Clinical Role of Microembolic Signals in Adult Moyamoya Disease With Ischemic Stroke.

Background and Purpose- Hemodynamic compromise has been implicated in moyamoya disease (MMD) with transient ischemic attacks or ischemic stroke. However, increasing evidence supports the notion that artery-to-artery embolism may also contribute to ischemic events based on microembolic signal (MES) monitoring. Methods- A total of 48 patients aged between 20 and 60 years with newly diagnosed MMD were enrolled and angiographically classified according to the Suzuki staging system. For detection of MESs, transcranial Doppler was performed at the middle cerebral artery bilaterally for a 30-minute period. Mean flow velocities in the middle cerebral artery were also evaluated and categorized into low (<40 cm/s), normal (40-80 cm/s), and high (>80 cm/s). Clinical characteristics, cerebral angiography findings, recent ischemic events within 3 months, and antiplatelet medication were correlated with transcranial Doppler findings. Results- MESs were detected in 11 of the 48 patients (23%), with a frequency of 11 of 89 (12%) examined hemispheres. The mean number of MESs was 2 (range, 1-6). Six of the 11 hemispheres (55%) presented with ischemic strokes or transient ischemic attacks, and 2 (18%) presented with hemorrhagic strokes. The presence of MESs was associated with recent ischemic events ( P=0.024) and high mean flow velocities ( P=0.016), which was usually observed in Suzuki stage I and II (early-stage MMD). After controlling for age, sex, and antiplatelet medication, both recent ischemic events (odds ratio, 6.294; 95% CI, 1.345-29.457; P=0.019) and high mean flow velocities (odds ratio, 6.172; 95% CI, 1.235-31.25; P=0.027) were found to be independent predictors of MESs. Conclusions- MESs were observed in patients with high mean flow velocities, particularly early-stage MMD, and clinically associated with recent ischemic events. A randomized controlled study is necessary to determine the efficacy of antiplatelet agents in the treatment of MES-positive MMD.

Early rebleeding of intracranial dural arteriovenous fistulas after an intracranial hemorrhage.

BACKGROUND: The aim of this study was to evaluate the clinical and angiographic characteristics of dural arteriovenous fistulas (DAVF) presenting with intracranial hemorrhage (ICH), with a focus on early rebleeding according to the initial hemorrhage type. METHOD: The clinical and radiologic features of 21 dAVFs that presented with intracranial hemorrhage were retrospectively reviewed. The hemorrhage type was classified as pure intraparenchymal hemorrhage (pIPH) and subarachnoid or subdural hemorrhage with IPH (non-pIPH). RESULTS: There were 13 patients with pIPH and 8 with non-pIPH. The median follow-up period was 30 months (range, 1-116 months), and the median interval from hemorrhage to treatment was 4 days (range, 0-72 days). Rebleeding occurred in 8 (38.1%) of 21 patients. Four (50%) of eight patients with non-pIPH suffered from early rebleeding within 3 days, while there was no early rebleeding in patients with pIPH. There was a significantly higher rate of early rebleeding in the non-pIPH group (p = 0.012). Angiographically, venous ectasia (p = 0.005) and direct cortical venous drainage (dCVD) (p = 0.008) showed a significantly higher proportion in the non-pIPH group than in the pIPH group. CONCLUSIONS: DAVFs with ICH is likely to rebleed after the first hemorrhage. Thus, early treatment can be needed in all DAVFs with ICH. In addition, DAVFs that presenting with non-pIPH and containing venous ectasia or dCVD on initial angiography may have a higher risk of early rebleeding. Therefore, cautious attention and urgent treatment are necessary for these patients.

Clinical Features of Superficially Located Brain Arteriovenous Malformations with Transdural Arterial Communication.

BACKGROUND: Contrary to deeply located brain arteriovenous malformations (AVMs), superficially located AVMs are more likely to have transdural arterial communications (TACs). However, the clinical and radiologic characteristics of patients presenting with AVMs and TACs are poorly understood. The purpose of this study is to determine whether clinicoradiological features of cerebral AVMs differ according to TAC. METHODS: Between 2002 and 2012, 438 consecutive patients with a brain AVM were treated in our hospital. Among them were 124 patients with superficially located brain AVMs who met the inclusion and exclusion criteria of our study. We retrospectively reviewed the clinicoradiological features of their TACs to explore the variation in characteristics. RESULTS: Thirty-two of the 124 patients with a superficially located AVM (25.8%) had TAC. Radiologic findings of brain AVM images with TAC showed that TAC occurred significantly more frequently among larger AVMs (with vs. without TAC, 11.2 vs. 4.0 ml) and among diffuse AVMs (56.3 vs. 28.3%, p = 0.004). Clinical findings indicate that TAC was associated with chronic headache (43.8 vs. 12.0%, p < 0.001) and older age (43.1 vs. 36.6 years, p = 0.037). CONCLUSIONS: Brain AVM with TAC seems to be accompanied by distinctive clinical features, such as chronic headache and older age. Larger size and diffuseness of the AVM were also associated with TAC. Findings from this study and the prognostic significance of TAC should be further explored in a large prospective study.

Morphological risk factors for the rupture of anterior communicating artery aneurysms: the significance of fenestration.

INTRODUCTION: The purpose of this study was to evaluate morphological factors associated with rupture in anterior communicating artery (AcomA) aneurysms and to investigate the significance of AcomA fenestration as a risk factor for aneurysm rupture. METHODS: The clinical and radiologic findings of 255 patients with AcomA aneurysms treated with coil embolization between January 2005 and March 2014 were retrospectively reviewed. We performed univariate and multivariate analyses to evaluate the associations between morphological variables and rupture status. RESULTS: The number of patients with AcomA fenestration was 17 out of 255 (6.6 %). There were no statistically significant differences between the fenestration group and non-fenestration group in clinical and morphological characteristics. Multivariate logistic regression tests showed that superior direction of aneurysm dome (OR 2.802, p = 0.023), presence of a bleb (OR 5.998, p < 0.001), high aspect ratio (OR 3.138, p = 0.009), size greater than 7 mm (OR 3.356, p = 0.013), and AcomA fenestration (OR 4.135, p = 0.026) were significantly associated with AcomA aneurysm rupture. CONCLUSIONS: The results of this study demonstrated that a fenestrated AcomA is associated with risk of aneurysm rupture. Therefore, AcomA fenestration can be considered as an important morphological risk factor for rupture, along with other known risk factors such as the direction of aneurysm dome, a bleb, high aspect ratio, and size.

Safety and efficacy of antiplatelet response assay and drug adjustment in coil embolization: a propensity score analysis.

INTRODUCTION: The purpose of this study was to explore the safety and efficacy of an antiplatelet response assay and drug adjustment to prevent delayed thromboembolic events after stent-assisted coil embolization. METHODS: A total of 370 patients were enrolled in this study between December 2005 and July 2014. Of these, 124 patients were placed into the drug resistance test (DRT) group with drug adjustment according to response to an antiplatelet agent, and 246 patients comprised the control group with a standard antiplatelet regimen. The response to the antiplatelet agent was evaluated with the VerifyNow Rapid Platelet Function Assay. Propensity score matching analysis was performed with one-to-multiple matching. RESULTS: Among 370 patients, delayed thromboembolic events occurred in 28 (7.6 %) patients including 25 (10.2 %) in the control group and three (2.4 %) in the DRT group. Antiplatelet response test (p = 0.012), diabetes mellitus (DM) (p = 0.014), and hypertension (HTN) (p < 0.001) were associated with delayed infarction in multivariate analysis. In propensity score matching analysis, 331 patients were matched (control group (n = 229) vs. DRT group (n = 103)), and antiplatelet response (hazard ratio 0.247, 95 % confidence interval 0.070-0.868, p = 0.029) was correlated with delayed infarction. Conversely, the two groups were not significantly different with regard to total (p = 0.368) or major hemorrhagic complications (p = 0.108). CONCLUSION: Antiplatelet drug adjustment according to the results of an antiplatelet response assay might be associated with a decreased risk of delayed thromboembolic infarction compared with the standard antiplatelet regimen.

Spontaneous angiographic changes in venous drainage patterns related to symptom changes in patients with untreated cavernous sinus dural arteriovenous fistula.

INTRODUCTION: We evaluated the relationship between symptomatic and angiographic changes in untreated cavernous sinus dural arteriovenous fistulas (CSdAVFs), focusing on venous drainage patterns. METHODS: The clinical and radiologic features of 34 cases of untreated CSdAVF were retrospectively reviewed. We classified venous drainage patterns as type I (only antegrade drainage), type II (combined antegrade drainage and venous reflux), type III (venous reflux without antegrade drainage), or type IV (stasis or occlusion of venous reflux). Symptom changes were categorized as improvement, aggravation of initial symptoms, or symptom pattern change. RESULTS: Twenty-one patients (61 %) showed symptom changes during follow-up (median, 12; range, 3-151 months). In the symptom improvement group (n = 10), patients who underwent follow-up angiography (n = 4) exhibited spontaneous occlusion. In the symptom aggravation group (n = 4), new venous reflux developed in 2 patients (type I to type II) and spontaneous occlusion in 2 patients (type III to spontaneous occlusion). In the symptom pattern change group (n = 7), 2 patients showed new venous reflux (type I to type II), and 5 showed stasis or occlusion of an engorged ophthalmic vein (type II or III to type IV). Angiographic regression was observed in all type III and IV patients, and cortical venous reflux (CVR) developed in 1 type I patient. CONCLUSION: Symptom changes correlated with chronological angiographic changes. Without treatment, most CSdAVFs behaved benignly and had a low incidence of CVR. Therefore, close observation is a possible protocol for managing CSdAVFs that have tolerable symptoms, no CVR, and no antegrade drainage despite aggravation or fluctuation in symptoms.

Treatment outcomes of surgical clipping for unruptured anterior circulation aneurysm-single institute experiences in the era of neurophysiologic monitoring and endovascular treatment.

Recently, the treatment of intracranial aneurysms entered a new phase due to safe surgical tool such as neurophysiologic monitoring and challenged by endovascular treatment. To determine the safety of clipping surgery in the modern era, we reviewed our experiences of simple unruptured anterior circulation aneurysm surgery which is commonly performed in many places. We retrospectively reviewed 610 consecutive patients who were treated with surgical clipping under motor evoked potential (MEP) monitoring for a tiny to large anterior circulation aneurysm in a single institute between 2008 and 2012. MEP changes were identified in 40 cases (6.6 %). MEP deterioration was associated with remote site epidural hematoma (n = 1), anesthesia (n = 2), temporary clipping (n = 21), and permanent clipping (n = 16). Despite that no persistent MEP deterioration was noted after prompt corrective measures, 56 (9.2 %) patients showed symptomatic (n = 14) and asymptomatic (n = 42) radiologic abnormalities. Anterior cerebral artery (ACA) aneurysm was associated with a higher radiologic complication rate (Fisher's exact test, P < 0.05). Two (0.3 %) patients showed severe morbidity (mRS >2) at latest follow-up. MEP monitoring can be helpful in preventing postoperative motor deterioration but seems to have some limitations. Although the permanent morbidity rate was low, a significant clinical (2.3 %) or radiologic (9.2 %) abnormality rate was identified even in simple aneurysm clipping that should be taken into account when performing interdisciplinary treatment planning and patient counseling. Also, direct vascular monitoring or new neurophysiologic monitoring techniques are needed to reduce surgical complications, especially in ACA aneurysm surgery.

Cerebellar retraction and hearing loss after microvascular decompression for hemifacial spasm.

BACKGROUND: This retrospective study evaluated the length of cerebellar retraction and the changes of intraoperative brainstem auditory evoked potential (BAEP) during microvascular decompression (MVD), and assessed the predictive value of the hearing loss as a prognostic indicator for the treatment outcome of hemifacial spasm (HFS). METHODS: This series included 1,518 consecutive patients affected with HFS who underwent MVD, during which BAEP was monitored. Patients were divided into two groups based on whether hearing loss occurred following decompression or not. Each patient underwent a similar procedure performed by one neurosurgeon. The two patients groups were matched with regard to sex, age, and degree of spasm. RESULTS: Among the 1,518 patients, 106 (6.98 %) displayed functional hearing changes. Hearing loss was permanent in 12 patients (0.79 %). Of the 1,412 patients with stationary hearing compared with preoperative audiometry, 96 patients were selected who were individually matched with respect to sex, age, and degree of spasm. BAEP changed immediately after cerebellar retraction in 7 of 12 hearing-loss patients, suggesting the importance of retraction on hearing outcomes. The distance from the cerebellar surface of the petrous temporal bone to the neurovascular compression point was measured. The median distance of cerebellar retraction in the hearing-loss group was 13.77 mm, which was longer than the median distance in the control group. CONCLUSIONS: Preoperative measurement of the cerebellar retraction distance can be a valuable clue to predict and prevent postoperative hearing loss in MVD for HFS.

Coronary heart disease in moyamoya disease: are they concomitant or coincidence?

The purpose of this study was to determine the prevalence and characteristics of symptomatic coronary heart disease (CHD) in patients with moyamoya disease (MMD). This retrospective study evaluated 456 patients who received examination for MMD between 1995 and 2012. We reviewed the patients' medical history and coronary imaging, including conventional coronary angiography and coronary computed tomography angiogram (CTA). Among 456 patients with MMD, 21 (4.6%) patients were found to have symptomatic CHD. Ten patients were treated with coronary artery bypass graft or percutaneous coronary intervention for unstable angina or myocardial infarction. Eleven were treated with medication for stable angina (n = 6) and variant angina with mild degree of stenosis (n = 5).The median age of these patients was 44 yr (range, 27-59). The median Framingham score at diagnosing MMD was < 1% (range, < 1%-16%). The old age was associated with CHD in uni- and multivariate analyses (P = 0.021, OR, 1.053; 95% CI, 1.008-1.110). Considering low age of onset and low stroke risk factor, CHD might be a systemic manifestation that is clinically relevant to MMD.

Clinical course of asymptomatic adult moyamoya disease.

BACKGROUND: As regular medical check-ups are becoming more common, the prevalence of asymptomatic moyamoya disease (MMD) is increasing. However, the definition and clinical features are still unclear. The lack of precision has hampered the establishment of guidelines for the management of asymptomatic MMD. The purpose of this study was to define and clarify the clinical characteristics of asymptomatic MMD in adults. METHODS: We identified all adults (aged ≥18 years) with MMD who underwent digital subtraction angiography or magnetic resonance angiography at our institution from 1995 through 2010. The authors defined asymptomatic MMD as asymptomatic or nonspecific symptom without any infarction or ischemia on magnetic resonance imaging. In our MMD registry, 40 patients (74 hemispheres) were identified and enrolled in this retrospective cohort study. Their demographic, radiological and clinical findings were evaluated. The log-rank test was used to assess prognostic factors. Pearson's correlation test and the Mann-Whitney U test were used to identify correlation angiographic staging and age or perfusion status. RESULTS: Overall, 6 patients underwent indirect bypass surgery and 36 received antiplatelet medication. On initial single positron emission tomography (35 patients, 67 affected hemispheres), basal and acetazolamide stress brain perfusion were decreased in 19 (28.4%) and 22 (32.8%) hemispheres, respectively. Among 70 angiographically evaluated hemispheres, 6 were unilateral MMD; 27 of 64 affected hemispheres (42.2%) had transdural collateral at evaluation. Age (p = 0.309, Pearson's correlation test) and hemodynamic impairment (p = 0.614, Mann-Whitney U test) did not correlate with angiographic staging. During a median 32-month (range 6-203) clinical follow-up, 3 nonsurgically treated patients had a transient ischemic attack, which was associated with decreased vascular reserve (p < 0.001, log-rank test) and smoking (p = 0.017). Other variables did not show a significant association with clinical progression. During a median 24-month (range 12-108) radiological follow-up, 3 patients displayed angiographic progression and 3 displayed new hemodynamic abnormalities. Radiological progressions were related to hypertension only (p = 0.022). In this case series, there was no case of ischemic or hemorrhagic stroke. CONCLUSION: The findings suggest that asymptomatic MMD in adults is not a stable disease in our definition. However, stroke rate (0%) was lower than previous reports. Lifestyle modification, stroke risk factor control and/or antiplatelet medication seem to be appropriate initial treatments for patients with normal cerebrovascular reserve. A clear definition of asymptomatic MMD and further clarification of its clinical course are needed to set precise treatment guidelines.

Eight-year experience of bloodless surgery at a tertiary care hospital in Korea.

BACKGROUND: The Soonchunhyang University Hospital Bloodless Center was established in 2000, and more than 2000 bloodless surgeries has been performed there since. This study was carried out to analyze the characteristics of patients who underwent bloodless surgery and the influences of postoperative lowest hemoglobin level (H(blow)) along with the lowest postoperative Hb/preoperative Hb ratio (H(blow/pre)) on successful completion of bloodless surgery. STUDY DESIGN AND METHODS: A total of 1407 patients were included. Patients were divided according to H(blow) into not more than 7 and more than 7 g/dL groups and compared regarding use of transfusion alternatives, coexisting risk factors, and mortality rate. They were also grouped as H(blow/pre) of not more than 0.5 or more than 0.5, and mortalities were compared between them. RESULTS: Jehovah's Witnesses comprised 1323 (94.0%) of the total population. The frequency of simultaneous use of erythropoietin and iron was significantly higher in H(blow) of not more than 7 group than in more than 7 g/dL group, as was the use of hemostatics. Among risk factors urging transfusion, the frequencies of cardiovascular disease and cerebrovascular accident were higher in H(blow) of not more than 7 than in the more than 7 g/dL group. Mortality rates in H(blow) of not more than 7 g/dL and H(blow/pre) of not more than 0.5 groups were significantly higher than those in H(blow) of more than 7 g/dL and H(blow/pre) of more than 0.5 groups, respectively. CONCLUSION: We have provided an effective bloodless surgery program for the past 10 years. A prospective multicenter study with other bloodless centers in Korea concerning mortality rates, actual operative blood loss, and postoperative complications in high-risk group of patients would be needed to establish evidence-based guidelines for bloodless surgery.

Radiosurgery to palliate symptoms in brain metastases from uterine cervix cancer.

BACKGROUND: The optimal management of brain metastases from uterine cervix cancer (UCC) is not well defined because of the rarity of the condition and the scarcity of published reports. Here we report our experience with stereotactic radiosurgery for the management of brain metastases from UCC. METHODS: Thirteen consecutive patients with brain metastases from UCC were managed with a Leksell gamma-knife at our institution between January 2003 and December 2010. Clinical features and radiosurgical outcomes of patients were analyzed retrospectively. RESULTS: Gamma-knife radiosurgery (GKRS) was chosen as the only treatment in four patients and performed in combination with whole-brain radiotherapy (WBRT) in nine patients. GKRS was conducted simultaneously with WBRT within a 1-month interval in six patients and was chosen as the salvage treatment after WBRT in three patients. The mean number of metastatic brain lesions per patient was 5.7 (range, 1-16). The median cumulative tumor volume was 23.7 cm(3) (range, 2.7-40.2 cm(3)), and the median marginal dose covering the tumors was 14 Gy of a 50 % isodose line (range, 8-25 Gy). Nine patients showed relief of main neurologic symptoms after GKRS. The median length of time that the patients spent in an improved neurologic state was 11.1 weeks (range, 2-39.6 weeks). The local and distant control rates were 66.7 % and 77.8 %, respectively. The median survival from the date of GKRS until death was 4.6 months (range, 1.0-15.9 months). The 6-month and 12-month survival rates after GKRS were 38 and 15 %, respectively. CONCLUSIONS: GKRS could be an efficient palliative measure to relieve neurologic symptoms caused by brain metastasis from UCC.

Predictors of thromboembolism during coil embolization in patients with unruptured intracranial aneurysm.

OBJECTIVES: To identify the incidence of thromboembolic complications based on magnetic resonance imaging (MRI) and to explore the potential risk factors for thromboembolism (TE) during the periprocedural period of elective coil embolization for unruptured intracranial aneurysms. METHODS: We retrospectively reviewed all aneurysm cases treated with coil insertion between January 2008 and March 2011. Two hundred eighty-two coiling procedures for unruptured aneurysms were included in this study. The patients' demographic characteristics were documented and records reviewed for abnormalities in diffusion-weighted imaging (DWI) seen on post-procedure MRI, intraoperative thrombus formation, and clinical signs of stroke. RESULTS: Overall, there were 87 (30.9 %) procedure-related complications in 282 aneurysms treated: 2 (0.7 %) procedural ruptures, 5 (1.8 %) symptomatic infarctions, and 80 (28.3 %) asymptomatic infarctions. Thromboembolic events during the procedure were observed more often in the the hyperlipidemia group (32/71 aneurysms, 45.1 %) than in the normal lipid profile group (39/196 aneurysms, 25.6 %; p = 0.002; chi-squre test). The coiling technique and size of the aneurysm were also associated with TE (p < 0.001 and p = 0.004). CONCLUSION: Hyperlipidemia seems to be associated with a significant increase in the rate of thromboembolic events. In preventive procedures, modifiable risk factors should be managed to reduce complications. Although permanent deficits are rare, the high rate of thromboembolic events suggests that improvements in the technique, such as the addition of antiplatelet agents and the development of new embolic materials, are necessary.

Effects of Recycled Polymer on Melt Viscosity and Crystallization Temperature of Polyester Elastomer Blends.

As the world is paying attention to the seriousness of environmental pollution, the need for a resource circulation economy is emerging due to the development of eco-friendly industrial groups. In particular, the recycling of thermoplastic elastomers without cross-link has been highlighted in the plastics field, which has rapidly developed the industry. Growing interests have been directed towards the advancement of thermoplastic polyether-ester elastomer (TPEE) as a material suitable for the circular economy owing to its remarkable recyclability, both in terms of mechanical and chemical processes. Due to its excellent processability, simple mechanical recycling is easy, which is a driving force towards achieving price competitiveness in the process. In molding TPEE resin, it is essential to check the thermal properties of the resin itself because the thermal properties, including the melting and crystallization temperatures of the resin, depend on the design of the polymer. In this study, the thermal and mechanical performances of TPEE blends were evaluated by manufacturing compounds by changing the amount of recycled resin and additives. When the recycled resin was added, the melt flow index (MFI) changed rapidly as the temperature of the melt flow index measurement increased. Rapid changes in MFI make the fiber spinning process uncontrollable and must be controlled by optimizing the addition of compatibilizers. Based on the thermal property results, compatibilizers such as Lotader and Elvaloy series exhibited minimal change in glass transition temperature, even with greater amounts added. This makes them well-suited as compatibilizers for fiber spinning.

Leptomeningeal seeding in patients with brain metastases treated by gamma knife radiosurgery.

To characterize the development of leptomeningeal seeding (LMS) in patients with brain metastases after gamma knife radiosurgery (GKRS). Eight hundred and twenty-seven patients that underwent GKRS as a part of an initial treatment plan for brain metastases between January 2002 and December 2010 were included in the study. Six hundred and fifty patients were treated with GKRS alone and 177 patients received GKRS combined with upfront whole brain radiation therapy (WBRT). Actuarial curves for overall survival (OS) and the development of LMS were plotted using the Kaplan-Meier method. Median overall survival for all patients was 55 weeks (95 % CI, 47.8-62.2), and the overall incidence of LMS was 5.3 %. The actuarial rates for LMS at 6 and 12 months were 3.1 and 5.8, respectively. Uni- and multivariate analysis suggested that breast cancer and a large number of metastases (n ≥ 4) are significant risk factors of LMS (P < 0.05). Regarding treatment modalities, the addition of WBRT was found to have a significant impact on lowering the risk of LMS by multivariate analysis (P = 0.045). LMS is an important pattern of CNS failure. The risk of LMS following GKRS may be associated with multiple lesions, breast cancer, and the omission of WBRT. Additional data from large-scale, randomized controlled trials are required to identify risk factors associated with the LMS more accurately.

Microsurgical resection of deep-seated lesions using transparent tubular retractor: pediatric case series.

BACKGROUND: To facilitate effective resection of deep-seated brain lesions without causing significant trauma to the overlying cortex, the authors used a transparent plastic tubular retractor to approach these lesions. METHODS: Between July 2009 and January 2011, we used an 11-mm diameter transparent plastic tubular retractor in combination with a frameless stereotactic navigation system to remove 18 deep lesions. RESULTS: Gross total resection of the lesions was achieved in 14 of 18 patients, and subtotal removal occurred in four patients. Effective resection of lesions was achieved in all patients through small size craniotomy window and small cortical incision. The histopathologic diagnosis was established in all 18 patients: 3 hematomas, 3 cavernous angioma, 7 low-grade glioma, 2 dysembryoplastic neuroepithelial tumor, 1 choroid plexus papilloma, 1 abscess, and 1 meningioma. CONCLUSION: Microsurgery using a transparent tubular retractor guided by a neuronavigation system facilitated accurate and effective removal of these deep-seated brain lesions.

Modified Arachnoid Plasty Reduces Chronic Subdural Hematoma after Unruptured Aneurysm Clipping : Technical Note.

OBJECTIVE: Chronic subdural hematoma (CSDH) is a rare complication of unruptured intracranial aneurysm (UIA) clipping surgery. To prevent postoperative CSDH by reducing subdural fluid collection, we applied the modified arachnoid plasty (MAP) during the UIA clipping surgery to seal the dissected arachnoid plane. METHODS: This retrospective study included 286 patients enrolled from July 2012 to May 2015. We performed arachnoid plasty in all patients, with MAP used after June 17, 2014. Patients were divided into two groups (non-MAP vs. MAP), and by using uni- and multivariate analyses, baseline characteristics, and relationships with postoperative CSDH between the two groups were analyzed. The degree of preoperative brain atrophy was estimated using the bicaudate ratio (BCR) index. RESULTS: Ten patients (3.5%) among 286 patients had postoperative CSDH after clipping. Nine (3.1%) were in the non-MAP group, and one (0.9%) was in the MAP group. The higher BCR index showed statistical significance with occurrence of postoperative CSDH in both uni- (p=0.018) and multivariate (p=0.012, odds ratio [OR] 8.547, 95% confidence interval [CI] 1.616-45.455) analyses. MAP was associated with a lower risk of postoperative CSDH (p=0.022, OR 0.068, 95% CI 0.007-0.683). CONCLUSION: This study shows that the degree of preoperative brain atrophy is associated with an increased occurrence of CSDH after clipping and that MAP could help reduce the risk of postoperative CSDH after unruptured aneurysm clipping via a lateral supraorbital approach.

Treatment Outcomes with Selective Coil Embolization for Large or Giant Aneurysms : Prognostic Implications of Incomplete Occlusion.

OBJECTIVE: The objectives of this study were to evaluate the immediate and long-term efficacy and safety of coil embolization for large or giant aneurysms. METHODS: One hundred and fifty large or giant aneurysm cases treated with endovascular coil embolization between January 2005 and February 2014 at a single institute were included in this study. Medical records and imaging findings were reviewed. Statistical analysis was performed to evaluate prognostic factors associated with major recurrence (major recanalization or rupture) and delayed thromboembolism after selective coil embolization. RESULTS: Procedure-related symptomatic complications occurred in five (3.3%) patients. The mean clinical and radiological follow-up periods were 38 months (range, 2-110) and 26 months (range, 6-108), respectively. During the follow-up period, the estimated recurrence rate was 4.6% per year. Multivariate analysis using Cox regression showed the degree of occlusion to be the only factor associated with recurrence (p=0.008, hazard ratio 3.15, 95% confidence interval 1.34-7.41). The patient's history of rupture in addition to the size and location of the aneurysm were not associated with recurrence in this study. Delayed infarction occurred in eight cases, and all were incompletely occluded. CONCLUSION: Although immediate postprocedural safety profiles were reasonable, longterm results showed recanalization and thromboembolic events to occur continuously, especially in patients with incomplete occlusion. In addition, incomplete occlusion was associated with delayed thromboembolic complications. Patients with incomplete occlusions should be followed carefully for delayed recurrence or delayed thromboembolic events.

Low flow velocity in the middle cerebral artery predicting infarction after bypass surgery in adult moyamoya disease.

OBJECTIVE Direct and indirect bypass surgeries are recognized as the most effective treatments for preventing further stroke in adults with moyamoya disease (MMD). However, the risk factors for postoperative infarction after bypass surgery for MMD are not well established. Therefore, the objective of this study was to investigate the risk factors for postoperative infarction. In particular, the authors sought to determine whether transcranial Doppler (TCD) ultrasonography measurements of mean flow velocity (MFV) in the middle cerebral artery (MCA) could predict postrevascularization infarction. METHODS The medical records of patients with MMD who underwent direct bypass surgery at the authors' institution between July 2012 and April 2015 were reviewed. The MFV in the MCA was measured with TCD ultrasonography and categorized as high (> 80 cm/sec), medium (40-80 cm/sec), and low (< 40 cm/sec). Postoperative MRI, including diffusion-weighted imaging, was performed for all patients within a week of their surgery. Angiographic findings were classified according to the Suzuki scale. Postrevascularization infarction was defined as any diffusion restriction on postoperative MRI scans. Postoperative neurological status was assessed through a clinical chart review, and the modified Rankin Scale was used to evaluate clinical outcomes. RESULTS Of 43 hemispheres in which bypass surgery for MMD was performed, 11 showed postrevascularization infarction. Ten of these hemispheres had low MFV and 1 had medium MFV in the ipsilateral MCA. In both univariate and multivariate analyses, a low MFV was associated with postrevascularization infarction (adjusted OR 109.2, 95% CI 1.9-6245.3). A low MFV was also statistically significantly associated with more advanced MMD stage (p = 0.02). CONCLUSIONS A low MFV in the ipsilateral MCA may predict postrevascularization infarction. Bypass surgery for MMD appears to be safe in early-stage MMD. Results of TCD ultrasonography provide clinical data on the hemodynamics in MMD patients before and after revascularization.

Clinical features of high-degree centrum semiovale-perivascular spaces in cerebral amyloid angiopathy.

BACKGROUND: There is no doubt that cerebral amyloid angiopathy (CAA) is a key risk factor for recurrent lobar ICH, however, the exact mechanism and interaction with MRI markers of disease severity are less well known. Centrum semiovale-perivascular spaces (CSO-PVS) have been suggested as adjunctive diagnostic criteria in order to enhance diagnostic power. The purposes of this study were to investigate the prevalence of CSO-PVS and its association with other imaging signatures {lobar microbleeds (CMB), cortical superficial siderosis (CSS), white matter hyperintensity (WMH)} in lobar ICH patients as well as recurrent lobar ICH risk, especially in patients taking antithrombotic agents. METHODS: This retrospective study included 85 patients who visited our institute between 2005 and 2013 with lobar ICH on magnetic resonance imaging(MRI). CSO-PVS were rated on axial T2-weighted sequences using a validated 2-point visual rating scale (high degree >20, low degree ≤20). The CSS, CMB and WMH were also evaluated. The relationship between CSO-PVS, CSS, CMB, antithrombotic usage and recurrent bleeding were explored. RESULTS: A high degree of CSO-PVS was present in 71.8% of patients. The prevalence of CSS and CMB was higher in patients with a high degree of CSO-PVS (CSS, 49.2% vs. 16.7%, P=0.006; CMB count, 7.3% vs. 2.1%, P=0.002). A high degree of CSO-PVS and antithrombotic usage following lobar ICH was not associated with recurrent hemorrhage. In multivariate logistic regression analysis of predictors of recurrent lobar ICH in lobar ICH patients, post-ICH antithrombotics use and disseminated CSS are independently associated with increased risk of recurrent lobar ICH. CONCLUSIONS: High-degree CSO-PVS is highly prevalent in probable cerebral amyloid angiopathy and is related to CSS and CMB. Disseminated CSS was associated with recurrent ICH in CAA. Our study might help physicians decide whether or not to use antithrombotic agents in hemorrhagic stroke patients with a high risk of ischemic stroke. A large prospective study is warranted to validate these findings.