Objective: Regional cerebral blood flow (CBF) increasing focally at sites of neural activity is called "hemodynamic response (HDR)". In cases with severe cerebral ischemia, HDR may be disturbed and cause disruption of normal neuro-vascular coupling. HDR was measured during a motor task using functional near infrared spectroscopy (fNIRS) in cases with severe cervical internal carotid artery (ICA) stenosis before and after carotid artery stenting (CAS). Ischemia and the influence of therapy for it on HDR was analyzed.
Methods: Seventeen right-handed patients with severe cervical ICA stenosis admitted for CAS were examined. fNIRS during a motor task was performed and concentration changes in oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HbR), and total hemoglobin (tHb) were calculated in these patients in addition to routine evaluations. The same measurements were repeated after CAS and serial data were evaluated. In order to analyze the relevance of HDR to CBF status, Xenon-enhanced computed tomography (Xe-CT) was performed before and after CAS.
Results: Some abnormalities in the HDR curve and its recovery after CAS were detected, including a delay in peak time of tHb concentration, of more than 10 seconds during the 20 second stimulation, in 9 cases. TTP^0.7 (time to peak) value, defined as the time to reach seventy percent of maximum tHb concentration, was observed to be higher in patients with low CBF at rest before CAS. In the group with a high TTP^0.7 value, CBF at rest before CAS was lower than 35mL/100g/min., significantly lower than the group without a high TTP^0.7 value (P<0.01). Additionally, in the group with a high TTP^0.7 value, CBF increase after CAS was significantly higher than the group with a lower TTP^0.7 value (P<0.01).
Conclusions: In some cases with severe ICA stenosis, cortical hemodynamics, and oxygen metabolism during functional activation are disturbed, and CAS can modulate these changes. This result is important in that intervention for cervical IC stenosis can not only reduce ischemic events, but also influence cortical hemodynamics during functional activity.

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Objective: Perioperative complications from embolization of unruptured cerebral aneurysms in one institute serial series were analyzed. Subjects: From 1997.6 to 2007.6, 127 cases of unruptured cerebral aneurysm were treated by endosaccular coil embolization at one institute. They consisted of 34 paraclinoid internal carotid, 21 posterior communicating, 13 other internal carotid, 15 middle cerebral, 20 anterior communicating, 6 other anterior cerebral artery, and 18 posterior circulation aneurysms. Number of patients was categorized by size of aneurysm (less than 5mm: 38, 5-10mm: 81, and greater than 10mm: 8 cases). 68 patients received an antiplatelet agent principally preoperatively, and an additional secondary antiplatelet agent was given to those treated by balloon neck plasty.
Results: Neurologically symptomatic complications were TIA in 2 (1.6%), and minor cerebral infarction in 2 patients (1.6%). Subarachnoid hemorrhage due to vessel perforation by guide-wire occurred in 1 patient (0.8%). Putaminal hemorrhage occurred in 1 patient (0.8%) at 11 days after treatment. Other complications were upper gastrointestinal bleeding requiring blood transfusion in 2 patients (1.6%) and puncture-site pseudo-aneurysm requiring surgical repair in 1 patient (0.8%).
Conclusion: Persistent neurological symptoms were observed in 3 patients (2.4%; mRS 1:1 and mRS 2:2), suggesting that complication rates for endovascular techniques are low or the same as previously reported surgical or endovascular series. These results indicate that endovascular coil embolization is a suitable alternative treatment for unruptured aneurysms. However, hemorrhagic complications related to the use of antiplatelet agents or anticoagulants are not negligible and require careful consideration.

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Objective: Endovascular treatment is thought to be minimally invasive and result in few infectious complications. However, in some cases, infectious complications occur due to the presence of intravascular foreign bodies. Previous studies have not provided sufficient data in this regard. Specifically, no studies on the frequency of sepsis following neuroendovascular surgery have been reported. Therefore, frequency of sepsis and associated risk factors were investigated in this study.
Methods: Serum samples and various cultures obtained after neuroendovascular surgical procedures (n=153) performed at our facility from September 2006 to September 2007 were examined. Frequency of bacteremia, sterility of the operating field, and associated risk factors were assessed.
Results: Twelve cases (7.8%) had complicated bacteremia and were successfully treated with antibiotics. However, two cases developed MRSA infection, that proved to be intractable. Organisms were isolated from more than half of the operating field. Risk factors for bacteremia were surgical procedures involving tumor embolization (odds ratio [OR] 7.6, P=0.034) and large sheath size (OR 3.9, P=0.047). Risk factors for a contaminated operating field were the operating surgeon, surgical procedure, large sheath size and use of a hemostatic device, of which the surgeon was a significant risk factor (OR 0.5, P=0.049). The organisms responsible for bacteremia varid from normal bacterial flora to gram-negative rods and MRSA. As antibiotic prophylaxis was not found to be effective in these cases (OR 4.7, P=0.035), the appropriate type and course of antibiotics had to be selected to prevent such complications.
Conclusion: Bacteremia occurring following neuroendovascular treatment can develop in an uncontrollable manner. Thus, surgical procedures must be performed in a sterile environment, especially complicated procedures involving large sheaths.

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Objective: In endovascular coil embolization for a cerebral aneurysm, excessive stress from coil insertion into an aneurysm may cause a catastrophic rupture or the microcatheter tip to dislocate from the aneurysm dome, resulting in insufficient embolization. Such mechanical stress caused by the coil insertion force can only be subjectively detected by the minor tactile feedback the surgeon receives. Therefore, a new sensor device, that adequately measures coil insertion force via an optical system was developed. This new sensor device is described here.
Method: This system is incorporated into a Y-connector (hemostatic valve which is connected to the proximal end of a microcatheter). The sensor principle is based on an optical system consisting of an LED and line sensor. The line sensor measures how the coil delivery wire slightly bends according to the insertion force by detecting the wire shadow. This information is translated into a given force level. An experimental silicon aneurysm embolization was performed with this optical sensor. The sensor continuously observed the mechanical force during the insertion of coils into the dummy aneurysm.
Results: The sensor adequately recorded the coil insertion force during embolization. When the embolization was successfully performed, the maximum insertion force did not exceed 0.3[N], and the record showed a repeated peak pattern change in force, reflecting actual clinical experience. Presence of the sensor did not hinder performance of embolization in any way.
Conclusion: This new sensor device adequately measures coil insertion force. This system provides potential for safer and more certain aneurysm embolization.

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Background and Purpose: 3D TOF MRA is widely used for follow-up study of patients with cerebral aneurysm treated with detachable coil embolization. Recently, several detachable coils have been introduced on to the market. This study aimed to evaluate imaging artifacts of detachable coils for cerebral aneurysm embolization with 1.5 T and 3.0 T MR imaging.
Materials and Methods: Ten types of detachable coil were evaluated. Coils were extended on the acryl phantom for MRI. Models were tested with T2* sequences and 3D TOF MRA sequences for visual evaluation of susceptibility artifacts.
Results: Minimal susceptibility artifacts were observed from the platinum coil itself. In two of the ten coils, spherical form susceptibility artifacts were observed at the detachment zone of the coil. The diameter of the artifact was over 4mm in TOF sequences on 3T MR system. The component of the detachment zone of the Electro Detach (ED) coil (Kaneka, Osaka, Japan) with anti-unraveling system was a cause of artifact as well.
Conclusion: MR image artifact was recognized from a small part of the ED coil. New materials for implants should be evaluated, not only for treatment efficacy but also for image quality in follow-up studies.

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Objective: Transarterial embolization (TAE) using liquid embolic material is adopted in the treatment of dural arteriovenous fistulas (DAVFs) with direct cortical venous drainage or in patients in whom transvenous access is limited. Arresting flow by wedging a microcatheter tip into a main feeding vessel is important to achieve complete obliteration of DAVF with TAE. The Masamune catheter is a double lumen microcatheter with a silicone balloon at its distal end, characterized by the shortness of its catheter tip to the distal balloon end. Two cases of DAVF treated by TAE with the balloon flow arrest technique using a Masamune balloon microcatheter are reported.
Case Report: Case 1, a 50-year-old man, was incidentally diagnosed with a tentorial DAVF with direct cortical venous drainage. An inflated Masamune balloon catheter was wedged in the occipital artery, and trans-arterial embolization was performed under a flow-arrested condition. As preparative embolization of the other minor feeding arteries had not been performed, complete obliteration of DAVF was not achieved by competing flow.
Case 2, a 64-year-old man, was diagnosed with a left transverse-sigmoid DAVF on angiogram. The DAVF was completely obliterated with the balloon flow arrest technique using liquid embolic material.
Conclusion: The Masamune catheter can easily achieve an artificial flow-arrest condition by inflation of its distal balloon to prevent fragmentation of liquid embolic material. In conjunction with preparative embolization of minor feeding vessels, curative embolization may be achieved from a main feeder using this catheter.

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Purpose: A neonatal case of vein of Galen aneurysmal malformation (VGAM) is described, and a review of published studies on pathophysiology and treatment of VGAM is presented.
Case presentation: A male neonate presenting with heart failure was diagnosed as VGAM by MRI at postnatal day 6. Angiography performed at postnatal day 11 showed a choroidal-type VGAM, of which the largest afferent artery was embolized on the same day. Following the first session, a series of transarterial embolization sessions were performed at postnatal days 19, 61, and 138, resulting in a marked reduction of shunt flow. Although the patient showed catch-up growth after serial treatments, he underwent additional embolization for the residual shunt at the age of two years. Angiograms also indicated stenosis of the sigmoid sinus and normal venous drainage, dependent largely on collateral pathways.
Conclusion: In treatment of VGAM, decisions about treatment modality and timing are critical. Also, careful observation is essential for detecting any subsequent change in cerebral blood flow dynamics.

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Objective: Arteriovenous malformations (AVM) of the maxillofacial region are rare. Here a case of pterygoid AVM is described.
Method: A patient presented with a large hemorrhage in the left basal ganglia, and found to have an AVM in the left pterygoid region. The AVM was mainly fed by the left internal maxillary artery, and partially drained into the left cavernous sinus and inferior petrosal sinuses. There was no angiographic evidence, such as cortical venous reflux, suggesting the AVM caused the hemorrhage.
Results: The AVM was completely obliterated by 2 sessions of endovascular embolization without complication. Although primarily a liquid embolic agent was used, platinum coils were also used in order to avoid ischemic cranial nerve plasty or non-target embolization across the dangerous anastomoses.
Conclusion: Experience with this single case suggests that an extra-cranial/extra-dural AVM can induce retrograde venous reflux into the intracranial venous vasculature. Careful evaluation of angiograms and appropriate selection of embolic agents are required for successful embolization of a maxillofacial AVM.

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Purpose: A retrospective analysis was conducted to determine risks and benefits of emergency air medical transportation for patients with subarachnoid hemorrhage (SAH) due to ruptured aneurysm treated by coil embolization.
Method: Analysis of 82 consecutive patients with SAH treated at our hospital over the last 4 years was performed. These patients were divided into two groups: those transported by air due to lack of access to a local neurosurgical facility (Islands group: 15 patients), and those transported by ground transportation, i.e. an ambulance (Vicinity group: 67 patients).
Results: Mean travel time was 66 minutes in the Islands group. Age distribution, sex, Hunt and Hess grade, and Fisher CT grade did not differ significantly between the two groups, however location of the aneurysm was significantly different (p<0.04). There were no re-ruptured aneurysms in the Islands group. At the time of discharge, 75% of the patients in the Islands group and 68% in the Vicinity group were considered to have a good outcome (good recovery and moderate disability on the Glasgow outcome scale), indicating that air transportation had no relationship to outcome.
Conclusion: Air transportation of patients with SAH had no disadvantages for outcome compared to ground transportation.

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Objective: Extracranial carotid artery aneurysm is a rare vascular lesion compared to stenotic or occlusive lesions. A case of extracranial giant carotid artery aneurysm that progressively enlarged to cause the complication of severe brain ischemia is presented.
Case presentation: A 73-year-old male presented to our hospital with hoarseness and a left inframandibular pulsatile mass. Angiography indicated a saccular aneurysm with a diameter of 35 mm at the bifurcation of the left common carotid artery and a severe internal carotid artery stenosis in contiguity with the aneurysm, that was asymptomatic at that time.
The aneurysm progressively enlarged, causing the complication of severe cerebral ischemia, prompting urgent carotid artery stenting. The orifice of the aneurysm was also covered by the stent struts. The inflow of the contrast into the aneurysm still remained just after stenting, however progressive thrombosis occurred gradually and the aneurysm eventually disappeared on the angiogram three months after stenting.
Conclusion: The flow dynamic change caused by the stent might have led to the thrombosis and healing of the aneurysm in this case.

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Objective: A case of acute internal carotid artery embolic occlusion, successfully recanalized by rescue clot disruption with a basket-shaped microsnare, in conjunction with local fibrinolysis therapy is described.
Clinical presentation: A 68-year-old female presented with abrupt onset of left hemiparesis and drowsiness. CT on admission indicated increased density in the right middle cerebral artery. Cerebral angiography demonstrated complete occlusion of the right internal carotid artery at the supraclinoid portion. Administration of intra-arterial urokinase and mechanical maceration failed to lyse the clot. A 5-mm basket-shaped microsnare was subsequently used to disrupt the residual clot. Successful recanalization was achieved immediately after snare maneuvers, followed by additional administration of urokinase. The clinical outcome was favorable.
Conclusion: Rescue use of a basket-shaped microsnare may be effective for fibrinolysis-resistant acute embolic stroke.

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