Posterior Cerebral Artery Occlusion Research Articles

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

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

Pure arterial malformation of the fetal PCA treated with flow diverter stent-case report and literature review.

Thirty-three-year-old female underwent diagnostic work-up for chronic headaches. Cerebral DSA on the right side showed fetal posterior cerebral artery (PCA) with unusually shaped arterial malformation on its proximal part. Malformation was formed by multiple convolutions and loops with no arteriovenous shunting. During endovascular procedure, flow diverter stent was placed in the right C6 segment. Patient was put on double antiaggregation therapy. Four weeks after procedure, patient was admitted to ER with signs of dyphasia. No recent ischemic lesions were detected on emergent magnetic resonance. Dyphasia resolved spontaneously. On follow-up magnetic resonance angiography 5 years after the procedure, main portion of malformation has diminished with slightly filling of posterior part supplied by right P1. Here, reported finding is consistent with previously described pure arterial malformation (PAM). Main intention of our treatment was to induce malformation remodeling with flow diverter placement. Two main risks arise when using flow diverters on fetal PCA region. Firstly, there is possibility of occluding fetal PCA alongside malformation. On the contrary, high flow through fetal PCA could hinder malformation thrombosis. Some case series reported high rate of fetal PCA occlusion without ischemic sequelae in the PCA teritory. Others consider flow diverters highly ineffective treatment for the fetal PCA aneurysms due to low rate of complete aneurysm occlusion. We presented first reported case in which flow diverter was used to treat PAM. Slow malformation thrombosis leaves enough time for collateral circulation to recruit and supply territory of the vessel affected by the malformation.

Hippocampus infarct following a posterior cerebral artery occlusion.

A 64-year-old gentleman, presented for subacute onset of short-term memory problem, preceded by headache, right arm numbness and visual disturbances. On neurological exam, he had anterograde amnesia, decreased pinprick sensation on his right arm and right homonymous hemianopsia. Brain Magnetic Resonance imaging (MRI) and Magnetic Resonance Angiography (MRA) showed subacute ischemic lesions in the left occipital lobe, hippocampus and thalamus, caused by a distal occlusion of the left Posterior Cerebral Artery (PCA). A distal occlusion of the PCA led to multiple infarcts in different anatomical structures, causing a constellation of variant neurological signs. Our case demonstrates an anterior hippocampus predominantly irrigated by the PCA.

Decompressive Craniectomy in Patients with Malignant Stroke with Additional Vascular Territory

IntroductionDecompressive craniectomy substantially reduces mortality and disability rates following a malignant stroke. This procedure remains a life-saving option, especially in contexts with little access to mechanical thrombectomy despite downward trends in the performance of decompressive craniectomy due to discussions on the acceptance of living with severe disabilities. However, the outcomes of the surgery in cases involving concomitant occlusion of anterior or posterior cerebral arteries have not been extensively studied. MethodsIn this retrospective cohort study, spanning January 2010 to December 2022 and including patients who underwent decompressive craniectomy, we compared outcomes between patients with and without additional vascular territory involvement. Independent variables included age, sex, comorbidities, admission National Institutes of Health Stroke Scale (NIHSS) and Glasgow Coma Scale (GCS) scores, time elapsed between stroke and surgery, laterality of the stroke, midline shift, and postoperative infarction volume. Outcomes included mortality and Modified Rankin Score at the 3-month follow-up. ResultsOf the 86 patients analyzed, 61 (70.9%) and 25 (29.1%) demonstrated no territory and additional territory involvement, respectively. Patients with involvement of additional territories exhibited lower admission GCS scores, higher NIHSS scores, and larger postoperative infarction volumes. However, these variables were not associated with poor outcomes. Univariate analyses revealed no differences in mortality or severe disability. Even after adjustment, the differences remained insignificant for mortality and severe disability. Age emerged as the sole variable linked to increased mortality. ConclusionOur data suggest that, for patients with malignant stroke undergoing decompressive craniectomy, the outcomes for patients with and without involvement of additional vascular territory are similar.

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

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. 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. 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. 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.

Derivation and Validation of a Scoring System for Predicting Poor Outcome After Posterior Circulation Ischemic Stroke in China.

Guidelines for posterior circulation ischemic stroke (PCIS) treatment are lacking and outcome prediction is crucial for patients and clinicians. We aimed to develop and validate a prognostic score to predict the poor outcome for patients with PCIS. The score was developed from a prospective derivation cohort named the Third China National Stroke Registry (August 2015-March 2018) and validated in a spatiotemporal independent validation cohort (December 2017-March 2023) in China. Patients with PCIS with acute infarctions defined as hyperintense lesions on diffusion-weighted imaging were included in this study. The poor outcome was measured as modified Rankin scale (mRS) score 3-6 at 3 months after PCIS. Multivariable logistic regression analysis was used to identify predictors for poor outcome. The prognostic score, namely PCIS Outcome Score (PCISOS), was developed by assigning points to variables based on their relative β-coefficients in the logistic model. The PCISOS was derived from 3,294 patients (median age 62 [interquartile range (IQR) 55-70] years; 2,250 [68.3%] men) and validated in 501 patients (median age 61 [IQR 53-68] years; 404 [80.6%] men). Among them, 384 (11.7%) and 64 (12.8%) had poor outcome 3 months after stroke in respective cohorts. Age, mRS before admission, NIH Stroke Scale on admission, ischemic stroke history, infarction distribution, basilar artery, and posterior cerebral artery stenosis or occlusion were identified as independent predictors for poor outcome and included in PCISOS. This easy-to-use integer scoring system identified a marked risk gradient between 4 risk groups. PCISOS performed better than previous scores, with an excellent discrimination (C statistic) of 0.80 (95% CI 0.77-0.83) in the derivation cohort and 0.81 (95% CI 0.77-0.84) in the validation cohort. Calibration test showed high agreement between the predicted and observed outcomes in both cohorts. PCISOS can be applied for patients with PCIS with acute infarctions to predict functional outcome at 3 months post-PCIS. This simple tool helps clinicians to identify patients with PCIS with higher risk of poor outcome and provides reliable outcome expectations for patients. This information might be used for personalized rehabilitation plan and patient selection for future clinical trials to reduce disability and mortality.

Endovascular therapy of isolated posterior cerebral artery occlusion stroke with and without general anesthesia

BackgroundThe optimal anesthetic strategy for endovascular therapy (EVT) in acute ischemic stroke is still under debate. The aim of this study was to compare the clinical outcomes of patients with...

Endovascular Thrombectomy Versus Intravenous Thrombolysis of Posterior Cerebral Artery Occlusion Stroke.

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. 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. 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). 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.

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). 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). 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. 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.

391 Intraarterial Verapamil for Neuroprotection in Ischemic Stroke

INTRODUCTION: Verapamil is an FDA-approved calcium channel blocker administered for the standard-of-care treatment of vasospasm. Preclinical studies have shown that verapamil reduces inflammation and protects penumbra neurons from further damage and eventual death. METHODS: Patients were recruited based on inclusion and exclusion criteria in a clinical protocol reviewed and approved by two institutional review boards. The final cohort comprised 42 emergency care patients with an acute onset focal neurological deficit consistent with ischemic stroke and/or a computed tomographic scan consistent with acute cerebral ischemia. All patients were 18 years of age or older that presented within 24 hours of symptom onset and had a significant but not severe neurological deficit, measured by a National Institutes of Health Stroke Scale (NIHSS) score greater than four but less than 22. All patients received a mechanical thrombectomy intervention after identifying a large vessel occlusion (LVO). RESULTS: The Verapamil-treated group (N = 23) included 22 patients with middle cerebral artery (MCA) occlusions and 1 with a basilar posterior cerebral artery (PCA) occlusion. In these patients, investigators administered 10 mg of Verapamil intraarterially following mechanical thrombectomy. Patients exposed to control conditions (N = 19) were matched for age, biological sex, admission NIHSS score, occlusion location, administration of tPA, and achieved TICI score. Intraarterial Verapamil treatment did not significantly increase sICH, hemorrhagic transformation, or death compared to standard of care treatment, demonstrating safety in an acute ischemic stroke patient population. Verapamil treatment was associated with significantly greater changes in mRS score, improved recovery time, and shortened length of hospital stay compared to standard-of-care treatment. CONCLUSIONS: This study suggests that verapamil is a safe and effective neuroprotective drug in ischemic stroke clinical populations that require mechanical thrombectomy for treatment.

Posterior Cerebral Artery–to–Superior Cerebellar Artery Side-to-Side Bypass via Extreme Lateral Supracerebellar Infratentorial Approach: Technical Note

Background and objectiveDifficult-to-treat aneurysms of the distal posterior cerebral artery (PCA) can often be treated by parent artery occlusion. A cerebrovascular bypass can complement PCA occlusion to curb the risk of ischemic complications.An in-situ bypass may be considered when the occipital artery or superficial temporal artery cannot serve as a bypass donor.This paper describes the use of a side-to-side bypass of superior cerebellar artery (SCA) as a donor to the posterior cerebral artery (PCA) via an extreme lateral supracerebellar infratentorial (ELSCIT) approach. This bypass approach can be a useful surgical strategy for PCA revascularization. MethodsA 40-year-old female patient underwent a side-to-side PCA-SCA bypass via the ELSCIT approach for the treatment of a complex and previously coiled PCA aneurysm.Bypass was followed by endovascular aneurysm and parent artery occlusion. ResultsPostoperatively, the patient experienced transient, partial trochlear nerve palsy of the left eye without ischemic lesions on MRI. The clinical condition was stable and angiography showed a patent bypass and complete aneurysm occlusion 12 months after surgery. ConclusionThe ELSCIT-approach offers access to the medial and distal PCA that is well suitable for a side-to-side PCA-SCA bypass. This type of approach and bypass may be of value when revascularization of a P2-P3 portion of the PCA is needed, but a suitable occipital artery (OA) or superficial temporal artery (STA) is not available.

Is Thrombectomy Worth It for Isolated Posterior Cerebral Artery Occlusion? Meta‐Analysis and Trial Sequential Analysis

Background Thrombectomy is well‐established management for acute ischemic stroke involving large vessel occlusion. However. the potential efficacy of thrombectomy for isolated posterior cerebral artery occlusion remains limited. The study aims to evaluate the benefits of thrombectomy for isolated posterior cerebral artery occlusion. Methods We searched PubMed, Cochrane, and Embase for articles published until September 2023. The primary outcome was good functional outcome at 3 months. The secondary outcomes included excellent functional outcome at 3 months and early neurological improvement. The safety outcomes were symptomatic intracerebral hemorrhage, and mortality at 3 months. Results Seven retrospective studies involving 2560 patients with isolated posterior cerebral artery occlusion were included (876 patients receiving thrombectomy). The odds ratio (OR) of good functional outcome at 3 months was 0.93 (95% CI, 0.68–1.28) between 2 groups. The OR of excellent functional outcome (OR 1.23; 95% CI 0.92–1.64) and early neurological improvement (OR 1.82; 95% CI 0.97–3.40) were not different between the 2 groups. Compared with patients with best medical management, those with thrombectomy demonstrated a significantly increased risk of mortality (OR 1.81; 95% CI 1.24–2.65), whereas the risk of symptomatic intracerebral hemorrhage (OR 2.033; 95% CI 0.996–4.148) did not show an increase. Additionally, the results of trial sequential analysis indicated all outcomes were inconclusive. Conclusion Thrombectomy stands as an available procedure for patients with isolated posterior cerebral artery occlusion; however, it shows no notable benefits in reducing symptomatic intracerebral hemorrhage risk or enhancing function and may raise mortality compared with standard medical management. Further randomized controlled trials are necessary to yield more conclusive evidence.

Abstract WP199: Outcomes Following Posterior Cerebral Artery Thrombolysis vs Medical Management in those with Atrial Fibrillation

Background: The benefits of endovascular thrombectomy (EVT) for posterior cerebral artery (PCA) occlusion remain controversial, but intravenous thrombolysis (IVT) has proven benefit across nearly all ischemic stroke types. We isolated a cohort of patients with likely embolic PCA occlusions (those with atrial fibrillation) and compared outcomes associated with IVT and EVT versus medical management (MM). Methods: The National Inpatient Sample (2015-2020) was retrospectively queried for patients with a primary diagnosis of a PCA occlusion (without a concomitant basilar occlusion, BAO) with a secondary diagnosis of atrial fibrillation. Descriptive statistics and propensity score matching for IVT with multivariable logistic regression were used to determine the odds of routine discharge, hospital length of stay, and death between those treated with IVT and EVT versus MM. Results: Of the 107,525 screened patients with a primary diagnosis of a PCA occlusion, 27730(25.7%) had a secondary diagnosis of atrial fibrillation, of whom 3010 underwent IVT. In a 1:1 matched cohort(n=3010 per group), patients treated with IVT had greater odds of discharge to home (adjusted OR 1.87,95% CI 1.22 to 2.87) with no difference in length of hospital stay (adjusted β 0.26, 95% -0.71 to 1.22) or in-hospital death (adjusted OR 0.81, 95% CI 0.27 to 2.47) as compared to patients treated with MM. These trends were preserved in a secondary analysis of unmatched patients in multi variable regression models, and no significant benefit of EVT for these outcomes (OR 1.75, 95%CI 0.62-4.93). Patterns were also similar when patients with a concomitant BAO were included (routine discharge adjusted OR for IVT: 1.57, 95% CI:1.03-2.38). Conclusion: Our findings show a potential real-world benefit for IVT in patients with a PCA occlusion secondary to presumed cardio embolism, but no significant advantage with EVT.

Abstract TP321: Real World Outcomes in Patients With a Posterior Cerebral Artery Occlusion With a Low NIHSS

Introduction: Observational studies have reported improved outcomes following endovascular treatment (EVT) for posterior cerebral artery (PCA) occlusions. Whether there is a benefit of EVT in patients with NIHSS &lt;6 is less well understood. Methods: The National Inpatient Sample (2015-2020) was retrospectively queried for patients with a primary PCA occlusion with a NIHSS &lt;6 and age&gt;17 without a concomitant basilar artery occlusion (BAO). A secondary analysis including patients with a BAO was also performed. Treatment with best medical management (BMM) versus endovascular therapy (EVT) was compared using propensity score matching. Results: In this time frame, 31,175 patients presented with a PCA occlusion as the primary diagnosis and had a NIHSS&lt;6. Of these patients, 8.8% of patients were treated with EVT. 31,050 patients did not have a concomitant BAO. In a propensity matched cohort of primary PCA and patients without a concomitant BAO, 2720 were treated with EVT and 2720 were treated with BMM. Patients treated with EVT had greater odds of routine discharge (adjusted OR 1.34, 95% CI 1.02 to 1.77, p=0.036) with no difference in length of hospital stay (adjusted β -0.35, 95% -0.83 to 0.13, p=0.15) or in-hospital death (adjusted OR 0.77, 95% CI 0.15 to 3.99, p=0.76) as compared to patients treated with BMM. Patterns were also similar when patients with a concomitant BAO were present (routine discharge adjusted OR: 1.67, 95% CI: 1.28-2.19, p&lt;0.001). Conclusions: Our findings suggest potential real-world benefit for EVT in patients with a PCA occlusion with a low NIHSS, irrespective of concomitant BAO.

Thrombectomy or medical management for isolated posterior cerebral artery occlusion: A systematic review and a meta-analysis

Thrombectomy or medical management for isolated posterior cerebral artery occlusion: A systematic review and a meta-analysis

First‐Line Stent Retriever Versus Contact Aspiration or Combined Technique for Endovascular Therapy of Posterior Cerebral Artery Occlusion Stroke: The PLATO Study

Background The optimal reperfusion technique in patients with isolated posterior cerebral artery (PCA) occlusion is uncertain. We compared clinical and technical outcomes with first‐line stent retriever (SR), contact aspiration (CA), or combined techniques in patients with isolated PCA occlusion. Methods This international case–control study was conducted at 30 sites in Europe and North America and included consecutive patients with isolated PCA occlusion presenting within 24 hours of time last seen well from January 2015 to August 2022. The primary outcome was the first‐pass effect (FPE), defined as expanded Treatment in Cerebral Infarction (TICI) 2c/3 on the first pass. Patients treated with SR, CA, or combined technique were compared with multivariable logistic regression. Results There were 326 patients who met inclusion criteria, 56.1% male, median age 75 (interquartile range 65–82) years, and median National Institutes of Health Stroke Scale score 8 (5–12). Occlusion segments were PCA‐P1 (53.1%), P2 (40.5%), and other (6.4%). Intravenous thrombolysis was administered in 39.6%. First‐line technique was SR, CA, and combined technique in 43 (13.2%), 106 (32.5%), and 177 (54.3%) patients, respectively; FPE was achieved in 62.8%, 42.5%, and 39.6%, respectively. FPE was lower in patients treated with first‐line CA or combined technique compared with SR (CA versus SR: adjusted odds ratio 0.45 [0.19–1.06]; P =0.07; combined versus SR: adjusted odds ratio 0.35 [0.016–0.80]; P =0.01). There were lower odds of functional independence (modified Rankin scale score 0–2) in the first‐line CA versus SR alone group (adjusted odds ratio 0.52 [0.28–0.95]; P =0.04). FPE was associated with higher rates of favorable outcomes (modified Rankin scale score 0–2: 58% versus 43.4%; P =0.01; modified Rankin scale score 0–1: 36.6% versus 25.8%; P =0.05). Overall, symptomatic intracranial hemorrhage was present in 5.6% (18/326) and mortality in 10.9% (35/326) without difference between first‐line technique. Conclusion In patients with isolated PCA occlusion, SR was associated with a higher rate of FPE compared with CA or combined techniques with no difference in final successful reperfusion. Functional independence at 90 days was more likely with first‐line SR compared with CA. FPE was associated with better 90‐day clinical outcomes.

Abstract 104: Fetal Posterior Cerebral Artery (PCA) Occlusion from Occluded Cavernous ICA Stent

Introduction Posterior Cerebral Artery (PCA) is a medium vessel occlusion (MVO) which is 5‐10% of all acute ischemic events. Safety and efficacy of mechanical thrombectomy in posterior circulation MVO is unclear compared to medical treatment only (1). There is concern that fragility of distal, smaller vessels may have an increased risk of procedural complications (e.g., arterial dissection and or perforations). More people are getting flow divertors over the years and rate of flow diverter of ICA occlusion is 0.05%‐0.08% (2). Here we present a case of embolic fetal PCA stroke with ICA stent occlusion. Methods We report a case of fetal origin posterior cerebral artery occlusion from ICA with literature search of Pubmed. Results 77 years old female with left cavernous‐ICA stent presented from a rehab facility with complaints of word finding difficulty, confusion, right hemiparesis, right sided neglect, and visual disturbance. In the emergency department (ED), her NIHSS was 28. ED presentation was 2.5 hrs after the last known well (LKW). Of note, patient had a with left cavernous‐ICA stent placement a month before the presentation and was noncompliant to antiplatelets. CT head was negative for intracranial bleeding and ASPECT score was 7. CT angiography head and neck was obtained, showing new complete interval occlusion of the intracranial extradural left ICA with reconstitution of distal branches through anterior communicating artery. Patient received IV thrombolytics, intubated for airway protection and was transferred to a comprehensive stroke center for possible mechanical thrombectomy. Time of the arrival was approximately 6 hours after the LKW, reexamination was hindered by the sedation and intubation but was concerning for possible PCA occlusion rather than ICA occlusion. As the localization of ischemic area was unclear, CT perfusion (CTP) was obtained. CTP showed 27 ml penumbra without core infarct in left PCA territory. As fetal origin of left PCA from ICA is occluded, without ability to access through occluded stent, noted risk of left ICA complications with attempts to recanalize stent for noted PCA hypoperfusion outweigh the benefits. With the exam improvement post thrombolytics administration and small penumbra, mechanical thrombectomy was not indicated. Conclusion In acute large vessel occlusion, utility of CT perfusion (CTP) usually recommended after 6 hours from last well known. In this case, patient presented within the 6 hours but the reexamination post thrombolytics was not localizing to suggest large vessel occlusion (LVO) and the territory at risk was unclear. We described a left intracranial ICA flow diversion occlusion without anterior circulation ischemia and left PCA ischemia demonstrated. In this case, CTP was employed to differentiate the territory at risk for triage to appropriate intervention, to differentiate the LVO vs MVO.

Abstract 012: First‐line Stent Retriever Versus Contact Aspiration or Combined Technique for Posterior Cerebral Artery Occlusion EVT

Introduction The optimal reperfusion technique in patients with isolated posterior cerebral artery (PCA) occlusion is uncertain. Previous studies in LVO and MeVO have demonstrated a correlation between good clinical outcomes and the first pass effect (FPE, eTICI 2c/3 on the first pass) but no differences in FPE rates or clinical outcomes between first‐line endovascular therapy techniques.1‐6 We compared clinical and technical outcomes with first‐line stent‐retriever (SR), contact aspiration (CA), or combined techniques in patients with isolated PCA occlusion. Methods This international cohort study was conducted at 30 sites in Europe and North America and included consecutive patients with isolated PCA occlusion and pre‐stroke modified Rankin Scale (mRS) 0‐3, presenting within 24 hours of time last seen well from January 2015 to August 2022.7 The primary outcome was the first‐pass effect (FPE), defined as eTICI 2c/3 on the first pass. Secondary outcomes included final successful reperfusion (eTICI 2b‐3), 90‐day excellent outcome (mRS 0 to 1), 90‐day functional independence (mRS 0 to 2), sICH, and 90‐day mortality. Patients treated with SR, CA, or combined technique were compared with multivariable logistic regression. This study was registered under NCT05291637. Results There were 326 patients who met inclusion criteria, consisting of 56.1% male, median age 75 (IQR 65‐82) years and median NIHSS 8 (5‐12). Occlusion segments were PCA P1 (53.1%), P2 (40.5%), and other (6.4%). Intravenous thrombolysis was administered in 39.6%. First‐line technique was SR, CA, and combined technique in 43 (13.2%), 106 (32.5%), and 177 (54.3%) patients, respectively; FPE was achieved in 62.8%, 42.5%, and 39.6%, respectively. Compared to SR, FPE was lower in patients treated with first‐line combined technique and similar in patients treated with first‐line CA (combined vs. SR: aOR 0.35 [0.016‐0.80], p=0.01; CA vs. SR: aOR 0.45 [0.19‐1.06], p=0.07). Final successful reperfusion (eTICI 2b‐3) was present in 81% of cases with no differences between treatment groups. Excellent outcome (mRS 0‐1) occurred in 30.7% of patients and functional independence (mRS 0‐2) occurred in 50.0% of patients. There were lower odds of functional independence in the first‐line CA versus SR alone group (aOR 0.52 [0.28‐0.95], p=0.04). FPE was associated with higher rates of favorable outcomes (mRS 0‐2: 58% vs. 43.4%, p=0.01; mRS 0‐1: 36.6% vs. 25.8%, p=0.05). sICH was observed in 5.6% (18/326) and mortality in 10.9% (35/326) with no differences between first‐line technique. Conclusion In patients with isolated PCA occlusion undergoing EVT, first line SR was associated with a higher rate of FPE compared to CA or combined techniques with no difference in final successful reperfusion. Functional independence at 90‐days was more likely with first‐line SR compared to CA in adjusted analyses. FPE was associated with higher rates of 90‐day excellent outcomes and functional independence. No difference in sICH or mortality was noted across the three techniques. As the endovascular field evolves to treat patients with distal vessel occlusion and milder severity of stroke, optimizing the efficacy and safety of the procedure is essential.8

Abstract 089: A Case of Complicated Dissection: Vertebral Artery Sacrifice for Recurrent Stroke Prevention

Introduction Posterior circulation strokes account for 20% of ischemic strokes (1). Optimal management for posterior circulation strokes has been studied less than for anterior circulation strokes (2). Endovascular parent vessel sacrifice is an established technique used to treat vascular pathologies. There is limited evidence for parent artery sacrifice for recurrent strokes and there is no current guideline for standard of care. Methods '‐ Results 51‐year‐old gentleman with history of tobacco use presented with left homonymous hemianopsia, onset 1.5 hours prior to arrival. CT brain showed no bleed and patient received IV tissue‐plasminogen activator (tPA). CT angiography (CTA) demonstrated occlusion of the right posterior cerebral artery (PCA) and dissection of the left vertebral artery (V2 segment) with distal reconstitution. He underwent emergent thrombectomy for right P2 thrombus with complete reperfusion TICI 3 (Thrombolysis in Cerebral Infarction Score). Less than 24 hours later, he developed a right homonymous hemianopsia, and was found to have a new occlusion of the left P1 segment of the left PCA. Emergent thrombectomy was performed with complete reperfusion (TICI3). MRI brain demonstrated bilateral PCA territory infarcts. Within 12 hours of the second thrombectomy, his neurological exam deteriorated, and interval imaging revealed a basilar trunk thrombus, for which he underwent a successful endovascular thrombectomy complete reperfusion (TICI3). His antiplatelet regimen was optimized with Aspirin. Heparin was considered as treatment but was not provided because of the hemorrhagic conversion of his ischemic strokes. Given the persistent recurrence of thromboemboli in the posterior circulation despite being on optimal medical management, and evidence of hemorrhagic conversion, a decision was made to perform endovascular coil embolization of the left vertebral artery V2 segment at the site of dissection. Angiographic imaging demonstrated antegrade blood flow through the dissection as the source of recurrent embolic strokes. Six Stryker Target coils were deployed spanning the region of dissection within the left V2 segment via a right radial access with the guide catheter in the right vertebral artery. Post coil embolization angiographic runs demonstrated complete occlusion of the left vertebral V2 segment at the region of dissection which was confirmed via a left vertebral injection from a left femoral arterial access. There was preservation of ascending cervical collaterals beyond the dissection with patency of the contralateral vertebral artery supplying the intracranial circulation. Following embolization, repeat imaging showed no new infarcts and no new or worsening hemorrhage. He was continued on Aspirin monotherapy. It is notable that though his neurological exam deteriorated during each recurrent thromboembolic event, his neurologic exam at the time of discharge significantly improved with NIHSS of 3. He is currently being followed at our neuroscience institute. Conclusion Cervical arterial dissections pose increased risk for ischemic strokes (3). Vertebral artery dissection accounts for approximately 2%, of which, 10‐25% occur in middle‐aged and younger patients (4). This is a case of a young patient that exemplifies a successful role for vertebral artery sacrifice with coil embolization to prevent recurrent thromboembolic posterior circulation strokes. However controlled studies are needed for safety and efficacy of these interventions.

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

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. 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. 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). 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.