Lipid Core Burden Index Assessed by Near-Infrared Spectroscopy of Symptomatic Carotid Plaques: Association with Magnetic Resonance T1-Weighted Imaging.

INTRODUCTION: Vulnerable plaques are a strong predictor of cerebrovascular ischemic events, and high lipid core plaques (LCPs) are associated with an increased risk of embolic infarcts during carotid artery stenting (CAS). Recent developments in magnetic resonance (MR) plaque imaging have enabled noninvasive assessment of carotid plaque vulnerability, and the lipid component and intraplaque hemorrhage (IPH) are visible as high signal intensity areas on T1-weighted MR images. Recently, catheter-based near-infrared spectroscopy (NIRS) has been shown to accurately distinguish LCPs without IPH. This study aimed to determine whether the results of assessment of high LCPs by catheter-based NIRS correlate with the results of MR plaque imaging. METHODS: We recruited 82 consecutive symptomatic carotid artery stenosis patients who were treated with CAS under NIRS and MR plaque assessment. Maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA), defined as max-LCBIMLA, and max-LCBI for any 4-mm segment in a target lesion, defined as max-LCBIAREA, were assessed by NIRS. Correlations were investigated between max-LCBI and MR T1-weighted plaque signal intensity ratio (T1W-SIR) and MR time-of-flight signal intensity ratio (TOF-SIR) in the same regions as assessed by NIRS. RESULTS: Both T1W-SIRMLA and T1W-SIRAREA were significantly lower in the high LCP group (max-LCBI >504, p < 0.001 for both), while TOF-SIRMLA and TOF-SIRAREA were significantly higher in the high LCP group (p < 0.001 and p = 0.004, respectively). A significant linear correlation was present between max-LCBIMLA and both TIW-SIRMLA and TOF-SIRMLA (r = -0.610 and 0.452, respectively, p < 0.0001 for both). Furthermore, logistic regression analysis revealed that T1W-SIRMLA and TOF-SIRMLA were significantly associated with a high LCP assessed by NIRS (OR, 44.19 and 0.43; 95% CI: 6.55-298.19 and 0.19-0.96; p < 0.001 and = 0.039, respectively). CONCLUSIONS: A high LCP assessed by NIRS correlates with the signal intensity ratio of MR imaging in symptomatic patients with unstable carotid plaques.

Near-infrared spectroscopy carotid plaque characteristics and cerebral embolism in carotid artery stenting.

BACKGROUND: Perioperative thromboembolism is the main consideration in carotid artery stenting (CAS). Precise evaluation of carotid plaque components is clinically important to reduce ischaemic complications since CAS mechanically pushes plaque outwards, which releases plaque debris into the bloodstream. AIMS: This study aimed to determine whether high lipid core plaque (LCP) assessed by catheter-based near-infrared spectroscopy (NIRS) is associated with ipsilateral cerebral embolism by diffusion-weighted magnetic resonance imaging during CAS using a first-generation stent. METHODS: Carotid stenosis magnetic resonance (MR) T1-weighted plaque signal intensity ratio (T1W-SIR) followed by NIRS assessment at the time of CAS (using the carotid artery Wallstent) was performed in 117 consecutive patients. RESULTS: The maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA; max-LCBIMLA) and the max-LCBI for any 4 mm segment in a target lesion defined as max-LCBIarea were significantly higher for the post-procedural new ipsilateral diffusion-weighted magnetic resonance imaging (DWI)-positive than negative patients (p<0.001 for all). There was a significant linear correlation between max-LCBIarea and the number of new emboli (r=0.544, p<0.0001). We also found that the second quantile (Q2) of T1W-SIRMLA had a significantly higher max-LCBIMLA and a higher incidence of DWI positivity than Q1 and Q3 (p<0.001 for all). Furthermore, max-LCBIMLA appeared to distinguish between patients with and without postoperative new ipsilateral DWI positivity (AUC 0.91, 95% CI: 0.86-0.96; p<0.0001). CONCLUSIONS: High LCP assessed by NIRS is associated with cerebral embolism by diffusion-weighted imaging in CAS using a first-generation stent.

Diagnostic impact of monitoring transcranial motor-evoked potentials to prevent ischemic complications during endovascular treatment for intracranial aneurysms.

The present study aimed to determine the incidence of intraprocedural motor-evoked potential (MEP) changes and to correlate them with intraprocedural ischemic complications and postprocedural neurological deficits in patients after endovascular intracranial aneurysm treatment. This study analyzed data from 164 consecutive patients who underwent endovascular coil embolization to treat intracranial aneurysms under transcranial MEP monitoring. We analyzed associations between significant changes in MEP defined as > 50% decrease in amplitude, and intraprocedural complications as well as postoperative neurological deficits. Factors associated with postprocedural neurological deficits were also assessed. The treated aneurysms were predominantly located in the anterior circulation (71%). Fourteen (9%) were located at perforators or branches that supplied the pyramidal tract. Intraprocedural complications developed in eight (5%) patients, and four of eight (50%) patients occurred postprocedural neurological deficits. Significant intraprocedural MEP changes occurred during seven of eight endovascular procedures associated with intraprocedural complications and salvage procedures were performed immediately. Among these changes, four transient MEP changes, recovered within 10 min, were not associated with postprocedural neurological deficits, whereas three permanent MEP changes were associated with postprocedural neurological deficits and mRS ≥ 1 at discharge. Aneurysms located at perforators/branches supplying the pyramidal tract, and permanent intraprocedural MEP changes were associated with postprocedural neurological deficits. We conclude that intraprocedural transcranial MEP monitoring can reliably identify ischemic changes and can initiate prompt salvage procedures during endovascular aneurysm treatment.

Elective carotid stenting after urgent best medical treatment suppresses recurrent stroke in patients with symptomatic carotid artery severe stenosis.

OBJECTIVE: Urgent carotid endarterectomy and carotid artery stenting (CAS) for symptomatic advanced carotid artery stenosis is controversial because carry risks of hemorrhagic and thromboembolic complications. As treatments for preventing recurrent stroke have recently advanced, this study evaluated whether elective CAS with urgent best medical therapy reduces recurrent stroke for symptomatic severe carotid artery stenosis. PATIENTS AND METHODS: A total of 131 consecutive patients who underwent CAS for severe stenosis of the carotid artery between 2013-2017 were divided into acute ischemic minor stroke (AIMS) and Asymptomatic groups. The AIMS group comprised 59 patients presenting with minor stroke who underwent elective CAS with oral dual antiplatelet therapy, statin therapy, and add-on oral omega-3 fatty acid ethyl esters from 4 weeks before CAS. The Asymptomatic group comprised 72 patients treated with best medical therapy for 4 weeks before CAS. RESULTS: No recurrent ischemic stroke was observed under urgent best medical treatment before elective CAS in the AIMS group. Although the frequency of vulnerable plaque and degree of stenosis were much higher in the AIMS group, no significant differences were seen in perioperative complications. Baseline serum eicosapentaenoic acid (EPA) levels and EPA/ arachidonic acid (AA) were significantly lower in the AIMS group (p = 0.04, 0.04, respectively) and serum EPA/AA was significantly increased a day before CAS and 3 months after CAS compared with baseline. CONCLUSION: Urgent best medical treatment reduces recurrent stroke and facilitates safe elective CAS in patients with symptomatic and severe carotid artery stenosis.

Enhanced Hematoma Membrane on DynaCT Images During Middle Meningeal Artery Embolization for Persistently Recurrent Chronic Subdural Hematoma.

OBJECTIVE: Chronic subdural hematoma (CSDH) is generally treated by burr-hole irrigation, but it can recur despite repeating these procedures. Embolization of the middle meningeal artery (MMA) has recently been proposed as a curative treatment for CSDH, but evidence for the indication and timing of MMA embolization is not definitive. The present study retrospectively analyzed the effects and safety of MMA embolization among patients with persistent CSDH recurrence. METHODS: We retrospectively assessed data from 381 consecutive patients who underwent burr-hole irrigation for CSDH between 2009 and 2017. Recurrent symptomatic ipsilateral CSDH in 71 (18%) patients was treated by a second burr-hole irrigation, and 20 of them had a further symptomatic CSDH recurrence thereafter. Those with persistent ipsilateral CSDH recurrence were treated by MMA embolization. Before the MMA embolization procedures, the amount of hematoma membrane enhancement determined using superselective MMA angiography-DynaCT imaging was classified into 3 stages. RESULTS: Embolization of the MMA proceeded without perioperative complications or further CSDH recurrence. The interval between recurrence and the amount of hematoma membrane enhancement significantly correlated (first to second and second to third treatments: P = 0.012 and P = 0.017, respectively). The frequency of bilateral CSDH was significantly higher and the recurrence interval between the first and second treatments was significantly shorter in the repeated recurrences group compared with the recurrence group (P = 0.023 and P = 0.006, respectively). CONCLUSIONS: Repeatedly recurrent CSDH can be safely treated and cured by MMA embolization. Hematoma membrane enhancement pattern using DynaCT images can predict repeated recurrences CSDH.

Pretreatment with and ongoing use of omega-3 fatty acid ethyl esters reduce the slow-flow phenomenon and prevent in-stent restenosis in patients undergoing carotid artery stenting.

OBJECTIVE: Carotid artery stenting (CAS) is a less invasive alternative to carotid endarterectomy, but it is essential to prevent thromboembolic complications during CAS and to suppress in-stent restenosis (ISR) after CAS because of the relatively high risk of periprocedural and follow-up stroke events. Clinical trials have demonstrated the strong relationship of carotid plaque vulnerability with the subsequent risk of ipsilateral ischemic stroke and thromboembolic complications during CAS. Recent studies demonstrated that both low eicosapentaenoic acid (EPA) and low docosahexaenoic acid (DHA) levels were significantly associated with lipid-rich coronary and carotid plaques, but little is known about the effect of administration of omega-3 fatty acids (O-3FAs) containing EPA and DHA before and after CAS for stabilizing carotid plaque, preventing thromboembolic complications, and suppressing ISR. In this study, the efficacy of pretreatment with and ongoing daily use of O-3FA in addition to statin treatment was evaluated in patients undergoing CAS. METHODS: This study was a nonrandomized prospective trial with retrospective analysis of historical control data. From 2012 to 2015, there were 100 consecutive patients with hyperlipidemia undergoing CAS for carotid artery stenosis who were divided into two groups. Between 2012 and 2013 (control period), 47 patients were treated with standard statin therapy. Between 2014 and 2015 (O-3FA period), patients were treated with statin therapy and add-on oral O-3FA ethyl esters containing 750 mg/d DHA and 1860 mg/d EPA from 4 weeks before CAS, followed by ongoing daily use for at least 12 months. In all patients, the plaque morphology by virtual histology intravascular ultrasound, the incidence of new ipsilateral ischemic lesions on the day after CAS, the slow-flow phenomenon during CAS, and ISR within 12 months after CAS were compared between the periods. RESULTS: The slow-flow phenomenon during CAS with filter-type embolic protection devices decreased in the O-3FA period (1 of 53 patients [2%]) compared with the control period (7 of 47 patients [15%]; P = .02). Furthermore, ISR for 12 months after CAS was significantly decreased in the O-3FA period (1 of 53 patients [2%]) compared with the control period (10 of 47 patients [21%]; P = .01). On virtual histology intravascular ultrasound analysis, the fibrofatty area was significantly smaller and the fibrous area was significantly greater in the O-3FA period. On multivariate logistic regression analysis, a low EPA/arachidonic acid ratio and a symptomatic lesion were the factors related to vulnerable plaque (P = .01 [odds ratio, 5.24; 95% confidence interval, 1.65-16.63] and P = .01 [odds ratio, 11.72; 95% confidence interval, 2.93-46.86], respectively). CONCLUSIONS: Pretreatment with O-3FA reduces the slow-flow phenomenon generated by plaque vulnerability during CAS, and on-going daily use of O-3FA suppresses ISR after CAS.

Efficacy of cilostazol-based dual antiplatelet treatment in patients undergoing carotid artery stenting.

BACKGROUND: It is essential that patients undergoing carotid artery stenting (CAS) receive optimal antiplatelet inhibition. Although a reduction in platelet reactivity and improved clinical outcomes occur when using adjunctive cilostazol with dual antiplatelet therapy, this can lead to an increased risk of hemorrhagic complications. Therefore, our current study examined patients undergoing CAS and evaluated the impact of cilostazol-based dual antiplatelet treatment on the outcomes. METHODS: Between 2010 and 2015, 137 consecutive patients underwent CAS. From 2010 to 2011 (period 1), 28 patients underwent CAS in conjunction with aspirin and clopidogrel dual antiplatelet treatment (DAPT). From 2010 to 2013 (period 2), 44 patients underwent a preoperative assessment of their platelet function, with the clopidogrel-resistant patients receiving adjunctive cilostazol in addition to the aspirin and clopidogrel. From 2013 to 2015 (period 3), 65 patients underwent CAS in conjunction with cilostazol and clopidogrel treatment. In all patients, the incidence of new ipsilateral ischemic lesions observed by diffusion-weighted imaging on the day after CAS, and ischemic or hemorrhagic events occurring within 30 days were assessed. RESULTS: Clopidogrel resistance was identified in 43% of the patients in period 1, in 16% in period 2, and in 5% in period 3 (P < 0.001). The on-treatment platelet reactivity results indicated that the PRU value during cilostazol-based DAPT was significantly lower than that observed for the standard DAPT (P < 0.05). New ipsilateral ischemic lesions decreased by 9% and 8% in periods 2 and 3, respectively, versus a 25% decrease in period 1 (P = 0.047). However, there were no significant differences noted for any of the hemorrhagic or thromboembolic events. CONCLUSIONS: Compared to the standard aspirin and clopidogrel dual antiplatelet therapy, cilostazol-based dual antiplatelet treatment reduces the rate of clopidogrel resistance and suppresses new ischemic lesions without hemorrhagic complications.

Platelet inhibition by adjunctive cilostazol suppresses the frequency of cerebral ischemic lesions after carotid artery stenting in patients with carotid artery stenosis.

OBJECTIVE: Optimal platelet inhibition is an important therapeutic adjunct in patients with carotid artery stenosis undergoing carotid artery stenting (CAS). Clopidogrel resistance is associated with increased periprocedural thromboembolic complications from neurovascular stent placement procedures. The addition of cilostazol to dual antiplatelet therapy (DAT) has been reported to reduce platelet reactivity and to improve clinical outcomes after percutaneous coronary intervention. This study was undertaken to evaluate the impact of adjunctive cilostazol in patients with CAS. METHODS: Platelet function was assessed by light transmittance aggregometry using the VerifyNow assay. Sixty-four consecutive patients who underwent CAS received standard DAT, clopidogrel (75 mg daily), and aspirin (100 mg daily) more than 4 weeks before the procedure. From 2010 to 2011 (period I), 28 patients underwent CAS under standard DAT. From 2011 to 2013 (period II), 36 patients prospectively had preoperative assessment of platelet function, and 13 patients with clopidogrel resistance received adjunctive cilostazol (200 mg daily) in addition to standard DAT. The incidence of new ipsilateral ischemic lesions on diffusion-weighted imaging a day after CAS and ischemic or hemorrhagic events within 30 days was assessed. RESULTS: Clopidogrel resistance was indentified in 12 patients (43%) in period I and 13 patients (36%) in period II (P = .615). In period II, the addition of cilostazol significantly decreased P2Y12 reaction units and % inhibition (P = .006 and P = .005, respectively), and there was a significant difference in P2Y12 reaction units between the two periods. New ipsilateral ischemic lesions were significantly decreased in period II (2/36 patients) compared with period I (7/28 patients; P = .034); however, there was no significant difference in hemorrhagic and thromboembolic events between the two periods. CONCLUSIONS: Adjunctive cilostazol (triple antiplatelet therapy) in clopidogrel-resistant patients reduces the rate of clopidogrel resistance and suppresses new ischemic lesions without hemorrhagic complications, as compared with standard DAT. Antiplatelet management based on the evaluation of antiplatelet resistance would be required for prevention of perioperative thromboembolic complications in CAS.

Accuracy for predicting adhesion between meningioma and the brain by using brain surface motion imaging: comparison between single and double acquisition methods.

INTRODUCTION: The presence of adhesions between the brain and the meningioma is an important factor that determines the success of total surgical removal. Brain surface motion imaging enables assessment of the dynamics of brain surface motion. A subtraction image of pulse-gated heavily T2-weighted images in different phases of the cardiac cycle provides a stripe pattern on the surface of the pulsating brain. Thus, the lack of a stripe pattern on the surface of extraaxial tumor indicates the presence of tumor-brain adhesion. The purpose of the present experiment was to evaluate the accuracy of predicting tumor-brain adhesion using the original double acquisition method and the improved single acquisition method. METHODS: The subjects were 67 meningioma cases patients who were surgically treated after brain surface motion imaging. Thirty-three cases were evaluated using the double acquisition method and 34 cases were evaluated with the single acquisition method. In the double acquisition method, the two sets of images are acquired as two independent scans, and in the single acquisition method, the images are acquired serially as a single scan. RESULTS: The findings for the double acquisition method agreed with the surgical findings in 23 cases (69.7 %), while findings from the single acquisition method agreed with the surgical findings in 26 cases (76.5 %). CONCLUSION: Pre-surgical evaluation for tumor-brain adhesion by brain surface motion imaging provides helpful information for meningioma surgery, especially when using the single acquisition method.

Brain surface motion imaging to predict adhesions between meningiomas and the brain surface.

INTRODUCTION: "Brain surface motion imaging" (BSMI) is the subtraction of pulse-gated, 3D, heavily T2-weighted image of two different phases of cerebrospinal fluid (CSF) pulsation, which enables the assessment of the dynamics of brain surface pulsatile motion. The purpose of this study was to evaluate the feasibility of this imaging method for providing presurgical information about adhesions between meningiomas and the brain surface. METHODS: Eighteen cases with surgically resected meningioma in whom BSMI was presurgically obtained were studied. BSMI consisted of two sets of pulse-gated, 3D, heavily T2-weighted, fast spin echo scans. Images of the systolic phase and the diastolic phase were obtained, and subtraction was performed with 3D motion correction. We analyzed the presence of band-like texture surrounding the tumor and judged the degree of motion discrepancy as "total," "partial," or "none." The correlation between BSMI and surgical findings was evaluated. For cases with partial adhesions, agreements in the locations of the adhesions were also evaluated. RESULTS: On presurgical BSMI, no motion discrepancy was seen in eight cases, partial in six cases, and total in four cases. These presurgical predictions about adhesions and surgical findings agreed in 13 cases (72.2%). The locations of adhesions agreed in five of six cases with partial adhesions. CONCLUSION: In the current study, BSMI could predict brain and meningioma adhesions correctly in 72.2% of cases, and adhesion location could also be predicted. This imaging method appears to provide presurgical information about brain/meningioma adhesions.