One-Stage Combined Open and Endovascular Treatment Using a Hybrid Operating Room is Safe and Effective for Distal Middle Cerebral Artery Aneurysms.

BACKGROUND: Aneurysms located in the distal middle cerebral artery (DMCA) are relatively rare and lack an established treatment strategy. For DMCA aneurysms, we performed a one-stage combined procedure of endovascular parent artery occlusion (PAO) with coils and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in a hybrid operating room (HOR). The aim of this study was to evaluate the safety and efficacy of this procedure. METHODS: Cases of unruptured DMCA aneurysms treated with the one-stage combined PAO and STA-MCA bypass in HOR were retrospectively examined, and patients' and aneurysmal backgrounds, surgical procedures, and treatment outcomes were analyzed. RESULTS: Six patients were included in the study. The average maximum diameter of the aneurysms was 14.4 mm. One aneurysm was located at M2 and five at M3. All aneurysms had a fusiform shape. No cases were associated with infection, trauma, or malignant tumors. In all 6 cases, the combined PAO and STA-MCA bypass was successfully completed. No postoperative hemorrhagic complications occurred. A symptomatic ischemic complication occurred in 1 case whose symptom disappeared in a week. Three months after surgery, complete obliteration of the aneurysm and patency of the bypass was confirmed in all cases. CONCLUSIONS: The one-stage combined PAO and STA-MCA bypass in the HOR is safe and effective for DMCA aneurysms, potentially serving as a treatment option for this complex aneurysm.

Short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE): a multicenter, open-label, randomized clinical trial.

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) after stent-assisted coil embolization (SACE) for cerebral aneurysm remains uncertain. This randomized trial of short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE) aimed to clarify whether long-term DAPT can reduce the occurrence of ischemic stroke in patients with cerebral aneurysms treated by SACE compared with short-term DAPT. METHODS: Patients treated for cerebral aneurysm with SACE were enrolled from 17 hospitals in Japan. Patients were enrolled within 30 days after SACE and assigned in a 1:1 ratio to receive long-term (12 months) or short-term (3 months) DAPT with aspirin and clopidogrel. Randomization was performed centrally through a web-based system. The primary outcome was the time to ischemic stroke event during 3 to 12 months after SACE. This trial was registered with the Japan Registry of Clinical Trials (jRCTs051180141). RESULTS: A total of 142 patients were recruited from November 4, 2016 to January 7, 2019. Among them, 65 and 68 patients assigned to the long- and short-term DAPT groups, respectively, were included in the full analysis set. Ischemic stroke occurred in no patients in the long-term DAPT group and in one patient in the short-term DAPT group. The incidence rate did not differ between the groups (0.0 vs 2.1/100 person-years; log rank test, P=0.33). CONCLUSIONS: In this multicenter randomized controlled trial, there was not a statistically significant difference in the rate of ischemic strokes between long- and short-term DAPT.

Rigid but nonmetallic cranioplasty after pterional craniotomy: Technical note.

Background: Given the popularity of pterional craniotomy, numerous modifications have been made to prevent postoperative deformities. With the advent of titanium plates, fixation has become both simple and excellent. However, titanium plates can cause skin problems, infection, or cause skull growth to fail. Methods: To develop a simple, cost-effective, and esthetically satisfactory fixation method, without the use of non-metallic materials, six young and older patients underwent pterional craniotomy. CranioFix Absorbable clamps were used to fix the bone flap in the frontal and temporal regions such that the frontal part was in close contact with the skull. After fixation, the bone chips and bone dust were placed in the bone gap and fixed with fibrin glue. We measured the computed tomography values of the reconstructed area and thickness of the temporal profiles postoperatively over time. Results: Bone fusion was achieved in all patients by 1 year after surgery. Both the thickness of the temporalis muscle and the thickness of the temporal profile had changed within 2 mm as compared with the preoperative state. Conclusion: Our simple craniotomy technique, gentle tissue handling, and osteoplastic cranioplasty yielded satisfactory esthetic results and rigidness in pterional craniotomy.

Relation between duration of dual antiplatelet therapy and risk of ischemic stroke after stent-assisted treatment of cerebral aneurysm (DAPTS ACE-registry).

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) in patients with cerebral aneurysm who undergo stent-assisted coil embolization (SACE) has not been established. We aimed to clarify the association between duration of DAPT and incidence of ischemic stroke in patients with cerebral aneurysm. METHODS: We registered patients with cerebral aneurysm who underwent SACE in 27 hospitals in Japan. Those treated with DAPT (aspirin and clopidogrel) were eligible for inclusion in a previously reported randomized control trial (RCT). Patients who were ineligible or refused to participate to the RCT were followed-up for 15 months after SACE as the non-RCT cohort. Our study examined both the RCT and non-RCT cohorts. The primary and secondary outcomes were ischemic stroke and hemorrhagic events. RESULTS: Among the 313 patients registered, 296 were included for analysis (of these, 136 were RCT patients and 160 were non-RCT patients). Patients who were treated with DAPT for more than 6 months (n=191) were classified as the long-term DAPT group. Those treated less than 6 months (n=105) were classified as the short-term group. The incidence of ischemic stroke did not significantly differ between the long-term group (2.5 per 100 person-years) and the short-term group (3.2 per 100 person-years); nor did incidence of hemorrhagic events (0.8 and 3.2 per 100 person-years, respectively). The period of DAPT was not significantly associated with incidence rates of ischemic stroke or hemorrhagic events. CONCLUSIONS: Duration of DAPT was not associated with the incidence of ischemic stroke in the first 15 months after SACE.

[Carotid Artery Stenosis:Indications and Outcomes].

Carotid artery stenting(CAS)has emerged as a less invasive alternative to carotid endarterectomy(CEA), the standard surgical treatment for carotid artery stenosis. Major international randomized control trials(RCTs)have demonstrated its non-inferiority to CEA, and it is now recommended in the Japanese stroke treatment guidelines for both symptomatic and asymptomatic severe stenotic lesions. To ensure safety, it is essential to use an embolic protection device to prevent ischemic complications and maintain the quality of physicians proficient in both techniques and devices. In Japan, these two essentials are guaranteed with the aid of a board certification system by the Japanese Society for Neuroendovascular Therapy. Furthermore, preprocedural carotid plaque evaluation using non-invasive methods such as ultrasonography and magnetic resonance imaging to detect vulnerable plaques, which are considered at high risk for embolic complications, is frequently performed, thereby determining therapeutic indications to avoid adverse events. Thus, the results of CAS in Japan are far superior to those of RCT abroad, making this procedure the first-line therapy for carotid revascularization for decades.

Bypass failure of internal mammary artery caused by subclavian artery stenosis: its clinical characteristics and cardiovascular outcomes in patients receiving coronary artery bypass graft surgery.

Background: While internal mammary artery (IMA) has become a major conduit of coronary artery bypass graft (CABG) surgery, subclavian artery stenosis (SAS) could cause subsequent coronary events due to ischemia of myocardial territory supplied by IMA. Clinical characteristics and cardiovascular outcomes of SAS-related IMA failure (SAS-IMAF) remain to be fully determined yet. Therefore, the current study was designed to characterize SAS-IMAF in patients receiving CABG with IMA. Methods: This is a retrospective observational study which analyzed 380 patients who presented acute coronary syndrome/stable ischemic heart disease (ACS/SIHD) after CABG using IMA (2005.01.01-2020.10.31). SAS-IMAF was defined as the presence of myocardial ischemia/necrosis caused by SAS. Clinical characteristics and cardiovascular outcomes [major adverse cardiovascular events (MACE) = cardiac death + non-fatal myocardial infarction + non-fatal ischemic stroke], were compared in subjects with and without SAS-IMAF. Multivariate Cox proportional hazards model and propensity score-matched analyses were used to compare cardiovascular outcomes between those with and without SAS-IMAF. Results: SAS-IMAF was identified in 5.5% (21/380) of study subjects. Patients with SAS-IMAF are more likely had a history of hemodialysis (P<0.001), stroke (P<0.001) and lower extremity artery disease (P<0.001). Furthermore, SAS-IMAF patients more frequently presented ACS (P=0.002) and required mechanical support (P=0.02). Despite SAS as a culprit lesion causing ACS/SIHD, percutaneous coronary intervention was firstly selected in 47.6% (10/21) of them. Consequently, 33.3% (7/21) of SAS-IMAF patients required additional revascularization procedure (vs. 0.3%, P<0.001). During 4.9-year observational period, SAS-IMAF exhibited a 5.82-fold [95% confidence interval (CI): 2.31-14.65, P<0.001] increased risk of MACE. Multivariate Cox proportional hazards model [hazard ratio (HR) 4.04, 95% CI: 1.44-11.38, P=0.008] and propensity score-matched analyses (HR 2.67, 95% CI: 1.06-6.73, P=0.038) consistently demonstrated the association of SAS-IMAF with MACE. Conclusions: SAS-IMAF reflects a high-risk phenotype of polyvascular disease, underscoring meticulous evaluation of subclavian artery after CABG using IMA.

Mechanical Thrombectomy Up to 24 Hours in Large Vessel Occlusions and Infarct Velocity Assessment.

Background We retrospectively compared early- (<6 hours) versus late- (6-24 hours) presenting patients using perfusion-weighted imaging selection and evaluated clinical/radiographic outcomes. Methods and Results Large vessel occlusion patients treated with mechanical thrombectomy from August 2017 to July 2020 within 24 hours of onset were retrieved from a single-center database. Perfusion-weighted imaging was analyzed by automated software and final infarct volume was measured semi-automatically within 14 days. The primary end point was good outcome (modified Rankin Scale 0-2 at 90 days). Secondary end points were excellent outcome (modified Rankin Scale 0-1 at 90 days), symptomatic intracranial hemorrhage, and death. Clinical characteristics/radiological values including hypoperfusion volume and infarct growth velocity (baseline volume/onset-to-image time) were compared between the groups. Of 1294 patients, 118 patients were included. The median age was 74 years, baseline National Institutes of Health Stroke Scale score was 14, and core volume was 13 mL. The late-presenting group had more female patients (67% versus 31%, respectively; P=0.001). No statistically significant differences were seen in good outcome (42% versus 53%, respectively; P=0.30), excellent outcome (26% versus 32%, respectively; P=0.51), symptomatic intracranial hemorrhage (6.5% versus 4.6%, respectively; P=0.74), and death (3.2% versus 5.7%, respectively; P=0.58) between the groups. The late-presenting group had more atherothrombotic cerebral infarction (19% versus 6%, respectively; P=0.03), smaller hypoperfusion volume (median: 77 versus 133 mL, respectively; P=0.04), and slower infarct growth velocity (median: 0.6 versus 5.1 mL/h, respectively; P=0.03). Conclusions Patients with early- and late-time windows treated with mechanical thrombectomy by automated perfusion-weighted imaging selection have similar outcomes, comparable with those in randomized trials, but different in infarct growth velocities. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02251665.

Outcome of Endovascular Therapy Aiming for Single-session Obliteration of Intracranial Dural Arteriovenous Fistulas.

The goal of dural arteriovenous fistula (dAVF) treatment is obliteration of the arteriovenous shunt and/or retrograde leptomeningeal venous drainage (RLVD). Single-session obliteration could improve symptoms early and reduce risk of neurological sequelae. This study investigated the efficacy and adverse events of endovascular therapy (EVT) aiming for single-session obliteration in dAVF treatment. We retrospectively examined post-treatment arteriovenous shunt status, number of treatments per case, treatment-related complications, and long-term outcome in 92 dAVF patients who underwent initial EVT at our institution. Single-session obliteration was intended in all cases, but a second session was performed in cases of partial shunt occlusion or remaining RLVD. Complete occlusion was achieved in 85 cases (92.4%) after the single session; RLVD was obliterated in 66 of the 67 Borden type II and III cases combined (98.5%). A second session was necessary in seven cases (7.6%). Complete shunt obliteration was eventually achieved in all cases. The average number of treatments was 1.08 per case. dAVF-related stroke and mortality did not occur after the treatment. On the other hand, radiation-induced skin erythema and alopecia, although all symptoms were transient, occurred in 26 cases (28.3%). Over an average 60.2-month follow-up period, recurrence was observed in seven cases (7.6%). Single-session obliteration was successful in 92% of cases. Especially, single-session obliteration of RLVD may contribute to early prevent of future stroke events. However, reducing total radiation dose during each session is an issue of further study.

Hyperperfusion Syndrome Detected by 15O-Gas Positron Emission Tomography after Clipping of a Large Unruptured Internal Carotid Artery Aneurysm: A Case Report.

Cerebral hyperperfusion syndrome (CHS) after surgical clipping for cerebral aneurysm is a rare entity. The authors present a 76-year-old woman with a large left internal carotid-posterior communicating artery aneurysm. After successful clipping with temporary occlusion of the internal carotid artery, the patient exhibited motor aphasia. 15O-gas positron emission tomography (PET) showed extreme elevation of the regional cerebral blood flow (rCBF) along with a mildly decreased regional cerebral metabolic rate for oxygen (rCMRO2) and a remarkable decrease in the oxygen extraction fraction (OEF) in the territory of the ipsilateral superior trunk of the middle cerebral artery. These data indicated local hyperperfusion. She had fully recovered from the aphasia by postoperative day (POD) 18. PET showed normalization of CBF on POD 27. To our knowledge, this is the first case report to show hyperperfusion syndrome, clearly detected by 15O-gas PET, after aneurysmal neck clipping.

Identifying large ischemic core volume ranges in acute stroke that can benefit from mechanical thrombectomy.

BACKGROUND: We aimed to identify the large ischemic core (LIC) volume ranges in acute ischemic stroke patients that can benefit from mechanical thrombectomy (MT). METHODS: Consecutive patients within 24 hours of onset of anterior circulation ischemic stroke with large vessel occlusion and ischemic core volumes of 70-300 mL were included from our single-center prospective database from March 2014 to December 2019. Subjects were divided into three groups by baseline ischemic core volume (A: 70-100 mL; B: 101-130 mL; C: >130 mL). We compared modified Rankin Scale (mRS) score 0-2 at 3 months and parenchymal hematoma between patients receiving MT and standard medical treatment (SMT), and determined clinically treatable core volume ranges for MT. RESULTS: Of 157 patients (86 women; median age, 81 years; median ischemic core volume, 123 mL), 49 patients underwent MT. In Group A (n=52), MT patients (n=31) showed a higher proportion of mRS 0-2 at 3 months (52% vs 5%, P<0.05) versus SMT, respectively. Group B (n=36) MT patients (n=14) also had a higher proportion of mRS 0-2 at 3 months (29% vs 9%, P=0.13) versus SMT, respectively. In Group C (n=69), only four patients received MT. The 95% confidence intervals for the probability of mRS 0-2 at 3 months in patients with MT (n=49) versus SMT (n=108) intersected at 120-130 mL. CONCLUSIONS: Ischemic core volumes between 70 and 100 mL may benefit from MT. The treatable upper core limit is approximately 120 mL in selected patients with LIC of 70-300 mL.

Factors related to adverse events during endovascular coil embolization for ruptured cerebral aneurysms.

BACKGROUND AND PURPOSE: The risk factors for adverse events for example, intraprocedural rupture (IPR), ischemic complication within 24 hours, and rebleeding after endovascular coil embolization for a ruptured cerebral aneurysm remain unclear. The aim of this study was to identify significant associated risk factors. METHODS: We retrospectively evaluated data from 5358 patients listed on the Japanese Registry of Neuroendovascular Therapy 3 during 2010-2014. RESULTS: IPR, ischemic complications, and rebleeding occurred during or after 221 (4.1%), 226 (4.2%), and 63 (1.2%) treatments, respectively. All of the adverse events were significantly associated with the patients' poor outcomes at 30 days. Multivariate analysis revealed the factors independently related to these adverse events as follows: (1) for IPR: female sex, bifurcation type, <5 mm aneurysm, emergent surgery, local anesthesia, a balloon-assisted technique; (2) for an ischemic complication: poor World Federation World Federation of Neurological Societies (WFNS) grade, wide neck, and stent-assisted technique; (3) for rebleeding: poor WFNS grade, bifurcation type, wide neck, and body filling as the initial result. CONCLUSIONS: Knowledge of the risk factors of endovascular coil embolization and paying attention to them are essential for patients' safe treatment and good outcomes.

The Current Status of Endovascular Treatment for Extracranial Steno-occlusive Diseases in Japan: Analysis Using the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3).

Endovascular treatment of extracranial steno-occlusive lesions is an alternative to direct surgery. There is no consensus regarding the natural course and standard treatment of these lesions. The aim of this study was to identify the current status of endovascular treatment for extracranial steno-occlusive lesions. A total of 1154 procedures for extracranial steno-occlusive lesions, except for internal carotid artery stenosis, were collected from the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3). Atherosclerotic lesions were most frequent (1021 patients, 88.5%). Endovascular treatment was performed for 456 (39.5%) patients with subclavian artery, 349 (30.2%) with extracranial vertebral artery, 172 (14.9%) with the origin of common carotid artery, and 38 (3.3%) with innominate artery stenosis; the overall technical success rate was 98.0%. Percutaneous transluminal angioplasty was performed in 307 patients (26.6%) and stenting in 838 (72.6%). An embolic protection device (EPD) was used in 571 patients (49.5%), and procedure under general anesthesia was performed in 168 (14.6%). Preoperative antiplatelet therapy was administered in 1091 procedures (94.5%). A good outcome was obtained for 962 patients (83.4%). Complications were observed in 89 patients (7.7%). The procedure under general anesthesia was statistically significant factors (P <0.01), and also after multivariable adjustment (odds ratio 2.29; 95% confidence interval 1.25-4.17; P <0.01). Comparisons between JR-NET3 and previous cohorts (JR-NET1&2), the utilization of EPD and complications increased significantly, and the type of antiplatelet therapy changed markedly. Based on the results of this study, endovascular treatment for extracranial steno-occlusive lesions is relatively safe. Further prospective studies are necessary to validate the beneficial effects.

A comparison of the prevalence and risk factors of complications in intracranial tumor embolization between the Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and JR-NET3.

BACKGROUND: The Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and 3 (JR-NET3) were nationwide surveys that evaluated clinical outcomes after neuroendovascular therapy in Japan. The aim of this study was to compare the prevalence and risk factors of complications of intracranial tumor embolization between JR-NET2 and JR-NET3. METHODS: A total of 1018 and 1545 consecutive patients with intracranial tumors treated with embolization were enrolled in JR-NET2 and JR-NET3, respectively. The prevalence of complications in intracranial tumor embolization and related risk factors were compared between JR-NET2 and JR-NET3. RESULTS: The prevalence of complications in JR-NET3 (3.69%) was significantly higher than that in JR-NET2 (1.48%) (p = 0.002). The multivariate analysis in JR-NET2 showed that embolization for tumors other than meningioma was the only significant risk factor for complication (odds ratio [OR], 3.88; 95% confidence interval [CI], 1.13-12.10; p = 0.032), and that in JR-NET3 revealed that embolization for feeders other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; p < 0.001) and use of liquid materials (OR, 2.65; 95% CI, 1.50-4.68; p < 0.001) were significant risks for complications. The frequency of embolization for feeders other than ECA in JR-NET3 (15.3%) was significantly higher than that in JR-NET2 (9.2%) (p < 0.001). Also, there was a significant difference in the frequency of use of liquid materials between JR-NET2 (21.2%) and JR-NET3 (41.2%) (p < 0.001). CONCLUSIONS: Embolization for feeders other than ECA and use of liquid materials could increase the complication rate in intracranial tumor embolization.

Treatment Outcome of Intracranial Tumor Embolization in Japan: Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3).

Embolization for intracranial tumor is performed as a standard endovascular treatment. A retrospective, multicenter, observational study was conducted to clarify the nature, frequency, and risk factors of complications in intracranial tumor embolization. Patients were derived from the Japanese Registry of NeuroEndovascular Therapy (JR-NET3) using data taken from January 2010 through December 2014 in Japan. A total of 40,169 patients were enrolled in JR-NET3, of which, 1,545 patients (3.85%) with intracranial tumors underwent embolization. The primary end point was the proportion of patients with a modified Rankin scale (mRS) score of 0-2 (independency) at 30 days after embolization. The secondary end point was the occurrence of complications related to the procedures. The risk factors of the development of complications were analyzed. The proportion of patients with mRS scores ≤2 at 30 days after procedure was 89.5%. Complications occurred in 57 of the 1544 patients (3.7%). Multivariate analysis showed that target vessels other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; P <0.001) and use of liquid material (OR, 2.65; 95% CI, 1.50-4.68; P <0.001) were significantly associated with the development of complications. In JR-NET3, the primary end point was 89.5%, and the procedure-related complication rate was 3.7%. Embolization from other than ECA was significant risk factor of the complications. In addition, increasing usage of liquid embolic material worsened the risk of complications.

Vascular wall components in thrombi obtained by acute stroke thrombectomy: clinical significance and related factors.

BACKGROUND AND PURPOSE: Vascular wall components (VWCs) are sometimes identified as collagen fibers in specimens retrieved by thrombectomy from acute stroke patients. However, their clinical significance and associated factors remain unclear. The purpose of this study was to clarify the factors associated with VWCs in retrieved thrombi. METHODS: Consecutive acute stroke patients treated endovascularly using the Penumbra aspiration catheter or stent retrievers (SRs) at our institute from November 2013 to April 2016 were retrospectively reviewed, and the retrieved thrombi were evaluated histopathologically. VWCs were defined as banded collagen fibers with a distinct boundary observed at the rim or outside of the retrieved thrombi. Factors associated with the presence of VWCs were studied. RESULTS: A total of 150 specimens (76 specimens retrieved by the Penumbra, 74 by SRs) from 101 patients (47 women, age 74.9±11.1 years) were investigated. Applied thrombectomy devices were aspiration catheters in 42 patients, SRs in 21 patients, and both in 38 patients. VWCs were observed in 24 specimens (16%) from 22 patients. A low proportion of erythrocyte components (41.7±24.8% vs 55.0±26.3%, P=0.01), a high frequency of the devices reaching the M2/P2 (75% vs 50%, P=0.02), and a high number of device passages (P for trend=0.02) were associated with VWC positive thrombi. Successful recanalization (Treatment in Cerebral Ischemia ≥2b) tended to be less frequent in patients with VWC positive thrombi than in those without (73% vs 89%, P=0.06). CONCLUSIONS: The histopathology of occlusive thrombi, arterial sites where devices reached, and number of device passages, might affect the presence of VWCs in retrieved thrombi.

Neurosurgical Management and Outcomes of Cerebrovascular Disease in Pediatric Patients with Heart Disease.

Antithrombotic treatment has substantial risks, even in pediatric patients. We retrospectively evaluated the management and outcomes of consecutive pediatric patients who underwent neurosurgical treatment for cerebrovascular disease with cardiovascular disease between 1998 and 2017. Patients were divided into patients with comorbid cardiovascular disease (group I); and patients with cardiovascular disease as a primary disease of intracranial complication, without (group IIa) or with (group IIb) extracorporeal circulations. Postoperative resumption of antithrombotic agents was generally initiated within 48 h. Our study included 26 patients; five were categorized as group I, 15 as group IIa, and six as group IIb. All intracranial diseases in groups IIa and IIb were exclusively hemorrhagic. Preoperative anticoagulation therapy was used in one patient (20%) in group I, 13 patients (86.7%) in group IIa, and six patients (100%) in group IIb. Postoperative intracranial hemorrhagic events were observed in one patient (20%) in group I, three patients (20%) in group IIa, and four patients (66.7%) in group IIb. Re-operations were conducted in two (13.3%) and three patients (50%) in groups IIa and IIb, respectively. Death occurred in five (33.3%) and four patients (66.7%) in groups IIa and IIb, respectively. The remaining two patients in group IIb returned to candidate status for implantation. Emergent surgery for patients with intracranial hemorrhage associated with cardiovascular disease has a high risk of postoperative hemorrhagic events and high rate of re-operations with poor vital outcomes, especially in patients with extracorporeal circulations. We should consider maximum neurosurgical treatment achievable with optimal management of antithrombotic treatment.

Clinical implications of the cortical hyperintensity belt sign in fluid-attenuated inversion recovery images after bypass surgery for moyamoya disease.

OBJECTIVE Transient neurological symptoms are frequently observed during the early postoperative period after direct bypass surgery for moyamoya disease. Abnormal signal changes in the cerebral cortex can be seen in postoperative MR images. The purpose of this study was to reveal the radiological features of the "cortical hyperintensity belt (CHB) sign" in postoperative FLAIR images and to verify its relationship to transient neurological events (TNEs) and regional cerebral blood flow (rCBF). METHODS A total of 141 hemispheres in 107 consecutive patients with moyamoya disease who had undergone direct bypass surgery were analyzed. In all cases, FLAIR images were obtained during postoperative days (PODs) 1-3 and during the chronic period (3.2 ± 1.13 months after surgery). The CHB sign was defined as an intraparenchymal high-intensity signal within the cortex of the surgically treated hemisphere with no infarction or hemorrhage present. The territory of the middle cerebral artery was divided into anterior and posterior parts, with the extent of the CHB sign in each part scored as 0 for none; 1 for presence in less than half of the part; and 2 for presence in more than half of the part. The sum of these scores provided the CHB score (0-4). TNEs were defined as reversible neurological deficits detected both objectively and subjectively. The rCBF was measured with SPECT using N-isopropyl-p-[123I]iodoamphetamine before surgery and during PODs 1-3. The rCBF increase ratio was calculated by comparing the pre- and postoperative count activity. RESULTS Cortical hyperintensity belt signs were detected in 112 cases (79.4%) and all disappeared during the chronic period. Although all bypass grafts were anastomosed to the anterior part of the middle cerebral artery territory, CHB signs were much more pronounced in the posterior part (p < 0.0001). TNEs were observed in 86 cases (61.0%). Patients with TNEs showed significantly higher CHB scores than those without (2.31 ± 0.13 vs 1.24 ± 0.16, p < 0.0001). The CHB score, on the other hand, showed no relationship with the rCBF increase ratio (p = 0.775). In addition, the rCBF increase ratio did not differ between those patients with TNEs and those without (1.15 ± 0.033 vs 1.16 ± 0.037, p = 0.978). CONCLUSIONS The findings strongly suggest that the presence of the CHB sign during PODs 1-3 can be a predictor of TNEs after bypass surgery for moyamoya disease. On the other hand, presence of this sign appears to have no direct relationship with the postoperative local hyperperfusion phenomenon. Vasogenic edema can be hypothesized as the pathophysiology of the CHB sign, because the sign was transient and never accompanied by infarction in the present series.

Relationship between histologic features and outcomes of carotid revascularization for radiation-induced stenosis.

OBJECTIVE: This study aimed to elucidate the relationships between preoperative carotid imaging results, histologic characteristics, and surgical treatment outcomes of radiation-induced carotid stenosis (RICS), using control subjects without RICS for comparison. METHODS: We retrospectively reviewed records of 17 patients who underwent carotid revascularization for 22 instances of RICS, including 10 cases of carotid artery stenting (CAS), 11 cases of carotid endarterectomy (CEA), and 1 case of CEA with retrograde CAS, between July 2004 and April 2013. The controls were 475 patients with no history of radiation therapy who underwent carotid revascularization in a similar period. Preoperative magnetic resonance imaging (MRI), ultrasonography (US), and computed tomography angiography results were correlated with outcomes of histologic analysis of CEA specimens. End points included ipsilateral and contralateral stroke, myocardial infarction, restenosis, in-stent thrombosis, and target lesion revascularization. RESULTS: Vulnerable plaques on carotid MRI (86% vs 64.2%; P = .010) and mobile (27% vs 8.0%; P = .008) and ulcerative (50% vs 15.8%; P < .001) plaques on US were more frequent in the RICS group. All revascularization procedures were successful, and no occlusion occurred. Adverse events in the CAS group, including one minor stroke and one transient ischemic attack within 30 days as well as five ipsilateral neurologic events after 30 days, including three minor strokes and two transient ischemic attacks, were significantly more frequent than in the CEA group. All three cases of late ipsilateral stroke displayed vulnerable plaque on preoperative MRI and late in-stent thrombosis or restenosis on US. CONCLUSIONS: Our radiologic and histologic analyses revealed that advanced RICS is often accompanied by formation of vulnerable plaque. CEA can prevent undesirable late outcomes in such cases.

Efficacy of FLOW 800 with indocyanine green videoangiography for the quantitative assessment of flow dynamics in cerebral arteriovenous malformation surgery.

OBJECTIVE: To evaluate the quantitative assessment of flow dynamics during surgery for arteriovenous malformations (AVMs) with FLOW 800 with indocyanine green videoangiography. METHODS: Changes in flow dynamics in the superficial AVM components (feeder, nidus, and drainer), the adjacent cortical artery, and the cortical vein surrounding AVM were evaluated. Analysis was performed at predissection, postclipping of the feeders, and postresection of the nidus with the use of quantitative values of the maximum fluorescence intensity, time to half-maximum fluorescence intensity (T1/2 FI), and the fluorescence intensity rate at T1/2 FI semiautomatically obtained with the use of FLOW 800 software. RESULTS: FLOW 800 assessments were performed in 7 cases. The time difference between the T1/2 FI, defined as transit time, in the cortical artery and the drainer was prolonged from 0.08 ± 0.65 seconds to 2.63 ± 1.79 seconds (P < 0.0001) at postfeeder clipping phase. The transit time between the cortical artery and the cortical vein was reduced to 3.76 ± 1.37 seconds at post feeder clipping phase (P = 0.024) and 2.63 ± 0.80 seconds at final phase (P = 0.005) compared with 4.56 ± 1.47 seconds at predissection phase. The maximum intensity and the fluorescence intensity rate at T1/2 FI were not significantly different at these phases, excluding the maximum intensity of the drainer decreasing from 533 ± 271 to 399 ± 217 (P = 0.006) at post feeder clipping phase. CONCLUSION: FLOW 800 analysis with indocyanine green videoangiography provides the real-time hemodynamic status of the AVMs and adjacent brain at various stages of resection. This technique is feasible to resect AVMs more safely and convincingly.