Preliminary Report of Fully Endoscopic Microvascular Decompression.

Objective: Microscopic microvascular decompression (MVD) has been considered to be a useful treatment modality for medically refractory hemifacial spasm (HFS) and trigeminal neuralgia (TN). But, the advent of the endoscopic era has presented new possibilities to MVD surgery. While the microscope remains a valuable tool, the endoscope offers several advantages with comparable clinical outcomes. Thus, fully endoscopic MVD (E-MVD) could be a reasonable alternative to microscopic MVD. This paper explores the safety and efficacy of the fully E-MVD technique. Methods: A single-center retrospective study was conducted in 25 patients diagnosed with HFS between September 2019 and July 2023. All surgeries were performed by a single neurosurgeon using the fully E-MVD technique without any assistance of a microscope. The study reviewed intraoperative brainstem auditory evoked potentials and disappearance of the lateral spread response. Outcomes were assessed based on the patients' clinical status immediately after surgery and at their last follow-up. Complications, including facial palsy, hearing loss, ataxia, dysphagia, palsy of other cranial nerves, and cerebrospinal fluid (CSF) leakage, were also examined. Results: The most common offending artery was the anterior inferior cerebellar artery (AICA) in 15 cases (60.0%), followed by the posterior inferior cerebellar artery (PICA) in 8 cases (32.0%), vertebral artery (VA) in 1 case (4.0%), tandem lesions involving the AICA and VA in 1 case (4.0%). Ten patients (40.0%) had pre-operative facial palsy on the ipsilateral side, and 8 patients (32.0%) experienced delayed facial palsy on the ipsilateral side, from which they fully recovered by the last follow-up. The median operation time was 105 minutes. All patients were symptom free immediately after surgery and at the last follow-up. One patient experienced a permanent complication, such as high-frequency hearing loss, from which he partially recovered over time. Conclusion: Fully E-MVD demonstrated similar clinical outcomes to microscopic MVD. It offered a similar complication rate, shorter operation time, and a panoramic view with a smaller craniectomy size. Although there is a learning curve associated with fully E-MVD, it presents a viable alternative in the endoscopic era.

Navigation guided small craniectomy and direct cannulation of pure isolated sigmoid sinus for treatment of dural arteriovenous fistula.

Dural arteriovenous fistula (DAVF) is a rare condition affecting approximately 1.5% of 1,000,000 individuals annually. It frequently occurs in the transsigmoid and cavernous sinuses. An isolated sigmoid sinus is extremely rare and is treated by performing transfemoral transvenous embolization along the opposite transverse sinus. A 69-year-old woman presented with asymptomatic Borden type III/Cognard type III DAVF involving an isolated sigmoid sinus. She underwent a staged operation in which a navigation system was used to expose the sigmoid sinus in the operating room before transferring the patient to the angio suite for transvenous embolization. Various modalities have been used to treat DAVF, including surgical disconnection, transarterial embolization, transvenous embolization, and stereotactic radiosurgery. However, treating DAVF cases where the affected sinus is isolated can be challenging because an easily accessible surgical route may not be available. In this case, direct sinus cannulation and transvenous embolization were the most effective treatments.

Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms: a nationwide registry study.

BACKGROUND: Antiplatelet therapy, where regimens are tailored based on platelet function testing, has been introduced into neurointerventional surgery. This nationwide registry study evaluated the effect and safety of tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms compared with conventional therapy using a standard regimen. METHODS: This study enrolled 1686 patients in 44 participating centers who received stent assisted coiling for unruptured aneurysms between January 1, 2019 and December 31, 2019. The standard regimen (aspirin and clopidogrel) was used for all patients in the conventional group (924, 19 centers). The regimen was selected based on platelet function testing (standard regimen for clopidogrel responders; adding cilostazol or replacing clopidogrel with other thienopyridines (ticlopidine, prasugrel, or ticagrelor) for clopidogrel non-responders) in the tailored group (762, 25 centers). The primary outcome was thromboembolic events. Secondary outcomes were bleeding and poor outcomes (increase in modified Rankin Scale score). Outcomes within 30 days after coiling were compared using logistic regression analysis. RESULTS: The thromboembolic event rate was lower in the tailored group than in the conventional group (30/762 (3.9%) vs 63/924 (6.8%), adjusted OR 0.560, 95% CI 0.359 to 0.875, P=0.001). The bleeding event rate was not different between the study groups (62/762 (8.1%) vs 73/924 (7.9%), adjusted OR 0.790, 95% CI 0.469 to 1.331, P=0.376). Poor outcomes were less frequent in the tailored group (12/762 (1.6%) vs 34 (3.7%), adjusted OR 0.252, 95% CI 0.112 to 0.568, P=0.001). CONCLUSION: Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms reduced thromboembolic events and poor outcomes without increasing bleeding.

Long-term outcomes of carotid artery stenting in patients with carotid artery stenosis: A single-center 14-year retrospective analysis.

OBJECTIVE: Carotid artery stenting (CAS) is currently widely used for the treatment of carotid artery stenosis. The objective of this study was to analyze the outcomes of CAS performed in a single institution. METHODS: We retrospectively analyzed 313 CAS cases from January 2007 to December 2020, including 206 (66%) symptomatic and 107 (34%) asymptomatic cases. Procedure-related morbidity and mortality were assessed. Rates of periprocedural (≤30 days after CAS) and postprocedural ipsilateral strokes (>30 days after CAS) were also assessed. Logistic regression analysis was used to identify risk factors for the periprocedural complication, in-stent restenosis (ISR), and ipsilateral stroke. RESULTS: The success rate of CAS was 98%. Among 313 cases, 1 patient died due to hyperperfusion-related intracerebral hemorrhage (ICH). The CAS-related mortality rate was 0.31%. The overall incidence of periprocedural complications is 5.1%. A risk factor for periprocedural complication was a symptomatic carotid artery stenosis (7.3% vs. 0.9%, p=0.016). Twenty cases of ISR occurred during 63.7±42.1 months of follow-up. The overall incidence of ISR was 10.2% (20/196). A risk factors for ISR were diabetes mellitus (17.6% vs. 5.7%, p=0.008) and patients who used Open-cell stents (19.6% vs. 6.9%, p=0.010). The overall incidence of ipsilateral stroke is 5.6%. A risk factors for ipsilateral stroke was ISR (95% CI, p=0.002). CONCLUSIONS: CAS is a safe and effective procedure for carotid artery stenosis. Although the incidence of complications is low, fatal complication such as hyperperfusion- related ICH can occur. To prevent hyperperfusion-related ICH, several methods such as strict blood pressure (BP) control, intentional less widening of stenotic segment should be used. To prevent ISR or stroke occurrence, special attention should be paid to patients who have ISR or ipsilateral stroke risk factors.

Multiple Cerebral Hemorrhages Caused by Paradoxical Reperfusion Injury After Cranioplasty.

Cranioplasty-related reperfusion injury has rarely been reported. Although there are several hypotheses, particularly regarding the mechanisms of the event, clear evidence is lacking. Here, we report the case of an 84-year-old man with traumatic intracranial hemorrhage and subdural hematoma who underwent decompressive craniectomy and hematoma evacuation in the right hemisphere. After 45 days, cranioplasty was performed using titanium. A preoperative perfusion study with 99m-Tc-HMPAO brain single-photon emission tomography revealed diffuse hypoperfusion in the left cerebral hemisphere with decreased vascular reserve. After cranioplasty, multiple cerebral hemorrhages were observed on immediate postoperative computed tomography. Cerebral hemorrhage eventually improved without surgery. Here, we report a case with findings revealed through perfusion studies before and after surgery.

Staged hybrid treatment for giant thrombosed fusiform aneurysm.

Partially thrombosed intracranial aneurysm was difficult to treat because of higher recurrence rate compared to non-thrombosed saccular aneurysm. The author reports a case of partially thrombosed intracranial aneurysm causing transient ischemic symptom. A 40-year-old man presented with transient right hemiparesis. Brain magnetic resonance imaging (MRI) depicted low-signal intensity target-like mass lesion on left sylvian fissure, and magnetic resonance angiography (MRA) showed aneurysm on left middle cerebral artery bifurcation (MCBF), suggested thrombosed aneurysm. On operative finding, aneurysm wall had thick and atherosclerotic change, and it was fusiform aneurysm not saccular type. We initially planned direct clip for the aneurysm, but it was failed due to collapse of parent artery after clipping on aneurysm neck. To prevent ischemia, extracranial-intracranial bypass was performed and then thrombectomy with clip reconstruction. To remodeling the fusiform aneurysm, stent-assisted coiling was performed for remnant portion of aneurysm. With staged hybrid technique, giant thrombosed fusiform aneurysm was completely obliterated and the patient did not suffer any neurologic symptoms no longer.

Efficacy and Safety of Emergency Extracranial-Intracranial Bypass for Revascularization within 24 Hours in Resolving Large Artery Occlusion with Intracranial Stenosis.

BACKGROUND: Endovascular treatment (EVT) is less effective for intracranial atherosclerosis-induced emergent large vessel occlusion. Extracranial-intracranial (EC-IC) bypass surgery is a possible treatment option to augment cerebral blood flow in the perfusion defect area. We compared the efficacy and safety of EC-IC bypass surgery with those of EVT and maximal medical treatment for acute ischemic stroke. METHODS: The data from 39 patients, for whom vessel revascularization had failed despite mechanical thrombectomy, were retrospectively analyzed. Of the 39 patients, 22 had undergone percutaneous transluminal angioplasty or intracranial stenting (PTA/S), 10 had undergone emergency EC-IC bypass surgery within 24 hours of symptom onset, and 7 had received maximal medical treatment (MMT) only. The patency, perfusion status, and postoperative infarct volume were evaluated. The clinical outcomes were assessed at 6 months postoperatively using the modified Rankin scale. RESULTS: The mean reperfusion time was significantly longer for the EC-IC bypass group (14.9 hours) compared with that in the PTA/S group (4.1 hours) and MMT group (7.5 hours; P < 0.05). The postoperative infarct volume on diffusion-weighted magnetic resonance imaging was significantly lower in the emergency EC-IC bypass group (11.3 cm3) than in the MMT group (68.0 cm3) but was not significantly different from that of the PTA/S group (14.0 cm3; P < 0.05). The proportion of patients with a modified Rankin scale score of 0-2 at 6 months after surgery was significantly higher in the EC-IC bypass group (80%) than in the PTA/S (59%) and MMT (14%) groups (P < 0.05). CONCLUSIONS: Emergency EC-IC bypass surgery is an effective and safe treatment option for intracranial atherosclerosis-induced acute ischemic stroke for which EVT is inadequate.

Short and Long-term Outcomes of Subarachnoid Hemorrhage Treatment according to Hospital Volume in Korea: a Nationwide Multicenter Registry.

BACKGROUND: Subarachnoid hemorrhage is a potentially devastating cerebrovascular attack with a high proportion of poor outcomes and mortality. Recent studies have reported decreased mortality with the improvement in devices and techniques for treating ruptured aneurysms and neurocritical care. This study investigated the relationship between hospital volume and short- and long-term mortality in patients treated with subarachnoid hemorrhage. METHODS: We selected subarachnoid hemorrhage patients treated with clipping and coiling from March-May 2013 to June-August 2014 using data from Acute Stroke Registry, and the selected subarachnoid hemorrhage (SAH) patients were tracked in connection with data of Health Insurance Review and Assessment Service to evaluate the short-term and long-term mortality. RESULTS: A total of 625 subarachnoid hemorrhage patients were admitted to high-volume hospitals (n = 355, 57%) and low-volume hospitals (n = 270, 43%) for six months. The mortality of SAH patients treated with clipping and coiling was 12.3%, 20.2%, 21.4%, and 24.3% at 14 days, three months, one year, and five years, respectively. The short-term and long-term mortality in high-volume hospitals was significantly lower than that in low-volume hospitals. On Cox regression analysis of death in patients with severe clinical status, low-volume hospitals had significantly higher mortality than high-volume hospitals during short-term follow-up. On Cox regression analysis in the mild clinical status group, there was no statistical difference between high-volume hospitals and low-volume hospitals. CONCLUSION: In subarachnoid hemorrhage patients treated with clipping and coiling, low-volume hospitals had higher short-term mortality than high-volume hospitals. These results from a nationwide database imply that acute SAH should be treated by a skilled neurosurgeon with adequate facilities in a high-volume hospital.

Pituitary apoplexy causing acute ischemic stroke: Which treatment should be given priority.

BACKGROUND: Pituitary apoplexy is syndrome of sudden onset of headache, visual loss, pituitary dysfunction, and altered consciousness. Pituitary apoplexy followed by acute cerebral ischemia is extremely rare. Here, we introduced the case of successful surgical resection of pituitary adenoma which induced acute cerebral ischemia. CASE DESCRIPTION: A 78-year-old man with a known pituitary macroadenoma presented with decreased consciousness and left hemiparesis. Magnetic resonance image (MRI) and computed tomography (CT) showed large pituitary macroadenoma with hemorrhage and diffusion-perfusion mismatch of right internal carotid artery (ICA) territory. Conventional angiography was done and severe stenosis of bilateral ICA and prominent flow delay of left ICA were noted at paraclinoid segment. Microscopic tumor mass removal with transsphenoidal approach was performed. Final pathological diagnosis was pituitary adenoma with apoplexy. Immediately after surgery, his symptoms were disappeared. Follow-up image studies revealed much improved perfusion in right ICA territory and patency of bilateral ICAs. CONCLUSION: Direct compression of ICA is rare complication of pituitary apoplexy, which caused cerebral ischemia. Conventional angiography should be necessary for accurate diagnosis and prompt surgical decompression should be the treatment of choice.

The Efficacy of P2Y12 Reactive Unit to Predict the Periprocedural Thromboembolic and Hemorrhagic Complications According to Clopidogrel Responsiveness and Safety of Modification of Dual Antiplatelet Therapy : A Meta-Analysis.

The efficacy of P2Y12 reaction unit (PRU) of VerifyNow still remains as a controversial issue in neurointervention. So we investigated the usefulness of PRU of VerifyNow to predict the peri-procedural thromboembolic events (TE) and hemorrhagic events (HE). And we evaluated the safety of modified dual antiplatelet therapy (DAPT) or triple antiplatelet therapy (TAPT) for clopidogrel hyporesponders. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science and Scopus on August 19 2018. Data was collected the 1) incidence of TE between clopidogrel responder and clopidogrel hypo-responder, 2) incidence of HE between clopidogrel hyper-responder and clopidogrel responder and hypo-responder, and 3) incidence of TE and HE between modified DAPT or TAPT and standard DAPT in clopidogrel hypo-responder. High cut-off value of PRU was defined as PRU >40% or <220. Fifteen studies were enrolled. Clopidogrel responder showed lower incidence of TE than hypo-responder (risk ratio [RR], 0.32; 95% confidence interval [CI], 0.17-0.61; p<0.001). With the high cut-off value of PRU, clopidogrel responder showed more lower incidence of TE than hypo-responder (RR, 0.11; 95% CI, 0.02-0.45; p=0.002). The incidence of periprocedural HE have higher on clopidogrel hyper-responder than clopidogrel responder and hypo-responder (RR, 4.26; 95% CI, 1.10-16.44; p=0.04; I2=66%). The incidence of periprocedural TE after changing regimen of DAPT for clopidogrel hypo-responder have a tendency to reduce, but there was no significant difference between modified DAPT or TAPT group and standard DAPT group (p>0.05). The incidence of periprocedural HE after changing regimen of DAPT for clopidogrel hypo-responder was no significant difference between modified DAPT or TAPT group and standard DAPT group (p>0.05). PRU is a useful tool as a predictor of peri-procedural TE or HE on neurointervention. PRU has a threshold effect of cut-off value to predict the peri-procedural TE. Modified DAPT or TAPT to prevent TE in clopidogrel hypo-responders could not reduce the incidence of TE. We should investigate the further research about modification of regiment on neurointervention.

Long-term Prognosis of Patients Who Contraindicated for Intravenous Thrombolysis in Acute Ischemic Stroke.

BACKGROUND: As intravenous thrombolysis (IVT) has very restricted inclusion criteria, eligible patients of IVT constitute a very small proportion and studies about their mortality are rare. The long-term mortality in a patients with contraindication of ineligible patients of IVT still under the debate. So, we investigated the proportion of patients with contraindication of IVT and the short and long-term mortality of them in AIS on emergency department comparing with the long-term effect of IVT in patients with moderate-to-severe stroke. METHODS: Using acute stroke assessment indication registry & Health Insurance Review and Assessment Service database, a total of 5,407 patients with NIHSS≥5 were selected from a total of 169 acute stroke care hospital nationwide during October-December 2011 and March-June 2013. We divided AIS patients into two groups: 1) IVT group who received IVT within 4.5 hours, and 2) non-IVT group who did not receive the IVT because of contraindications. And we divided the subgroups according to the reason of contraindication of IVT. The 5-year survival rate of each group was assessed using Kaplan-Meyer survival analysis. RESULTS: Of the 5,407 patients, a total of 1,027 (19%) patients who received IVT using r-tPA within 4.5 h after onset. Compared with the IVT group, hazard ratios of non-IVT group were 1.33 at 3 months, 1.53 at 1 year and 1.47 at 5 years (p<.001). A total of 4,380 patients did not receive IVT because of the following contraindications to IVT. 1) Time restriction: 3,378 (77.1 %) patients were admitted after 4.5 h following stroke onset, and 144 (3.3%) patients failed to determine the stroke onset time. 2) Mild symptoms:137 (3.1%) patients had rapid improvement or mild stroke on emergency room, 3) Bleeding diathesis or non-adjustable hypertension: 53 (1.2%) patients showed a bleeding tendency or severe hypertension. Compared with the IVT group, the subgroups of non-IVT group showed consistently high mortality during short and long term follow up. Mild symptom and bleeding diathesis or non-adjustable hypertension subgroup in the non-IVT group consistently showed the higher mortality than time restriction subgroup during the short and long-term follow-up (log-rank p<.001). Patients who had rapid improvement or mild stroke on emergency department had the higher mortality than time restriction group in short and long term follow up. CONCLUSION: The AIS patients with rapid improvement or mild stroke on emergency room had higher mortality than ineligible patients of IVT due to time restriction during the short and long-term follow-up. A further management and special support on emergency department is needed for these patients with initially mild stroke and rapid improvement in AIS to reduce the poor outcome.

Current Training Status of Neurosurgical Residents in South Korea: A Nationwide Multicenter Survey.

BACKGROUND: In South Korea, special legislation was introduced in December 2016 to limit residents' training time to a maximum of 80 hours per week. The aim of this study was to survey the current training system and environment of neurosurgical residents and to find ways to improve the quality of neurosurgical training. METHODS: The questionnaire survey included 373 neurosurgical residents at 66 training hospitals nationwide, who were members of the Korean Neurosurgical Society. The survey method included a questionnaire link through a text message and was carried out anonymously. The survey was conducted for 7 days and targeted a total of 106 residents (28.4%). RESULTS: Most respondents selected "excessive training time" as a reason for dissatisfaction with the training environment (n = 61, 57.5%), followed by "limited number of opportunities for surgery" (n = 50, 47.2%), and "little experience for research" (n = 42, 39.6%). Respondents still believe that they have to work excessively longer, even after 80 hours of training per week. CONCLUSIONS: The major reason that neurosurgical residents are dissatisfied with the current training system and environment is the excessive time spent on it. These survey results are expected to be used as the basis for improvement of the residents' training system and work environment in South Korea.

Causes and Trauma Apportionment Score of Chronic Subdural Hematoma.

OBJECTIVE: The pathophysiology of chronic subdural hematoma (CSH) is not yet clear. Trauma alone is not sufficient to result in CSH in young individuals, while a trivial injury can result in CSH in older adults. Although the causality and apportionment of trauma are important issues in CSH, especially in terms of insurance, it is too obscure to solve all struggles. METHODS: There are three key factors for producing CSH. First, CSH necessitates a potential subdural reservoir. Other important precipitating factors are trauma and coagulopathy. However, these factors are not sufficient to cause CSH development. The trauma apportionment score (TAS) can be used to compare the relative importance of these three factors. Here, we applied the TAS to 239 consecutive cases of CSH. We retrospectively obtained the patients' history and laboratory results from their medical records. RESULTS: The TAS ranged from -5 to 5. The most common score was 0. If we defined the cause of CSH as being combined when the TAS was 0, then the cause was combined in 30 cases (12.6%). If we extended the criteria for a combined cause from 0 to -1 to 1, the cause was combined in 107 cases (44.8%). Regardless of the criteria used, traumatic CSHs were more common than were spontaneous CSHs. Spontaneous CSHs were more common in older than in younger patients (p<0.01, Fisher's exact test). CONCLUSION: The TAS is a useful tool for differentiating the causality of CSH.

Gliosarcoma of Cerebello-Pontine Angle: A Case Report and Review of the Literature.

Gliosarcoma (GS), known as variant of glioblastoma multiforme, is aggressive and very rare primary central nervous system malignant neoplasm. They are usually located in the supratentorial area with possible direct dural invasion or only reactive dural thickening. However, in this case, GS was located in lateral side of left posterior cranial fossa. A 78-year-old man was admitted to our hospital with 3 month history of continuous dizziness and gait disturbance without past medical history. A gadolinium-enhanced MRI demonstrated 5.6×4.8×3.2 cm sized mass lesion in left posterior cranial fossa, heterogeneously enhanced. The patient underwent left retrosigmoid craniotomy with navigation system. The tumor was combined with 2 components, whitish firm mass and gray colored soft & suckable mass. On pathologic report, the final diagnosis was GS of WHO grade IV. In spite of successful gross total resection of tumor, we were no longer able to treat because of the patient's rejection of adjuvant treatment. The patient survived for nine months without receiving any special treatment from the hospital.

Cerebral Aneurysms in Judicial Precedents.

OBJECTIVE: From November 30, 2016, the Korean Government carried the revised Medical Dispute Mediation and Arbitration Act into effect. Mediation will start automatically without agreements of the defendant, when the outcome of the patient was death, coma more than a month or severe disability. Cerebral aneurysm has a definite risk of bad outcome, especially in the worst condition. Any surgical intervention to this lesion has its own high risk of complications. Recently, Seoul central district court decided 50% responsibility of the doctors who made a rupture of the aneurysm during coiling (2015Ga-Dan5243104). We reviewed judicial precedents related to cerebral aneurysms in lawsuit using a web search. METHODS: We searched judicial precedents at a web search of the Supreme Court, using the key words, "cerebral aneurysm". RESULTS: There were 15 precedents, six from the Supreme Court, seven from the High Court, and two from district courts. Seven precedents were related to the causation analysis, such as work-relationship. Five precedents were malpractice suits related bad results or complications. Remaining three precedents were related to the insurance payment. In five malpractice precedents, two precedents of the Supreme Court reversed former two precedents of the High Court. CONCLUSION: Judicial precedents on the cerebral aneurysm included not only malpractice suits, but also causation analysis or insurance payment. Attention to these subjects is needed. We also need education of the independent medical examination. To avoid medical disputes, shared decision making seems to be useful, especially in cases of high risk condition or procedures.

Delayed Monocular Blindness after Coil Embolization of Large Paraclinoid Aneurysm.

Treatment of paraclinoid aneurysms weather by surgery, or endovascular embolization has a risk of visual loss due to optic neuropathy, or diplopia due to cranial nerve palsies. Visual complications occur immediately after the clipping, whereas they can occur variable time after endovascular coiling. Recently, endovascular coiling for paraclinoid aneurysm is regarded as a safe and feasible treatment. But it still has risks of acute thromboembolic complication, or cranial nerve palsies. A 45-year-old woman was referred from local hospital to our hospital due to ruptured large ICA dorsal wall aneurysm. A total of 12 coils (195 cm) were used for obliteration of aneurysm. Postoperative diffusion weighted image showed no abnormal signal intensity lesion and magnetic resonance angiography demonstrated no sign of vasospasm, or vessel narrowing. But, she complained visual problem 23 days after coil embolization. Ophthalmologist confirmed the left optic disc atrophy on fundoscopy. Although steroid was started, but monocular blindness did not recover completely. The endovascular embolization of paraclinoid aneurysm, especially projecting superiorly with large irregular shape, has the risk of progressive visual loss because of the proximity to optic nerve.

Surgical removal of embolic material after its unexpected migration through extracranial-intracranial anastomosis in the treatment of Barrow Type D carotid-cavernous fistula: case report.

Endovascular occlusion via the transvenous route is the favored treatment for indirect carotid-cavernous fistulas (CCFs). However, transarterial embolization can be used as an alternative method in patients with an inaccessible venous route. The authors present the case of a 49-year-old woman with a 2-month history of chemosis and proptosis in her right eye. Angiography demonstrated a Barrow Type D CCF. Transarterial Onyx embolization through the accessory meningeal artery was performed after an unsuccessful transvenous approach. Unexpected Onyx migrations to the cerebral arteries were detected while injecting the embolic material. Three hours after failed attempts to retrieve the Onyx cast endovascularly, it was microsurgically removed from the right middle cerebral artery. To the authors' knowledge, this is the first report of the surgical removal of Onyx from a normal cerebral artery.

Clinical Features of Interhemispheric Subdural Hematomas.

OBJECTIVE: Interhemispheric subdural hematoma (IHSDH) is uncommon, because of their unusual location. However, it is a distinct lesion with its unique characteristics. We investigated clinical features and outcomes of consecutive 42 patients with IHSDH, retrospectively. METHODS: From 2006 to 2015, we treated 105 patients with IHSDH. All patients were diagnosed by computed tomography (CT) or magnetic resonance imaging. We selected 42 patients with thick (3 mm or more) IHSDH. We retrospectively reviewed the clinical and radiological findings, management and outcomes. RESULTS: The male to female ratio was 2:1. Two thirds of the patients were over 60 years old. Slip or fall was the most common cause of trauma. The level of consciousness on admission was Glasgow Coma Scale (GCS) 13 to 15 in 25 patients. The most common symptom was headache. All IHSDH was hyperdense in CT at the time of diagnosis. IHSDH frequently accompanied convexity subdural hematoma. The outcome was favorable in 27 patients, however, six patients were expired. Twenty-two patients were managed conservatively. Surgery was performed in ten patients to remove the concurrent lesion. The outcome was poor in spontaneous one, patients with low GCS, and patients with conservative treatment. CONCLUSION: IHSDH is rare especially the isolated one. The outcome was dependent to the severity of injury. Surgery may be helpful to remove the concurrent mass lesion, however, conservative treatment is generally preferred.

Procedure-related Complications during Endovascular Treatment of Intracranial Saccular Aneurysms.

OBJECTIVE: We evaluate the rates and outcomes of major procedure-related complications during coiling. MATERIALS AND METHODS: Between 2007 and 2015, 436 intracranial saccular aneurysms were treated. Complications are categorized as three types: intraprocedural aneurysm rupture (IAR), thromboembolism (TE), and post-procedural early rebleeding (PER). And we evaluated the risk factors of procedure related complications by multivariate analysis. RESULTS: Complications occurred in 61 aneurysms (14%). The overall incidence of complications in subarachnoid hemorrhage (SAH) was significantly higher than in unruptured intracranial aneurysm (UIA) (20% vs. 6%). The incidence of IAR and TE were higher in SAH than in UIA (IAR 12% vs. 4%, TE 7% vs. 3%, p < 0.05). Five PER occurred only in SAH. In 34 UIA which were treated with balloon-assisted coiling (BAC), all these patients had good recovery despite 3 patients had the IAR. The incidence of IAR and TE were not different between BAC and non-BAC groups (p > 0.05). All 7 patients who had IAR during BAC had good recovery. In multiple logistic regression analysis, female gender, SAH, and intraventricular hemorrhage were associated with procedure related complication (p < 0.05). CONCLUSION: Endovascular coil embolization is a minimally invasive procedure, but incidence of its complication is not low, especially in SAH. BAC can be a good tool to avoid poor outcome from unexpected IAR during coiling. While IA tirofiban injection is a useful therapy in TE during coiling, sometimes we are aware of the risk of the early rebleeding in SAH patients.