In the present study, we assess whether a new technique of surgical microscope-based videoangiography (VAG) using indocyanine green (ICG) is suitable for confirming a patent extracranial-intracranial bypass or a complete aneurysmal clipping. We also describe the usefulness of our approach combined with ICG-VAG and motor evoked potentials (MEP) for the intraoperative assessment of blood flow in cerebral arteries of clipping or bypass operations.
We clinically and scientifically tested ICG VAG in 22 patients. In each patient, ICG (0.10-0.50 mg/kg body weight) was given systemically via an intravenous bolus injection. We used the Carl Zeiss Surgical Microscope OPMI Pentero INFRARED 800 system (Carl Zeiss Co., Tokyo, Japan). Images of ICG video angiography were excellent and permitted a real-time surgical assessment if the structures of interest were visible to the surgeon under the microscope. The visible structures included venous vessels or perforating arteries with a diameter of less than 0.3 mm. Of the 22 patients operated on, none suffered surgically related complications.
ICG VAG is a simple, reliable method, and its real-time character allows the early confirmation of complete aneurysmal clipping in patient bypass surgery. This technique may improve neurosurgical procedures and reduce the application of intra- or postoperative digital subtraction angiography.

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Twenty-two patients with cerebrovascular occlusive disease including 6-moyamoya disease underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery between February 2007 and March 2008. In atherosclerotic cases, a single bypass between the parietal branch of STA and the posterior temporal artery was performed. In cases of moyamoya disease, a double bypass between both branches of STA and MCA (M4) on both frontal and temporal lobe with indirect bypass was performed. Perfusion areas of bypass flow from STA were evaluated by intraoperative near-infrared indocyanine green (ICG) videoangiography. This allowed unprecedented direct visualization of bypass flow in detail. In most atherosclerotic cases, perfusions of bypass flow were localized on the surface within the temporal lobe. In cases of advanced moyamoya disease, local perfusion areas only around the recipient artery were observed. This is the first report of perfusion areas of bypass flow being evaluated by intraoperative direct observation. With more cases, intraoperative ICG videoangiography may help surgeons select the recipient artery or decide if supplementary indirect bypass is necessary in moyamoya disease.

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We evaluated the usefulness of fluorescence cerebral angiography using fluorescein sodium (fluorescein-FCAG) for detecting the blood flow in the cerebral artery and vein during neurological surgery.
The study population comprised 81 patients who underwent aneurysm clipping (76 cases), superficial temporal artery-middle cerebral artery anastomosis (4 cases) and occipital artery-posterior inferior cerebellar artery anastomosis (1 case). After aneurysm clipping and/or anastomosis, the target arteries were illuminated using a beam from a pencil-type probe with a blue light-emitting diode at its tip. After a 2.5-5 ml of 10% fluorescein sodium was injected intravenously, fluorescence in the vessels was clearly observed through a microscope and recorded on videotape. The excellent image quality and spatial resolution of fluorescence facilitated intraoperative real-time assessment of the patency of the target arteries. In large arteries such as internal cerebral artery, images by FCAG using indocyanine green (ICG-FCAG) were clearer than those by fluorescein-FCAG. On the other hand, in perforating arteries, fluorescein-FCAG was superior to ICG-FCAG in resolution. The fluorescence by fluorescein-FCAG disappeared faster than that when ICG-FCAG was used.
Fluorescein-FCAG is very promising because it allows confirmation of the intravascular blood flow from outside. Our findings suggest that observation of the blood flow by fluorescein-FCAG can prevent unexpected cerebral infarctions and improve the surgical outcome.

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Nowadays, young neurosurgeons need to brush up their skills with lower surgical case volume compared with what senior neurosurgeons have experienced before due to the increasing number of endovascular treatments as well as the trend toward less invasive treatment. To overcome such difficulties, under the instruction of the senior author (KT), the first author underwent suturing training using 10-0 nylon under desktype microscope, accumulating up to 80,000 stitches over the past 8 years. In addition, the junior author (NK, AK, RO) underwent the same training, accumulating up to 10,000-40,000 stitches. The training resulted in the surgeons being able to achieve stable STA-MCA anastomosis under supervision after 10,000 stitches, STA-MCA anastomosis within 20 minutes occlusion time and mastery of aneurysmal clipping of anterior circulation (normal size) after 30,000 stitches, deep anastomosis and clipping of large aneurysm under supervision after 50,000 stitches. After 80,000 stitches, it was possible to manage 280 surgical cases/year institution (clipping, 50; bypass, 30; ICH removal, 30) as a chief. Although there are various factors to improve surgical skills, this simple, daily and long-term training could help overcome the steep learning curve of cerebrovascular surgical skills by improving dexiterity and maneuverability under high magnification.

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While poor-grade subarachnoid hemorrhage (SAH) is generally associated with high mortality and morbidity, some patients make an unexpected dramatic recovery. To estimate prognosis for severe SAH, we assessed cerebral blood circulation by computed tomography perfusion (CTP) imaging on admission. CTP studies were performed for 25 of 49 SAH patients with World Federation of Neurosurgical Societies (WFNS) Grade V between March 2006 and July 2008. Four patients were excluded due to rerupture of aneurysm after CTP images were obtained. We measured cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the cerebral cortex or basal ganglia. Outcomes were assessed using the modified Rankin Scale (mRS), and patients were classified into 3 groups (n＝7 each): Group A, mRS 0-3; Group B, mRS 4, 5; and Group C, mRS 6. All patients of Groups A and B underwent surgery, while 6 patients in Group C with mydriasis on admission were treated conservatively. CBF of the cerebral cortex was significantly lower in Group C than in Groups A or B. No significant differences were seen in CBV among the 3 groups. MTTs of cerebral cortex were significantly longer in Group C than in Groups A or B, with a cutoff value of 6.6 s. CTP is a potential modality for poor-grade SAH, in that discrimination between “false” and “true” Grade V patients could be made rapidly and less invasively.

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Cerebral salt wasting syndrome (CSWS) is defined as the renal loss of sodium associated with intracranial diseases (e.g., aneurysmal subarachnoid hemorrhage [SAH]) that leads to hyponatremia and decreased extracellular fluid volume. CSWS increases the risk of symptomatic vasospasm (SVS) in SAH patients. To prevent SVS, CSWS was managed by administering physiological saline and sodium chloride so as to maintain a positive water balance and serum sodium level of >140 mEq/l.
The study population comprised 115 patients; the above-mentioned treatment was administered just after surgery, which was performed within 72 h after SAH. SVS occurred in 7 patients (6.09%): 5 (4.35%) presented with permanent deficits and 2 (1.74%) with transient deficits. Further, SVS occurred within a week in 6 of these patients.
On Day 2, the accumulative water balance was significantly higher in the non-SVS group than in the SVS group; the water balance tended to decline in the SVS group for a few days. Until Day 6, the amount of sodium chloride administered to maintain the serum sodium level to >140 mEq/l was higher in the SVS group than in the non-SVS group. However, on Days 3-5, the serum sodium level was lower in the SVS group than in the non-SVS group.
The use of physiological saline and sodium chloride therapy to maintain a positive accumulated water balance and control the serum sodium level in the management of CSWS, especially within the initial 7 days after SAH, can effectively prevent SVS.

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Terson's syndrome (TS) is a vitreous hemorrhage that develops in patients with subarachnoid hemorrhage (SAH) most frequently due to ruptured aneurysm. The reported incidence of TS has varied between 1.4 and 16.7%. Of 36 consecutive SAH patients that we treated, TS was diagnosed in 12 patients (33%). The reason that the incidence of TS in our patients series was much higher than previously reported was due to the use of a mydriatic agent to accurately diagnose TS and the examination of all 36 consecutive patients, including those with a high Hunt and Kosnik grade. In our study, the incidence of TS was significantly greater among patients with a higher grade of SAH according to a H & K classification, as noted in past reports (P-value＝0.0047<0.05). Additionally, the incidence of TS was greater in patients with a higher SAH grade according to the classification proposed by Fisher (P-value＝0.088>0.05). In this connection, we speculated that the mechanism of TS was the reflux of an abundance of blood drained into the orbital cavity via the Virchow-Robin space.
Long-term retention of blood in the vitreous body may cause cell damage and delay the start of rehabilitation. Therefore, early treatment is preferable.

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We reviewed data regarding the clinical course and treatment outcome in 8 consecutive cases (4 men, 4 women; average age, 71.3 yr) with progressing ischemic stroke at our institution. They were refractory to the best medication and underwent endovascular revacularization. Lesion locations were cervical internal carotid artery stenosis in 4 cases, intracranial internal carotid artery occlusion in 1, vertebro-basilar artery occlusion in 2, and basilar artery occlusion in 1. Six cases demonstrated stepwise neurological deterioration, with a depressed level of consciousness probably due to recurrent thrombo-embolism concomitant with hemodynamic compromise. In 2 other cases with cervical internal carotid artery stenosis who demonstrated gradual neurological deterioration, etiology seemed to be due to hemodynamic compromise. Seven patients achieved primary interventional success followed by clinical improvement. However, 1 case with basilar artery occlusion demonstrated worsening in clinical and radiological aspects despite recanalization with intracranial stenting, indicative of time delay of revascularization.
Although decisions about intervention should be carefully made after assessing whether the tissue at risk of cerebral infarction is salvageable, endovascular revascularization can be feasible and safe for progressing ischemic stroke based on atherosclerotic stenosis/occlusion of major cranio-cervical arteries.

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To improve the safety of the treatment of unruptured aneurysms, the bypass technique is useful and sometimes necessary. Between 2004 and 2007, the first author treated 42 unruptured aneurysms, including 7 cases in which bypass was performed. In this article, we classify bypasses by purposes into 3 categories and explain each case. In the first category, the bypass is used as a substitute for the parent or daughter artery in conjunction with aneurysmal trapping or proximal ligation. In the second category, the bypass is used as an addition in cases in which atherosclerotic disease is concomitant with aneurysm. In the third category, the bypass is used for temporary revascularization for expected prolonged occlusion of the parent artery during aneurysmal clipping. All 3 of these uses of bypass can improve the safety of aneurysmal clipping by reducing ischemia if the bypass procedure itself is carefully performed.

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Fusion imaging of magnetic resonance angiography (MRA) and MR imaging (MRI) is valuable to assess the location of the horizontal portion of the middle cerebral artery (MCA), MC bifurcation aneurysm (AN) and limen insulae. In this study, we evaluated the usefulness of fusion imaging in MC bifurcation aneurysm surgery.
Between October 2007 and February 2008, 18 patients underwent clipping for unruptured MC bifurcation ANs at the authors’ institution. Preoperatively, 3DFSPGR MRI and 3DSPGR MRA data were fused. The distance of limen insulae and distal end of the horizontal portion of MCA were calculated.
The mean distance in 9 distal approaches was ＋4.3±1.8 mm and －7.2±6.3 mm in 9 superior approaches, respectively. Preoperative simulation images were coincident with operative findings in all cases.
Fusion images of MRA and MRI are useful for planning the treatment of unruptured MCA ANs.

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Dissecting aneurysm of the anterior cerebral artery (ACA) is an unusual condition. Observation or trapping and bypass are recommended for the treatment of dissecting aneurysm of the ACA. We present a very unusual case of a 52-year-old female with subarachnoid hemorrhage due to the rupture of a dissecting aneurysm in the peripheral ACA successfully treated by wrapping and clipping technique. We discuss the surgical treatments for dissecting aneurysm of the ACA.

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