Cervical Internal Carotid Artery Stenosis Research Articles

A New Preoperative Simulation Using Magnetic Resonance Imaging Bone-Like Imaging with Zero-Echo-Time Sequence

This study aimed to evaluate the clinical usefulness of zero-echo time(ZTE)-based magnetic resonance imaging(MRI)in planning an optimal surgical approach and applying ZTE for anatomical guidance during transcranial surgery. P atients who underwent transcranial surgery and carotid endarterectomy and for whom ZTE-based MRI and magnetic resonance angiography(MRA)data were obtained, were analyzed by creating ZTE/MRA fusion images and 3D-ZTE-based MRI models. We examined whether these images and models could be substituted for computed tomography imaging during neurosurgical procedures. Furthermore, the clinical usability of the 3D-ZTE-based MRI model was evaluated by comparing it with actual surgical views. ZTE/MRA fusion images and 3D-ZTE-based MRI models clearly illustrated the cranial and intracranial morphology without radiation exposure or the use of an iodinated contrast medium. The models allowed the determination of the optimum surgical approach for cerebral aneurysms, brain tumors near the brain surface, and cervical internal carotid artery stenosis by visualizing the relationship between the lesions and adjacent bone structures. However, ZTE-based MRI did not provide useful information for surgery for skull base lesions, such as vestibular schwannoma, because bone structures of the skull base often include air components, which cause signal disturbances in MRI. ZTE sequences on MRI allowed distinct visualization of not only the bone but also the vital structures around the lesion. This technology is minimally invasive and useful for preoperative planning and guidance of the optimum approach during surgery in a subset of neurosurgical diseases.

Another cause of treatable dementia: rapid cognitive improvement after carotid endarterectomy. Illustrative case.

Revascularization techniques in cervical internal carotid artery (ICA) stenosis are indicated to prevent the onset or recurrence of ischemic events in the setting of atherosclerotic carotid artery disease. Recent reports, case series, and comparative studies have suggested that revascularization techniques may also improve cognitive outcome in both symptomatic and asymptomatic patients, thus raising the question of whether another surgically treatable dementia has presented itself. A 70-year-old right-handed female with a history of hypertension, diabetes, and bilateral silent cerebral infarcts was evaluated for progressive cognitive impairment over a 1-year period, which was associated with a severe left cervical ICA stenosis. Carotid endarterectomy (CEA) was indicated as a revascularization technique, and the patient showed significant neurocognitive improvement as early as one month postoperatively, consistent with blood flow restoration to the left hemisphere on control imaging. This case serves as a reminder that CEA may improve the cognitive outcome of patients previously impaired by uncomplicated severe cervical ICA atherosclerotic disease, which can be another cause of treatable dementia. Further prospective studies may help to assess this potential benefit.

Abstract WMP116: A P2X4 Inhibitor Dramatically Suppresses the Progression of Cervical Internal Carotid Artery Stenosis - An Attempt to Develop a Therapeutic Agent for Carotid Artery Stenosis Focusing on the Role of Hemodynamic Factors-

Introduction: Medical treatment of internal carotid artery stenosis consists of treatment of underlying conditions such as hypertension, dyslipidemia, and diabetes mellitus, as well as antiplatelet therapy. Hemodynamic studies suggest that endothelial cells sense disturbances and stagnation of blood flow caused by vessel geometry, which trigger the progression of stenosis. Similarly, cerebral aneurysms are known to progress due to hemodynamic effects. We have shown in animal studies that inhibition of P2X4 purinoceptor, an endothelial blood flow sensing-related protein, significantly inhibits the development of cerebral aneurysms. In the present study, we examined whether P2X4 disruption can suppress the progression of internal carotid artery stenosis using an animal model of carotid artery stenosis. Methods: Carotid stenosis coils were implanted in the left carotid artery of 7-week-old P2X4(-/-) and (+/+) mice fed a high-cholesterol diet. Four weeks after placement, the carotid arteries were removed and the occlusion rates of the carotid arteries were compared. The expression of known stenosis-related inflammatory factors was also examined by Western blotting. Results: The carotid occlusion rate was significantly lower in the P2X4 gene-deficient mice, with 5 of 16 occlusions, compared with 9 of 13 occlusions in the control group (p=0.0394, Student's t-test). The expression levels of MCP-1, COX-2, TNFα, and IL-1β were significantly increased in the carotid arteries of P2X4(+/+) mice with the coil compared to the non-operated group (p=0.0073, 0.0012, 0.0016, 0.0031, respectively, Wilcoxon's signed rank test). The carotid arteries of P2X4(-/-) mice with coils showed significantly lower expression of all of the above compared to those of P2X4(+/+) mice (p=0.0233, 0.0020, 0.0098, 0.0046, respectively). Conclusions: These results suggest that inhibition of endothelial blood flow sensing by P2X4 disruption may have reduced the progression of carotid artery stenosis by suppressing the expression of a group of inflammatory factors associated with carotid artery stenosis. This may lead the way to new drug therapies for carotid artery stenosis.

Abstract 059: The Tenzing‐Dotter Technique for Endovascular Management of Atherosclerotic Cervical ICA Tandem Large Vessel Occlusions

Introduction The endovascular treatment of acute ischemic stroke due to atherosclerotic occlusion/near‐occlusion of the cervical internal carotid artery (ICA) and a concurrent intracranial large vessel occlusion (LVO) remains challenging, and the optimal approach remains unclear. Options include initial angioplasty and/or stenting of the cervical lesion followed by intracranial thrombectomy versus Dotter navigation of catheters through the cervical lesion to first target the intracranial LVO. We describe a novel Tenzing‐Dotter technique which utilizes a Tenzing device for the Dotter delivery of large bore (0.070”) and super‐large bore (0.088”) catheters through cervical atherosclerotic lesions to gain access to the intracranial circulation in tandem LVO patients. Methods We performed a retrospective review our single center experience of atherosclerotic tandem occlusion patients in which the Route 92 Medical Tenzing ® 7 (T7®) and Tenzing ® 8 (T8®) delivery catheters were used to Dotter‐deliver large bore or super‐large bore catheters, respectively, through the cervical ICA lesion to gain access to the intracranial circulation. We reviewed clinical, radiographic and procedural data to describe the safety and efficacy of this approach. Results Twenty patients were identified that that atherosclerotic occlusion/near‐occlusion of the cervical ICA and a single symptomatic intracranial LVO. The mean age was 65 (44 – 89), and 40% were female. The mean NIHSS was 14 (7‐25) and 40% were treated initially with intravenous thrombolytics. The ipsilateral cervical ICA was occluded in 11 of 20 patients (55%) and nearly‐occluded (degree of stenosis 90‐99%) in 9 of 20 patients (45%). The intracranial occlusions were carotid terminus (5), M1 middle cerebral artery (14) and M2 middle cerebral artery (1). Seven patients were treated with Tenzing 7 paired with a large bore catheter (6 with Medtronic React 71 and 1 with Route 92 Medical Hipoint 70), while 13 were treated with Tenzing 8 paired with a super‐large bore catheter (11 with Route 92 Medical Hipoint 88 catheter and 2 with Route 92 Medical Freeclimb 88 catheter). In all cases, successful navigation of the paired catheter through the cervical lesion was achieved in 100% of patient using the Tenzing‐Dotter delivery technique. The mean time from groin puncture to successful Tenzing‐Dotter delivery was 11 minutes, and the mean time from groin puncture to device delivery to the intracranial occlusion was 15 minutes. TICI 2B or greater reperfusion (self‐adjudicated) as achieved in 100% of patients, with a mean time to best TICI of 21 minutes. The degree of cervical ICA stenosis following thrombectomy improved from 96.5% to 67.4%. No symptomatic intracranial hemorrhage or cervical arterial dissections were noted. Conclusion The Tenzing‐Dotter technique, in which a Route 92 Medical Tenzing ® delivery catheter is utilized to Dotter navigate a large or super‐large bore catheter through an occluded or nearly‐occluded cervical atherosclertotic lesion, may be a promising technique for safe and fast access to the intracranial circulation in patients presenting with tandem large vessel occlusion acute ischemic strokes.

Strategy of cerebral endovascular treatment for cervical internal carotid artery stenosis with a persistent primitive hypoglossal artery.

Persistent primitive hypoglossal artery (PPHA) is a rare residual arterial anastomosis. We placed a CASPER stent using Spider FX as an embolic protection device (EPD) in a patient with internal carotid artery (ICA) stenosis and PPHA. There are no reports of carotid artery stenting (CAS) using a CASPER stent for ICA stenosis with PPHA. We report the EPD strategy used in this case and the usefulness and precautions of CASPER stent insertion for cervical ICA stenosis in association with PPHA. A 9Fr sheath was placed in the right femoral artery and a 9Fr Branchor balloon guide catheter was guided to the common carotid artery. A Spider FX was placed proximal to the bifurcation of the ICA and the PPHA. A 10 mm × 20 mm CASPER stent was deployed at the site of the stricture with no postoperative ischemic complications. There was no intra-stent occlusion, stenosis, or plaque protrusion immediately after surgery, and no postoperative ischemic complications were observed. CASPER stent deployment with the Spider FX in the ICA and PPHA bifurcation can be considered to be an effective treatment method for ICA stenosis associated with PPHA. However, care should be taken in selecting the appropriate EPDs and stents depending on the location of the stenosis and bifurcation of the PPHA.

Cadaver investigation of the usefulness of the transstyloid diaphragm approach for high-position plaque carotid endarterectomy

ObjectivesPatients sometimes present with high cervical internal carotid artery (ICA) stenosis. This study demonstrates the usefulness of the transstyloid approach to expose the distal ICA by dissection of the styloid diaphragm covering the distal cervical ICA for carotid endarterectomy (CEA). In particular, the possible exposure length achieved by this approach was investigated using cadaveric heads. MethodsThe procedure of the transstyloid diaphragm approach was confirmed in 10 cadaveric heads (20 sides). After the carotid triangle was opened, both the posterior belly of the digastric muscle (PBDM) and the stylohyoid muscle could be divided. Then, the carotid sheath was dissected, and the glossopharyngeal nerve was identified crossing over the distal ICA. The revealed length of the ICA was measured with or without dissection of both the PBDM and the stylohyoid muscle. The specimens were dissected under the surgical microscope. ResultsThe transstyloid diaphragm approach was achieved successfully in all specimens. The revealed lengths of the ICA with and without dissection of the styloid diaphragm were 53.7 ± 5.9 mm and 38.8 ± 2.9 mm (mean ± standard deviation), respectively. Therefore, the revealed length of the distal ICA was 14.9 ± 4.5 mm greater using the transstyloid diaphragm approach compared to the regular CEA approach. ConclusionsMore of the ICA can be revealed by dissection of both the PBDM and the stylohyoid muscle. The transstyloid diaphragm approach might be helpful to reveal the distal ICA in cases of high cervical ICA stenosis.

Carotid artery stenting after balloon aortic valvuloplasty in cervical internal carotid artery stenosis associated with severe aortic stenosis: A case report

AbstractCarotid artery stenting (CAS) is contraindicated in patients with severe aortic stenosis (AS). However, it is required for treating those with symptomatic internal CA (ICA) stenosis and severe AS. This is the first report of successful CAS after balloon aortic valvuloplasty (BAV) in a patient having ICA stenosis accompanied with severe AS. An 82‐year‐old man with a history of severe AS presented with amaurosis fugax due to severe stenosis at the left ICA. We performed CAS just after BAV. No perioperative complications were reported. It might be a useful treatment strategy for symptomatic ICA stenosis with severe AS.

A Novel Staged Revascularization Strategy for Bilateral Severe Internal Carotid Artery Stenosis at High Risk for Hyperperfusion Syndrome

Since bilateral severe internal carotid artery stenosis often is associated with severely decreased cerebrovascular reactivity (CVR) due to poor collateral blood flow, revascularization carries a high risk for development of hyperperfusion syndrome. In this study, we report a new staged strategy to prevent postoperative hyperperfusion syndrome in such patients. Bilateral severe cervical internal carotid artery stenosis patients with decreased CVR to 10% or less on one side were prospectively enrolled in this study. We first performed carotid artery stenting on the side with the milder CVR decrease (lower-risk side), aiming to improve hemodynamics associated with the severe CVR decrease on the greater-risk side. Then, carotid endarterectomy or carotid artery stenting was performed on the contralateral side after an interval of 4-8 weeks. In all 3 cases enrolled in this study, CVR on the greater-risk side improved to 10% or more 1 month after the first treatment. The ratio of regional cerebral blood flow on the contralateral greater-risk side was 114% 1 day after the second treatment, and HPS did not develop in any of the cases. Our treatment strategy, in which revascularization on the lower-risk side precedes that on the greater-risk side, is effective for the prevention of HPS in bilateral ICA stenosis patients.

Management of Cervical Internal Carotid Artery Stenosis or Occlusion in Tandem Lesion with Acute Ischemic Stroke: Which Is More Appropriate Percutaneous Transluminal Angioplasty or Stent?

Carotid artery stenting (CAS) is the established treatment strategy of the cervical internal carotid artery (cICA) stenosis, but its use for acute tandem lesions remains controversial. We investigated the clinical and procedural outcomes of management of cICA lesions and evaluated the risk factors for complications. Fifty patients who underwent acute mechanical thrombectomy for tandem lesion between January 2014 and June 2022 were included. Treatment of the cICA lesion was classified into the CAS group or the non-CAS group. The risk factors for postoperative ischemic events or symptomatic intracranial hemorrhage (sICH) were analyzed. The CAS group included 36 patients (72%) and the non-CAS group 14 (28%). Postoperative complications were observed in 9 patients (18%). Thromboembolic complications occurred in 4 patients (29%) of the non-CAS group but in 1 patient (3%) of the CAS group. Severe calcification of the cICA (P= 0.04), non-CAS (P= 0.018), and more than 60% residual stenosis (P= 0.016) were significant risk factors associated with thromboembolic complications. sICH occurred in 4 patients (11%) of the CAS group but in none of the non-CAS group. More than 80% stenosis improvement was significantly associated with sICH (P= 0.049). Twenty-nine patients (58%) had a good clinical outcome at 90 days after onset. Acute CAS is effective for the management for cICA tandem lesions during mechanical thrombectomy, but care not to overextend may be important to reduce the risk of sICH. Severe calcification of the cICA may increase the risk of postoperative thromboembolic complications using non-CAS treatment.

Abstract WP142: Risk Of New Ischemic Events In Patients With Symptomatic Internal Carotid Artery Stenosis While Awaiting Carotid Artery Stent Placement

Introduction: Although there is emphasis on performing carotid artery stent placement (CAS) within two weeks after index event of transient ischemic attack (TIA) or minor stroke in patients with cervical internal carotid artery (ICA) stenosis, the risk and characteristics of recurrent cerebral ischemic events while waiting for CAS are not well defined. Method: We analyzed patients admitted to our institution over a 45-month period with symptomatic cervical ICA stenosis. All patients were initiated on daily aspirin and clopidogrel 75mg on the day of admission. We identified any new cerebral ischemic events that occurred between index event and CAS and categorized them as TIA, and minor or major ischemic strokes. We calculated the risk of new ipsilateral cerebral ischemic events between index ischemic event and CAS. Results: The mean age of 150 patients analyzed was 67 years (range: 46-94 years; 106 were men); and 94 and 56 patients had ≥ 70% and 50-69% stenosis, respectively. The mean and median time intervals between index event and CAS performance were 25 and 6 days, respectively. A total of 6 new cerebral ischemic events (5 TIAs and 1 major stroke) were observed over 3,776 patient days of observation. The risk of new ipsilateral cerebral ischemic events between index ischemic event and CAS performance was 1.6 per 1000 patient days of observation. Conclucion: We identified a low risk of new ipsilateral cerebral ischemic events in patients with ≥ 50% ICA stenosis while waiting for CAS presumably due to early initiation of dual antiplatelets.

Abstract 13392: 3D TEE Aids in Assessment of Embolic Stroke Due to Aortic Atherosclerotic Plaque

Case Presentation: A 69-year-old right-handed man presented with new left-sided weakness and recurrent ischemic strokes. His had history of coronary artery disease, diabetes mellitus, hypertension, dyslipidemia, chronic kidney disease stage 3, obstructive sleep apnea and obesity. Plasma low-density lipoprotein was 127 mg/dL. Brain MRI showed diffusion restriction in the left caudate head, left corona radiata, left anterior lentiform nucleus, and left periventricular white matter from acute to subacute infarction. CT angiogram showed diffuse atheromatous disease in the anterior and posterior circulation, bilateral mild cervical internal carotid artery stenosis, and calcifications in the aortic arch ( Figure 1 ). Transthoracic echocardiogram (TTE) showed mild generalized left ventricular hypokinesis (ejection fraction 45%) without thrombus. Transesophageal echocardiogram (TEE) showed complex mobile atherosclerotic plaques in the aortic arch ( Figure 2 ) after which Apixaban & Clopidogrel were started and statins increased. At 1-year follow-up there was no recurrent stroke. Discussion: This case highlights the role of 3D TEE in the detection of complex aortic arch atherosclerotic plaque with mobile components as the etiology of recurrent embolic stroke. 2D TTE & TEE and CT chest were unable to show mobile components in the aortic arch plaque. Many patients identified as having “cryptogenic stroke” after 2D TTE & TEE may in fact have mobile aortic arch plaques which can only be delineated by 3D TEE, thus reducing the need for further workup and expediting appropriate treatment.

Clinical utility of new bone imaging using zero-echo-time sequence in neurosurgical procedures: Can zero-echo-time be used in clinical practice in neurosurgery?

The purpose of this study was to evaluate the clinical usefulness of zero-echo-time (ZTE)-based magnetic resonance imaging (MRI) in planning the optimum surgical approach and applying ZTE for anatomical guidance during transcranial surgery. Eleven of 26 patients who underwent transcranial surgery and carotid endarterectomy and in whom ZTE-based MRI and magnetic resonance angiography (MRA) data were obtained were analyzed by creating ZTE/MRA fusion images and 3D ZTE-based MRI models. We examined whether these images and models can be substituted for computed tomography imaging for neurosurgical procedures. Furthermore, the clinical usability of the 3D ZTE-based MRI models was evaluated by comparing them with actual surgical views. Zero-echo-time/MRA fusion images and 3D ZTE-based MRI models clearly illustrated the cranial and intracranial morphology without radiation exposure or the use of iodinated contrast medium. The models allowed determination of the optimum surgical approach to cerebral aneurysms, brain tumors near the brain surface, and cervical internal carotid artery stenosis by visualizing the relationship of lesions with adjacent bone structures. However, ZTE-based MRI did not provide useful information for surgery for skull base lesions such as vestibular schwannoma because bone structures of the skull base often include air components, which cause signal disturbance in MRI. Zero-echo-time sequences on MRI allowed distinct visualization of not only bone but also vital structures around the lesion. This technology has low invasiveness for patients and was useful for preoperative planning and guidance of the optimum approach during surgery in a subset of neurosurgical diseases.

Intra-arterial infusion of fasudil hydrochloride for cerebral vasospasm secondary to carotid artery stenting: illustrative case

BACKGROUNDHypoperfusion due to intracranial cerebral vasospasm after carotid artery stenting (CAS) is rare. The authors presented a case of selective intraarterial infusion of fasudil hydrochloride for cerebral vasospasm after CAS.OBSERVATIONSA 73-year-old man received CAS for asymptomatic right cervical internal carotid artery stenosis. Twelve hours after CAS, disturbance of consciousness, left hemiplegia, and right conjugate deviation appeared in the patient. Head computed tomography angiography showed diffuse vasospasm of the right middle cerebral artery (MCA). The authors hypothesized that the cause of the symptoms was hypoperfusion due to intracranial cerebral vasospasm. Medical treatment was started; however, the focal symptoms worsened rapidly. Therefore, the authors decided to infuse fasudil intraarterially. This treatment resulted in a remarkable improvement in blood flow and gradual recovery from neurological symptoms. Head magnetic resonance angiography on the day after fasudil infusion showed improved visualization of the right MCA. The neurological symptoms almost completely disappeared 22 hours after fasudil infusion (40 hours after CAS).LESSONSAs a complication after CAS, the possibility of hypoperfusion due to cerebral vasospasm should be considered. If symptoms due to hypoperfusion worsen even after medical treatment, intraarterial infusion of fasudil may be an effective option.

Persistent Primitive Hypoglossal Artery with Ipsilateral Symptomatic Carotid Artery Stenosis and Cerebral Aneurysm

ObjectivePersistent primitive hypoglossal artery (PPHA) is a rare type of persistent carotid-basilar anastomosis sometimes associated with other vascular lesions. We treated an extremely rare case of PPHA with concomitant ipsilateral symptomatic cervical internal carotid artery (ICA) stenosis and unruptured aneurysm. Case presentationA 67-year-old woman visited our institution with acute onset of diplopia. Magnetic resonance imaging revealed multiple acute infarctions in the right anterior and posterior circulations. Digital subtraction angiography demonstrated the right PPHA concomitant with ipsilateral cervical ICA stenosis and an unruptured ICA aneurysm with maximum diameter of 8 mm. The multiple infarctions were considered to result from artery-to-artery embolism due to microthrombi from the ICA plaque passed along the PPHA, so carotid endarterectomy was performed as the first step with preoperative modified Rankin Scale (mRS) grade 1. During the operation, the patient had impaired ICA perfusion due to internal shunt catheter migration into the PPHA followed by acute infarction in the right hemisphere causing mild left hemiparesis. The patient was transferred to the rehabilitation hospital with mRS grade 3. After 3 months of rehabilitation, the patient recovered to mRS grade 1 and clipping surgery for the unruptured right ICA aneurysm was performed as the second step with uneventful postoperative course. ConclusionThe treatment strategy should be carefully considered depending on the specific blood circulation for such cases of PPHA with unique vasculature.

Skull shape abnormalities in ischemic cerebrovascular and mental diseases in adults

Morphological changes in the child skull due to mechanical and metabolic stimulation and synostosis of the suture are well known. On the other hand, few studies have focused on clinical conditions relevant for adult skull deformity. We retrospectively reviewed computed tomography (CT) findings obtained from 365 cases that were treated for head injuries, moyamoya disease, cervical internal carotid artery stenosis, and mental diseases, and investigated the morphological changes in the skull associated with these diseases. The findings from head injuries were used not only for control subjects, but also for the analysis of generational changes in skull shape based on birth year. Head shape had a brachiocephalic tendency with occipital flattening in people born from the 1950s onwards. Cases of moyamoya disease, cervical internal carotid artery stenosis, and mental diseases showed significantly thicker frontal and occipital bone than those of control subjects. The skull thickening was especially noticeable in the frontal bone in moyamoya disease. Plagiocephaly was significantly frequent in moyamoya disease. These uncommon skull shapes are useful CT findings in screening subjects for early evidence of mental diseases and intracranial ischemic diseases with arterial stenosis.

Future stroke risk in the chronic phase of post-percutaneous coronary intervention.

A percutaneous coronary intervention (PCI) is widely performed for acute coronary syndromes or chronic coronary syndromes. Periprocedural stroke is a clinically significant complication during PCI. The incidence of cerebrovascular events (CVEs) after PCI in the chronic phase is obscure. This study aimed to investigate the prevalence of CVEs after PCI in the chronic phase and evaluate the usefulness of a simple coronary artery calcification (CAC) evaluation method. This prospective observational study included 179 patients who underwent PCI between January 2016 and December 2018. The incidence of cerebral infarction was examined from one month after PCI to December 2019. In total, 171 individuals (134 men; mean age, 69.8 ± 9.8 years) were recruited. During a median follow-up period of 33 months, the onset of cerebral infarction was observed in 20 individuals (11.7%). More CAC sites (p = 0.009) and post-PCI for the chronic coronary syndrome (p = 0.049) showed a significant association with future CVEs. There was no significant cervical internal carotid artery stenosis for patients who occurred CVEs. The cutoff value for the number of CAC sites for predicting future CVEs was 4.5. The new and easy method accurately reflected future CVEs risk and may be clinically applicable.

Usefulness of 2D-Perfusion Analysis for the Assessment of Unilateral Cervical Internal Carotid Artery Stenosis.

We investigated the usefulness of 2D-perfusion analysis for the evaluation of cerebral blood flow in unilateral cervical internal carotid artery stenosis. We conducted a 2D-perfusion analysis during cerebral angiography and 123I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) for unilateral cervical internal carotid artery stenosis without contralateral stenosis. The relationship between the ratio of the lesion side to the normal side in the parameters obtained by 2D-perfusion and the value calculated by stereotactic extraction estimation (SEE) analysis of SPECT was statistically examined. The ratios of the lesion side to the normal side regarding the peak arrival time (AT; time to peak [TTP]) of the contrast agent and the mean filling time (mean transit time [MTT]) of the contrast agent in 2D-perfusion significantly correlated with the area of Stage II and increase ratio (I.R) ≤30% in the SEE analysis (p = 0.002, 0.003). 2D-perfusion analysis can be used to estimate the extent of impaired cerebrovascular reserve (CVR) area in unilateral internal carotid artery stenosis.

Case series of acute ischemic stroke with tandem lesions of intracranial large vessel occlusion and cervical internal carotid artery stenosis or occlusion

要旨：頭蓋内主幹動脈閉塞に頸部内頸動脈狭窄もしくは閉塞を伴う tandem lesions を有する急性期脳梗塞に対し，早期再灌流最優先の方針で加療した rt-PA 非投与の自験5例をもとに，その治療戦略について検討した．頸動脈狭窄が高度で血栓回収とCASを一期的に併用した3症例については，血栓吸引カテーテルが近位部病変を通過困難な1例ではCASを先行し，通過可能な2例では血栓回収先行後，CASを追加した．全例で良好な再開通が得られたが，1例でステント内血栓症を合併した．ステント留置による過凝固傾向を惹起した可能性があった．頸動脈中等度狭窄で術中狭窄の進行がない2例では，CEAによる二期的血行再建術を選択したが，web状狭窄を伴った1例に脳梗塞の再発が生じた．中等度狭窄であっても可及的早期の CAS/CEA を検討すべきである．

One-Way Valve Method for Achieving Effective Flow Reversal on Carotid Artery Stenting.

We report a simplified method of manual transfusion with a one-way valve during carotid artery stenting (CAS) with flow reversal. A 77-year-old man with cervical internal carotid artery stenosis who developed vulnerable plaques was scheduled for CAS using flow reversal. Blood flow reversal was naturally caused by the arteriovenous pressure gradient, and a method with a one-way valve, which enables simplified manual transfusion using a syringe technique, was used for the patient. CAS was completed without distal embolization. Manual transfusion can be simplified using a one-way valve in cases of flow reversal during CAS, which often require complicated procedures.

White-matter hyperintensities in patients with carotid artery stenosis: An exploratory connectometry study.

White-matter lesions (WMLs) are frequently found in magnetic resonance imaging (MRi), and the WML load tends to be higher in patients affected by cervical internal carotid artery (cICA) stenosis. This study aimed to investigate whether and how WMLs influence cerebral networking in patients with asymptomatic cICA stenosis eligible for carotid endarterectomy (CEA) by exploiting the connectometry technique. The study was designed as a cross-sectional exploratory investigation, and 28 patients with cICA stenosis eligible for CEA were enrolled. All patients received an MRI scan, including a T1-weighted, a FLAIR and a diffusion-weighted (DW) sequence. The T1 and FLAIR sequences were analysed for quantification of WML burden (WMLB) and total number of WMLs (TNWMLs). The DW data were reconstructed in the MNI space using q-space diffeomorphic reconstruction, and were grouped to create a connectometry database. The connectometry analysis evaluated the influence of both the WMLB and TNWMLs to local connectivity in a multiple regression model that included age, WMLB and TNWMLs, adopting three different T-score thresholds (1, 2 and 3). A p-value corrected for false discovery rate of <0.05 was adopted as a threshold to identify statistically significant results. The connectometry analysis identified several white-matter bundles negatively correlated with WMLB; no statistically significant correlation was found for TNWMLs. Results of our study suggest that WMLs influence brain connectivity measured by the connectometry technique in patients with cICA stenosis eligible for CEA. Further studies are warranted to understand the role of WMLs better as a marker of disease in patients with cICA stenosis.