed on June 3, 2021 in EMBASE, PubMed, Web-of-Science, Scopus, and CINAHL Databases.

INCLUSION CRITERIA

(1) studies reporting outcomes on AIS-COVID+; (2) original articles published in 2020 or later; (3) study participants aged ≥18 years.

EXCLUSION CRITERIA

(1) case reports with <5 patients, abstracts, review articles; (2) studies analyzing novel interventions. Risk of bias was assessed using the Mixed Methods Appraisal Tool. Random-effects models estimated the pooled OR and 95% confidence intervals (95% CI) for mortality, modified Rankin Scale (mRS) score, length of stay (LOS), and discharge disposition.

RESULTS

Of the 43 selected studies, 46.5% (20/43) reported patients with AIS without COVID-19 (AIS-COVID-) for comparison. Random-effects model included 7294 AIS-COVID+ and 158 401 AIS-COVID-. Compared with AIS-COVID-, AIS-COVID+ patients had higher in-hospital mortality (OR=3.87 (95% CI 2.75 to 5.45), P<0.001), less mRS scores 0-2 (OR=0.53 (95% CI 0.46 to 0.62), P<0.001), longer LOS (mean difference=4.21 days (95% CI 1.96 to 6.47), P<0.001), and less home discharge (OR=0.31 (95% CI 0.21 to 0.47), P<0.001).

CONCLUSIONS

Patients with AIS-COVID had worse outcomes, with almost fourfold increased mortality, half the odds of mRS scores 0-2, and one-third the odds of home discharge. These findings confirm the significant impact of COVID-19 on early stroke outcomes.

Endovascular therapy versus best medical management for isolated posterior cerebral artery occlusion: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Isolated posterior cerebral artery occlusions (iPCAO) were underrepresented in pivotal randomized clinical trial (RCTs) of endovascular thrombectomy (EVT) in ischemic stroke, and the benefit of EVT in this population is still indeterminate. We performed a systematic review and a meta-analysis to compare the safety and efficacy of EVT compared to best medical management (BMM) in patients with iPCAO.

METHODS

We searched Medline/PubMed, Embase, Web of Science, and the Cochrane databases up to May 2023 for eligible studies reporting outcomes of patients with iPCAO treated with EVT or BMM. We pooled odds ratios (ORs) with corresponding 95% confidence intervals (CI) using a random-effects model.

RESULTS

Seven studies involving 2560 patients were included. EVT was associated with significantly higher likelihood of early neurological improvement (OR, 2.31 [95% CI, 1.38-2.91]; p < 0.00001) and visual field normalization (OR, 3.08 [95% CI, 1.76-5.38]; p < 0.0001) compared to BMM. Rates of good functional outcomes (mRS 0-2) were comparable between the two arms (OR, 0.88 [95% CI, 0.70-1.10]; p = 0.26). Symptomatic intracranial hemorrhage (sICH) was comparable between the two groups (OR, 1.94 [95% CI, 0.96-3.93]; p = 0.07). Mortality was also similar between the two groups (OR, 1.36; [95% CI, 0.77-2.42]; p = 0.29).

CONCLUSIONS

In patients with iPCAO, EVT was associated with visual and early neurological improvement but with a strong trend toward increased sICH. Survival and functional outcomes may be slightly poorer. The role of EVT in iPCAO remains uncertain.

Revascularization of arterial occlusions in posterior circulation acute ischemic stroke

PURPOSE OF REVIEW

This review highlights the latest advancements achieved in the revascularization of arterial occlusions associated with an acute ischemic stroke affecting the posterior circulation. It delves into the frequency and outcomes based on specific arterial segments and presents current evidence supporting revascularization treatments, including intravenous thrombolysis and endovascular thrombectomy.

RECENT FINDINGS

Comprehensive evidence for treatment across major arterial segments of the posterior circulation -- vertebral artery, basilar artery, posterior cerebral artery, cerebellar arteries, and multilevel posterior occlusions -- is provided. Additionally, the latest findings from randomized clinical trials on basilar artery occlusion are explored alongside results from extensive retrospective analyses of isolated vertebral and posterior cerebral artery occlusions.

SUMMARY

Current research supports the treatment decision in acute ischemic strokes of the posterior circulation using both intravenous thrombolysis and endovascular thrombectomy. This review also emphasizes existing knowledge gaps in the management of these strokes and advocates for more randomized clinical trials, notably concerning the posterior cerebral artery (currently ongoing), isolated vertebral artery, and multilevel posterior circulation occlusions.

Endovascular therapy for acute ischemic stroke with distal medium vessel occlusion: a systematic review and meta-analysis

AIMS

Endovascular therapy (EVT) for distal medium vessel occlusions (DMVOs) is a potential frontier of acute ischemic stroke (AIS) treatment, but its efficacy against best medical therapy (BMT) remains unknown. We performed a systematic review and meta-analysis evaluating the efficacy and safety of EVT versus BMT in primary DMVO.

METHODS

We systematically searched PubMed, Cochrane Library and Embase, from inception to August 14, 2022, for studies comparing EVT with BMT in DMVO-AIS. We adopted the Distal Thrombectomy Summit Group's definition of DMVO. Efficacy outcomes were functional independence (90-day modified Rankin Scale (mRS) 0-2) and excellent functional outcomes (90-day mRS 0-1). Safety outcomes were symptomatic intracranial hemorrhage (sICH) and 90-day mortality.

RESULTS

Fourteen observational and two randomized-controlled studies were included, with 1202 patients receiving EVT and 1267 receiving BMT. After trim-and-fill correction, EVT achieved significantly better odds of functional independence than BMT (adjusted OR 1.61, 95% CI 1.06 to 2.43). There were no significant differences in overall excellent functional outcomes (OR 1.23, 95% CI 0.88 to 1.71), sICH (OR 1.44, 95% CI 0.78 to 2.66), and mortality (OR 1.03, 95% CI 0.73 to 1.45). Stratified by EVT method, mechanical thrombectomy±intra-arterial thrombolysis achieved more excellent functional outcomes than BMT (OR 1.59, 95% CI 1.13 to 2.23). In mild strokes (National Institutes of Health Stroke Scale score <6), EVT caused significantly more sICH (OR 6.30, 95% CI 1.55 to 25.64).

CONCLUSIONS

EVT shows promising efficacy benefit over BMT for primary DMVO-AIS. Further randomized controlled trials are necessary to evaluate the efficacy and safety of EVT in DMVO-AIS.

Intravenous thrombolysis for acute ischemic stroke is associated with lower risk of post-stroke dementia: A nationwide cohort study

INTRODUCTION

Dementia after stroke is common and is a great concern for patients and their caregivers. The objective was to investigate if intravenous thrombolysis (IVT) for acute ischemic stroke (AIS) was associated with lower risk of dementia after stroke.

PATIENTS AND METHODS

When IVT was introduced in Denmark, not all eligible patients were treated due to restricted access. We conducted a nationwide register-based cohort study of all patients with AIS in Denmark from 2004 to 2011. IVT-treated patients were propensity score-matched with comparable non-treated patients. Cox proportional hazards regression was used to estimate the hazard ratio (HR) for all-cause and vascular dementia 2, 5, and 10 years after stroke.

RESULTS

Of the 5919 patients eligible for the study, 2305 IVT-treated patients were propensity score-matched with 2305 non-treated patients. Mean (SD) age was 66.6 (13.3) and 61.2% were male. Rate of all-cause dementia was lower for the IVT-treated 2 years (8.4/1000 person years (PY) vs 13.6/1000 PY, HR 0.63 (0.40-0.99)) and 5 years after stroke (7.3/1000 PY vs 11.4/1000 PY, HR 0.65 (0.46-0.91)). 10 years after stroke, the rates of all-cause dementia remained in favor of IVT (8.0/1000 PY vs 9.8/1000 PY, HR 0.83 (0.64-1.07)). IVT-treated had lower rates of vascular dementia 2 years (2.4/1000 PY vs 7.4/1000 PY, HR 0.33 (0.15-0.71)), 5 years (2.3/1000 PY vs 6.2/1000 PY, HR 0.38 (0.23-0.65)), and 10 years after stroke (3.0/1000 PY vs 5.4/1000 PY, HR 0.56 (0.38-0.81)).

CONCLUSION

IVT treatment was associated with lower long-term risk of both vascular and all-cause dementia after AIS.

Considering Psychological and Cognitive Factors in Interventional Neuroradiology: A Systematic Literature Review

BACKGROUND

Interventional neuroradiology is a relatively recent discipline that diagnoses and treats cerebral vascular diseases. However, specific literature on cognitive and psychological domains of patients undergoing interventional neuroradiology procedures is limited.

PURPOSE

Our aim was to review the existent literature on cognitive and psychological domains in patients undergoing interventional neuroradiology procedures to raise clinicians' awareness of their mental status.

DATA SOURCES

Articles were searched in PubMed, EMBASE, and Scopus from 2000 to 2022 using terms such as "interventional neuroradiology," "psychology," and "cognition" according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

STUDY SELECTION

Of 1483 articles in English, 64 were included and analyzed. Twelve focused on psychological aspects; 52, on cognitive ones.

DATA ANALYSIS

Regarding psychological aspects, it appears that early psychological consultations and "nonpharmacologic" strategies can impact the anxiety and depression of patients undergoing endovascular procedures. Regarding cognitive aspects, it appears that endovascular treatment is safe and generates similar or even fewer cognitive deficits compared with analogous surgical procedures.

DATA SYNTHESIS

Among the 12 articles on psychological aspects, 6/12 were retrospective with one, while 6/12 were prospective. Among the 52 articles on cognitive aspects, 7/54 were retrospective, while 45/52 were prospective.

LIMITATIONS

The main limitation derives from the inhomogeneity of the cognitive and psychological assessment tools used in the articles included in our analysis.

CONCLUSIONS

Our review highlights the need to include cognitive and psychological assessments in clinical practice in case patients eligible for interventional neuroradiology procedures. In the future, much more research of and attention to cognitive and psychologic aspects of neurovascular disease is needed. Systematic incorporation of strategies and tools to access and address pre, peri-, and postprocedural psychological and cognitive components could have major benefits in patient satisfaction, recovery, and the success of endovascular practice.

Pearls for the Emergency Clinician: Posterior Circulation Stroke

BACKGROUND

Posterior circulation (PC) stroke in adults is a rare, frequently misdiagnosed, serious condition that carries a high rate of morbidity.

OBJECTIVE OF THE REVIEW

This review evaluates the presentation, diagnosis, and management of PC stroke in the emergency department (ED) based on current evidence.

DISCUSSION

PC stroke presents most commonly with dizziness or vertigo and must be distinguished from more benign diagnoses. Emergency clinicians should consider this condition in patients with dizziness, even in younger patients and those who do not have traditional stroke risk factors. Neurologic examination for focal neurologic deficit, dysmetria, dysarthria, ataxia, and truncal ataxia is essential, as is the differentiation of acute vestibular syndrome vs. spontaneous episodic vestibular syndrome vs. triggered episodic vestibular syndrome. The HINTS (head impulse, nystagmus, and test of skew) examination can be useful for identifying dizziness presentations concerning for stroke when performed by those with appropriate training. However, it should only be used in patients with continuous dizziness who have ongoing nystagmus. Contrast tomography (CT), CT angiography, and CT perfusion have limited sensitivity for identifying PC strokes, and although magnetic resonance imaging is the gold standard, it may miss some PC strokes early in their course. Thrombolysis is recommended in patients presenting within the appropriate time window for thrombolytic therapy, and although some data suggest endovascular therapy for basilar artery and posterior cerebral artery infarcts is beneficial, its applicability for all PC strokes remains to be determined.

CONCLUSIONS

An understanding of PC stroke can assist emergency clinicians in diagnosing and managing this disease.

Efficacy and safety of short-term high dosage dual antiplatelet therapy after 0.6 mg/kg rt-PA intravenous thrombolysis for acute ischemic stroke

OBJECTIVE

To evaluate the efficacy and safety of short-term high-dose of dual antiplatelet therapy after 0.6 mg/kg rt-PA intravenous thrombolysis for acute ischemic stroke (AIS).

METHODS

All 208 patients with AIS were randomized into group 1 (103 cases, after 0.6 mg/kg rt-PA, 300 mg of oral aspirin(ASP) q.d. and 225 mg of oral clopidogrel (CLO) q.d. for for 5 days, then 100 mg of oral ASP q.d. for the next 85 days and 75 mg of oral CLO q.d. for the next 16 days) and group 2 (105 cases, after 0.9 mg/kg rt-PA, 100 mg of oral ASP q.d. for 90 days and 75 mg of oral CLO q.d. for 21 days).The efficacy index was the mRS score, NIHSS score and recurrence risk of stroke, while the safety index was the incidence of bleeding events and mortality. All parameters were evaluated at 30 and 90 days after thrombolysis. Patients whose characteristics may provide the best treatment benefit were further analyzed using the logistic regression model in group 1.

RESULTS

The proportion of mRS scores between 0 and 1 in group 1 was higher than that in group 2 at both 30 days (44.7% vs 32.4%, P < .05) and 90 days (50.5% vs 35.2%, P < .05). Compared to group 2, the proportion of NIHSS scores less than 4 was significantly higher in group 1 at both 30 days (37.9% vs 25.7%, P < .05) and 90 days (46.6% vs 30.5%, P < .05). At 90 days, Group 1 had a lower stroke recurrence risk than Group 2 (3.9% vs 10.5%, P < .05). The incidence of SICH was significantly different between the 2 groups at both 30 days (2.9% vs 9.5%, P < .05) and 90 days (2.9% vs 10.5%, P < .05). However, other bleeding events and mortality rates were not significantly different between the 2 groups. The lower the baseline NIHSS score and the shorter the OTT, the more favorable the outcomes obtained at 90 days.

CONCLUSIONS

Compared to standard doses, short term high-dose dual antiplatelet therapy after 0.6 mg/kg rt-PA intravenous thrombolysis may be a good choice for AIS patients.

Endovascular Therapy for Acute Stroke: New Evidence and Indications

Endovascular therapy (EVT) has revolutionized the treatment of acute ischemic stroke. In the past few years, endovascular treatment indications have expanded to include patients being treated in the extended window, with large ischemic core infarction, basilar artery occlusion (BAO) thrombectomy, as demonstrated by several randomized clinical trials. Intravenous thrombolysis (IVT) bridging to mechanical thrombectomy has also been studied via several randomized clinical trials, with the overall results indicating that IVT should not be skipped in patients who are candidates for both IVT and EVT. Simplification of neuroimaging protocols in the extended window to permit non-contrast CT, CTA collaterals have also expanded access to mechanical thrombectomy, particularly in regions across the world where access to advanced imaging may not be available. Ongoing study of areas to develop include rescue stenting in patients with failed thrombectomy, medium vessel occlusion thrombectomy, and carotid tandem occlusions. In this narrative review, we summarize recent trials and key data in the treatment of patients with large ischemic core infarct, simplification of neuroimaging protocols for the treatment of patients presenting in the late window, bridging thrombolysis, and BAO EVT evidence. We also summarize areas of ongoing study including medium and distal vessel occlusion.

Posterior Circulation Stroke Patients Receive Less Reperfusion Therapy Because of Late Arrival and Relative Contraindications: A Retrospective Study

BACKGROUND

Reperfusion treatment (RT) is administered to individuals with posterior circulation strokes (PCS) later and less frequently. We aimed to study the impact of demographic and clinical factors on the decision for RT in PCS.

METHODS

We conducted a retrospective analysis of the data from 500 subjects admitted to the tertiary stroke centre's emergency department between 2018 and 2020 due to PCS. Demographic and clinical factors were analysed among three groups: the RT group, the group with no RT because of absolute contraindications (ACI), and the group with no RT because of relative contraindications (RCI).

RESULTS

Of the patients, 202 (40.3%) were female. The median NIHSS was four (4), and the subjects' median age was 69 (18). RT was performed on 120 (24%) subjects. FAST symptoms (OR-5.62, 95% CI [2.90-12.28]) and higher NIHSS (OR-1.13, 95% CI [1.09-1.18]) at presentation, atrial fibrillation (OR-1.56, 95% CI [1.02-2.38]), hypertension (OR-2.19, 95% CI [1.17-4.53]) and diabetes (OR-1.70, 95% CI [1.06-2.71]) increased the chance of RT. Late arrival was the most prevalent ACI for 291 (58.2%) patients. FAST-negative subjects (OR-2.92, 95% CI [1.84-4.77]) and males (OR-1.58, 95% CI [1.11-2.28]) had a higher risk of arriving late. Because of RCI, 50 (10%) subjects did not receive RT; the majority were above 80 and had NIHSS ≤ 5. Subjects with RCI who received the RT had a higher NIHSS (4 vs. 3, p < 0.001), higher hypertension (59 (92.2%) vs. 35 (77.8%), p = 0.032) and heart failure (23 (35.9%) vs. 7 (15.6%), p = 0.018) prevalence. There was a trend for less RT in females with RCI.

CONCLUSIONS

Late arrival was the most common barrier to RT, and the male gender increased this risk. because of relative contraindications, 10% of subjects were not considered for RT. The presence of FAST symptoms, vascular risk factors, and a higher NIHSS increased the chance of RT.

Feasibility and safety of ADAPT in acute distal posterior cerebral artery occlusions

PURPOSE

The direct aspiration first pass technique (ADAPT) is an effective and safe endovascular treatment for distal medium vessel occlusions (DMVO) of the anterior circulation. Clinical experience with ADAPT in the distal posterior circulation, however, is still limited and published data is scarce. In this original work, feasibility, safety and efficacy of ADAPT with distal access catheters (DAC) for treatment of acute distal posterior cerebral artery occlusions (DPCAOs) is evaluated.

METHOD

All acute ischemic stroke patients between 2017 and 2022 with primary or secondary DPCAOs in the P2 or P3 segment, that underwent thrombectomy of the DPACO using ADAPT with DACs as frontline therapy, were identified. Demographic data, recanalization rates, procedural safety, and clinical outcome were assessed.

RESULTS

Twenty-four patients with primary (n = 6) or secondary (n = 18) DPCAOs (P2: 21/24; P3: 3/24) were included. Median NIHSS score at admission was 14.5 (IQR 9.5). In all cases, the DPCAO could be reached with the DAC. Successful revascularization (DMVO-p-TICI ≥ 2b) with ADAPT was achieved in 79.2% (19/24), including a first pass effect of 62.5% (15/24), leading to complete recanalization (DMVO-p-TICI 3). Median number of passes was 1 (range 1-2). No complications related to distal PCA aspiration thrombectomy occurred. Median NIHSS and mRS scores at discharge were 4 (IQR 8) and 3 (IQR 2), respectively.

CONCLUSIONS

ADAPT appears to be feasible, safe and effective for the treatment of acute DPCAOs in the setting of different occlusion patterns. High revascularization rates without procedural complications can be achieved. Further studies are needed to consolidate these results.

Inflammatory-associated proteomic predictors of cognitive outcome in subjects with ELVO treated by mechanical thrombectomy

BACKGROUND

Emergent Large Vessel Occlusion (ELVO) stroke causes devastating vascular events which can lead to significant cognitive decline and dementia. In the subset of ELVO subjects treated with mechanical thrombectomy (MT) at our institution, we aimed to identify systemic and intracranial proteins predictive of cognitive function at time of discharge and at 90-days. These proteomic biomarkers may serve as prognostic indicators of recovery, as well as potential targets for novel/existing therapeutics to be delivered during the subacute stage of stroke recovery.

METHODS

At the University of Kentucky Center for Advanced Translational Stroke Sciences, the BACTRAC tissue registry (clinicaltrials.gov; NCT03153683) of human biospecimens acquired during ELVO stroke by MT is utilized for research. Clinical data are collected on each enrolled subject who meets inclusion criteria. Blood samples obtained during thrombectomy were sent to Olink Proteomics for proteomic expression values. Montreal Cognitive Assessments (MoCA) were evaluated with categorical variables using ANOVA and t-tests, and continuous variables using Pearson correlations.

RESULTS

There were n = 52 subjects with discharge MoCA scores and n = 28 subjects with 90-day MoCA scores. Several systemic and intracranial proteins were identified as having significant correlations to discharge MoCA scores as well as 90-day MoCA scores. Highlighted proteins included s-DPP4, CCL11, IGFBP3, DNER, NRP1, MCP1, and COMP.

CONCLUSION

We set out to identify proteomic predictors and potential therapeutic targets related to cognitive outcomes in ELVO subjects undergoing MT. Here, we identify several proteins which predicted MoCA after MT, which may serve as therapeutic targets to lessen post-stroke cognitive decline.

Endovascular Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke: An Evolution of Trials

The last decade's progress in demonstrating the clinical benefit of endovascular thrombectomy (EVT) in patients with large vessel occlusion stroke has transformed the paradigm of care for these patients. This review presents the milestones in implementing EVT as standard of care, demonstrates the current state of evidence, provides guidance for identifying the candidate patient for EVT, and highlights unsolved and controversial issues. Ongoing trials investigate broadening of EVT indications for patients who present with large core infarction, adjunctive intra-arterial thrombolysis, medium vessel occlusion, low NIHSS, and tandem occlusion.

What Is the Evidence for Endovascular Thrombectomy in Posterior Circulation Stroke?

Posterior circulation infarcts comprise approximately 25% of ischemic strokes but are less often treated with recanalization therapy and have longer treatment delays compared with anterior circulation strokes. Among posterior circulation strokes, basilar artery occlusion is associated with the most severe deficits and the worst prognosis. Endovascular thrombectomy is a standard of care for patients with anterior circulation large vessel occlusion, but not until recently were the first randomized controlled trials on endovascular thrombectomy in basilar artery occlusion published. Two of the trials were neutral, whereas two others showed better functional outcome after thrombectomy up to 24 hours of symptom onset compared with best medical treatment, which in most cases had low rates of intravenous thrombolysis. According to observational data, thrombectomy seems to be safe also in isolated posterior cerebral artery occlusions and might be an option for selected patients, even if its outcome benefit is yet to be demonstrated.

Endovascular therapy outcome in isolated posterior cerebral artery occlusion strokes: A multicenter analysis of the Swiss Stroke Registry

PURPOSE

There is little data on the safety and efficacy of endovascular treatment (EVT) in comparison with intravenous thrombolysis (IVT) in acute ischemic stroke due to isolated posterior cerebral artery occlusion (IPCAO). We aimed to investigate the functional and safety outcomes of stroke patients with acute IPCAO treated with EVT (with or without prior bridging IVT) compared to IVT alone.

METHODS

We did a multicenter retrospective analysis of data from the Swiss Stroke Registry. The primary endpoint was overall functional outcome at 3 months in patients undergoing EVT alone or as part of bridging, compared with IVT alone (shift analysis). Safety endpoints were mortality and symptomatic intracranial hemorrhage. EVT and IVT patients were matched 1:1 using propensity scores. Differences in outcomes were examined using ordinal and logistic regression models.

FINDINGS

Out of 17,968 patients, 268 met the inclusion criteria and 136 were matched by propensity scores. The overall functional outcome at 3 months was comparable between the two groups (EVT vs IVT as reference category: OR = 1.42 for higher mRS, 95% CI = 0.78-2.57, p = 0.254). The proportion of patients independent at 3 months was 63.2% in EVT and 72.1% in IVT (OR = 0.67, 95% CI = 0.32-1.37, p = 0.272). Symptomatic intracranial hemorrhages were overall rare and present only in the IVT group (IVT = 5.9% vs EVT = 0%). Mortality at 3 months was also similar between the two groups (IVT = 0% vs EVT = 1.5%).

CONCLUSION

In this multicenter nested analysis, EVT and IVT in patients with acute ischemic stroke due to IPCAO were associated with similar overall good functional outcome and safety. Randomized studies are warranted.

Endovascular treatment for isolated posterior cerebral artery occlusion stroke in the MR CLEAN registry

BACKGROUND

Endovascular treatment (EVT) is standard of care in anterior circulation large vessel occlusions. In posterior circulation occlusions, data on EVT in isolated posterior cerebral artery (PCA) occlusions are limited, although PCA occlusions can cause severe neurological deficit.

OBJECTIVE

To describe in a prospective study the clinical manifestations, outcomes, and safety of EVT in isolated PCA occlusions.

METHODS

We used data (2014-2017) from the MR CLEAN Registry, a nationwide, prospective cohort of EVT-treated patients in the Netherlands. We included patients with acute ischemic stroke (AIS) due to an isolated PCA occlusion on CT angiography. Patients with concurrent occlusion of the basilar artery were excluded. Outcomes included change in National Institutes of Health Stroke Scale (ΔNIHSS) score, modified Rankin Scale (mRS) score 0-3 after 90 days, mortality, expanded Thrombolysis in Cerebral Infarction (eTICI), and periprocedural complications.

RESULTS

Twenty (12%) of 162 patients with posterior circulation occlusions had an isolated PCA occlusion. Median age was 72 years; 13 (65%) were women. Median baseline NIHSS score was 13 (IQR 5-21). Six (30%) patients were comatose. Twelve patients (60%) received IVT. Median ΔNIHSS was -4 (IQR -11-+1). At follow-up, nine patients (45%) had mRS score 0-3. Seven (35%) died. eTICI 2b-3 was achieved in 13 patients (65%). Nine patients (45%) had periprocedural complications. No symptomatic intracranial hemorrhages (sICH) occurred.

CONCLUSIONS

EVT should be considered in selected patients with AIS with an isolated PCA occlusion, presenting with moderate-severe neurological deficits, as EVT was technically feasible in most of our patients and about half had good clinical outcome. In case of lower NIHSS score, a more conservative approach seems warranted, since periprocedural complications are not uncommon. Nonetheless, EVT seems reasonably safe considering the absence of sICH in our study.

Optimal CT perfusion thresholds for core and penumbra in acute posterior circulation infarction

Background

At least 20% of strokes involve the posterior circulation (PC). Compared to the anterior circulation, posterior circulation infarction (POCI) are frequently misdiagnosed. CT perfusion (CTP) has advanced stroke care by improving diagnostic accuracy and expanding eligibility for acute therapies. Clinical decisions are predicated upon precise estimates of the ischaemic penumbra and infarct core. Current thresholds for defining core and penumbra are based upon studies of anterior circulation stroke. We aimed to define the optimal CTP thresholds for core and penumbra in POCI.

Methods

Data were analyzed from 331-patients diagnosed with acute POCI enrolled in the International-stroke-perfusion-registry (INSPIRE). Thirty-nine patients with baseline multimodal-CT with occlusion of a large PC-artery and follow up diffusion weighted MRI at 24-48 h were included. Patients were divided into two-groups based on artery-recanalization on follow-up imaging. Patients with no or complete recanalisation were used for penumbral and infarct-core analysis, respectively. A Receiver operating curve (ROC) analysis was used for voxel-based analysis. Optimality was defined as the CTP parameter and threshold which maximized the area-under-the-curve. Linear regression was used for volume based analysis determining the CTP threshold which resulted in the smallest mean volume difference between the acute perfusion lesion and follow up MRI. Subanalysis of PC-regions was performed.

Results

Mean transit time (MTT) and delay time (DT) were the best CTP parameters to characterize ischaemic penumbra (AUC = 0.73). Optimal thresholds for penumbra were a DT >1 s and MTT>145%. Delay time (DT) best estimated the infarct core (AUC = 0.74). The optimal core threshold was a DT >1.5 s. The voxel-based analyses indicated CTP was most accurate in the calcarine (Penumbra-AUC = 0.75, Core-AUC = 0.79) and cerebellar regions (Penumbra-AUC = 0.65, Core-AUC = 0.79). For the volume-based analyses, MTT >160% demonstrated best correlation and smallest mean-volume difference between the penumbral estimate and follow-up MRI (R ² = 0.71). MTT >170% resulted in the smallest mean-volume difference between the core estimate and follow-up MRI, but with poor correlation (R ² = 0.11).

Conclusion

CTP has promising diagnostic utility in POCI. Accuracy of CTP varies by brain region. Optimal thresholds to define penumbra were DT >1 s and MTT >145%. The optimal threshold for core was a DT >1.5 s. However, CTP core volume estimates should be interpreted with caution.

Acute isolated posterior cerebral artery stroke treated with mechanical thrombectomy: A single-center experience and review of the literature

BACKGROUND

Acute isolated posterior cerebral artery (PCA) occlusions account for 5-10% of all ischemic events. Due to peculiar patient presentation, the potential benefit of mechanical thrombectomy (MT) remains controversial. We evaluated the safety, feasibility, and effectiveness of MT in our patients and compared our results with the literature review conducted.

METHODS

Charts were reviewed retrospectively for consecutive patients diagnosed with acute PCA stroke who underwent MT. Demographics, procedural, and follow-up details were noted. For the literature review, a systematic search of PubMed, MEDLINE, and EMBASE databases was conducted for the keywords "posterior cerebral artery" and "thrombectomy" for articles published between January 1, 2010 and June 30, 2021. Estimated rates for recanalization, favorable outcomes (modified Rankin Scale [mRS] score 0-2), symptomatic intracerebral hemorrhage (sICH), and mortality were extracted.

RESULTS

Our cohort included 21 patients. Mean age was 71.2 years (standard deviation [SD] ± 10.2). Median National Institutes of Health Stroke Scale (NIHSS) presentation score was 9 (interquartile range [IQR] 5-15), with visual symptoms reported in 12(57.1%) patients. Overall, final modified thrombolysis in cerebral infarction (mTICI) 2b-3 was achieved in 17 patients (80.9%) with first-pass mTICI 2b-3 attained in 8 (38.1%). Postprocedure sICH occurred in 1 (4.8%) patient. Fifteen (71.4%) patients had a 0-2 mRS score at 90 days. Visual symptoms resolved in 10 of 12(83.3%) patients. Mortality occurred in 2 (9.5%) patients. For the systematic review, cohorts from 4 articles plus ours were included, totaling 222 patients. The estimated rate of successful recanalization was 85.25% (95% confidence interval[CI], 73.05%-97.45%), sICH was 3.60% (95% CI, 1.11%-6.09%), and mortality was 10.51% (95% CI, 5.88%-15.15%).

CONCLUSION

The results of our series and systematic review indicate MT as a potentially safe and effective treatment modality for acute PCA stroke. These results also indicate that patient selection and assessment may be the key in obtaining favorable outcomes.

A review article on neuroprotective, immunomodulatory, and anti-inflammatory role of vitamin-D3 in elderly COVID-19 patients

Vitamin D3 is a secosteroid, broad-spectrum immunomodulatory, antioxidant, and anti-inflammatory hormone produced either by the internal subcutaneous pathway in the presence of ultraviolet B (UVB) rays or by the external pathway in the form of supplements. Vitamin D3 deficiency is a common and reversible contributor to mortality and morbidity among critically ill patients, including Coronavirus Disease 2019 (COVID-19) and other viral infections. The major functions of vitamin D3 are inhibiting the proinflammatory pathways, including nuclear factor kappa B (NF-kB), inflammatory cytokines, such as interleukin-6 (ILs-6), interleukin-18 (ILs-18), and tumour necrosis factor (TNF), preventing the loss of neural sensation in COVID-19, maintaining respiratory homeostasis, and acting as an antiviral, antimalarial, and antihypertensive agent. Vitamin D3 has an important role in reversing the COVID-19 infection in patients who have previously suffered from a neurological disease, such as Alzheimer's disease, Parkinson disease, motor neuron disease, multiple sclerosis, Creutzfeldt-Jakob disease, stroke, cardiovascular problems, headache, sleep-associated disorder, and others. Moreover, vitamin D3 plays a key role in regulating the gene expression of different pro-inflammatory cytokines. In addition to the information provided above, the current review article provides the most recent information on Vitamin D against COVID-19 with comorbid neurological disorders. Furthermore, we present the most recent advancement and molecular mechanism of action of vitamin D3. Diabetes, cardiovascular disease, and neurological disorders are comorbid conditions, and vitamin D3 is a critical regulator of COVID-19 infection during these conditions. In the midst of the COVID-19 epidemic, factors such as sex, latitudes, nutrition, demography, pollution, and gut microbiota warrants for additional research on vitamin D supplements.

COVID-19-Induced Stroke and the Potential of Using Mesenchymal Stem Cells-Derived Extracellular Vesicles in the Regulation of Neuroinflammation

Ischemic stroke (IS) is a known neurological complication of COVID-19 infection, which is associated with high mortality and disability. Following IS, secondary neuroinflammation that occurs can play both harmful and beneficial roles and lead to further injury or repair of damaged neuronal tissue, respectively. Since inflammation plays a pivotal role in the pathogenesis of COVID-19-induced stroke, targeting neuroinflammation could be an effective strategy for modulating the immune responses following ischemic events. Numerous investigations have indicated that the application of mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) improves functional recovery following stroke, mainly through reducing neuroinflammation as well as promoting neurogenesis and angiogenesis. Therefore, MSC-EVs can be applied for the regulation of SARS-CoV-2-mediated inflammation and the management of COVID-19- related ischemic events. In this study, we have first described the advantages and disadvantages of neuroinflammation in the pathological evolution after IS and summarized the characteristics of neuroinflammation in COVID-19-related stroke. Then, we have discussed the potential benefit of MSC-EVs in the regulation of inflammatory responses after COVID-19-induced ischemic events.

Aspiration versus Stent Retriever Thrombectomy in Posterior Circulation Stroke: A Systematic Review and Meta-Analysis

INTRODUCTION

The management of posterior circulation stroke is primarily carried out by endovascular approaches including aspiration or stent retrevier thrombectomy. Existing reviews have attempted to comparatively evaluate their efficacy in terms of morbidity and mortality-related outcomes, however, with several limitations. Therefore, in this review, we attempt to address the gap in the existing literature by evaluating the comparative impact of stent retriever-based and aspiration-based thrombectomy interventions in posterior circulation stroke patients on the following parameters: overall procedure duration, recanalization time, rescue therapy usage, complication risk, and mortality risk.

METHODS

A systematic search of the academic literature was performed according to PRISMA guidelines across five databases. We conducted a random-effect meta-analysis to evaluate comparative outcomes, including procedural duration, time to recanalization, risk of complications, use of rescue therapy, and risk of mortality in patients with posterior circulation stroke undergoing stent retriever- and aspiration-based thrombectomies. We also performed comparative subgroup analyses to evaluate differences in outcomes between contact and manual aspiration interventions.

RESULTS

From 963 studies, we found nine eligible studies containing data on 840 patients. Meta-analysis revealed a large-to-medium size positive effect for stent retriever-based thrombectomy on overall procedure duration and recanalization compared to aspiration-based thrombectomy. Additional analysis revealed higher risk of complications and mortality in posterior circulation stroke patients undergoing stent retriever-based thrombectomy as compared to aspiration-based thrombectomy. We also observed that the use of rescue therapy was elevated in patients undergoing aspiration-based thrombectomy compared to stent retriever-based thrombectomy.

CONCLUSION

This study provides preliminary evidence for improved morbidity and mortality outcomes in posterior circulation stroke patients undergoing aspiration-based thrombectomies as compared to stent retriever-based thrombectomy. The study also provides evidence for improved endovascular outcomes for patients undergoing aspiration-based thrombectomies. The findings from this study can have implications in developing awareness among neurosurgeons for stratifying patients to manage posterior circulation stroke according to the risks associated with aspiration and stent retriever-based thrombectomies.

Neurovascular and infectious disease phenotype of acute stroke patients with and without COVID-19

Background

The infectious disease phenotype of acute stroke associated with COVID-19 has been poorly characterized.

Objective

We investigated the neurovascular and infectious disease phenotype of stroke patients with and without COVID-19 infection, and their effect on in-hospital mortality.

Methods

This is a retrospective cohort study of consecutive patients with acute stroke, admitted to any ward of a hub hospital for stroke in Lombardy, Italy, during the first wave of COVID-19. Demographic, neurovascular, infectious disease, and respiratory characteristics were collected. The effect of clinical variables on survival was evaluated using logistic regression models.

Results

One hundred thirty-seven patients with acute stroke were recruited; 30 (21.9%) patients had COVID-19 and represented 2.5% of the 1218 COVID-19 patients hospitalized in the study period. Demographics, comorbidities, stroke type, stroke severity, and etiology did not differ between COVID + stroke patients and non-COVID stroke patients, except for an excess of multi-embolic ischemic stroke in the COVID + group. Most COVID + stroke patients had symptomatic infection (60%) and interstitial pneumonia (70%). COVID + stroke patients required more frequently respiratory support (77% versus 29%; p < 0.0001) and had higher in-hospital mortality (40% versus 12%; p = 0.0005) than non-COVID stroke patients. Mortality was independently associated with symptomatic interstitial pneumonia (aOR 6.7; 95% CI 2.0–22.5; p = 0.002) and, to a lesser extent, with NIHSS on admission (aOR 1.1; 95% CI 1.03–1.2; p = 0.007) and recanalization therapies (aOR 0.2; 95% CI 0.04–0.98; p = 0.046).

Conclusion

Symptomatic interstitial pneumonia was the major driver of in-hospital mortality in COVID + stroke patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-022-06133-5.

The Problem of Restrictive Thrombectomy Trial Eligibility Criteria

Since 2015, a series of endovascular trials transformed the management of patients with large vessel occlusion stroke. Most thrombectomy trials used restrictive eligibility criteria to optimize the chances of showing that thrombectomy could work. The problem arises when generalizing trial results into evidence-based recommendations. Many organizations, oblivious of this problem, translated verbatim restrictive trial eligibility criteria into authoritative guidelines, which limit the use of thrombectomy to highly selected patients. The clinical problem becomes as follows: what to do for all other stroke patients equally in need of care? The cycle of restrictive trial eligibility criteria, corresponding restrictive guidelines, observational studies of unvalidated practices showing other patients benefit, a new trial is needed, has been repeated often. Thrombectomy trials ought to have included all patients that could potentially benefit. If the signal that was looked for by restricting eligibility is at risk of being lost in the noise generated by the heterogeneity of patients, D. Sackett proposed a solution: to use the same criteria, not to select some patients and exclude others but to prespecify the subgroup of patients most likely to benefit. In this commentary, we propose a tiered approach, where the boundaries of treatment beneficiaries can be more rigorously tested and confirmed. Identification of these patients before the development of guidelines, which would have otherwise neglected these individuals, may open innumerable treatment opportunities to those who will instead be denied of them.

Endovascular intervention for bilateral paramedian thalamic stroke due to occlusion of the unilateral P1 segment of the posterior cerebral artery: illustrative cases

BACKGROUND

Occlusion of the unilateral P1 segment can result in bilateral paramedian thalamic infarction in patients with anatomical variants of the bilateral paramedian thalamic artery arising from a single P1 segment. Despite the life-threatening presentation of bilateral paramedian thalamic stroke, timely diagnosis is often challenging.

OBSERVATIONS

The authors herein describe 3 patients treated with endovascular intervention for occlusion of the unilateral P1 segment wherein the bilateral paramedian thalamic arteries arose. All patients were admitted to the authors' emergency department with sudden-onset coma and respiratory distress; however, initial computed tomography was unremarkable. Despite suspicion of basilar artery occlusion, vertebral and carotid angiography revealed occlusion of the unilateral P1 segment. All patients were successfully treated with endovascular intervention. Overall, 2 patients had favorable outcomes (modified Rankin scale [mRS] scores of 0 and 1), whereas in 1 patient, the mRS score reached a baseline score of 3.

LESSONS

In patients with the variant of the bilateral paramedian thalamic artery arising from a single P1 segment, occlusion of the unilateral P1 segment can be life threatening; nevertheless, timely endovascular treatment is effective. Carotid and vertebral angiography, rather than magnetic resonance or computed tomography angiography, is useful for immediate and reliable diagnosis of the relatively small vascular lesions.

Molecular characteristics, immune evasion, and impact of SARS-CoV-2 variants

The persistent COVID-19 pandemic since 2020 has brought an enormous public health burden to the global society and is accompanied by various evolution of the virus genome. The consistently emerging SARS-CoV-2 variants harboring critical mutations impact the molecular characteristics of viral proteins and display heterogeneous behaviors in immune evasion, transmissibility, and the clinical manifestation during infection, which differ each strain and endow them with distinguished features during populational spread. Several SARS-CoV-2 variants, identified as Variants of Concern (VOC) by the World Health Organization, challenged global efforts on COVID-19 control due to the rapid worldwide spread and enhanced immune evasion from current antibodies and vaccines. Moreover, the recent Omicron variant even exacerbated the global anxiety in the continuous pandemic. Its significant evasion from current medical treatment and disease control even highlights the necessity of combinatory investigation of the mutational pattern and influence of the mutations on viral dynamics against populational immunity, which would greatly facilitate drug and vaccine development and benefit the global public health policymaking. Hence in this review, we summarized the molecular characteristics, immune evasion, and impacts of the SARS-CoV-2 variants and focused on the parallel comparison of different variants in mutational profile, transmissibility and tropism alteration, treatment effectiveness, and clinical manifestations, in order to provide a comprehensive landscape for SARS-CoV-2 variant research.

Treatment of posterior circulation stroke: acute management and secondary prevention

One-fifth of strokes occur in the territory of the posterior circulation, but their management, particularly acute reperfusion therapy and neurointervention procedures for secondary prevention, has received much less attention than similar interventions for the anterior circulation. In this review, we overview the treatment of posterior circulation stroke, including both interventions in the acute setting and secondary prevention. We focus on areas in which the management of posterior circulation stroke differs from that of stroke in general and highlight recent advances.

Effectiveness of acute revascularization of posterior circulation strokes remains in large parts unproven. Thrombolysis seems to have similar benefits and lower hemorrhage risks than in the anterior circulation. The recent ATTENTION and BAOCHE trials have demonstrated that thrombectomy benefits strokes with basilar artery occlusion, but its effect on other posterior occlusion sites remains uncertain. Ischemic and hemorrhagic space-occupying cerebellar strokes can benefit from decompressive craniectomy.

Secondary prevention of posterior circulation strokes includes aggressive treatment of cerebrovascular risk factors with both drugs and lifestyle interventions and short-term dual anti-platelet therapy. Randomized controlled trial (RCT) data suggest basilar artery stenosis is better treated with medical therapy than stenting, which has a high peri-procedural risk. Limited data from RCTs in stenting for vertebral stenosis suggest that intracranial stenosis is currently best treated with medical therapy alone; the situation for extracranial stenosis is less clear where stenting for symptomatic stenosis is an option, particularly for recurrent symptoms; larger RCTs are required in this area.

Thrombectomy of symptomatic isolated occlusions of posterior cerebral arteries in segment P1 and P2 in acute stroke treatment

BACKGROUND

Interventional stroke treatments for occlusions of the posterior circulation are established procedures. However, there are limited data on the treatment of isolated symptomatic P1 and P2 occlusions, which we have examined in this study.

PURPOSE

To investigate the mechanical thrombectomy of distal posterior occlusions.

MATERIAL AND METHODS

Retrospectively, data from patients with isolated P1 and P2 occlusions treated with MT were evaluated. Successful reperfusions have been defined as modified thrombolysis in cerebral infarct (mTICI) Grade 2b-3. A good clinical outcome was defined as a 90-day modified Rankin score 0-2.

RESULTS

All 79 treated patients were primarily aspirated. Stent retrievers were used secondarily in nine patients. Successful reperfusion was achieved in 95% of patients. Of the patients, 57% had a favorable clinical outcome after 90 days.

CONCLUSION

Mechanical thrombectomy with first line aspiration of symptomatic P1 and P2 occlusions is a safe and effective procedure.

Endovascular Treatment of Acute Ischemic Stroke Due to Isolated Proximal Posterior Artery Occlusion

Background

Acute ischemic stroke (AIS) due to isolated proximal posterior cerebral artery (PPCA) occlusion is rare but associated with high morbidity and mortality rates. However, the optimal treatment strategy for patients with AIS caused by PPCA remains unclear. We discuss our single-center experience with endovascular treatment (EVT) in patients with PPCA.

Methods

Data from patients with AIS due to PPCA occlusion were retrospectively analyzed. We analyzed procedural details, the degree of reperfusion, functional outcomes, and complications. Functional outcomes were determined using the modified Rankin Scale (mRS) at 90 days, and good outcome was defined as mRS 0–2 at 90 days. Successful reperfusion was defined as modified treatment in cerebral ischemia (mTICI) 2b−3 after endovascular therapy. Safety variables included symptomatic hemorrhage (defined as an increase of four or more points in the National Institute of Health Stroke Scale score), vessel perforation or dissection, and new ischemic stroke in different territories.

Results

Seven patients were included in this study. The mean age of the patients was 64 ± 12.4 years. Successful reperfusion was achieved in all seven patients (100%). Good outcomes were achieved at 90 days in 2 patients (28.6%), and favorable outcomes were observed in five patients (71.4%). One patient underwent angioplasty as rescue therapy after three attempts. One patient died because of severe gastrointestinal bleeding 24 h after EVT, which was probably a complication of intravenous alteplase. One patient had an embolism in the basilar artery and achieved complete reperfusion after rescue thrombectomy. Another patient had a complication of vessel dissection in the PPCA and underwent stent implantation as rescue therapy. We observed no recurrence of ischemic stroke or any intracranial hemorrhage on non-contrast computed tomography 24 h after the procedure.

Conclusion

EVT may represent an alternative treatment strategy for patients with acute ischemic stroke caused by PPCA.

Endovascular Therapy versus No Endovascular Therapy in Patients receiving Best Medical Management for Acute Isolated Occlusion of the Posterior Cerebral Artery: Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Endovascular therapy (EVT) is increasingly reported for treatment of isolated posterior cerebral artery (PCA) occlusions although its clinical benefit remains uncertain. This study-level meta-analysis investigated functional outcome and safety of EVT and best medical management (BMM) compared to BMM for treatment of PCA occlusion stroke.

METHODS

We conducted a literature search in PubMed, Web of Science and Embase for articles reporting patients with isolated PCA occlusion stroke treated with EVT+BMM or BMM including intravenous thrombolysis. There were no randomized trials and all studies were retrospective. Primary outcome was a modified Rankin Scale score of 0-2 at 3 months; safety outcomes included mortality rate and incidence of symptomatic intracranial hemorrhage.

RESULTS

Twelve articles with a total of 679 patients were included in the meta-analysis consisting of 338 patients with EVT+BMM and 341 patients receiving BMM alone. Good functional outcome at 3 months was achieved in 58.0% [95% confidence interval (CI) 43.83-70.95] of patients with EVT+BMM and 48.1% [95% CI 40.35-55.92] of patients with BMM with respective mortality rates of 12.6% [7.30-20.93] and 12.3% [8.64-17.33]. Symptomatic intracranial hemorrhage occurred in 4.2% [95% CI 2.47-7.03] of patients with EVT+BMM and 3.2% [95% CI 1.75-5.92] of patients with BMM. Comparative analyses were performed of publications reporting both treatments and demonstrated no significant differences.

CONCLUSIONS

The results demonstrate that EVT represents a safe treatment for patients with isolated PCA occlusion stroke. There were no differences in clinical or safety outcomes between treatments, supporting randomization of future patients into distal vessel occlusion trials.

Endovascular Treatment Combined With Standard Medical Treatment Improves Outcomes of Posterior Circulation Stroke: A Systematic Review and Meta-Analysis

Aims

Whether endovascular treatment (EVT) can further improve the prognosis of patients with posterior circulation ischemic stroke (PCIS) is unclear. This meta-analysis aims to compare the efficacy and safety of PCIS patients treated with EVT plus standard medical treatment (SMT) and SMT alone.

Methods

We systematically searched for relevant randomized controlled trials (RCTs) and prospective cohort trials in MEDLINE, EMBASE, and the Cochrane Library up to February 2022. The primary outcome was favorable functional outcome of the modified Rankin Scale (mRS) with scores of 0-2 or 0-3; secondary outcomes included successful recanalization rate, intracranial hemorrhage (ICH), or symptomatic intracranial hemorrhage (sICH) after treatment and 90-day mortality.

Results

We identified six studies including 1, 385 PCIS patients (957 with EVT plus SMT; 428 with SMT alone). EVT plus SMT substantially improved 90-day functional outcomes compared with SMT alone [mRS score of 0-2: RR=1.95, 95% CI (1.52 - 2.51), P < 0.001; mRS score of 0-3: RR = 1.85, 95% CI (1.49 - 2.30), P < 0.001, respectively]. Moreover, compared with SMT, combined treatment significantly improved the rate of successful recanalization [RR = 5.03, 95% CI (3.96-6.40), P < 0.001] and reduced 90-day mortality [RR = 0.71, 95% CI (0.63-0.79), P < 0.001] despite a higher risk of ICH [RR = 6.13, 95% CI (2.50-15.02), P < 0.001] and sICH [RR = 10.47, 95% CI [2.79-39.32), P = 0.001].

Conclusion

Low-to-moderate evidence from RCTs and non-RCTs showed that increased ICH and sICH risk of EVT plus SMT did not translate to a higher risk of unfavorable outcomes compared with SMT and could even promote independence at 90 days in a real-world cohort.

Flow dynamics in acute ischemic stroke due to embolic occlusion of a fetal posterior cerebral artery treated with endovascular thrombectomy - report of two cases

The fetal variant of the posterior cerebral artery (fPCA) conserves a major blood flow from the anterior to the posterior cerebral circulation via a strong persistent caudal portion of the embryonic internal carotid artery. We present two cases where endovascular treatment in acute ischemic stroke was complicated by this flow diversion. Though direct thrombectomy of the fPCA using a stent retriever was feasible and successful in both cases outcome remained unfavourable due to a continuous redirection of embolic material into the posterior circulation. Knowledge of flow dynamics in a fPCA is important for endovascular treatment in acute ischemic stroke.

Cardiovascular disturbances in COVID-19: an updated review of the pathophysiology and clinical evidence of cardiovascular damage induced by SARS-CoV-2

Severe acute respiratory coronavirus-2 (SARS-Co-2) is the causative agent of coronavirus disease-2019 (COVID-19). COVID-19 is a disease with highly variable phenotypes, being asymptomatic in most patients. In symptomatic patients, disease manifestation is variable, ranging from mild disease to severe and critical illness requiring treatment in the intensive care unit. The presence of underlying cardiovascular morbidities was identified early in the evolution of the disease to be a critical determinant of the severe disease phenotype. SARS-CoV-2, though a primarily respiratory virus, also causes severe damage to the cardiovascular system, contributing significantly to morbidity and mortality seen in COVID-19. Evidence on the impact of cardiovascular disorders in disease manifestation and outcome of treatment is rapidly emerging. The cardiovascular system expresses the angiotensin-converting enzyme-2, the receptor used by SARS-CoV-2 for binding, making it vulnerable to infection by the virus. Systemic perturbations including the so-called cytokine storm also impact on the normal functioning of the cardiovascular system. Imaging plays a prominent role not only in the detection of cardiovascular damage induced by SARS-CoV-2 infection but in the follow-up of patients' clinical progress while on treatment and in identifying long-term sequelae of the disease.