Cerebral hyperperfusion syndrome

Utility of ultrasound in the perioperative phase of carotid endarterectomy and carotid artery stent implantation

BACKGROUND

This article reviews the latest research results of the use of ultrasound technology in the perioperative period of carotid endarterectomy and carotid stenting and discusses the role of ultrasound technology in accurately evaluating carotid stenosis and plaque stability, assisting in selecting the most suitable surgical method, and providing optimal perioperative imaging to guide carotid endarterectomy (CEA) and carotid artery stenting (CAS) to reduce the occurrence and progression of stroke.

METHODS

The research published in recent years on the application of ultrasound in the perioperative period of CEA and CAS was reviewed through the databases of CNKI, Pubmed, and Web of Science.

RESULTS

Ultrasound has high clinical value in preoperative screening for indications, assessing the degree of carotid artery stenosis and the nature of plaque; monitoring hemodynamic changes intraoperatively to prevent cerebral ischemia or overperfusion; and evaluating surgical outcomes postoperatively and in late follow-up review.

CONCLUSION

Ultrasound is currently widely used perioperatively in CEA and CAS and has even become the preferred choice of clinicians to evaluate the efficacy of surgery and follow-up. The presence of vulnerable plaque is an important risk factor for ischemic stroke. Contrast-enhanced ultrasound is an excellent tool to assess plaque stability. In most studies, ultrasound has been used only in a short follow-up period after CEA and CAS, and data from longer follow-ups are needed to provide more reliable evidence.

The effect of controlled vs uncontrolled hypertension on outcomes of carotid revascularization procedures

BACKGROUND

Hypertension (HTN) has been implicated as a strong predictive factor for poorer outcomes in patients undergoing various vascular procedures. However, limited research is available that examines the effect of uncontrolled HTN (uHTN) on outcomes after carotid revascularization. We aimed to determine which carotid revascularization procedure yields the best outcome in this patient population.

METHODS

We studied patients undergoing carotid endarterectomy (CEA), transfemoral carotid artery stenting (TFCAS), or transcarotid artery revascularization (TCAR) from April 2020 to June 2022 using data from the Vascular Quality Initiative. Patients were stratified into two groups: those with cHTN and those with uHTN. Patients with cHTN were those with HTN treated with medication and a blood pressure of <130/80 mm Hg. Patients with uHTN had a blood pressure of ≥130/80 mm Hg. Our primary outcomes were in-hospital stroke, death, myocardial infarction (MI), and 30-day mortality. Our secondary outcomes were postoperative hypotension or HTN, reperfusion syndrome, prolonged length of stay (LOS) (>1 day), stroke/death, and stroke/death/MI. We used logistic regression models for the multivariate analysis.

RESULTS

A total of 34,653 CEA (uHTN, 11,347 [32.7%]), 8199 TFCAS (uHTN, 2307 [28.1%]), and 17,309 TCAR (uHTN, 4990 [28.8%]) patients were included in this study. There was no significant difference in age between patients with cHTN and patients with uHTN for each carotid revascularization procedure. However, compared with patients with cHTN, patients with uHTN had significantly more comorbidities. uHTN was associated with an increased risk of combined in-hospital stroke/death/MI after CEA (adjusted odds ratio [aOR], 1.56; 95% confidence interval [CI], 1.30-1.87; P < .001), TFCAS (aOR, 1.59; 95% CI, 1.21-2.08; P < .001), and TCAR (aOR, 1.39; 95% CI, 1.12-1.73; P = .003) compared with cHTN. Additionally, uHTN was associated with a prolonged LOS after all carotid revascularization methods. For the subanalysis of patients with uHTN, TFCAS was associated with an increased risk of stroke (aOR, 1.82; 95% CI, 1.39-2.37; P < .001), in-hospital death (aOR, 3.73; 95% CI, 2.25-6.19; P < .001), reperfusion syndrome (aOR, 6.24; 95% CI, 3.57-10.93; P < .001), and extended LOS (aOR, 1.87; 95% CI, 1.51-2.32; P < .001) compared with CEA. There was no statistically significant difference between the outcomes of TCAR compared with CEA.

CONCLUSIONS

The results from this study show that patients with uHTN are at a higher risk of stroke and death postoperatively compared with patients with cHTN, highlighting the importance of treating HTN before undergoing elective carotid revascularization. Additionally, in patients with uHTN, TFCAS yields the worst outcomes, whereas CEA and TCAR proved to be safer interventions. Patients with uTHN with symptomatic carotid disease treated with CEA or TCAR have better outcomes compared with those treated with TFCAS.

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.

Evaluation of dynamic cerebrovascular autoregulation during liver transplantation

BACKGROUND

Cerebrovascular autoregulation in patients with acute and chronic liver failure is often impaired, yet an intact autoregulation is essential for the demand-driven supply of oxygenated blood to the brain. It is unclear, whether there is a connection between cerebrovascular autoregulation during liver transplantation (LTX) and the underlying disease, and if perioperative anesthesiologic consequences can result from this.

METHODS

In this prospective observational pilot study, data of twenty patients (35% female) undergoing LTX were analyzed. Cerebral blood velocity was measured using transcranial doppler sonography and was correlated with arterial blood pressure. The integrity of dynamic cerebrovascular autoregulation (dCA) was evaluated in the frequency domain through transfer function analysis (TFA). Standard clinical parameters were recorded. Mixed one-way ANOVA and generalized estimating equations were fitted to data involving repeated measurements on the same patient. For all other correlation analyses, Spearman's rank correlation coefficient (Spearman's-Rho) was used.

RESULTS

Indications of impaired dCA are seen in frequency domain during different phases of LTX. No correlation was found between various parameter of dCA and primary disease, delirium, laboratory values, length of ICU or hospital stay, mortality or surgical technique.

CONCLUSIONS

Although in most cases the dCA has been impaired during LTX, the heterogeneity of the underlying diseases seems to be too diverse to draw valid conclusions from this observational pilot study.

The Potential Role of Preoperative Posterior Cerebral Artery Involvement in Predicting Postoperative Transient Neurological Deficits and Ischemic Stroke After Indirect Revascularization in Patients With Moyamoya Disease

OBJECTIVE

Transient neurological deficits (TNDs) are known to develop after direct bypass for Moyamoya disease and may be risk factors for subsequent stroke. However, the factors involved in the development of TNDs and stroke after indirect revascularization alone, including their association with subsequent stroke, remain unclear. The purpose of this study was to investigate this issue.

METHODS

The subjects of the study were 30 patients with Moyamoya disease who underwent a total of 40 indirect revascularization procedures at our institution. Clinical and radiological data were collected retrospectively. To examine factors associated with the development of postoperative TND/stroke/asymptomatic disease, the clinical characteristics of each group were statistically compared.

RESULTS

The mean age at surgery was 7 years (range 1-63). TNDs developed after surgery in 9 out of 40 patients (22.5%). Stroke in the acute postoperative period occurred in 3 patients (7.5%), all of whom experienced cerebral infarctions. Demographic data and preoperative clinical information were not different between the groups. However, posterior cerebral artery involvement on preoperative imaging was significantly associated with the development of TNDs and stroke (P = 0.006). Furthermore, postoperative stroke was associated with unfavorable outcomes (P = 0.025).

CONCLUSIONS

Posterior cerebral artery involvement is significantly associated with the occurrence of TNDs. In contrast, TNDs after indirect revascularization have little relationship with the subsequent development of stroke. TNDs usually resolve without new strokes, and a better understanding of this particular pathology could help establish an optimal treatment regimen.

Role of Point-of-Care Cerebral Ultrasonography in Determining the Etiology of Post-carotid Endarterectomy Deficit: A Case Report

Carotid revascularization surgery is notorious for its neurological morbimortality. We report the case of a 74-year-old hypertensive patient, who underwent left internal carotid artery endarterectomy for a 90% stenosis under general anesthesia, presenting in the immediate postoperative period with right hemiplegia without consciousness disorders. Evaluation by cerebral ultrasound at bedside led to suspicion of intracerebral hemorrhage, which was confirmed by cerebral CT scan. The patient was treated by neuroresuscitation measures in the absence of the possibility of surgical intervention. This hemorrhage may be explained by a reperfusion injury due to the loss of cerebral autoregulation of these vessels, the loss of controlling blood pressure, and the use of heparin in vascular surgery. This is a rare but fatal complication with a high mortality rate.

Early Detection of hyperemia with Magnetic Resonance Fluid Attenuation Inversion Recovery Imaging after Superficial Temporal Artery to Middle Cerebral Artery Anastomosis

OBJECTIVE

Cerebral hyperperfusion syndrome (CHS) manifests as a collection of symptoms brought on by heightened focal cerebral blood flow (CBF), afflicting nearly 30% of patients who have undergone superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis. The aim of this study was to investigate whether the amalgamation of magnetic resonance imaging (MRI) fluid-attenuated inversion recovery (FLAIR) and apparent diffusion coefficient (ADC) imaging via MRI can discern cerebral hyperemia after STA-MCA anastomosis surgery.

METHODS

A retrospective study was performed of patients who underwent STA-MCA anastomosis due to Moyamoya disease or atherosclerotic steno-occlusive disease. A protocol aimed at preventing CHS was instituted, leveraging the use of MRI FLAIR. Patients underwent MRI diffusion with FLAIR imaging 24 hours after STA-MCA anastomosis. A high signal on FLAIR images signified the presence of hyperemia at the bypass site, triggering a protocol of hyperemia care. All patients underwent hemodynamic evaluations, including perfusion MRI, single-photon emission computed tomography (SPECT), and digital subtraction angiography, both before and after the surgery. If a high signal intensity is observed on MRI FLAIR within 24 hours of the surgery, a repeat MRI is performed to confirm the presence of hyperemia. Patients with confirmed hyperemia are managed according to a protocol aimed at preventing further progression.

RESULTS

Out of a total of 162 patients, 24 individuals (comprising 16 women and 8 men) exhibited hyperemia on their MRI FLAIR scans following the procedure. SPECT was conducted on 23 patients, and 11 of them yielded positive results. All 24 patients underwent perfusion MRI, but nine of them showed no significant findings. Among the patients, 10 displayed elevations in both CBF and cerebral blood volume (CBV), three only showed elevation in CBF, and two only showed elevation in CBV. Follow-up MRI FLAIR scans conducted 6 months later on these patients revealed complete normalization of the previously observed high signal intensity, with no evidence of ischemic injury.

CONCLUSION

The study determined that the use of MRI FLAIR and ADC mapping is a competent means of early detection of hyperemia after STA-MCA anastomosis surgery. The protocol established can be adopted by other neurosurgical institutions to enhance patient outcomes and mitigate the hazard of permanent cerebral injury caused by cerebral hyperemia.

Application of individual brain connectome in chronic ischemia: mapping symptoms before and after reperfusion

How brain functions in the distorted ischemic state before and after reperfusion is unclear. It is also uncertain whether there are any indicators within ischemic brain that could predict surgical outcomes. To alleviate these issues, we applied individual brain connectome in chronic steno-occlusive vasculopathy (CSOV) to map both ischemic symptoms and their postbypass changes. A total of 499 bypasses in 455 CSOV patients were collected and followed up for 47.8 ± 20.5 months. Using multimodal parcellation with connectivity-based and pathological distortion-independent approach, areal MR features of brain connectome were generated with three measurements of functional connectivity (FC), structural connectivity, and PageRank centrality at the single-subject level. Thirty-three machine-learning models were then trained with clinical and areal MR features to obtain acceptable classifiers for both ischemic symptoms and their postbypass changes, among which, 11 were deemed acceptable (AUC > 0.7). Notably, the FC feature-based model for long-term neurological outcomes performed very well (AUC > 0.8). Finally, a Shapley additive explanations plot was adopted to extract important individual features in acceptable models to generate "fingerprints" of brain connectome. This study not only establishes brain connectomic fingerprint databases for brain ischemia with distortion, but also provides informative insights for how brain functions before and after reperfusion.

Safety and Efficacy of Intensive Blood Pressure-Lowering After Successful Endovascular Therapy in AIS: A Meta-Analysis

OBJECTIVES

Higher blood pressure has been proven to be associated with poorer functional outcomes after successful reperfusion by EVT. However, the effect of intensive blood pressure-lowering regimens in these patients remains controversial and ambiguous in clinical practice. We propose further analysis aimed at determining the effect of an intensive blood pressure-lowering regimen after EVT in AIS.

METHODS

The protocol registered in PROSPERO CRD42023360989. We performed a systematic search that was comprehensively executed in online databases for studies published up to June 2022. Eligibility criteria were established based on the PICOS model. The Cochrane risk of bias algorithm was used to evaluate the risk of bias. The effect models were applied to calculate the pooled ORs and CIs via Review Manager 5.4 software.

RESULTS

A total of 1582 citations were identified, 3 randomized clinical trials and 2 retrospective cohort studies were included. Data from 3211 patients were analyzed. We revealed that intensive blood pressure-lowering interventions could significantly reduce symptomatic intraparenchymal hemorrhage compared with standard blood pressure lowering. Nevertheless, favorable functional outcome, poor outcome, all-cause mortality within 3 months and intraparenchymal hemorrhage in 24 hours showed no significant differences. Subgroup analysis revealed the variability of systolic blood pressure within 24 hours after EVT was not associated with odds of poor outcome and intraparenchymal hemorrhage.

CONCLUSIONS

Based on the current evidence, intensive blood pressure-lowering regimen was superior to standard blood pressure-lowering regimen for a reduced risk of symptomatic intraparenchymal hemorrhage in AIS patients treated with EVT, but there was no statistically significant difference found between the 2 regimens for the other outcomes.

A case report of the treatment of carotid artery stenosis by staged angioplasty based on intraoperative TCD monitoring

Objective

Cerebral hyperperfusion syndrome (CHS) is the most severe complication of carotid artery stenting (CAS) or endarterectomy (CEA). Staging treatment can effectively reduce the risk of CHS without increasing the risk of ischemic stroke. The first stage of balloon dilatation is critical for staged treatment. However, the successful criterion of the first stage balloon dilatation is still inconsistent.

Method

In the current study presents a case of a 61-year-old male with bilateral internal carotid subtotal occlusion, transcranial doppler (TCD) was used to measure middle cerebral artery (MCA) flow rate on the narrow side of surgery and the results are promising.

Result

Intraoperative TCD monitoring is expected to be an evaluation criterion for staged angioplasty for carotid artery stenosis.

Conclusion

The approach of blood flow velocity in the brain based on intraoperative measurement of TCD during the treatment of this patient is a new idea for staging treatment in the future.

Carotid artery dissection and non-aneurysmal subarachnoid hemorrhage following carotid endarterectomy

Stroke continues to be a major public health issue resulting in high mortality and severe long-term disability. Carotid endarterectomy (CEA) plays an important role in the prevention of ischemic stroke. Complications associated with CEA can be life threatening and prompt recognition is crucial. In this report, we present a patient who presented to the hospital with progressive headache, 2 weeks following CEA. He was neurologically intact and hypertensive. Non-contrast head computed tomography (CT) scan showed convexity subarachnoid hemorrhage (SAH). He was found to have a left internal carotid artery dissection. Patients who present to the hospital following CEA with headache and hypertension benefit from a non-contrast head CT scan. The presence of SAH can be a warning sign of cerebral hyperperfusion syndrome. Carotid artery dissection is also a disease entity that can occur in the post-operative period. Prompt recognition and treatment is crucial for the management of these disease entities.

Global hyperperfusion after successful endovascular thrombectomy is linked to worse outcome in acute ischemic stroke

Patients with stroke may develop hyperperfusion after a successful endovascular thrombectomy (EVT). However, the relationship between post-EVT hyperperfusion and clinical outcomes remains unclear and requires further clarification. We reviewed consecutive patients with anterior circulation occlusion who were successfully recanalized with EVT. Based on post-EVT arterial spin-labeling images, hyperperfusion was categorized as follows: global hyperperfusion (GHP), increased cerebral blood flow (CBF) in ≥ 50% of the culprit vessel territory; focal hyperperfusion (FHP), increased CBF in < 50% of the culprit vessel territory; no hyperperfusion (NHP), no discernible CBF increase. Factors associated with hyperperfusion were assessed, and clinical outcomes were compared among patients under different hyperperfusion categories. Among 131 patients, 25 and 40 patients developed GHP and FHP, respectively. Compared to other groups, the GHP group had worse National Institutes of Health Stroke Scale score (GHP vs. NHP/FHP, 18.1 ± 7.4 vs. 12.3 ± 6.0; p < 0.001), a larger post-EVT infarct volume (98.9 [42.3-132.7] vs. 13.5 [5.0-34.1] mL; p < 0.001), and a worse 90-day outcome (modified Rankin Scale, 3 [1-4] vs. 2 [0-3]; p = 0.030). GHP was independently associated with infarct volume (B = 0.532, standard error = 0.163, p = 0.001), and infarct volume was a major mediator of the association of GHP with unfavorable outcomes (total effect: β = 0.176, p = 0.034; direct effect: β = 0.045, p = 0.64; indirect effect: β = 0.132, p = 0.017). Patients presenting with post-EVT GHP had poorer neurological prognosis, which is likely mediated by a large infarct volume.

Safety and effectiveness assessment of endovascular recanalization for non-acute middle cerebral artery occlusion

BACKGROUND

Endovascular treatment for patients with symptomatic nonacute middle cerebral artery occlusion remains clinically challenging, and proof of a beneficial effect on functional outcome is lacking. We aim to evaluate the effectiveness and safety of endovascular recanalization for patients with symptomatic nonacute middle cerebral artery occlusion.

METHODS

Ninety-eight patients with symptomatic atherosclerotic nonacute middle cerebral artery occlusion were divided into drug treatment groups (42) and endovascular treatment groups (56). The rate of recanalization, peri-procedural complications, and follow-up results were evaluated.

RESULTS

Among the 56 patients who received endovascular treatment, 53 (94.6%) achieved successful recanalization. The rate of peri-procedural complications was 7.1% (4/56), and the death rate was 1.8% (1/56). Any stroke within 90 days was 7.1% (4/56). Among the 42 patients in drug treatment group, any stroke within 90 days was 19.0% (8/42), death rate was 0.

CONCLUSION

Among patients with symptomatic nonacute middle cerebral artery occlusion with a short length of occlusion and a moderate-to-good collateral circulation, endovascular treatment seems to be safe. And endovascular treatment could reduce the recurrence rate of stroke.

Ultrasonography monitoring with Superb Microvascular Imaging during cerebrovascular surgery

INTRODUCTION

Ultrasonography (US) is used as a real-time dynamic imaging modality during neurosurgery. A novel Doppler US technique, Superb Microvascular Imaging (SMI), can be used to visualize low-velocity flow of small vessels at high resolution with high frame rates. We visualized vessel flow using this US SMI technique and contrast agent during cerebrovascular surgery.

METHODS

Forty-three patients with an unruptured cerebral aneurysm (control), ischemic and hemorrhagic moyamoya disease, carotid artery stenosis, hemangioblastoma, severe stenosis of the middle cerebral artery, venous angioma, and intracerebral hemorrhage (ICH) underwent neurosurgery with US SMI monitoring using a contrast agent. The diameter, length, and number of penetrating vessels were analyzed in patients with an unruptured cerebral aneurysm (control), moyamoya disease, and ICH.

RESULTS

Diameter and length of cerebral penetrating vessels were significantly increased in patients with moyamoya disease and ICH compared to control patients. The number of penetrating vessels was increased in moyamoya disease patients compared to control and ICH patients. In hemorrhagic moyamoya disease, flow in the penetrating vessels originated from a deep periventricular point and extended to the cerebral surface. Pulsatile cerebral aneurysms during clipping surgery and carotid artery stenosis during carotid endarterectomy were easily identified by SMI. Drastically increased vessel flow in patients with a hemangioblastoma or a venous angioma was observed.

CONCLUSION

Using the US SMI technique and contrast agent, we obtained useful flow information of the vascular disease structure and intracerebral deep small vessels during cerebrovascular surgery. Further quantitative analysis will be informative and helpful for cerebrovascular surgery.

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.

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.

Risk Factors for Cerebral Hyperperfusion Syndrome After Combined Revascularization in Adult Patients with Moyamoya Disease

BACKGROUND

Cerebral hyperperfusion syndrome (CHS) is known as a complication after bypass surgery for Moyamoya disease (MMD). However, the incidence of CHS has not been accurately reported, and there is no consensus on the risk factors associated with it.

AIM

The aim of this study was to determine the risk factors associated with postoperative CHS after surgical combined revascularization used to treat adult patients with MMD.

OBJECTIVE

To assess the frequency and characteristics of CHS in patients with MMD after revascularization operations.

METHODS

Patients who received combined revascularization from Jan 2021 to Nov 2022 were retrospectively reviewed. Preoperative clinical characteristics and radiographic features were recorded. Postoperative CHS after surgery were examined. Multivariate logistic regression analyses were performed to identify the risk factors for CHS.

RESULTS

A total of 133 patients (141 hemispheres) were included in this study. Postoperative CHS were observed in 28 hemispheres (19.8%), including focal cerebral hyperperfusion syndrome (FCHS) in 20 hemispheres (14.2%), hemorrhage in 4 (2.8%) hemispheres, seizures in 4 (2.8%) hemispheres. The results of multivariate logistic regression analysis indicated that preoperative hypertension (OR 4.705, 95% CI 1.323 ~ 12.554, p = 0.014), cerebral hemorrhage onset (OR 5.390, 95% CI 1.408 ~ 20.642, p = 0.014) and higher Hct level (OR 1.171, 95% CI 1.051 ~ 1.305, p = 0.004) were significantly associated with CHS after combined revascularization.

CONCLUSIONS

Preoperative hypertension, cerebral hemorrhage onset, and higher Hct level were independent risk factors for CHS after combined revascularization.

Clinical applications of arterial spin labeling of the intracranial compartment in vascular anomalies-A case-based review

Arterial spin labeling (ASL) is a magnetic resonance perfusion technique that allows for quantification of cerebral blood flow (CBF) without the use of contrast or radiation. Several applications of ASL have been described in diagnosis of strokes and stroke mimics, intracranial tumors, and other conditions. Various vascular anomalies exhibit specific CBF patterns that correlate with different signal intensities on ASL. In this case-based review, we demonstrate the utility of ASL in diagnosis and surveillance of vascular anomalies in the intracranial compartment.

Cerebral Hyperperfusion Syndrome Presenting as Epilepsia partialis Continua Following Carotid Stenting: A Case Report

Cerebral hyperperfusion syndrome (CHS) is a rare prodrome of symptoms, including headaches, focal neurological deficits, seizures, or encephalopathy. Herein, we report a unique case of focal motor status epilepticus (Epilepsia partialis continua [EPC]). A 76-year-old male underwent right carotid stenting (CAS) for symptomatic high-grade stenosis. Immediately post-operation, he was recovering well without neurologic deficits; however, four days later, his blood pressure increased, and he experienced focal motor seizures involving the left arm and face without impaired awareness. He was managed with antihypertensive and antiseizure medications. Subsequently, his respiratory function worsened, necessitating intubation for status epilepticus. Repeated imaging demonstrated only the previously known infarcts without cerebral edema, bilaterally patent carotid arteries or any signs of acute infarct or intracerebral hemorrhage.  While CHS is a rare syndrome with well-documented symptomatology, focal motor status epilepticus can occur abruptly without the more typical CHS symptoms, despite the best preventive measures.

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.

Supratentorial hemangioblastoma: correlation between phenotype, gender and vascular territory affected

Supratentorial hemangioblastomas are rare, vascular lesions. The presence of peri-tumoral cysts and edema has meaningful clinical, diagnostic and therapeutic implications. Nevertheless, the pathogenesis of both cyst and edema formation is not fully understood. This study sought to determine if the radiologic phenotype of supratentorial hemangioblastoma is affected by the different cerebral arterial circulations. Review of the English-language literature from 1973 to 2023 yielded 53 cases of parenchymal supratentorial hemangioblastomas eligible for analysis. Patients were divided by the vascular territorial distribution of the lesions: anterior circulation (n = 36) or posterior circulation (n = 17), and the groups were compared for demographic, clinical, radiologic and molecular variables. Univariate analyses yielded a significant difference between the groups in five variables. Cystic changes and "classic" radiological phenotype were associated with hemangioblastomas of the posterior circulation (OR = 0.19, p = 0.045 and OR = 0.287, p = 0.048, respectively), while female gender, significant peritumoral edema and purely solid phenotype were associated with hemangioblastomas of the anterior circulation (OR = 3.384, p = 0.045 and OR = 5.25, p = 0.05 and OR = 14.0, p = 0.015; respectively). On multivariate analysis, solid phenotype and female gender remained significantly associated with the anterior circulation (OR = 36.04, p = 0.014 and OR = 4.45, p = 0.045). The incidence of von-Hippel Lindau disease was higher in the anterior-circulation group. Cystic tumors were present in all females in the posterior-circulation group compared to 43.4% in the anterior-circulation group (OR = 20.714, 95% CI 1.061 to 404.122; p = 0.045). Based on historical cases of supratentorial hemangioblastoma, this study shows that different tumor phenotypes are associated with the different cerebral circulations. Gender was also associated with differences in tumor distribution and radiologic phenotype. These novel data may improve our understanding of unique vascular diseases of the central nervous system.

Screening of postoperative cerebral hyperperfusion syndrome in moyamoya disease: a three-dimensional pulsed arterial-spin labeling magnetic resonance imaging approach

Introduction

Moyamoya disease (MMD) is associated with a risk of postoperative cerebral hyperperfusion syndrome (CHS) after revascularization surgery. This study aimed to explore the feasibility of using three-dimensional pulsed arterial spin labeling (3D PASL) and phase contrast (PC) magnetic resonance imaging (MRI) for predicting CHS occurrence in patients with MMD before revascularization surgery.

Methods

Overall, 191 adult patients (207 hemispheres) with MMD who underwent combined revascularization surgery were included in this study. Preoperative 3D PASL-MRI and PC-MRI were performed before surgery. The PASL-MRI data were analyzed using SPM12. Patient clinical information, average flow, and preoperative cerebral blood flow (CBF) were compared between the non-CHS and CHS groups.

Results

Among the patients, 45 (21.74%) developed CHS after revascularization surgery. No significant differences were noted in age, sex, clinical symptoms, hypertension, diabetes, surgical side, or history of revascularization surgery between the non-CHS and CHS groups. However, the average flow in the superficial temporal artery was significantly lower in the CHS group than in the non-CHS group (p < 0.05). Furthermore, 11 clusters of preoperative CBF values were significantly greater in the CHS group than in the non-CHS group [p < 0.05, false discovery rate (FDR) corrected]. A significant correlation was also observed between the preoperative time-to-flight MR angiography (MRA) scores and CBF values in patients with MMD (p < 0.05).

Conclusion

Compare patients with lower preoperative CBF and higher preoperative average flow in the STA, patients with higher preoperative CBF and lower preoperative average flow in the STA are more likely to develop postoperative CHS Preoperative PASL-MRI and PC-MRI examinations may help to screen patients at high risk of developing CHS after revascularization surgery.

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.

Ultrasound assessment of brain supplying arteries (transcranial)

Ultrasonography of intracranial arteries is a non-invasive and highly efficient method for the diagnosis and follow-up of patients with cerebrovascular diseases, also in the bedside setting of the critically ill. For reliable assessment and interpretation of sonographic findings, the technique requires - apart from dedicated anatomic and pathophysiological knowledge of cerebral arteries and their hemodynamics - the comprehension of alternative imaging modalities such as CT or MR angiography. This article reviews the transcranial color-coded duplex sonographic (TCCS) examination technique including the transcranial Doppler sonography (TCD) for a standardized ultrasound assessment of the intracranial arteries and typical pathological cases. As a complementary tool, transorbital ultrasound for the assessment of the optic nerve sheath diameter and adjacent structures is also described in this article.

Todd's paralysis due to hyperperfusion syndrome after carotid endarterectomy mimicking postoperative stroke

Todd's paralysis is a neurological deficit that is observed in <10% of patients following epileptic seizures. Cerebral hyperperfusion syndrome (CHS) is a rare complication following carotid endarterectomy (CEA), seen in 0-3% of the patients, characterized by focal neurological deficit, headache, disorientation, and sometimes seizures. In this case report, we present a case of CHS after CEA followed by seizures and Todd's paralysis that mimicked postoperative stroke. A 75-year-old female patient was admitted for CEA of the right internal carotid artery, following a transient ischemic attack two months prior. Four hours after CEA with graft interposition, the patient suffered a temporary weakness of the left arm and leg followed by generalized spasms within a few seconds. CT angiography showed regular patency of the carotid arteries and the graft, and brain CT showed no sign of oedema, ischemia or hemorrhage. However, left-sided hemiplegia occurred following the seizure, and the patient suffered four more seizures over the next 48 hours, with persisting hemiplegia. On the second postoperative day, the motor skills of the left side fully recovered, and the patient was communicative, and of orderly mental status. Brain CT performed on the third postoperative day showed entire right hemisphere oedema. A moderate hemiparesis with seizures as a consequence of CHS after CEA has been described, however in all cases with seizures and hemiplegia, the underlying cause was always a verified stroke or intracerebral hemorrhage. This case highlights the importance of considering Todd's paralysis in patients with seizures after CEA due to CHS and prolonged periods of hemiplegia after the seizures.

Designing a flow-controlled STA-MCA anastomosis based on the Hagen-Poiseuille law for preventing postoperative hyperperfusion in adult moyamoya disease

Background

Technical improvements for preventing postoperative symptomatic cerebral hyperperfusion (CHP) during superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD) were seldom reported.

Objectives

The aim of this study was to investigate the significance of application of a novel flow-controlled concept which voluntarily reduces the hemodynamic difference between the donor and recipient arteries based on the Hagen-Poiseuille law when performing direct anastomoses of recipient parasylvian cortical arteries (PSCAs) with anterograde hemodynamic sources from the MCA (M-PSCAs) in adult MMD.

Design

This was a retrospective observational study.

Methods

Direct anastomoses of recipient M-PSCAs were performed on 89 symptomatic hemispheres in 82 adult MMD patients in our hospital from January 2020 to June 2021. They were divided into the flow-controlled group (patients who received direct anastomosis under designed flow-controlled principles) and non-flow-controlled group (patients who received conventional direct anastomosis to obtain maximum flow). The patients' basic characteristics and incidence of postoperative CHP were compared between the two groups. Risk factors for occurrence of postoperative CHP were analyzed.

Results

Overall, 36 hemispheres were included in the non-flow-controlled group and 53 in flow-controlled group. The incidences of postoperative focal (22.6%) and symptomatic CHP (5.7%) in the flow-controlled group were significantly lower than those (focal, 52.8%; symptomatic, 25.0%) in the non-flow-controlled group (p = 0.003 and 0.009, respectively). Multivariate analysis revealed that the flow-controlled concept was significantly associated with the development of focal (p = 0.005) and symptomatic (p = 0.012) CHP.

Conclusion

The flow-controlled STA-MCA anastomosis can significantly decrease the incidence of postoperative CHP during direct anastomoses of recipient M-PSCAs in adult MMD.

Depression among Patients with an Implanted Left Ventricular Assist Device: Uncovering Pathophysiological Mechanisms and Implications for Patient Care

Depression is a common and devastating mental illness associated with increased morbidity and mortality, partially due to elevated rates of suicidal attempts and death. Select patients with end-stage heart failure on a waiting-list for a donor heart undergo left ventricular assist device (LVAD) implantation. The LVAD provides a circulatory flow of oxygenated blood to the body, mimicking heart functionality by operating on a mechanical technique. LVAD improves functional capacity and survivability among patients with end-stage heart failure. However, accumulating data suggests that LVAD recipients suffer from an increased incidence of depression and suicide attempts. There is scarce knowledge regarding the pathological mechanism and appropriate treatment approach for depressed LVAD patients. This article summarizes the current evidence on the association between LVAD implantation and occurrence of depression, suggesting possible pathological mechanisms underlying the device-associated depression and reviewing the current treatment strategies. The summarized data underscores the need for a rigorous pre-(LVAD)-implantation psychiatric evaluation, continued post-implantation mental health assessment, and administration of antidepressant treatment as necessary.

Nonconvulsive Status Epilepticus Associated with Cerebral Hyperperfusion Syndrome after Carotid Endarterectomy: A Case Report

We report a case of a 73-year-old man who developed nonconvulsive status epilepticus as a complication of cerebral hyperperfusion syndrome after carotid endarterectomy for carotid artery stenosis. On postoperative day 1, the patient experienced headaches and vomiting. Resting N-isopropyl-p-[¹²³I] iodoamphetamine single-photon emission computed tomography showed increased cerebral blood flow to the entire right hemisphere, and the patient was diagnosed with cerebral hyperperfusion syndrome. He was treated with antihypertensive and antiseizure medications, sedated using propofol, intubated, and placed under mechanical ventilation. On postoperative day 3, computed tomography perfusion imaging showed a reduction in hyperperfusion, and propofol sedation was terminated on postoperative day 4. However, the patient exhibited prolonged impaired awareness and roving eye movements, and long-term video electroencephalographic monitoring revealed electrographic seizures. The patient was diagnosed with nonconvulsive status epilepticus. Propofol sedation was resumed, and the antiseizure medication dose was increased. Subsequently, the state of hyperperfusion in the right hemisphere diminished, and electroencephalographic findings improved, allowing sedation to be terminated on postoperative day 7. The findings from this case suggest that when clinical subtle symptoms, such as impaired awareness and roving eye movements, are observed during treatment of cerebral hyperperfusion syndrome, video electroencephalography should be performed to detect electrographic seizures.

Intraoperative Hemodynamics of Parasylvian Cortical Arteries for Predicting Postoperative Symptomatic Cerebral Hyperperfusion after Direct Revascularization in Patients with Moyamoya Disease: A Preliminary Study

Objective. The search for methods by which to predict the risks of cerebral hyperperfusion syn-drome (CHS) in adults with moyamoya disease (MMD), including those utilizing new biomarkers, still deserves further research. The objective of this study was to investigate the association between the hemodynamics of parasylvian cortical arteries (PSCAs) and postoperative CHS. Methods. A consecutive number of adults with MMD who had undergone direct bypass between September 2020 and December 2022 were recruited. Intraoperative microvascular doppler ultrasonography (MDU) was performed to evaluate the hemodynamics of PSCAs. The intraoperative flow direction, mean value of velocity (MVV) of recipient artery (RA) and bypass graft were recorded. According to flow direction after bypass, RA was divided into entering sylvian (RA.ES) and leaving sylvian (RA.LS) subtypes. Univariate, multivariate, and ROC analyses of the risk factors for postoperative CHS were performed. Results. A total of 16 (15.09%) cases in 106 consecutive hemispheres (101 patients) sat-isfied the postoperative CHS criteria. According to univariate analysis, advanced Suzuki stage, MVV of RA before bypass, and fold increase of MVV in RA.ES after bypass were significantly associated with postoperative CHS (p < 0.05). Multivariate analysis indicated that left-operated hemisphere (OR (95%CI), 4.58 (1.05-19.97), p = 0.043), advanced Suzuki stage (OR (95%CI), 5.47 (1.99-15.05), p = 0.017), and fold increase of MVV in RA.ES (OR (95%CI), 1.17 (1.06-1.30), p = 0.003) were statistically significantly associated with the occurrence of CHS. The cut-off value of fold increase of MVV in RA.ES was 2.7-fold (p < 0.05). Conclusions. Left-operated hemisphere, advanced Suzuki stage, and postoperative fold increase of MVV in RA.ES were potential risk factors for postoperative CHS. Intraoperative MDU was useful for evaluating hemodynamics and predicting CHS.

Risk factors of postoperative cerebral hyperperfusion syndrome and its relationship with clinical prognosis in adult patients with moyamoya disease

BACKGROUND

To investigate the incidence, risk factors, and clinical prognosis of cerebral hyperperfusion syndrome (CHS) after superficial temporal artery-middle cerebral artery anastomosis combined with encephalo-duro-arterio-synangiosis (STA-MCA/EDAS) in adult patients with moyamoya disease (MMD).

METHODS

The clinical data of 160 adult patients with MMD treated by STA-MCA/EDAS from January 2016 to January 2017 were retrospectively analyzed. According to CHS diagnosis, MMD patients were divided into CHS and non-CHS group. Univariate and multivariate analysis of risk factors and Kaplan-Meier curve of stroke-free survival for CHS were performed.

RESULTS

A total of 12 patients (7.5%) developed postoperative CHS, of which 4 patients (2.5%) presented with cerebral hemorrhage. Univariate and multivariate analysis showed moyamoya vessel on the surgical hemisphere (OR = 3.04, 95% CI = 1.02-9.03, P = 0.046) and left operated hemisphere (OR = 5.16, 95% CI = 1.09-21.34, P = 0.041) were independent risk factors for CHS. The other variables, such as age, gender, presentation, hypertension, diabetes, smoking, mean mRS score on admission, modified Suzuki stage and pre-infarction stage on surgical hemisphere, and bypass patency, had no association with postoperative CHS (P > 0.05). At final follow-up with average 38 months, there were 18 out of 133 patients (13.5%, 4.91% per person year) presented with newly developed complications. There was no significant difference between newly developed complications, mean mRS scores, and Kaplan-Meier curve of stroke-free survival in patients with and without CHS (P > 0.05).

CONCLUSION

The concentration of moyamoya vessels and left operated hemisphere was independent risk factors for CHS, which could not affect the clinical prognosis if treated timely and properly. The current study offers a new perspective of moyamoya vessels and supporting data for choosing MMD candidates on cerebral revascularization.

Incidence and association of seizures in stroke patients following endovascular treatment: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Post-stroke seizures (PSSs) are some of the most common complications of stroke and are associated with poor outcomes in patients. Endovascular treatment (EVT) is the standard of care for patients with acute ischaemic stroke related large-vessel occlusion. However, whether EVT increases the risk of PSSs remains controversial; the association between PSSs and EVT is poorly understood.

METHODS

PubMed, Embase and the Cochrane Library were searched for relevant studies published from 1995 to 6 December 2021. The overall incidence of PSSs in patients treated with EVT and the separate incidence for all included studies in each subgroup, stratified by the type of treatment or time of onset, were calculated. The pooled odds ratio and confidence interval were calculated to quantify the effects of EVT on PSS occurrence.

RESULTS

In all, 946 studies were screened and 16 articles were included, with a total sample size of 12,664 patients; 7836 patients received EVT, of whom 460 had PSS. The pooled incidence of PSS after EVT was 5.8%, which was similar to patients treated with mechanical thrombectomy (5.3%), intra-arterial thrombolysis (6.8%) or bridging therapy (5.4%). The cumulative incidence of post-stroke epilepsy (6.0%) was almost twice that of acute symptomatic seizures (3.6%). The pooled odds ratio for the relationship between EVT and PSS was 1.91 (95% confidence interval 0.98-3.73).

CONCLUSIONS

The cumulative incidence of stroke patients treated with EVT who developed seizures was 5.8%, and EVT was non-significantly associated with the occurrence of seizures after stroke.

Risk factors for early seizure after revascularization in patients with moyamoya disease

BACKGROUND

To investigate the risk factors for early seizure after revascularization in patients with moyamoya disease (MMD).

METHODS

A total of 298 patients with MMD diagnosed in our hospital from 2015 to 2018 were analyzed retrospectively. We summarized the characteristics of seizure after revascularization in patients with MMD and analyzed the predictors of early postoperative seizure.

RESULTS

We identified 15 patients with MMD who developed seizures within 1 week after revascularization. According to logistic regression analysis, age (OR: 1.04, 95% CI 0.998-1.086; P = 0.060) and infarct side (OR: 1.92, 95% CI 0.856-4.290; P = 0.113) were not significantly associated with incident early seizure. Postoperative infarction (OR: 12.89, 95% CI 4.198-39.525; P = 0.000) and preoperative cerebral infarction (OR: 4.08, 95% CI 1.267-13.119; P = 0.018) were confirmed as risk factors for early seizure.

CONCLUSIONS

We believe that a history of preoperative infarction and new infarction are independent risk factors of early seizure in patients with MMD after revascularization.

Indirect revascularization vs. non-surgical treatment for Moyamoya disease and Moyamoya syndrome: A comparative effectiveness study

Background

The efficacy of indirect revascularization vs. non-surgical treatment in adults with Moyamoya disease (MMD) and Moyamoya syndrome (MMS) remains controversial.

Objective

To compare the clinical outcomes of indirect revascularization and non-surgical treatments in adult patients with MMD and MMS.

Methods

We collected medical records and follow-up results of adult patients with MMD and MMS who received treatment in the China-Japan Union Hospital of Jilin University between January 2019 and December 2021. A Shapiro-Wilk test, independent sample t-test or Mann-Whitney U-test, and Pearson chi-square test were used to compare baseline variables. The propensity-score analysis was used to compare clinical outcomes of patients with MMD and MMS who underwent indirect revascularization and non-surgical treatments. The color-coded digital subtraction angiography (CC-DSA) was used to quantitatively analyzed the preoperative and postoperative (at 6-month follow-up) images of patients in the surgical group.

Results

A total of 144 patients were included in this study, of whom 37 received indirect revascularization treatment and 107 received non-surgical treatment. The average age of the patients was 58.3 ± 13.4 years. Perioperative complications were observed in eight of the operations. During the follow-up period, a total of 35 stroke events occurred, including two cases (5.4%) in the surgery group and 33 cases (30.8%) in the non-surgery group (p < 0.05). The preoperative mean transit time (MTT) of bypass vessel (superficial temporal artery, STA) was 0.26 ± 0.07, and the postoperative MTT of bypass vessel was 3.0 ± 0.25, and there was no statistical difference between the subgroups.

Conclusion

Indirect revascularization surgery can significantly reduce the recurrent stroke incidence of MMD and MMS patients.

Critical Care of the Vascular Surgery Patient

Patients that require major vascular surgery suffer from widespread atherosclerosis and have multiple comorbidities that place them at increased risk for postoperative complications and require admission to the intensive care unit (ICU). Postoperative critical care of these patients is focused on hemodynamic optimization, and early identification and management of complications to improve outcomes.

Effect of perioperative blood pressure variability on cerebral hyperperfusion syndrome after carotid artery stenting: A retrospective study

OBJECTIVE

To investigate the effect of perioperative blood pressure variability on cerebral hyperperfusion syndrome after carotid artery stenting.

METHODS

A retrospective analysis was conducted of data collected from 418 patients who underwent carotid artery stenting in Guangxi Zhuang Autonomous Region People's Hospital in China. The blood pressure data were collected during operation (after balloon dilation, before stent release, after stent release) and within 3 days after the operation. The blood pressure variability was evaluated by measuring the mean, maximum, minimum, max-min, standard deviation (SD) of systolic blood pressure (SBP) and diastolic blood pressure (DBP). The correlation between blood pressure variability and cerebral hyperperfusion syndrome was analysed.

RESULTS

Blood pressure data from 418 patients were analysed. Twenty patients (4.8%) developed cerebral hyperperfusion syndrome. The parameters of blood pressure variability were divided into four groups according to quartile. After adjusting for age, symptomatic carotid stenosis, unilateral carotid stenosis, bilateral carotid stenosis, collateral circulation, diabetes mellitus and chronic kidney disease, multivariate analysis showed that SBPMax, SBPMin, SBPMax-Min, SBPCV, DBPSD, DBPMax, DBPMin, DBPMax-Min and DBPCV were associated with the occurrence of cerebral hyperperfusion syndrome (P < 0.05), respectively.

CONCLUSION

This study suggests that blood pressure variability during the perioperative period may increase the risk of cerebral hyperperfusion syndrome.

Endarterectomy, Stenting, or Medical Treatment for Symptomatic Carotid Near-Occlusion: Results from CAOS, a Multicenter Registry Study

BACKGROUND AND PURPOSE

The treatment of symptomatic carotid near-occlusion is controversial. Our aim was to analyze the results of carotid endarterectomy and carotid artery stent placement in patients with symptomatic carotid near-occlusion and to identify factors related to technical failure, periprocedural complications, and restenosis.

MATERIALS AND METHODS

We conducted a multicenter, prospective nonrandomized study. Patients with angiography-confirmed carotid near-occlusion were included. We assessed the revascularization rate and periprocedural stroke or death. Twenty-four-month clinical and carotid imaging follow-up was performed, and rates of carotid restenosis or occlusion, ipsilateral stroke, and mortality were analyzed. Carotid artery stent placement, carotid endarterectomy, and medical treatment were compared.

RESULTS

One hundred forty-one patients were included. Forty-four carotid artery stent placement and 23 carotid endarterectomy procedures were performed within 6 months after the event. Complete revascularization was achieved in 83.6%, 81.8% in the carotid artery stent placement group and 87% with carotid endarterectomy (P = .360). Periprocedural stroke or death occurred in 6% (carotid artery stent placement = 2.3%; carotid endarterectomy = 13%; P = .077) and was not related to revascularization failure. The carotid restenosis or occlusion rate was 8.3% (5% restenosis, 3.3% occlusion); with carotid artery stent placement it was 10.5%; and with carotid endarterectomy it was 4.5% (P = .419). The 24-month cumulative rate of ipsilateral stroke was 4.8% in the carotid artery stent placement group, 17.4% for carotid endarterectomy, and 13.1% for medical treatment (P = .223). Mortality was 12%, 4.5%, and 5.6%, respectively (P = .422). Revascularization failure and restenosis occurred more frequently in patients with full collapse compared with patients without full collapse (33.3% versus 5.6%, P = .009; 21.4% versus 2.9%, P = .032, respectively).

CONCLUSIONS

Carotid artery stent placement and carotid endarterectomy are associated with high rates of failure and periprocedural stroke. Carotid near-occlusion with full collapse appears to be associated with an increased risk of technical failure and restenosis. Carotid near-occlusion revascularization does not seem to reduce the risk of stroke at follow-up compared with medical treatment.

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.

Relationship between cerebral hyperperfusion syndrome and the immediate change of cerebral blood flow after carotid artery stenting evaluated by single-photon emission computed tomography

PURPOSE

Cerebral hyperperfusion syndrome (CHS) is a critical complication after carotid artery stenting (CAS). However, few CAS studies have evaluated immediate and temporary changes in ipsilateral cerebral blood flow (CBF) quantitatively. The study was performed to evaluate immediate changes in CBF after CAS and subsequent CBF changes in patients with cerebral hyperperfusion (HP) using ¹²³I-IMP SPECT.

METHODS

The subjects were 223 patients with chronic extracranial carotid artery stenosis who underwent CAS in our department between March 2010 and March 2020. Quantitative CBF and cerebrovascular reactivity to acetazolamide in the middle cerebral artery were assessed before CAS by ¹²³I-IMP SPECT. CBF was also measured immediately after CAS by ¹²³I-IMP SPECT. When HP was detected, CBF was measured again 3 and 7 days after CAS.

RESULTS

The median (interquartile range) ipsilateral quantitative CBF change after CAS was - 0.1% (- 9.5-8.2%), and the upper value of the 95% CI of the quantitative CBF change was 48.2%. Thus, we defined HP after CAS as an increase in quantitative CBF of > 48.2% compared with the preoperative value. Of 223 patients, 5 (2.2%) had HP, and 4 of these patients (80%) developed CHS. In the CHS patients, HP was maintained for about 3 days and improved after about 7 days.

CONCLUSION

An immediate CBF increase of > 48.2% after CAS may lead to development of CHS. In CHS after CAS, HP persisted for about 1 week and postoperative management may be required for at least 1 week.

Sonografisches Neuromonitoring auf der Stroke Unit und in der neurologischen Intensivmedizin

Hintergrund Der Artikel gibt einen Überblick über die aktuellen diagnostischen Einsatzmöglichkeiten sonographischer Anwendung in der neurologischen Intensivmedizin.

Methoden Selektive Literaturrecherche mit kritischer Beurteilung ab dem Jahr 1984 sowie nationaler und internationaler Leitlinien sowie Expertenmeinung.

Ergebnisse Neben der raschen validen Abklärung akuter Schlaganfälle bieten verschiedene neurosonografische Monitoring-verfahren gerade in der Intensivmedizin spezifische Vorteile wie die beliebig häufige Wiederholbarkeit am Patientenbett selbst und die Darstellung in Echtzeit. Innovative Entwicklungen machen die Neurosonografie auch wissenschaftlich zu einem interessanten Gebiet.

Schlussfolgerung Die neurosonografische Diagnostik nimmt seit Jahren einen wichtigen Stellenwert in der neurologischen Intensivmedizin ein. Weitere Anstrengungen sind notwendig, um die Verbreitung der Methode zu fördern und durch wissenschaftliche Evidenz zu stärken.

Outcomes of Early Trans-Carotid Artery Revascularization Versus Carotid Endarterectomy after Acute Neurologic Events

OBJECTIVE

Carotid revascularization within 14 days of a neurologic event is recommended by society guidelines. Transcarotid artery revascularization (TCAR) carries the lowest overall stroke rate for any carotid artery stenting technique; however, outcomes of TCAR within 14 days of a neurologic event have not been directly compared to carotid endarterectomy (CEA).

METHODS

We compared 30-day outcomes of symptomatic patients undergoing TCAR and CEA within 14 days of stroke or transient ischemic attack (TIA) from January 2016 to February 2020 using the Society for Vascular Surgery Vascular Quality Initiative (VQI) carotid artery stenting and CEA databases. Propensity score matching was used to adjust for patient risk factors. The primary outcome was a composite of postoperative ipsilateral stroke, death, and myocardial infarction (MI).

RESULTS

A total of 1,281 symptomatic patients underwent TCAR and 13,429 patients underwent CEA within 14 days of a neurologic event. After 1:1 propensity matching, 728 matched pairs were included for analysis. The primary composite outcome of stroke, death, or MI was more frequent in the TCAR group (4.7% vs. 2.6%, p= 0.04). This was driven by a higher rate of post-operative ipsilateral stroke in the TCAR group (3.8% vs. 1.8%, p=0.005). There was no difference between TCAR and CEA in terms of death (0.7% vs. 0.8%, p= 0.8) or MI (0.8% vs. 1%, p= 0.7). Although TCAR procedures were shorter (69 minutes IQR 53-85 vs. 120 minutes IQR 93-150, p<0.001) and post procedure length of stay was similar (2 days, p= 0.3) compared to CEA, TCAR patients were more likely to be discharged to a facility other than home (26% vs. 19%, p<0.01). Performing TCAR within 48 hours of a stroke was an independent predictor of post-operative stoke or TIA (OR 5.4 95% CI 1.8-16). This increased risk of post-operative stroke or TIA was not seen when performing TCAR within 48 hours of a TIA.

CONCLUSION

TCAR within 14 days of a neurologic event results in higher ipsilateral post-operative stroke rates when compared to CEA, especially when performed within 48 hours of a stroke.

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.

Arterial transit artifacts on arterial spin labeling MRI can predict cerebral hyperperfusion after carotid endarterectomy: an initial study

OBJECTIVES

To investigate whether preoperative arterial spin labeling (ASL) MRI can predict cerebral hyperperfusion after carotid endarterectomy (CEA) in patients with carotid stenosis.

METHODS

Consecutive patients with carotid stenosis who underwent CEA between May 2015 and July 2021 were included. For each patient, a cerebral blood flow ratio (rCBF) map was obtained by dividing postoperative CBF with preoperative CBF images from two pseudo-continuous ASL scans. Hyperperfusion regions with rCBF > 2 were extracted and weighted with rCBF to calculate the hyperperfusion index. According to the distribution of the hyperperfusion index, patients were divided into hyperperfusion and non-hyperperfusion groups. Preoperative ASL images were scored based on the presence of arterial transit artifacts (ATAs) in 10 regions of interest corresponding to the Alberta Stroke Programme Early Computed Tomography Score methodology. The degree of stenosis and primary and secondary collaterals were evaluated to correlate with the ASL score. Logistic regression and receiver operating characteristic curve analyses were performed to assess the predictive ability of the ASL score for cerebral hyperperfusion.

RESULTS

Of 86 patients included, cerebral hyperperfusion was present in 17 (19.8%) patients. Carotid near occlusion, opening of posterior communicating arteries with incomplete anterior semicircle, and leptomeningeal collaterals were associated with lower ASL scores (p < 0.05). The preoperative ASL score was an independent predictor of cerebral hyperperfusion (OR = 0.48 [95% CI [0.33-0.71]], p < 0.001) with the optimal cutoff value of 25 points (AUC = 0.98, 94.1% sensitivity, 88.4% specificity).

CONCLUSIONS

Based on the presence of ATAs, ASL can non-invasively predict cerebral hyperperfusion after CEA in patients with carotid stenosis.

KEY POINTS

• Carotid near occlusion, opening of posterior communicating arteries with incomplete anterior semicircle, and leptomeningeal collaterals were associated with lower ASL scores. • The ASL score performed better than the degree of stenosis, type of CoW, and leptomeningeal collaterals, as well as the combination of the three factors for the prediction of cerebral hyperperfusion. • For patients with carotid stenosis, preoperative ASL can non-invasively identify patients at high risk of cerebral hyperperfusion after carotid endarterectomy without complex post-processing steps.

Peri-Procedural Management of Hemodynamic Instability in Patients Undergoing Carotid Revascularization

Acute perioperative changes in arterial pressure occur frequently, particularly in patients with cardiovascular disease or those receiving vasoactive medications, or in relation to certain cardiovascular surgical procedures. Hemodynamic Instability (HI) are common in patients undergoing carotid revascularization because of unique patho-physiological and surgical factors. The operation, by necessity, disrupts the afferent pathway of the baroreflex, which can lead to postendarterectomy HI. Poor arterial pressure control is associated with increased morbidity and mortality after carotid revascularization, but good control of arterial pressure is often difficult to achieve in practice. The incidence, implications, and etiology of HI associated with carotid surgery are reviewed, and some recommendations made for its management. Close monitoring and titration of therapy are probably the most important considerations rather than specific choice of agents.