Update on cerebral hyperperfusion syndrome

Ischemia-reperfusion injury in a salvaged penumbra: Longitudinal high-tesla perfusion magnetic resonance imaging in a rat model

INTRODUCTION

Although ischemia-reperfusion (I/R) injury varies between cortical and subcortical regions, its effects on specific regions remain unclear. In this study, we used various magnetic resonance imaging (MRI) techniques to examine the spatiotemporal dynamics of I/R injury within the salvaged ischemic penumbra (IP) and reperfused ischemic core (IC) of a rodent model, with the aim of enhancing therapeutic strategies by elucidating these dynamics.

MATERIALS AND METHODS

A total of 17 Sprague-Dawley rats were subjected to 1 h of transient middle cerebral artery occlusion with a suture model. MRI, including diffusion tensor imaging (DTI), T2-weighted imaging, perfusion-weighted imaging, and T1 mapping, was conducted at multiple time points for up to 5 days during the I/R phases. The spatiotemporal dynamics of blood-brain barrier (BBB) modifications were characterized through changes in T1 within the IP and IC regions and compared with mean diffusivity (MD), T2, and cerebral blood flow.

RESULTS

During the I/R phases, the MD of the IC initially decreased, normalized after recanalization, decreased again at 24 h, and peaked on day 5. By contrast, the IP remained relatively stable. Both the IP and IC exhibited hyperperfusion, with the IP reaching its peak at 24 h, followed by resolution, whereas hyperperfusion was maintained in the IC until day 5. Despite hyperperfusion, the IP maintained an intact BBB, whereas the IC experienced persistent BBB leakage. At 24 h, the IC exhibited an increase in the T2 signal, corresponding to regions exhibiting BBB disruption at 5 days.

CONCLUSIONS

Hyperperfusion and BBB impairment have distinct patterns in the IP and IC. Quantitative T1 mapping may serve as a supplementary tool for the early detection of malignant hyperemia accompanied by BBB leakage, aiding in precise interventions after recanalization. These findings underscore the value of MRI markers in monitoring ischemia-specific regions and customizing therapeutic strategies to improve patient outcomes.

Optimal target mean arterial pressure for patients with sepsis-associated encephalopathy: a retrospective cohort study

BACKGROUND

Sepsis-associated encephalopathy (SAE) patients often experience changes in intracranial pressure and impaired cerebral autoregulation. Mean arterial pressure (MAP) plays a crucial role in cerebral perfusion pressure, but its relationship with mortality in SAE patients remains unclear. This study aims to investigate the relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients, providing clinicians with the optimal MAP target.

METHODS

We retrospectively collected clinical data of patients diagnosed with SAE on the first day of ICU admission from the MIMIC-IV (v2.2) database. Patients were divided into four groups based on MAP quartiles. Kruskal-Wallis H test and Chi-square test were used to compare clinical characteristics among the groups. Restricted cubic spline and segmented Cox regression models, both unadjusted and adjusted for multiple variables, were employed to elucidate the relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients and to identify the optimal MAP. Subgroup analyses were conducted to assess the stability of the results.

RESULTS

A total of 3,816 SAE patients were included. The Q1 group had higher rates of acute kidney injury and vasoactive drug use on the first day of ICU admission compared to other groups (P < 0.01). The Q1 and Q4 groups had longer ICU and hospital stays (P < 0.01). The 28-day and in-hospital mortality rates were highest in the Q1 group and lowest in the Q3 group. Multivariable adjustment restricted cubic spline curves indicated a nonlinear relationship between MAP and mortality risk (P for nonlinearity < 0.05). The MAP ranges associated with HRs below 1 for 28-day and in-hospital mortality were 74.6-90.2 mmHg and 74.6-89.3 mmHg, respectively.The inflection point for mortality risk, determined by the minimum hazard ratio (HR), was identified at a MAP of 81.5 mmHg. The multivariable adjusted segmented Cox regression models showed that for MAP < 81.5 mmHg, an increase in MAP was associated with a decreased risk of 28-day and in-hospital mortality (P < 0.05). In Model 4, each 5 mmHg increase in MAP was associated with a 15% decrease in 28-day mortality risk (HR: 0.85, 95% CI: 0.79-0.91, p < 0.05) and a 14% decrease in in-hospital mortality risk (HR: 0.86, 95% CI: 0.80-0.93, p < 0.05). However, for MAP ≥ 81.5 mmHg, there was no significant association between MAP and mortality risk (P > 0.05). Subgroup analyses based on age, congestive heart failure, use of vasoactive drugs, and acute kidney injury showed consistent results across different subgroups.Subsequent analysis of SAE patients with septic shock also showed results similar to those of the original cohort.However, for comatose SAE patients (GCS ≤ 8), there was a negative correlation between MAP and the risk of 28-day and in-hospital mortality when MAP was < 81.5 mmHg, but a positive correlation when MAP was ≥ 81.5 mmHg in adjusted models 2 and 4.

CONCLUSION

There is a nonlinear relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients. The optimal MAP target for SAE patients in clinical practice appears to be 81.5 mmHg.

The effectiveness and safety of human urinary kallidinogenase in acute ischemic stroke patients undergoing endovascular therapy

The effectiveness and safety of human urinary kallidinogenase (HUK) in acute ischemic stroke (AIS) patients undergoing endovascular therapy (EVT) due to large vessel occlusion (LVO) was unclear. A pooled analysis was performed using individual data from the DEVT and RESCUE BT trials. Patients were divided into two groups based on HUK treatment. The primary outcome was the 90-day modified Rankin Scale (mRS) score. Safety outcomes included 90-day mortality and symptomatic intracranial hemorrhage (sICH) within 48 hours. A total of 1174 patients were included in the study. Of these, 150 (12.8%) patients received HUK. The adjusted common odds ratio (OR) of the mRS score was 1.458 (95% confidence interval [CI] = 1.072-1.983; p = 0.016) favoring HUK. The incidence of sICH (2.0% vs. 8.6%; adjusted OR: 0.198; 95% CI: 0.061-0.638; p = 0.007) and mortality (11.3% vs.18.5%; adjusted OR: 0.496; 95% CI: 0.286-0.862; p = 0.013) was lower in HUK group than non-HUK group. This association was consistent with propensity score-matching and the inverse probability of treatment weighting analysis. In conclusion, HUK was safe and associated with a preferable prognosis in AIS patients due to LVO in the anterior circulation.

Predicting impaired cerebrovascular reactivity and risk of hyperperfusion syndrome in carotid artery stenosis using BeamSAT magnetic resonance imaging

Pencil-beam presaturation (BeamSAT) magnetic resonance imaging (MRI) produces selective magnetic resonance angiography (MRA) images of specific arteries, including the unilateral internal carotid artery (ICA-selective MRA) or vertebral artery (VA-selective MRA). We evaluate the influence of flow pattern, visualized using BeamSAT MRI, on preoperative cerebral hemodynamic status and postoperative hyperperfusion syndrome (HPS). Patients undergoing carotid artery stenting or carotid endarterectomy were categorized into two groups to evaluate flow pattern. Patients with neither crossflow on BeamSAT MRI nor mismatch in middle cerebral artery (MCA) signal intensity between ICA-selective and conventional MRA were classified into Group I, comprising 29 patients. Group II included all other patients comprising 19 patients, who were suspected of experiencing changes in intracranial flow patterns. Cerebral blood flow and cerebrovascular reactivity (CVR) were assessed using single-photon emission computed tomography, and potential HPS symptoms were retrospectively assessed by chart review. Preoperative ipsilateral CVR was significantly lower in Group II than in Group I (18.0% ± 20.0% vs. 48.3% ± 19.5%; P < 0.0001). Group II showed significantly impaired CVR (odds ratio 17.7, 95% confidence interval 1.82-171; P = 0.013) in multivariate analysis. The partial areas under the curve of the BeamSAT logistic model (0.843) were significantly larger than those of the conventional logistic model (0.626) over the range of high sensitivity (0.6-1) (P = 0.04). The incidence of postoperative HPS symptoms was significantly higher in Group II than in Group I (8/19 vs. 1/29; P = 0.001). BeamSAT MRI may be a valuable and non-invasive tool for assessing cerebral hemodynamics and predicting postoperative HPS.

Development and validation of a nomogram for cerebral hemorrhage in patients with carotid stenosis undergoing stenting: a multicenter retrospective study

BACKGROUND

Hyperperfusion-induced cerebral hemorrhage (HICH) is a rare but severe complication in patients with carotid stenosis undergoing stent placement for which predictive models are lacking. Our objective was to develop a nomogram to predict such risk.

METHODS

We included a total of 1226 patients with carotid stenosis who underwent stenting between June 2015 and December 2022 from three medical centers, divided into a development cohort of 883 patients and a validation cohort of 343 patients. The model used LASSO regression for feature optimization and multivariable logistic regression to develop the predictive model. Model accuracy was assessed via the receiver operating characteristic curve, with further evaluation of calibration and clinical utility through calibration curves and decision curve analysis (DCA). The model underwent internal validation using bootstrapping and external validation with the validation cohort.

RESULTS

Older age (OR 1.07, p=0.005), higher degrees of carotid stenosis (OR 1.07, p=0.006), poor collateral circulation (OR 6.26, p<0.001), elevated preoperative triglyceride levels (OR 1.27, p=0.041) and neutrophil counts (OR 1.36, p<0.001) were identified as independent risk factors for HICH during hospitalization. The nomogram constructed based on these predictive factors demonstrated an area under the curve (AUC) of 0.817. The AUCs for internal and external validation were 0.809 and 0.783, respectively. Calibration curves indicated good model fit, and DCA confirmed substantial clinical net benefit in both cohorts.

CONCLUSION

We developed and validated a nomogram to predict HICH in patients with carotid stenosis post-stenting, facilitating early identification and preventive intervention in high-risk individuals.

The effects of anastomoses between anterior and posterior circulation on postoperative prognosis of patients with moyamoya disease

BACKGROUND

Moyamoya disease (MMD) is a chronic ischemic cerebrovascular disease. Collateral circulation in MMD has emerged as a research focus. Our aims were to assess the impact of anastomoses between the anterior and posterior circulations on the prognosis of MMD patients.

METHODS

We reviewed the preoperative digital subtraction angiography images of patients with MMD who underwent revascularization surgery at our hospital between March 2014 and May 2020 and divided the patients into two groups: those with anastomoses (PtoA group) and those without anastomoses (non-PtoA group). The differences in follow-up (more than 6 months) collateral vessel establishment (Matsushima grade) and the modified Rankin Scale (mRS) were compared between the two groups as well as between the patients with different degrees of anastomoses. The early complications following revascularization were also compared between the two groups.

RESULTS

This study included 104 patients with MMD, of which 38 were non-PtoA and 66 were PtoA. There were no significant differences in Matsushima score (P = 0.252) and mRS score (P = 0.066) between the two groups. In addition, Matsushima score (P = 0.243) and mRS score (P = 0.360) did not differ significantly between patients with different degrees of anastomoses. However, the non-PtoA group had a significantly higher rate of cerebral hyperperfusion syndrome (CHS) than the PtoA group (34.2% vs 16.7%, P = 0.041).

CONCLUSION

MMD patients without anastomoses between anterior and posterior circulations preoperatively should be vigilant of the occurrence of CHS in the early stages after revascularization.

Acute Treatment of Ischemic Stroke Caused by Stent Graft Thrombosis After Thoracic Endovascular Aortic Repair

Planning for the acute phase of ischemic stroke in postoperative patients with aortic dissection is difficult from the perspective of concerns about worsening disease related to aortic dissection due to intravenous thrombolytic agents and securing access routes when mechanical thrombectomy is planned. Herein, we report that a 52-year-old man underwent thoracic endovascular aortic repair for acute type B aortic dissection. One year after the procedure, the patient developed a stroke caused by stent graft thrombosis, and computed tomography angiography showed occlusion of the left common carotid artery and left internal carotid artery. Stroke neurologists performed mechanical thrombectomy via a direct approach from the left common carotid artery, and successful recanalization was achieved. Furthermore, ligation of the proximal portion of the left common carotid artery and bypass surgery on the distal portion of the left common carotid artery were performed by cardiovascular surgeons. Although the patient had a postoperative hemorrhagic infarction, he returned to work without a recurrence of stroke after two years of follow-up. A direct carotid artery puncture we performed is an alternative in cases of anatomical difficulty or an unfavorable aortic arch. This case highlights not only the significance of interdisciplinary collaboration between cardiac and neurological specialists but also the impact of training dual-specialty cerebrovascular neurosurgeons on patient outcomes.

Comparing the Impact of Stenting vs. Medical Therapy for Intracranial Arterial Stenosis : A Systematic Review and One-stage and Two-stage Meta-Analysis of Randomized Clinical Trials

PURPOSE

In the treatment of intracranial arterial stenosis (ICAS), controversies remain regarding the optimal treatment strategy. Our study aims to conduct an individual patient-level data meta-analysis of existing RCTs comparing PTAS versus best medical therapy and to identify differences in outcomes such as incidence of ischemic stroke or death.

METHODS

Randomised controlled trials comparing the outcomes of stenting versus best medical therapy for patients who had symptomatic ICAS of >50%. Excluded studies included case reports, case series, reviews, observational studies,  letters or studies evaluating isolated angioplasty techniques without stenting. Data was extracted in accordance with PRISMA guidelines.

RESULTS

7 studies involving 1425 participants were included. There was an increased risk in the incidence of stroke and death within the first 30 days post-procedure for patients treated with PTAS over best medical therapy (RR = 2.22 [1.28-3.86], I² = 0%). Patients who underwent stenting also had a significantly higher risk of intracranial haemorrhage (RR = 12.66 [2.41-66.45], I² = 0%) and death (RR = 5.41 [1.20-24.28], I² = 0%).Under the shared frailty model, stenting when compared to medical therapy has a HR of 1.81 (95% CI:1.25-2.6) of stroke or death across 1 year. Under the parametric Royston-Parmar model, stenting has a significant decrease in the RMST(-0.83 months; 95% CI: -1.30-0.37). Stenting continued to show worse outcomes up to the 3 year mark with a HR of 1.60 (95% CI: 1.11-2.32).

CONCLUSIONS AND RELEVANCE

There is an increased risk of peri- and post-procedural stroke and death over best medical therapy in patients with symptomatic ICAS who undergo PTAS. Further work is required to refine patient selection and mitigate peri-procedural risks.

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

Cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion: A case report

Cerebral hyperperfusion syndrome is a rare but serious complication after revascularization procedures for cerebrovascular diseases. Cerebral hyperperfusion syndrome can develop after treatment of acute ischemic stroke, including intravenous thrombolysis and endovascular treatment of large vessel occlusion. However, to the best of our knowledge, there are no previous reports describing cerebral hyperperfusion syndrome after endovascular treatment of medium vessel occlusion (eg, anterior cerebral artery A2/3 segment). We report a case of cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion. A 70-year-old woman with a history of hypertension and dyslipidemia was transferred by ambulance to our hospital because of immobility and slurred speech. She had mild right lower extremity paralysis, and her symptoms appeared improved compared with onset. She was diagnosed with cerebral infarction in the left frontal lobe. After hospitalization, her neurological symptoms worsened and she was referred to our department. We performed endovascular reperfusion therapy for left anterior cerebral artery A2 occlusion. Recanalization was achieved with residual stenosis. Despite the lack of complications associated with the procedure, the patient had prolonged disorientation, severe hemiplegia, and aphasia. Arterial spin labeling demonstrated hyperperfusion in the left anterior cerebral artery area. The symptoms gradually improved under strict blood pressure control. This report provides evidence that cerebral hyperperfusion syndrome can occur even after endovascular treatment for medium vessel occlusion. Arterial spin labeling was useful in detecting hyperperfusion.

Blood-brain barrier disruption imaging in postoperative cerebral hyperperfusion syndrome using DCE-MRI

Little has been reported about the association between cerebral hyperperfusion syndrome (CHS) and blood-brain barrier (BBB) disruption in human. We aimed to investigate the changes in permeability after bypass surgery in cerebrovascular steno-occlusive diseases using dynamic contrast-enhanced MRI (DCE-MRI) and to demonstrate the association between CHS and BBB disruption. This retrospective study included 36 patients (21 hemispheres in 18 CHS patients and 20 hemispheres in 18 controls) who underwent combined bypass surgery for moyamoya and atherosclerotic steno-occlusive diseases. DCE-MRI and arterial spin labeling perfusion-weighted imaging (ASL-PWI) were obtained at the baseline, postoperative state, and discharge. Perfusion and permeability parameters were calculated at the MCA territory (CBF(territorial), Ktrans(territorial), Vp(territorial)) and focal perianastomotic area (CBF(focal), Ktrans(focal), Vp(focal)) of operated hemispheres. As compared with the baseline, both CBF(territorial) and CBF(focal) increased in the postoperative period and decreased at discharge, corresponding well to symptoms in the CHS group. Vp(focal) was lower in the postoperative period and at discharge, as compared with the baseline. In the control group, no parameters significantly differed among the three points. In conclusion, Vp at the focal perianastomotic area significantly decreased in patients with CHS during the postoperative period. BBB disruption may be implicated in the development of CHS after bypass surgery.

Hemodynamic predictors of early neurological deterioration and clinical outcome after endovascular treatment in large artery occlusion

Objective

Half of the patients with acute large artery occlusion (LAO) have poor outcomes after endovascular treatment (EVT). Early complications such as cerebral edema and symptomatic intracranial hemorrhage (sICH) can lead to early neurological deterioration (END), which correlates with hemodynamics. This study aimed to identify the hemodynamic predictors of END and outcomes in LAO patients after EVT.

Methods

A total of 76 patients with anterior circulation LAO who underwent EVT and received transcranial Doppler (TCD) monitoring were included. Bilateral middle cerebral artery (MCA) blood flow velocities (BFVs) were measured repeatedly within 1 week. Mean flow velocities (MFV) and MFV index (ipsilateral MFV/contralateral MFV) were calculated. The primary outcome was the incidence of END within 72 h. The secondary outcome was the functional outcome at 90 days-a good outcome was defined as a modified Rankin scale (mRS) score of 0-2, while a poor outcome was defined as an mRS score of 3-6.

Results

A total of 13 patients (17.1 %) experienced END within 72 h, including 5 (38.5 %) with cerebral edema, 5 (38.5 %) with sICH, and 3 (23.0 %) with infarct progression. Multivariable logistic regression analysis showed that a higher 24 h MFV index was independently associated with END (aOR 10.5; 95 % CI 2.28-48.30, p = 0.003) and a poor 90-day outcome (aOR 5.10; 95 % CI 1.38-18.78, p = 0.014). The area under the receiver operating characteristic (ROC) curve (AUC) of the 24 h MFV index for predicting END was 0.807 (95 % CI 0.700-0.915, p = 0.0005), the sensitivity was 84.6 %, and the specificity was 66.7 %. At the 1-week TCD follow-up, patients who had poor 90-day outcomes showed significantly higher 1-week iMFV [73.5 (58.4-99.0) vs. 57.7 (45.3-76.3), p = 0.004] and MFV index [1.24 (0.98-1.57) vs.1.0 (0.87-1.15) p = 0.007]. A persistent high MFV index (PHMI) was independently associated with a poor outcome (aOR 7.77, 95 % CI 1.81-33.3, p = 0.006).

Conclusion

TCD monitoring within 24 h after EVT in LAO patients can help predict END, while dynamic follow-up within 1 week is valuable in predicting clinical outcomes.

Migraine - a borderland disease to epilepsy: near it but not of it

BACKGROUND

Migraine and epilepsy are two paroxysmal chronic neurological disorders affecting a high number of individuals and being responsible for a high individual and socioeconomic burden. The link between these disorders has been of interest for decades and innovations concerning diagnosing and treatment enable new insights into their relationship.

FINDINGS

Although appearing to be distinct at first glance, both diseases exhibit a noteworthy comorbidity, shared pathophysiological pathways, and significant overlaps in characteristics like clinical manifestation or prophylactic treatment. This review aims to explore the intricate relationship between these two conditions, shedding light on shared pathophysiological foundations, genetic interdependencies, common and distinct clinical features, clinically overlapping syndromes, and therapeutic similarities. There are several shared pathophysiological mechanisms, like CSD, the likely underlying cause of migraine aura, or neurotransmitters, mainly Glutamate and GABA, which represent important roles in triggering migraine attacks and seizures. The genetic interrelations between the two disorders can be observed by taking a closer look at the group of familial hemiplegic migraines, which are caused by mutations in genes like CACNA1A, ATP1A2, or SCN1A. The intricate relationship is further underlined by the high number of shared clinical features, which can be observed over the entire course of migraine attacks and epileptic seizures. While the variety of the clinical manifestation of an epileptic seizure is naturally higher than that of a migraine attack, a distinction can indeed be difficult in some cases, e.g. in occipital lobe epilepsy. Moreover, triggering factors like sleep deprivation or alcohol consumption play an important role in both diseases. In the period after the seizure or migraine attack, symptoms like speech difficulties, tiredness, and yawning occur. While the actual attack of the disease usually lasts for a limited time, research indicates that individuals suffering from migraine and/or epilepsy are highly affected in their daily life, especially regarding cognitive and social aspects, a burden that is even worsened using antiseizure medication. This medication allows us to reveal further connections, as certain antiepileptics are proven to have beneficial effects on the frequency and severity of migraine and have been used as a preventive drug for both diseases over many years.

CONCLUSION

Migraine and epilepsy show a high number of similarities in their mechanisms and clinical presentation. A deeper understanding of the intricate relationship will positively advance patient-oriented research and clinical work.

Safety of Tailored Transfemoral Carotid Artery Stenting for Symptomatic Elderly Patients: A Single Center Observational Study

OBJECTIVE

Transfemoral carotid artery stenting (TFCAS) in symptomatic elderly patients (≥70 years old) may have a high periprocedural stroke rate. This study was performed to examine whether tailored TFCAS for symptomatic elderly patients is as safe as that for symptomatic nonelderly patients.

METHODS

The subjects were 185 patients with symptomatic internal carotid artery stenosis. Tailored TFCAS including postoperative management was performed based on preoperative examinations of vascular anatomy, plaque imaging, platelet aggregation activity, and cerebral hemodynamic impairment. The major 30-day perioperative stroke rates were examined.

RESULTS

The patients included 51 (27.6%) <70 (group Y) and 134 (72.4%) ≥70 (group E) years old. Group E included significantly more cases with an elongated aortic arch, tortuous target lesion, and longer plaques (all P < 0.05). Among all cases, 181 (97.8%) procedures were performed as per preoperative planning. Group E had more frequent use of a proximal embolic protection device and a closed-cell or dual-layer micromesh stent (all P < 0.05). Seven patients (3.8%) had major stroke. Rates of major ischemic stroke (2.0% vs. 3.0%, P = 1.00) and intracranial hemorrhage (2.0% vs. 0.8%, P = 0.48) were low and did not differ significantly between groups Y and E.

CONCLUSIONS

Symptomatic elderly patients have several unfavorable factors. However, tailored TFCAS for each patient based on preoperative examinations in symptomatic elderly patients may be as safe as that in symptomatic nonelderly patients.

Impaired Dynamic Cerebral Autoregulation as a Predictor for Cerebral Hyperperfusion After Carotid Endarterectomy: A Prospective Observational Study

OBJECTIVE

Cerebral hyperperfusion syndrome (CHS) is a severe complication of carotid endarterectomy (CEA). Because cerebral hyperperfusion (CH) reduces the benefits of CEA, it is important to identify patients at high risk of developing CH. We investigated dynamic cerebral autoregulation (dCA) as a potential predictor of CH after CEA.

METHODS

In a prospective observational study of 90 patients, we defined CH as a ≥100% increase in the transcranial Doppler ultrasound-derived mean flow velocity of the middle cerebral artery compared to baseline, with or without clinical manifestations. We examined dCA in the supine position and during squat-stand maneuvers using the transfer function, analyzing phase, gain, and coherence. Logistic regression analysis and receiver operating characteristic (ROC) curves were used to assess the relationships between variables and outcomes.

RESULTS

Cerebral hyperperfusion (CH) occurred in 18 patients after CEA. The CH group had a lower ipsilateral phase for both body postures than the non-CH group at very low and low frequencies, respectively (both P < 0.01). Postoperative CH was independently associated with the preoperative peak systolic velocity (PSV)sten/PSVdis ratio and the ipsilateral phase in both body postures at a very low frequency. Receiver operating characteristic (ROC) curve analysis showed that the ipsilateral phase had excellent CH predictive accuracy in the supine position and squat-stand maneuvers at a very low frequency (areas under the curve: 0.809 and 0.839, respectively, both P < 0.001; cutoff values: 24.7 and 11.7, respectively).

CONCLUSIONS

The lower ipsilateral phase may serve as a predictor of CH after CEA.

TRUST Technique for Neurointervention: A Promising Alternative for Complex Cases

BACKGROUND

Neurointervention via Transradial Access (TRA) is becoming increasingly popular as experience with this technique increases. However, approximately 8.6-10.3% of complex TRA cases are converted to femoral access due to a lack of support or radial artery spasm. This study aimed to assess the efficacy and safety of the TRUST (trans-radial coaxial catheter technique using a short sheath, Simmons catheter, and Tethys intermediate catheter) technique in interventional procedures via TRA.

METHODS

This was a single-center retrospective analysis of 16 patients admitted to our institute between January 2023 to May 2023 to undergo endovascular interventions with the TRUST technique via the TRA.

RESULTS

The mean age of the study population was 63.8 years, and 62.5% were male (10/16). The most common procedure was intracranial atherosclerotic stenosis (93.75%, 15/16). All procedures were performed successfully, and the most common procedures in our cohort were ballooning (50.0%, 8/16), stenting (18.75%, 3/16), and both procedures combined (31.25%, 1/16). All procedures were performed using the TRA, and the distal and proximal radial arteries were used for access in 31.35% (5/16) and 68.75% (11/16) of the cases, respectively. Technical success was achieved in all patients and most cases demonstrated mTICI ≥2b recanalization (93.75%, 15/16). In this case, no major access-site complications occurred.

CONCLUSION

The TRUST technique is technically safe and feasible and had a high technical success rate and low complication rate in our study. These results demonstrate that the TRUST technique is a promising alternative for patients undergoing complex neurointerventions.

Combination of intraoperative indocyanine green video-angiography FLOW 800 and computed tomography perfusion to assess the risk of cerebral hyperperfusion syndrome in chronic internal carotid artery occlusion patients after revascularization surgery

Background and purpose

To study the changes of corticocerebral hemodynamics in surgical area and postoperative hyperperfusion syndrome in patients with chronic internal carotid artery occlusion (CICAO) by intraoperative indocyanine green videoangiography (ICGA)-FLOW 800 and CT perfusion after superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery.

Methods

From October 2019 to January 2021, 77 patients diagnosed with CICAO underwent direct bypass surgery at Huadong hospital (affiliated with Fudan University) were enrolled. Regions of interest (ROIs) at STA, proximal MCA (PMCA), distal MCA (DMCA), cortical blood capillary (CBC), and cortical vein (CV) were identified after anastomosis by ICGV-FLOW 800 including peak fluorescence intensity (PFI), time to peak (TTP), and area under the time curve (AUC) of fluorescence intensity. All patients underwent perfusion-weighted CT before bypass surgery and those patients with HPS were verified by CTP after bypass.

Results

14 patients with HPS were verified by perfusion-weighted CT after bypass. In HPS group, the AUCTTP of DMCA was significantly larger (T = -3.301, p = 0.004) and TTP of CBC was shorter (T = -2.929, p = 0.005) than patients in non-HPS group. The larger AUCTTP of DMCA (OR = 3.024, 95%CI 1.390-6.578, p = 0.0050) was an independent risk factor by further multivariate logistic regression analysis.

Conclusion

The hemodynamic changes of cortical vessels during STA-MCA bypass surgery could be recorded accurately by ICGV-FLOW 800. Furthermore, the increased AUCTTP of DMCA and shorter TTP of CBC may be potential risk factors of HPS.

Risk Factors for Cerebral Hyperperfusion Syndrome following Carotid Revascularization

BACKGROUND

Cerebral hyperperfusion syndrome (CHS) is a rare but known complication of carotid revascularization that can result in severe postoperative disability and death. CHS is a well-described sequela of carotid endarterectomy (CEA) and, more recently, of transfemoral carotid artery stenting (TFCAS), but its incidence after transcarotid artery revascularization (TCAR) has not been delineated. The aims of this study were to determine the impact of procedure type (CEA versus TCAR versus TFCAS) on the development of CHS as well as to identify perioperative risk factors associated with CHS.

METHODS

The Society for Vascular Surgery Vascular Quality Initiative was queried for patients aged ≥18 years who underwent CEA, TCAR, or TFCAS from 2015-2021. Emergent procedures were excluded. The primary outcome was postoperative development of CHS, defined as the presence of postoperative seizures, intracerebral hemorrhage due to hyperperfusion, or both. Bivariate and multivariable logistic regression analyses were performed to identify factors associated with CHS.

RESULTS

156,003 procedures were included (72.7% CEA, 12.4% TCAR, and 14.9% TFCAS). The incidence of CHS after CEA, TCAR, and TFCAS were 0.15%, 0.18%, and 0.53%, respectively. There was no significant difference in risk of CHS after TFCAS compared to CEA (odds ratio [OR]: 1.21; 95% confidence interval [CI] 0.76-1.92; P = 0.416), nor was there a difference between TCAR and CEA (OR: 0.91; 95% CI 0.57-1.45; P = 0.691). Perioperative risk factors associated with an increased risk of CHS included previous history of transient ischemic attack or stroke (OR: 2.50; 95% CI 1.69-3.68; P < 0.0001), necessity for urgent intervention within 48 hr (OR: 2.03; 95% CI 1.43-2.89; P < 0.0001), treatment of a total occlusion (OR: 3.80; 95% CI 1.16-12.47; P = 0.028), and need for postoperative intravenous blood pressure medication (OR: 5.45; 95% CI 3.97-7.48; P < 0.0001). Age, preoperative hypertension, degree of ipsilateral stenosis less than or equal to 99%, and history of prior carotid procedures were not statistically associated with an increased risk of CHS. Discharging patients on an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker was associated with a decreased risk of developing CHS (OR: 0.47; 95% CI 0.34-0.65; P < 0.0001).

CONCLUSIONS

Compared with CEA, TCAR and TFCAS were not statistically associated with an increased risk of postoperative CHS. Patients with a previous history of transient ischemic attack or stroke, who require urgent intervention or postoperative intravenous blood pressure medication, or who are treated for a total occlusion are at a higher risk of developing CHS. Using an angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker on discharge appears to be protective against CHS and should be considered for the highest risk patients.

Safety and efficacy of drug coated balloon angioplasty for intracranial atherosclerotic disease

BACKGROUND

Drug coated balloon (DCB) angioplasty can provide sustained anti-restenotic efficacy without the limitations of permanent vascular implantation and is presumably ideal for treating intracranial atherosclerotic disease. However, the safety of paclitaxel in the neurovasculature remains a concern.

METHODS

242 patients with angiographically verified symptomatic stenosis >70% in intracranial arteries treated with DCB angioplasty were reviewed divided into two groups: group A, patients with stenotic intracranial arteries; and group B, patients with acute, subacute, or chronic occluded intracranial arteries. The primary endpoint was any stroke or death within 30 days. The secondary endpoint was arterial restenosis of >50% during follow-up.

RESULTS

16 major and 12 minor complications occurred among 245 procedures (6.5% and 4.9%, respectively). Five patients died within 30 days after the procedure (2.1%, 5/242). 12 major and 12 minor complications occurred among 211 procedures in group A (5.7% and 5.7%). In group B, four major complications occurred among 34 procedures (11.8%). Hyperperfusion and perforator stroke accounted for half of all complications (53.6%, 15/28). Restenosis >50% was present in eight lesions during the follow-up period (4.8%, 8/167).

CONCLUSIONS

After treatment with DCB angioplasty, complications were no different from those after standard balloon angioplasty or stenting. This study suggests that DCB angioplasty may be a safe and effective procedure for intracranial arterial stenosis.

Blood Oxygenation Level-Dependent Cerebrovascular Reactivity-Derived Steal Phenomenon May Indicate Tissue Reperfusion Failure After Successful Endovascular Thrombectomy

In acute ischemic stroke due to large-vessel occlusion (LVO), the clinical outcome after endovascular thrombectomy (EVT) is influenced by the extent of autoregulatory hemodynamic impairment, which can be derived from blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR). BOLD-CVR imaging identifies brain areas influenced by hemodynamic steal. We sought to investigate the presence of steal phenomenon and its relationship to DWI lesions and clinical deficit in the acute phase of ischemic stroke following successful vessel recanalization.From the prospective longitudinal IMPreST (Interplay of Microcirculation and Plasticity after ischemic Stroke) cohort study, patients with acute ischemic unilateral LVO stroke of the anterior circulation with successful endovascular thrombectomy (EVT; mTICI scale ≥ 2b) and subsequent BOLD-CVR examination were included for this analysis. We analyzed the spatial correlation between brain areas exhibiting BOLD-CVR-associated steal phenomenon and DWI infarct lesion as well as the relationship between steal phenomenon and NIHSS score at hospital discharge.Included patients (n = 21) exhibited steal phenomenon to different extents, whereas there was only a partial spatial overlap with the DWI lesion (median 19%; IQR, 8-59). The volume of steal phenomenon outside the DWI lesion showed a positive correlation with overall DWI lesion volume and was a significant predictor for the NIHSS score at hospital discharge.Patients with acute ischemic unilateral LVO stroke exhibited hemodynamic steal identified by BOLD-CVR after successful EVT. Steal volume was associated with DWI infarct lesion size and with poor clinical outcome at hospital discharge. BOLD-CVR may further aid in better understanding persisting hemodynamic impairment following reperfusion therapy.

Flow volume mismatch dramatically affects transient neurologic symptoms after direct bypass in Moyamoya disease

Transient neurological events (TNEs) occur after bypass surgery in Moyamoya disease (MMD); however, their pathology remains unknown. To elucidate the pathophysiology of TNEs, we investigated their relationship with perioperative superficial temporal artery (STA) blood flow volume, which was evaluated using ultrasonography. Forty-nine patients with MMD, who underwent direct bypass surgery, were included and stratified into TNE and non-TNE groups, respectively. The STA blood flow volume was evaluated at four time points (preoperatively and 2-4, 7, and 10-14 days postoperatively), and a change in volume during the postoperative period was defined as a flow volume mismatch. We investigated the association between ultrasonographic findings of flow volume mismatch and TNEs and magnetic resonance imaging findings, such as the cortical hyperintensity belt (CHB) sign, using univariate and path analyses. The STA blood flow volume increased immediately postoperatively, gradually decreasing over time, in both groups. The TNE group showed a significant increase in blood flow volume 2-4 days postoperatively (P = 0.042). Flow volume mismatch was significantly larger in the TNE group than in the non-TNE group (P = 0.020). In the path analysis, STA flow volume mismatch showed a positive association with the CHB sign (P = 0.023) and TNEs (P = 0.000). Additionally, the CHB sign partially mediated the association between STA flow volume mismatch and TNEs. These results suggest that significantly high STA blood flow volume changes occurring during the acute postoperative period after direct bypass surgery in MMD are correlated with TNEs and the CHB sign, suggesting involvement in the pathophysiology of TNEs.

Multidelay MR Arterial Spin Labeling Perfusion Map for the Prediction of Cerebral Hyperperfusion After Carotid Endarterectomy

BACKGROUND

Multidelay arterial spin labeling (ASL) generates time-resolved perfusion maps, which may provide sufficient and accurate hemodynamic information in carotid stenosis.

PURPOSE

To use imaging markers derived from multidelay ASL magnetic resonance imaging (MRI) and to determine the optimal strategy for predicting cerebral hyperperfusion after carotid endarterectomy (CEA).

STUDY TYPE

Prospective observational cohort.

SUBJECTS

A total of 79 patients who underwent CEA for carotid stenosis.

FIELD STRENGTH/SEQUENCE

A 3.0 T/pseudo-continuous ASL with three postlabeling delays of 1.0, 1.57, and 2.46 seconds using fast-spin echo readout.

ASSESSMENT

Cerebral perfusion pressure, antegrade, and collateral flow were scored on a four-grade ordinal scale based on preoperative multidelay ASL perfusion maps. Simultaneously, quantitative hemodynamic parameters including cerebral blood flow (CBF), arterial transit time (ATT), relative CBF (rCBF) and relative ATT (rATT; ipsilateral/contralateral values) were calculated. On the CBF ratio map obtained through dividing postoperative by preoperative CBF map, regions of interest were placed covering ipsilateral middle cerebral artery territory. Three neuroradiologists conducted this procedure. Cerebral hyperperfusion was defined as a CBF ratio >2.

STATISTICAL TESTS

Weighted κ values, independent sample t test, chi-square test, Mann-Whitney U-test, multivariable logistic regression analysis, receiver-operating characteristic curve analysis, and Delong test. Significance level was P < 0.05.

RESULTS

Cerebral hyperperfusion was observed in 15 (19%) patients. Higher blood pressure (odd ratio [OR] = 1.08) and carotid near-occlusion (NO; OR = 7.31) were clinical risk factors for postoperative hyperperfusion. Poor ASL perfusion score (OR = 37.33), decreased CBF (OR = 0.74), prolonged ATT (OR = 1.02), lower rCBF (OR = 0.91), and higher rATT (OR = 1.12) were independent imaging predictors of hyperperfusion. ASL perfusion score exhibited the highest specificity (95.3%), while CBF exhibited the highest sensitivity (93.3%) for the prediction of hyperperfusion. When combined with ASL perfusion score, CBF and ATT, the predictive ability was significantly higher than using blood pressure and NO alone (AUC: 0.98 vs. 0.78).

DATA CONCLUSIONS

Multidelay ASL can accurately predict cerebral hyperperfusion after CEA with high sensitivity and specificity.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 5.

Modern endovascular management of chronic total carotid artery occlusion: technical results and procedural challenges

BACKGROUND

The optimal management of chronic total carotid artery occlusion (CTO) is still debated. Endovascular treatment is being increasingly used with heterogeneous technical and clinical results.

METHODS

Patients with CTO treated with modern endovascular approaches during the past several years (January 2018-December 2021) were retrospectively reviewed.

RESULTS

Twenty patients, with a mean age of 63.7 years, were treated during the study period. Indications for treatment were recurrent stroke in 12 (60%), hemodynamic impairment in 4 (20%), and progressive stroke in 4 (20%) patients. In 6 (30%) patients, the occlusion was limited to the cervical portion, in 5 (25%) to the petrous segment, and in 9 (45%) to the cavernous segment. Technical treatment success was achieved in 80% of cases. In patients with successful recanalization, median pretreatment hypoperfusion volumes dropped from 126 mL (25-75 IQR, 33-224 mL) to 0 mL (25-75 IQR, 0-31.5 mL). Symptomatic procedure-related complications were 30% and permanent procedure-related morbidity-mortality was 5%. Early stent occlusion occurred in 5 (25%) cases. Two cases were asymptomatic and were not retreated, 3 cases presented transient symptoms of which two were successfully recanalized. Stent occlusion was not associated with permanent symptoms. In successfully recanalized patients no intraprocedural emboli were observed.

CONCLUSIONS

In the modern endovascular era, revascularization of CTO is a feasible procedure in most cases, and it may be offered in selected patients. However, the high re-occlusion rate is still a limitation of the technique, underlining the need for more research on the technical procedural and periprocedural management.

Temperature measurement of intracranial cerebrospinal fluid using diffusion tensor imaging after revascularization surgery in Moyamoya disease

OBJECTIVE

Brain temperature monitoring using a catheter thermometer has been reported to be a useful technique to predict prognosis in neurosurgery. To investigate the possibility of measuring intracranial cerebrospinal fluid temperature for postoperative monitoring in patients with Moyamoya disease (MMD) after bypass surgery.

MATERIALS AND METHODS

This study evaluated fifteen patients with MMD who were indicated for bypass surgery. Diffusion tensor imaging for brain thermometry were performed on a 1.5-T MR scanner. Intracranial cerebrospinal fluid temperature with/without considering the fractional anisotropy component, body temperature, C-reactive protein levels, white blood cell count, and cerebral blood flow measured by ¹²³I-IMP single-photon emission computed tomography were obtained before surgery and 1-3 days after surgery. Pixel values considered to be signal outliers in fractional anisotropy processing were defined as cerebrospinal fluid noise index and calculated. Wilcoxon signed-rank test and effect size were performed to compare the changes before and after revascularization. Spearman's rho correlation coefficient was used to analyze the correlations between each parameter. Statistical significance was defined as p < 0.05.

RESULTS

All parameter values became significantly higher compared to those measured before revascularization (p < 0.01 in all cases). The effect sizes were largest for the cerebrospinal fluid temperature with fractional anisotropy processing and for C-reactive protein levels (Rank-biserial correlation = 1.0). The cerebrospinal fluid noise index and cerebrospinal fluid temperatures with fractional anisotropy processing (r = 0.84, p < 0.0001) or without fractional anisotropy processing (r = 0.95, p < 0.0001) showed highly significant positive correlations. Although no significant correlation was observed, cerebrospinal fluid temperatures with fractional anisotropy had small or moderately positive correlations with cerebral blood flow, body temperature, C-reactive protein levels, and white blood cell count (r = 0.37, 0.42, 0.41, and 0.44, respectively; p > 0.05).

CONCLUSION

Our findings suggest the possibility of postoperative monitoring for MMD patients by measuring intracranial cerebrospinal fluid temperature with fractional anisotropy processing. Intracranial cerebrospinal fluid temperature might be considered as combined response since cerebrospinal fluid, body temperature, and inflammation are equally correlated.

Non responsible vascular area hyperperfusion syndrome after mechanical thrombectomy for vertebral artery occlusion: A case report

Introduction

There are currently no published reports of hyperperfusion syndrome in the non responsible vascular area after mechanical thrombectomy for acute cerebral infarction with large vessel occlusion. Here, we report a case of hyperperfusion syndrome in the blood supply area of the right middle cerebral artery after mechanical thrombectomy for acute cerebral infarction after vertebral artery occlusion.

Patient concerns

A 21-year-old woman developed left vertebral artery occlusion, for which she received mechanical thrombectomy and successful recanalization of her occluded cerebral vessel. Subsequently, the patient became extremely agitated, with high blood pressure and headache.

Diagnosis

Two hours after the operation, bedside transcranial Doppler ultrasound examination found that the cerebral blood flow velocity of the M1 segment of the right middle cerebral artery was more than twice that of the left middle cerebral artery. Combined with the symptoms, signs and examination results of the patient, hyperperfusion syndrome in the blood supply area of the right middle cerebral artery was considered.

Interventions

The patient was administered sedation, and her pressure and ventricular rate were strictly controlled. She was no longer agitated, and her headache was significantly relieved at 36 hours after the operation.

Outcomes

On the 5th day after the operation, the blood flow velocity of her right middle cerebral artery decreased to normal level, and the patient recovered well.

Conclusion

In this case, after mechanical thrombectomy, such patients with acute posterior circulation cerebral infarction can experience hyperperfusion syndrome in the non responsible vascular area of the anterior circulation. Bedside transcranial Doppler cerebral blood flow examination can identify the hyperperfusion state of cerebral vessels in a timely manner and effectively guide treatment.

Cerebral hyperperfusion syndrome after stenting for revascularization of intracranial internal carotid artery dissection

Cerebral hyperperfusion syndrome (CHS) is one of the complications of cerebral revascularization. The main pathophysiology of CHS was considered to be cerebral autoregulation impairment due to long-standing cerebral hypoperfusion. Herein, we describe the case of a 40-year-old man with symptomatic intracranial arterial dissection (IAD) related to internal carotid artery stenosis. The patient underwent intracranial stenting 11 days after onset due to severe cerebral hypoperfusion presenting with neurological symptoms, and CHS presenting with intracerebral hemorrhage, post-operatively. The present case indicated not only the potential risk of CHS after intracranial stenting in IAD-related stenosis but also that cerebral hypoperfusion-even in a short period-might lead to CHS.

Staged Carotid Artery Stenting for Prevention of Hyperperfusion-Induced Intracerebral Hemorrhage in Patients with Very High-Grade Carotid Stenosis and Poor Collateral Compensation

OBJECTIVE

Hyperperfusion-induced intracerebral hemorrhage (HICH) is a relatively rare but potentially devastating event after carotid artery stenting (CAS). Staged angioplasty (SAP), a 2-stage form of CAS, has been shown to be effective for preventing cerebral hyperperfusion syndrome. The aim of our retrospective single-center study was to investigate the safety and efficacy of SAP to prevent HICH in patients with very severe carotid stenosis (90%-99%) and poor collateral compensation.

METHODS

Between November 2011 and August 2018, 153 patients presented with severe symptomatic carotid artery stenosis ≥90%; 96 were scheduled to undergo regular CAS, and 57 were scheduled for SAP. High risk of HICH were identified based on severe stenosis degree (90%-99%) and poor collateral compensation, which were determined using digital subtraction angiography and qualitative computed tomography perfusion. Patients' clinical data, procedural details, and occurrence of HICH were compared between regular CAS and SAP groups.

RESULTS

Of 57 patients scheduled for SAP, 3 were switched to regular CAS because of intraoperative dissection. The median interval between stages I and II was 8 days (IQR: 4-20 days). One patient who was switched to regular CAS experienced HICH. HICH occurred in 1 patient (1.75%; 1/57) in the SAP group and 12 patients (12.5%; 12/96) in the regular CAS group (odds ratio 0.117, 95% confidence interval 0.014-0.990, P = 0.049). Multivariate analysis showed that SAP was negatively related to cerebral hyperperfusion syndrome (odds ratio 0.117; 95% confidence interval 0.014-0.990; P = 0.049).

CONCLUSIONS

SAP is an effective treatment for avoiding HICH in patients with carotid preocclusive stenosis (90%-99%) and poor collateral compensation.

Comparative effect of stenting plus medical therapy vs medical therapy alone on the risk of stroke and death in patients with symptomatic intracranial stenosis: a systematic review and meta-analysis

BACKGROUND

Recently, several randomized controlled trials (RCTs) of stenting plus medical therapy versus medical therapy alone have been successfully conducted for the treatment of patients with symptomatic intracranial stenosis. This study aimed to evaluate differences between these two therapies in the risk of stroke and death.

METHODS

MEDLINE, EMBASE, the Cochrane Library, and ClinicalTrials.gov were systematically searched to identify relevant studies published before August 24, 2022. Review Manager 5.3 software was used to assess the data. The risk ratio (RR) was analysed and calculated with a random effect model or a fixed effects model.

RESULTS

We pooled 921 participants from three RCTs. Compared to the medical therapy alone group, the stenting plus medical therapy group had a higher risk of 30-day death or stroke (RR = 2.69 [1.64-4.41], P < 0.0001, I² = 0%). When the follow-up period exceeded 1 year (≥ 1 year), there was no significant difference in the risk of stroke or death between these two groups. The subgroup analysis showed that if the time from stroke onset to implantation was extended, additional stenting would have no effect on the risk of stroke or death, whether within 30 days or within 1 year (P = 0.16 and 0.78).

CONCLUSION

Medical therapy alone has a lower risk of stroke and death in the short term than stenting plus medical therapy, while no difference exists in the long term. More studies are still needed to further explore the precision strategy of stent implantation for symptomatic intracranial stenosis patients.

Predictors of hyperperfusion syndrome after stent implantation in symptomatic intracranial atherosclerotic stenosis

Background

Hyperperfusion syndrome (HPS) is a serious complication after stent implantation in symptomatic intracranial atherosclerotic stenosis (ICAS). This study aims to explore the predictive value of preprocedural computed tomography perfusion (CTP) for HPS after intracranial stenting.

Methods

In this retrospective case-control study we collected data from consecutive patients from June 2012 to September 2019 who underwent stent implantation due to severe symptomatic ICAS. Patients who underwent CTP before the procedure were enrolled. CTP was postprocessed using the automated RAPID software to assess the preoperative cerebral perfusion. According to the presence or absence of HPS, the patients were classified into two groups: the HPS group and the non-HPS group. The baseline data, lesion characteristics, and preoperative CTP parameters between the two groups were compared. The receiver operating characteristic (ROC) curve analysis was performed to determine the optimal predictor of HPS.

Results

Among the 170 eligible patients, 6 patients (3.53%) had HPS, including 3 who presented with intracranial hemorrhages (ICHs), 1 who had dysphoria, 1 who had delirium, and 1 who had a headache. There were no significant differences in baseline and lesion characteristics between the HPS and non-HPS groups. Compared with the non-HPS group, the HPS group had a significantly higher volume of time-to-maximum (T_max) >4 s (429.5 vs. 93 mL; P=0.006) and T_max >6 s (200 vs. 0 mL; P=0.003). The optimal volume threshold for maximizing sensitivity in predicting HPS was 65.5 mL with T_max >4 s [area under the curve (AUC), 0.832; 95% confidence interval (CI): 0.650 to 1.000; P=0.006].

Conclusions

T_max >4 s volume may be a predictor of HPS after stent implantation in symptomatic ICAS. Further prospective studies should be conducted to confirm our conclusion.

Pictorial Review on Imaging Findings in Cerebral CTP in Patients with Acute Stroke and Its Mimics: A Primer for General Radiologists

The imaging evaluation of computed tomography (CT), CT angiography (CTA), and CT perfusion (CTP) is of crucial importance in the setting of each emergency department for suspected cerebrovascular impairment. A fast and clear assignment of characteristic imaging findings of acute stroke and its differential diagnoses is essential for every radiologist. Different entities can mimic clinical signs of an acute stroke, thus the knowledge and fast identification of stroke mimics is important. A fast and clear assignment is necessary for a correct diagnosis and a rapid initiation of appropriate therapy. This pictorial review describes the most common imaging findings in CTP with clinical signs for acute stroke or other acute neurological disorders. The knowledge of these pictograms is therefore essential and should also be addressed in training and further education of radiologists.

Case report: Medulla oblongata and cervical cord reperfusion injury after intracranial vertebral artery angioplasty and stenting

Background

White cord syndrome is an uncommon complication characterized by delayed neurologic deterioration with no other identified cause after spinal decompression surgery. Its etiology is attributed to spinal cord reperfusion injury. Here, we present the first case of an extended version of white cord syndrome, with concomitant involvement of the medulla oblongata and cervical cord reperfusion injury after intracranial vertebral artery angioplasty and stenting.

Case presentation

A 56-year-old male suffered an ischemic stroke in the right anteromedial medulla oblongata. Angiography revealed bilateral vertebral artery stenosis in the intracranial segment. We performed elective left vertebral artery angioplasty and stenting. An intraoperative flow arrest in the left VA occurred and was stopped after the withdrawal of the catheter. Several hours after the operation, the patient developed occipital headache, back neck pain, dysarthria, and worsening left-sided hemiplegia. Magnetic resonance imaging revealed hyperintensity and swelling in the medulla oblongata and cervical cord, in addition to small medullary infarction. A digital subtraction angiography revealed intact vertebrobasilar arteries and patency of the left vertebral artery, left posterior inferior cerebellar artery, and implanted stent. We considered that the reperfusion injury had caused the complication. After treatment, the patient's symptoms and neurologic deficits greatly improved. He achieved a favorable outcome at the 1-year follow-up, with normal intensity restored in the medulla oblongata and cervical cord on magnetic resonance imaging.

Conclusion

Concomitant reperfusion injury in the medulla oblongata and cervical cord secondary to vertebral artery angioplasty and stenting is extremely rare. However, this potentially devastating complication requires early recognition and prompt treatment. Maintaining the antegrade flow during vertebral artery endovascular treatment is a precaution against reperfusion injury.

Laser speckle contrast imaging for blood flow monitoring in predicting outcomes after cerebral ischemia-reperfusion injury in mice

BACKGROUND

In the treatment of ischemic cerebral stroke (ICS), most conventional treatments, including carotid endarterectomy and carotid artery stenting, may cause cerebral ischemia-reperfusion injury (CIRI). For treated ICS patients, changes in cerebral blood flow are directly related to brain function. At present, computed tomography perfusion, dynamic susceptibility contrast-enhanced perfusion weighted imaging and magnetic resonance arterial spin labeling perfusion imaging are used to monitor cerebral blood flow, but they still have some limitations. Our study aimed to monitor the changes in cerebral cortical blood flow by laser speckle contrast imaging (LSCI) in CIRI model mice and to propose a new method for predicting outcomes after CIRI. C57BL/6 N mice were used to establish a mouse CIRI model based on a modified thread-occlusion method and divided into a good outcome group and a poor outcome group according to survival within 7 days. The cerebral cortical blood flow of the area supplied by the left middle cerebral artery was monitored by LSCI at baseline (before modeling), 1 h after ischemia, immediately after reperfusion and 24 h after reperfusion. Then, the brains of the mice were removed immediately and stained with hematoxylin and eosin to observe the pathological changes in brain neurons.

RESULTS

The cerebral cortical blood flow in the poor outcome group was obviously reduced compared with that less in the good outcome group at 24 h after reperfusion (180.8 ± 20.9 vs. 113.9 ± 6.4, p = 0.001), and at 24 h after reperfusion, the cerebral cortical blood flow was negatively correlated with the severity of brain tissue injury (p = - 0.710, p = 0.010).

CONCLUSIONS

LSCI can monitor the changes in cerebral cortical blood flow during CIRI in mice and could be used as a feasible method for predicting outcomes after CIRI in mice.

Acidosis in arterial blood gas testing is associated with clinical outcomes after endovascular thrombectomy

Background

Despite recanalization, some of the patients undergoing endovascular thrombectomy (EVT) still suffer from unfavorable outcomes. Patients with poor prognoses are often accompanied by acidosis in arterial blood gas (ABG) testing. We, therefore, explored the ABG testing results in the early phase of recanalization and analyzed their association with poor prognosis.

Patients and methods

We identified all patients with ischemic stroke and successful endovascular recanalization for anterior circulation vessel occlusion between June 2019 and May 2022. ABG testing was performed in all patients within 0-30 min and 8 h after endovascular therapy. We investigated the relationship between the ABG testing results with symptomatic intracerebral hemorrhage (sICH), hemicraniectomy, and mortality.

Results

A total of 123 patients with stroke after endovascular thrombectomy were analyzed. Of those, eight (6.5%) patients had postinterventional sICH. Acidosis was associated with sICH. Decreased HCO 3 - levels and HCO 3 - levels at 8 h after EVT were independently related to a higher risk of sICH. Twelve (9.8%) patients underwent hemicraniectomy for postischemic malignant edema and similar results were found for hemicraniectomy. Increased lactate at 8 h after EVT and decreased HCO 3 - levels at 8 h after EVT were closely associated with hemicraniectomy. Twenty-two (17.9%) patients died within 3 months. Decreased HCO 3 - levels were independently related to mortality, as were decreased pH levels at 8 h after EVT and decreased HCO 3 - levels at 8 h after EVT.

Conclusion

Acidosis is associated with clinical outcomes after endovascular therapy and may help to select patients with poor prognosis in the acute early phase of recanalization.

What You Always Wanted to Know about Endovascular Therapy in Acute Ischemic Stroke but Never Dared to Ask: A Comprehensive Review

In 2015, mechanical thrombectomy (MT) in combination with intravenous thrombolysis was demonstrated to be superior to best medical treatment alone in patients with anterior circulation stroke. This finding resulted in an unprecedented boost in endovascular stroke therapy, and MT became widely available. MT was initially approved for patients presenting with large vessel occlusion in the anterior circulation (intracranial internal carotid artery or proximal middle cerebral artery) within a 6-hour time window. Eventually, it was shown to be beneficial in a broader group of patients, including those without known symptom-onset, wake-up stroke, or patients with posterior circulation stroke. Technical developments and the implementation of novel thrombectomy devices further facilitated endovascular recanalization for acute ischemic stroke. However, some aspects remain controversial. Is MT suitable for medium or very distal vessel occlusions? Should emergency stenting be performed for symptomatic stenosis or recurrent occlusion? How should patients with large vessel occlusion without disabling symptoms be treated? Do certain patients benefit from MT without intravenous thrombolysis? In the era of personalized decision-making, some of these questions require an individualized approach based on comorbidities, imaging criteria, and the severity or duration of symptoms. Despite its successful development in the past decade, endovascular stroke therapy will remain a challenging and fascinating field in the years to come. This review aims to provide an overview of patient selection, and the indications for and execution of MT in patients with acute ischemic stroke.

Intraoperative Transcranial Doppler Monitoring Predicts the Risk of Cerebral Hyperperfusion Syndrome After Carotid Endarterectomy

OBJECTIVE

Cerebral hyperperfusion syndrome (CHS) is a rare but serious complication following carotid endarterectomy (CEA). The aim of this study was to identify intraoperative transcranial Doppler (TCD) hemodynamic predictors of CHS after CEA.

METHODS

Between January 2013 and December 2018, intraoperative TCD monitoring was performed for 969 patients who underwent CEA. The percentage increase in the mean velocity of the middle cerebral artery (MCAV%) at 3 postdeclamping time points (immediately after declamping, 5 minutes after declamping, and after suturing the skin) over baseline was compared between CHS and non-CHS patients.

RESULTS

CHS was diagnosed in 31 patients (3.2%), including 11 with intracranial hemorrhage. The MCAV% values at the 3 postdeclamping time points over baseline were 177% (81%-275%), 90% (41%-175%), and 107% (55%-191%) in the CHS group, significantly higher than those in the non-CHS group (40% [14%-75%], 15% [1%-36%], and 18% [3%-41%], respectively, all P < 0.001). Receiver operating characteristic curve analysis showed that the 3 intraoperative MCAV% parameters all had excellent accuracy in identifying CHS (areas under the curve: 0.854, 0.839, and 0.858, respectively, all P < 0.001). The predictive value of the model consisting only of preoperative parameters was significantly increased by adding the intraoperative TCD hemodynamic parameters (area under the curve: 0.747 vs. 0.858, P = 0.006). Multivariate analyses identified the intraoperative MCAV% immediately after declamping (odds ratio: 9.840, 95% confidence interval: 2.638-36.696, P < 0.001) as an independent predictor of CHS.

CONCLUSIONS

Our results indicate that intraoperative TCD monitoring helps predict CHS after CEA at an early stage.

Flat Detector CT with Cerebral Pooled Blood Volume Perfusion in the Angiography Suite: From Diagnostics to Treatment Monitoring

C-arm flat-panel detector computed tomographic (CT) imaging in the angiography suite increasingly plays an important part during interventional neuroradiological procedures. In addition to conventional angiographic imaging of blood vessels, flat detector CT (FD CT) imaging allows simultaneous 3D visualization of parenchymal and vascular structures of the brain. Next to imaging of anatomical structures, it is also possible to perform FD CT perfusion imaging of the brain by means of cerebral blood volume (CBV) or pooled blood volume (PBV) mapping during steady state contrast administration. This enables more adequate decision making during interventional neuroradiological procedures, based on real-time insights into brain perfusion on the spot, obviating time consuming and often difficult transportation of the (anesthetized) patient to conventional cross-sectional imaging modalities. In this paper we review the literature about the nature of FD CT PBV mapping in patients and demonstrate its current use for diagnosis and treatment monitoring in interventional neuroradiology.

Perioperative functional imaging after extracranial carotid endarterectomy for the detection of cerebral hyperperfusion syndrome

INTRODUCTION

SyngoDynaPBVNeuro® is a tool to perform cerebral blood volume (CBV) measurements intraoperatively by functional imaging producing CT-like images. Aim of this prospective study was to analyze the clinical relevance and benefit of CBV measurement with regard to neurological complications like cerebral hyperfusion syndrome (CHS).

METHODS

Forty-five patients undergoing endarterectomy (CEA) of the internal carotid artery were included; functional imaging with CBV measurement was performed before and after CEA. To evaluate and analyze CBV, six regions of interest (ROI) were identified for all patients with an additional ROI in patients with symptomatic ICA stenosis and previous stroke. The primary endpoint of the study was a perioperative change in CBV measurements. Secondary outcomes were incidence of stroke, TIA, CHS, and perioperative morbidity and mortality.

RESULTS

Thirty-day stroke incidence and thirty-day mortality were 0%. Thirty-day morbidity was 6.7%. Two patients from the asymptomatic group suffered from transient neurological symptoms without signs of intracerebral infarction in CT or MR scan, meeting diagnostic criteria for CHS. In 83.3% of ROIs in these patients, an increase of blood volume was detected. Overall, 26.7% patients suffered from unilateral headache as expression of potential CHS. A total of 69.4% of ROIs in patients with postoperative unilateral headache showed an increase when comparing pre- and postoperative CBV measurements.

CONCLUSION

The results show that increased CBV measured by functional imaging is a possible surrogate marker of neurological complications like CHS after CEA. By using intraoperative CBV measurement, the risk of CHS can be estimated early and appropriate therapeutic measures can be applied.

Determinants of Symptomatic Intracranial Hemorrhage After Endovascular Stroke Treatment: A Retrospective Cohort Study

Symptomatic intracranial hemorrhage (sICH) is a serious complication after endovascular treatment for ischemic stroke. We aimed to identify determinants of its occurrence and location.

Carotid Endarterectomy for the Treatment of Carotid Near-Occlusion With Recurrent Symptoms

Objective

Report our preliminary experience of carotid endarterectomy (CEA) for the treatment of carotid near-occlusion (CNO) with recurrent symptoms.

Materials and Methods

Retrospectively analyze the demographics, treatment detail, and outcomes data of 122 patients with CNO from 2014 to 2020. According to whether distal full collapse exists, patients were classified into the full collapse group and the non-full collapse group. The incidence of death, myocardial infarction, stroke, and other variables were compared between the two groups.

Results

A total of 122 patients with CNO and recurrent symptoms were enrolled. The demographics were comparable between the two groups. Thirty-day incidence of primary endpoints was 1.85% in the full collapse group and 4.41% in the non-full collapse group. Twelve-month incidence of primary endpoints was 7.41% in the full collapse group and 4.41% in the non-full collapse group. One re-stenosis occurred in the non-full collapse group 8 months after CEA.

Conclusion

For patients with CNO with recurrent symptoms, CEA is not worse than the results described in historical control groups, despite whether distal full collapse exists. The shunt is important to avoid intraoperative hypoperfusion and postoperative hyperperfusion. The long-term results should be further evaluated.

Carotid Artery Stenting in Patients with Symptomatic and Asymptomatic Stenosis: In-Hospital Clinical Outcomes at a Single Neurovascular Center

Background: Carotid artery stenting (CAS) is a minimally invasive and proven percutaneous procedure that is widely used to treat patients with symptomatic and asymptomatic carotid artery stenosis. The purpose of this study was to characterize the in-hospital outcomes of symptomatic and asymptomatic patients undergoing CAS at a single neurovascular center. Methods: The study was conducted as a retrospective analysis of 1158 patients (asymptomatic, n = 636; symptomatic, n = 522; male, n = 816; median age, 71 years; NASCET method, 70–99% stenosis, n = 830) who underwent CAS between May 2009 and December 2020. In-hospital neurological outcomes, adverse reactions to iodinated contrast media, acute myocardial infarction, intraprocedural complications, and access-site issues were evaluated. The primary endpoints were disabling stroke (including disabling cerebral hyperperfusion syndrome [CHS]) and all in-hospital deaths. Results: A carotid stent could not be deployed in one patient due to calcified plaques (technical failure rate of 0.09%). Four patients (0.3%) experienced in-hospital, stroke-associated death, while five patients (0.4%) died from non-stroke-related causes. All stroke-associated deaths occurred in the symptomatic group and were due to CHS. The disabling stroke rate was 0.9% overall (n = 10; 0.5% versus 1.3% in asymptomatic versus symptomatic patients, respectively). Nineteen patients (1.6%) reached the in-hospital primary endpoint. More patients in the symptomatic group achieved this endpoint than in the asymptomatic group (2.5% versus 0.9%, respectively; p = 0.060). Conclusions: An evaluation was conducted on the in-hospital outcomes of 1158 patients at a single center who underwent CAS and was performed by trained physicians who were supervised by a senior neurovascular interventionist with over 20 years of experience, confirming the excellent safety profile of this procedure with a low rate of complications.

Stepwise improvement in limb shaking achieved by staged angioplasty for severe carotid stenosis

Cerebral hyperperfusion syndrome is a rare but severe complication of carotid artery stenting or carotid endarterectomy. Staged angioplasty is reportedly an effective strategy to avoid cerebral hyperperfusion syndrome. We encountered a case of internal carotid artery stenosis with a rare clinical presentation of limb shaking that was successfully improved by staged angioplasty. To our knowledge, there are no reported cases of limb shaking treated with staged angioplasty.A 76-year-old woman presented with continuous chorea in her left lower limb and shoulder. Medical examination revealed a tiny cerebral infarction in the right corona radiata and severe right internal carotid artery stenosis. Angiography showed near occlusion of the right internal carotid artery. Staged angioplasty was performed to avoid the risk of cerebral hyperperfusion syndrome. The first angioplasty resulted in an expanded diameter of 2.5 mm and was followed by definitive carotid artery stenting using a closed-cell stent 3.5 weeks later. Limb shaking improved in a stepwise manner along with an improvement in internal carotid artery stenosis and distal flow state with no signs of cerebral hyperperfusion syndrome. Patients with internal carotid artery stenosis or occlusion presenting with limb shaking have been suggested to have impaired cerebrovascular reactivity, which is also thought to be a risk factor for cerebral hyperperfusion syndrome. The stepwise improvement in limb shaking observed in this case supports the idea that the pathophysiology of limb shaking is related to cerebral haemodynamic impairment. Measures to prevent cerebral hyperperfusion syndrome, including staged angioplasty, should be actively considered in patients with limb shaking because the symptoms themselves suggest severe hypoperfusion.

TCD hemodynamics findings in the subacute phase of anterior circulation stroke patients treated with mechanical thrombectomy

Despite mechanical thrombectomy, the prognosis for many patients with anterior circulation ischemic stroke (ACIS) remains poor. This retrospective study reports consecutive mechanical thrombectomy procedures for ACIS at our hospital over 4 years. Hemodynamics were explored using transcranial Doppler ultrasound. The functional outcome was assessed using the modified Rankin scale. A total of 121 eligible cases were included: 61 (50.4%) exhibited good outcomes (modified Rankin scale score ≤2) by day 90. The logistic regression analysis showed that ipsilateral middle cerebral artery (iMCA) systolic blood flow (SBF) (OR = 0.983, 95% CI: 0.969–0.997, P = 0.014), preoperative National Institutes of Health Stroke Scale (NIHSS)score (OR = 1.160, 95% CI: 1.067–1.261, P < 0.001), intracranial hemorrhage after therapy (OR = 19.514, 95% CI: 4.364–87.265, P < 0.001), and Alberta Stroke Program Early Computed Tomography Score (OR = 0.639, 95% CI: 0.416–0.981, P = 0.040) were independently associated with prognosis. The iMCA SBF and preoperative NIHSS score were significantly predictive of a good outcome in the receiver operating characteristic analysis. In conclusion, elevated iMCA SBF might be a prognostic indicator of a good 90-day outcome following endovascular treatment in ACIS patients treated with mechanical thrombectomy, but large prospective studies are mandatory to validate the findings of our study.

Characteristics and outcomes of elderly patients undergoing carotid stenting: Experience of a high-volume interventional cardiology center

BACKGROUND

Carotid artery stenting (CAS) is an attractive option in order to treat carotid artery stenosis. However, its safety in elderly patients is questioned. Aim of this single-center retrospective study was to assess data of elderly patients undergoing CAS, and to compare them with those of the younger (< 75 years).

METHODS

We collected data of 580 consecutive patients undergoing CAS between December 2007 and June 2020 and compared clinical and procedural characteristics as well as in-hospital major adverse events (MACCE) and long-term mortality between patients < 75 years and patients ≥ 75 years old.

RESULTS

There were 272 patients (46.9%) with age ≥ 75 years and 308 patients (53.1%) with age < 75 years. The median follow-up was 48 months (range 2-144). There was no significant difference about in-hospital MACCE between the two groups (4.7% in the older vs. 3.5% in the younger group, p = 0.9), but a higher rate of cerebral hemorrhage occurred in the older group (1.8% vs. = 0.3%, p = 0.07), even if not significant. Long-term mortality was significantly higher in the older group (27.9 vs. 20.1%, p = 0.027). Multivariate predictors of 12-months mortality were neurologic symptoms within 6 months (OR: 4.83; 95% CI: 2.04-11.42; p ≤ 0.001), smoking status (OR: 2.84; 95% CI: 1.17-6.86; p = 0.02) and age ≥ 75 years (OR: 2.78; 95% CI: 1.14-6.76; p = 0.024).

CONCLUSIONS

In elderly patients, CAS can be carried out efficaciously with acceptable procedural risks, if performed by expert operators and after a correct selection by a multidisciplinary team.

Clinical Outcomes of Endovascular Treatment for Carotid Artery Dissection Without Intracranial Large Vessel Occlusion in Patients With Cerebral Ischemia Presentation

Background and Purpose

We describe the clinical characteristics and outcomes (including the long-term patency of endovascular treatment [EVT]) of patients with acute ischemic strokes (AISs) featuring carotid artery dissection (CAD) but not intracranial large vessel occlusion.

Methods

We retrospectively reviewed patients who underwent EVT for spontaneous or post-traumatic AISs with CAD over a 13 year period from September 2005 to November 2018. The indications for EVT in patients with AIS-related CAD were a pretreatment diffusion-weighted imaging-Alberta Stroke Program early computed tomography (ASPECT) score &gt; 6 and, clinical-diffusion mismatch. But, if the patients showed fluctuated ischemic symptoms, the joint decision by a stroke neurologist and neurointerventionist was done according to the onset-to-door time, symptoms, patient data, and the initial neuroimaging findings whether indicated that EVT was appropriate.

Results

Twenty-two dissected carotid arteries underwent balloon angioplasty and/or stent placement. The patients were 6 women and 16 men of median age 46 years. Twelve lacked any trauma history. Recombinant tissue plasminogen activator was prescribed for two (9.1%) patients. Four developed symptomatic intracranial hemorrhages (18.2%) but 86.4% exhibited modified Rankin scores ≤ 2.

Conclusions

Although attention to the hemorrhagic complication is required, EVT for selective patients with cerebral ischemia associated with CAD may be safe and acceptable treatment strategy for reconstruction of luminal patency, with good clinical outcomes. Prospective large-scale randomized studies are required to optimize EVT for CAD patients.

Staged angioplasty: A sensible approach to prevent hyperperfusion syndrome after carotid artery stenting? A meta-analysis

OBJECTIVE

To investigate whether staged angioplasty (SAP) is a safe and effective treatment to prevent hyperperfusion syndrome after carotid artery stenting (CAS).

METHODS

A systematic literature search was performed according to established criteria to identify eligible articles published before October 2020. Pooled dichotomous data were presented as odds ratios (OR) and corresponding 95% confidence intervals (CI) using random-effect models. The efficacy endpoints were hyperperfusion syndrome (HPS), hyperperfusion phenomenon (HPP), and intracerebral hemorrhage (ICH). The safety endpoint was post-procedural thromboembolic events. The feasibility of the procedure was assessed by device-related adverse events (vessel dissection and failed angioplasty) in SAP.

RESULTS

Ten studies (1030 participants) were eligible. SAP was superior to regular CAS in preventing HPS (OR = 0.35, 95% CI 0.14-0.86, P = 0.02). There was no significant difference in the rate of thromboembolic events between the SAP group and the regular CAS group. The rates of vessel dissection and failed angioplasty with the use of a 3.0-mm-diameter balloon were 5.4% and 0.4%, respectively.

CONCLUSION

SAP may reduce the incidence of post-CAS HPS without increasing procedure-related complications. A 3.0-mm-diameter balloon used in SAP may be appropriate for Asian populations. However, the confounded study design and confused definitions of reporting items hinder the current recommendation of SAP in clinical use.