Cerebral Hyperperfusion Phenomenon Research Articles

Prolonged/delayed cerebral hyperperfusion in adult patients with moyamoya disease with RNF213 gene polymorphism c.14576G>A (rs112735431) after superficial temporal artery-middle cerebral artery anastomosis.

Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis is the standard surgical management for moyamoya disease (MMD), whereas cerebral hyperperfusion (CHP) is one of the potential complications of this procedure that can result in delayed intracerebral hemorrhage and/or neurological deterioration. Recent advances in perioperative management in the early postoperative period have significantly reduced the risk of CHP syndrome, but delayed intracerebral hemorrhage and prolonged/delayed CHP are still major clinical issues. The clinical implication of RNF213 gene polymorphism c.14576G>A (rs112735431), a susceptibility variant for MMD, includes early disease onset and a more severe form of MMD, but its significance in perioperative pathology is unknown. Thus, the authors investigated the role of RNF213 polymorphism in perioperative hemodynamics after STA-MCA anastomosis for MMD. Among 96 consecutive adult patients with MMD comprising 105 hemispheres who underwent serial quantitative cerebral blood flow (CBF) analysis by N-isopropyl-p-[123I]iodoamphetamine SPECT after STA-MCA anastomosis, 66 patients consented to genetic analysis of RNF213. Patients were routinely maintained under strict blood pressure control during and after surgery. The local CBF values were quantified at the vascular territory supplied by the bypass on postoperative days (PODs) 1 and 7. The authors defined the radiological CHP phenomenon as a local CBF increase of more than 150% compared with the preoperative values, and then they investigated the correlation between RNF213 polymorphism and the development of CHP. CHP at POD 1 was observed in 23 hemispheres (23/73 hemispheres [31.5%]), and its incidence was not statistically different between groups (15/41 [36.6%] in RNF213-mutant group vs 8/32 [25.0%] in RNF213-wild type (WT) group; p = 0.321). CHP on POD 7, which is a relatively late period of the CHP phenomenon in MMD, was evident in 9 patients (9/73 hemispheres [12.3%]) after STA-MCA anastomosis. This prolonged/delayed CHP was exclusively observed in the RNF213-mutant group (9/41 [22.0%] in the RNF213-mutant group vs 0/32 [0.0%] in the RNF213-WT group; p = 0.004). Multivariate analysis revealed that RNF213 polymorphism was significantly associated with CBF increase on POD 7 (OR 5.47, 95% CI 1.06-28.35; p = 0.043). Prolonged/delayed CHP after revascularization surgery was exclusively found in the RNF213-mutant group. Although the exact mechanism underlying the contribution of RNF213 polymorphism to the prolonged/delayed CBF increase in patients with MMD is unclear, the current study suggests that genetic analysis of RNF213 is useful for predicting the perioperative pathology of patients with MMD.

Prediction of the Cerebral Hyperperfusion Phenomenon after Carotid Endarterectomy or Carotid Stenting by Computed Tomography Perfusion Imaging

Prediction of the Cerebral Hyperperfusion Phenomenon after Carotid Endarterectomy or Carotid Stenting by Computed Tomography Perfusion Imaging

Efficacy of arterial spin labeling magnetic resonance imaging with multiple post-labeling delays to predict postoperative cerebral hyperperfusion in carotid endarterectomy

ABSTRACT Introduction: Cerebral hyperperfusion (CHP) syndrome is one of the most deleterious complications after carotid endarterectomy (CEA). Arterial spin labeling (ASL) is a promising non-invasive method to evaluate various hemodynamic parameters in cerebrovascular diseases. The aim of this study was to clarify whether ASL with multiple post-labeling delays (PLDs) can predict postoperative CHP after CEA. Methods: Sixty-one patients with carotid artery stenosis treated by CEA were retrospectively analyzed. The asymmetry index of the preoperative CBF was obtained from ASL using 3 PLDs (1525 ms, 2025 ms, and 2525 ms) and single-photon emission computed tomography (SPECT). Cerebrovascular reactivity (CVR) was measured from SPECT with acetazolamide challenge. The slope of the regression line obtained from the asymmetry index of three PLDs was defined as the slope index. Results: The CHP phenomenon was observed in seven patients (11.5%), one of whom developed CHP syndrome (1.6%). Using the CHP phenomenon as a reference standard, the area under the receiver operating characteristics (ROC) was 0.68 for the asymmetry index of the preoperative SPECT, 0.71 for the asymmetry index of the preoperative ASL,0.73 for CVR, and 0.78 for the slope index. Using the cutoff value obtained by ROC analysis, the slope index demonstrated a sensitivity of 85%, specificity of 74%, positive predictive value of 30% and the negative predictive value of 98% for predicting CHP. Conclusions: The slope index calculated by ASL with multiple PLDs is a useful screening tool to predict postoperative CHP after CEA.

Prediction of Cerebral Hyperperfusion after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis by Three-Dimensional-Time-of-Flight Magnetic Resonance Angiography in Adult Patients with Moyamoya Disease

Introduction: Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is an effective surgical procedure for adult patients with moyamoya disease (MMD) and is known to have the potential to prevent cerebral ischemia and/or hemorrhagic stroke. Cerebral hyperperfusion (CHP) syndrome is one of the serious complications of this procedure that can result in deleterious outcomes, such as delayed intracerebral hemorrhage, but the prediction of CHP before revascularization surgery remains challenging. The present study evaluated the diagnostic value of preoperative three-dimensional (3D)-time-of-flight (TOF) magnetic resonance angiography (MRA) for predicting CHP after STA-MCA anastomosis for MMD. Materials and Methods: The signal intensity of the peripheral portion of the intracranial major arteries, such as the anterior cerebral artery (ACA), MCA, and posterior cerebral artery (PCA) ipsilateral to STA-MCA anastomosis, on preoperative MRA was graded (0–2 in each vessel) according to the ability to visualize each vessel on 97 affected hemispheres in 83 adult MMD patients. Local cerebral blood flow (CBF) at the site of anastomosis was quantitatively measured by N-isopropyl-p-[¹²³I]-iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, in addition to the preoperative CBF value at the corresponding area. Then, we investigated the correlation between the preoperative MRA score and the development of CHP. Results: The CHP phenomenon 1 day after STA-MCA anastomosis (local CBF increase over 150% compared with the preoperative value) was evident in 27 patients (27/97 hemispheres; 28%). Among them, 8 (8 hemispheres) developed CHP syndrome. Multivariate analysis revealed that the hemispheric MRA score (0–6), the summed ACA, MCA, and PCA scores for the affected hemisphere, was significantly associated with the development of CHP syndrome (p = 0.011). The hemispheric MRA score was also significantly correlated with the CHP phenomenon, either symptomatic or asymptomatic (p < 0.001). Conclusion: The signal intensity of the intracranial major arteries, including the ACA, MCA, and PCA, on preoperative 3D-TOF MRA may identify adult MMD patients at higher risk for CHP after direct revascularization surgery.

Prediction of the Cerebral Hyperperfusion Phenomenon after Carotid Endarterectomy Using a Transit Time Flowmeter.

The purpose of this study was to investigate the relationship between the cerebral hyperperfusion phenomenon (CHP) and carotid artery flow volume as measured by a transit time flowmeter during carotid endarterectomy (CEA). We retrospectively investigated 74 patients who underwent both transit time flowmetry and single photon emission computed tomography (SPECT). The flow volumes of the internal carotid artery (ICA) before and after the endarterectomy were recorded during surgery as the pre- and the post-ICA (mL/min), respectively. We defined the difference between the pre- and the post-ICA as the ΔIC (mL/min). Two independent board-certified neurosurgeons analyzed the asymmetry index (affected side/contralateral side) of regional qualitative cerebral blood flow before and after the CEA respectively. We defined the CHP as an excessive increase in this asymmetry index between preoperative and postoperative SPECT. The CHP was observed in five of the 74 patients (6.8%). The pre-ICA of the CHP cases was significantly lower than that of the non-CHP cases (in mL/min, median 29 vs. 97; P = 0.01). The ΔIC of the CHP cases was significantly higher than that of the non-CHP cases (in mL/min, median 154 vs. 50; P = 0.002). The cut-off value of the ΔIC was 81 mL/min (sensitivity 100%, specificity 78.3%, area under the curve 0.912). The findings of this study suggest that the ΔIC is associated with the CHP. The transit time flowmeter is useful to predict the CHP during surgery.

Significance of Quantitative Cerebral Blood Flow Measurement in the Acute Stage after Revascularization Surgery for Adult Moyamoya Disease: Implication for the Pathological Threshold of Local Cerebral Hyperperfusion

Objective: Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is a standard surgical procedure for adult patients with moyamoya disease (MMD) and plays a role in preventing ischemic and/or hemorrhagic stroke. Cerebral hyperperfusion (CHP) syndrome is a potential complication of this procedure that can result in deleterious outcomes, such as delayed intracerebral hemorrhage, but the exact threshold of the pathological increase in postoperative cerebral blood flow (CBF) is unclear. Thus, we analyzed local CBF in the acute stage after revascularization surgery for adult MMD to predict CHP syndrome under modern perioperative management. Materials and Methods: Fifty-nine consecutive adult MMD patients, aged 17–66 years old (mean 43.1), underwent STA-MCA anastomosis with indirect pial synangiosis for 65 affected hemispheres. All patients were perioperatively managed by strict blood pressure control (systolic pressure of 110–130 mm Hg) to prevent CHP syndrome. Local CBF at the site of anastomosis was quantitatively measured using the autoradiographic method by N-isopropyl-p-[¹²³I] iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, in addition to the preoperative CBF value at the corresponding area. We defined CHP phenomenon as a local CBF increase over 150% compared to the preoperative value. Then, we investigated the correlation between local hemodynamic change and the development of CHP syndrome. Results: After 65 surgeries, 5 patients developed CHP syndrome, including 2 patients with delayed intracerebral hemorrhage (3.0%), 1 with symptomatic subarachnoid hemorrhage (1.5%), and 2 with focal neurological deterioration without hemorrhage. The CBF increase ratio was significantly higher in patients with CHP syndrome (270.7%) than in patients without CHP syndrome (135.2%, p = 0.003). Based on receiver operating characteristic analysis, the cutoff value for the pathological postoperative CBF increase ratio was 184.5% for CHP syndrome (sensitivity = 83.3%, specificity = 94.2%, area under the curve [AUC] value = 0.825) and 241.3% for hemorrhagic CHP syndrome (sensitivity = 75.0%, specificity = 97.2%, AUC value = 0.742). Conclusion: Quantitative measurement of the local CBF value in the early postoperative period provides essential information to predict CHP syndrome after STA-MCA anastomosis in patients with adult MMD. The pathological threshold of hemorrhagic CHP syndrome was as high as 241.3% by the local CBF increase ratio, but 2 patients (3.0%) developed delayed intracerebral hemorrhage in this series that were managed following the intensive perioperative management protocol. Thus, we recommend routine CBF measurement in the acute stage after direct revascularization surgery for adult MMD and satisfactory blood pressure control to avoid the deleterious effects of CHP.

Effectiveness of Near-Infrared Spectroscopy (NIRO-200NX, Pulse Mode) for Risk Management in Carotid Artery Stenting

Near-infrared spectroscopy (NIRS) is an alternative monitoring method during carotid artery stenting (CAS). NIRS has been reported to be effective in emergency care; however, it is unknown whether it can predict intraoperative ischemic intolerance and cerebral hyperperfusion during CAS. Perioperative ischemic intolerance and cerebral hyperperfusion are potential events during CAS for carotid artery stenosis. We evaluated whether perioperative monitoring of the tissue oxygenation index (TOI) using NIRS with the NIRO system can predict the occurrence of ischemic intolerance and cerebral hyperperfusion. The TOI of 27 patients was measured during CAS. The relationship between the TOI and ischemic intolerance or cerebral hyperperfusion was analyzed, and the cutoff TOI was calculated to predict their occurrence. Ischemic intolerance occurred in 5 patients during balloon protection. The TOI in the presence of ischemic intolerance was significantly lower than that without ischemic intolerance. The cutoff TOI to detect ischemic intolerance was 50% and that of the TOI change rate before and after balloon protection was 80%. The ischemic symptoms in all patients had resolved immediately after balloon deflation. The cerebral hyperperfusion phenomenon was detected using single-photon emission computed tomography in 4 patients. These patients showed a transient increase in the TOI immediately after CAS; however, none of these patients showed symptomatic cerebral hyperperfusion phenomenon. The cutoff TOI to detect cerebral hyperperfusion was 109% compared with the TOI before CAS. Monitoring of the TOI using the NIRO system could be useful for the detection of ischemic intolerance and cerebral hyperperfusion during CAS and to prevent perioperative adverse events.

Abstract TP523: A Randomized Controlled Trial Evaluating the Effectiveness of Pretreatment With the Free Radical Scavenger, Edaravone, Before Carotid Artery Stenting

Objective: Cerebral hyperperfusion syndrome (CHS) is likely to occur after carotid revascularization in patients with severe hemodynamic failure. It is important to control cerebral hyperperfusion phenomenon (CHP) to prevent the development of CHS. To determine whether pretreatment with the free radical scavenger, edaravone, could prevent the onset of CHP after carotid artery stenting (CAS). Methods: Patients with severe carotid artery stenosis were randomized to receive either pretreatment with edaravone immediately before CAS or the common CAS procedure. Cerebral blood flow (CBF) was assessed in the affected middle cerebral artery (MCA) region and in the ipsilateral cerebellum using single-photon emission computed tomography (SPECT) of the brain before and immediately after CAS. Cerebrovascular reactivity (CVR) in the MCA region was also evaluated using the stereotactic extraction estimation based on the Japanese extracranial-intracranial bypass trial (SEE-JET) program and classified as reduced when it was &lt;18.4%. The ratio of MCA to cerebellar activity was defined as the CBF in the affected MCA region divided by the CBF in the ipsilateral cerebellar hemisphere. CHP was defined as an increase in the ratio of MCA to cerebellar activity after CAS ≥10%. Results: Of the 52 patients recruited in this study, 26 were assigned to the pretreatment with edaravone group and 26 were assigned to the treatment as the usual group. Eleven patients showed reduced CVR. CHP occurred in 0 of 6 patients in the edaravone group and in 4 of 5 patients in the usual group (0% vs. 80%, p=0.0152). However, there was no significant difference in the overall patient population between the two groups. Conclusion: Pretreatment with edaravone could reduce the incidence of CHP after CAS in patients with reduced CVR.

Usefulness of Bilateral rSO2 Monitoring for Predicting Cerebral Hyperperfusion Syndrome after Carotid Artery Stenting

Cerebral hyperperfusion syndrome(CHS)and cerebral hyperperfusion phenomenon(CHP)induce intracranial hemorrhage and can become critical complications after carotid artery stenting(CAS). The purpose of the present study was to predict and avoid CHS after CAS using bilateral rSO2 intraoperative monitoring. We retrospectively analyzed 100 consecutive patients who underwent CAS between January 2012 and May 2014 in our institution. We performed continuous bilateral rSO2 monitoring from anesthetic induction to the day following CAS. CHS was defined as the deterioration of neurological conditions post-CAS, no ischemic changes on post-CAS head CT or brain MRI, an increase in cerebral blood flow(CBF)and cerebral blood volume(CBV), and shortening of the mean transit time(MTT)or time to peak(TTP)on CT perfusion. To compare the CHS/CHP group and non-CHS/CHP group, we defined four parameters:rSO2 difference(rSO2 at the endpoint of the procedure-baseline rSO2), ΔrSO2 difference(affected side rSO2 difference-unaffected side rSO2 difference), rSO2 ratio(rSO2 at the endpoint of the procedure/baseline rSO2), and ΔrSO2 ratio(affected side rSO2 ratio/unaffected side rSO2 ratio). There were 2 CHS cases(2.2%)and 3 CHP cases(3.3%). In the CHS/CHP group, the ΔrSO2 difference and ΔrSO2 ratio were significantly higher than those in the non-CHS/CHP group(p value<0.05);however, no significant differences were found in the affected side rSO2 difference(p value=0.063)and affected side rSO2 ratio(p value=0.054)between the groups. We could promptly detect CHS and CHP in all cases by using continuous bilateral rSO2 monitoring and analysis of the ΔrSO2 difference and ΔrSO2 ratio.

Prediction of Cerebral Hyperperfusion After Carotid Artery Stenting by Cerebral Angiography and Single-Photon Emission Computed Tomography Without Acetazolamide Challenge.

Definitive preoperative predictors of cerebral hyperperfusion following carotid artery stenting are yet to be established. To determine the preprocedural risk factors for cerebral hyperperfusion phenomenon (CHP) following carotid artery stenting. Patients undergoing preprocedural single-photon emission computed tomography (SPECT) and cerebral angiography prior to their first carotid artery stenting were monitored for occurrence of CHP. In addition to patient characteristics, we investigated imaging parameters, such as cerebral blood flow, cerebral vasoreactivity, and asymmetry index on SPECT, and presence of near occlusion and leptomeningeal anastomosis on cerebral angiography. Out of 100 patients (mean age: 73.0 ± 7.6 years; 85 men), 9 developed CHP. On multivariate logistic regression analysis, asymmetry index (%) on SPECT (odds ratio [OR] 0.81, 95% confidence interval [CI] 0.70-0.93, P = .003) and presence of leptomeningeal anastomosis on cerebral angiography (OR 72.1, 95% CI 3.52-1480, P = .006) were independent predictors of CHP. Combined use of cerebral angiography and SPECT may obviate the need for acetazolamide challenge to predict the risk of CHP following carotid artery stenting.

Abstract TP152: Computed Tomography Perfusion Parameter to Predict Cerebral Hyperperfusion Phenomenon Following Carotid Artery Stenting

Background: Although SPECT is useful for predicting and finding cerebral hyperperfusion phenomenon (CHP) following carotid artery stenting (CAS), there are few institutions that could perform SPECT during peri-CAS period. The purpose of our study is to evaluate whether or not parameters derived from CT perfusion (CTP) used widely can predict CHP. Methods: Patients who underwent CTP before elective CAS and SPECT before and immediately after elective CAS in our institution from December 2010 to May 2012. We defined CHP as post-CAS increase of more than 10% of the ratio of cerebral blood flow (CBF) in the territory of the affected middle cerebral artery (MCA) divided by CBF in the ipsilateral cerebellum (MCA/CE ratio) measured by SPECT. We assessed the correlation of pre-CAS CTP’s parameters’ ratio to MCA/CE ratio change between pre-CAS and post-CAS SPECT. The CTP’s parameters’ ratio was calculated as (parameters in the affected side divided by in the unaffected side). CTP parameters we assessed are as follows: time-to-peak (TTP), mean-transit-time (MTT), cerebral blood volume (CBV) and CBF. Results: Fifty patients were analyzed. Pre-CAS TTP ratio showed a significant positive correlation with MCA/CE ratio change (r = 0.2863, p = 0.044). Other parameters (MTT, CBV and CBF) had no significant correlation. The cut-off value of pre-CAS TTP ratio was 1.08 to predict CHP (AUC = 0.77859, p = 0.032). Conclusion: Increase of pre-CAS TTP ratio is probably correlated with CHP following elective CAS.