To clarify current treatment status of ruptured cerebral aneurysms in Japan, a prospective multicenter observational study on the treatment results for aneurysmal subarachnoid hemorrhage was conducted over calendar year 2005 and final 1-year outcomes were collected. Studied centers were selected from among institutes of committee member of Japanese stroke surgery organization or symposium of vasospasm in Japan. A total of 927 patients were enrolled in this study and treatment policies were left to each institution according to the patients’ background and aneurysmal characteristics. The observational protocol was similar to those of ISAT, especially the categorization of aneurysms, follow-up timing at 2 months and 1 year, patient outcome evaluation and recording of incomplete treatment results.
Finally, 770 patients were treated, and clipping was performed on 79% of them. Coil embolization was preferred in aged or vertebro-basilar artery aneurysm patients, and the 2-month outcome was identical in both the clipping and coil-treated groups. The 1-year outcome was better in the clipping group, but the initial patient condition in the clipping group was definitely better. The completeness of treatment was better in clipping, but post-treatment bleeding, hydrocephalus and epilepsy were identical in each group.
Evaluation of overall management outcome is mandatory to elucidate the contribution of endovascular treatment on the treatment result for ruptured cerebral aneurysms.

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To elucidate the contribution of endovascular treatment to the overall management outcome of ruptured cerebral aneurysms, prospective multicenter observational studies conducted over calendar years 1994 and 2005 are compared. The study in 2005 (Study 05) enrolled a total of 927 patients from 30 centers selected from among institutes of committee member of Japanese stroke surgery organization or symposium of vasospasm. Treatment modalities were left to each institute and finally 770 patients were treated. Clipping and coil embolization were performed on 79% and 21% of the patients, respectively. The study in 1994 (Study 94) enrolled 785 patients obtained from 11 institutes, and all the 525 patients were treated by clipping. Patient outcomes were evaluated 3 months (Study 94) and 1 year (Study 05) after onset and treatment, and overall management outcomes were evaluated. Patients’ background such as age, aneurysm location and World Federation of Neurological Surgery (WFNS) grade were not significantly different in the 2 studies. As a result, favorable treatment outcomes were obtained in 74.5% of the cases in Study 94 and 75.6% in Study 05. However, overall favorable management outcomes including non-treated cases were obtained in 58.5% of the cases in Study 94 and 64.4% in Study 05, a significant improvement (p<0.01). A sub-group analysis demonstrated improvement of treatment outcomes in poor-grade (WFNS IV and V) patients and increased ratio of treated patients in poor grade, aged (>70 years old) and vertebro-basilar aneurysm patients. Compared with Study 05 to Study 94, treatment of ruptured cerebral aneurysm by either clipping or coil embolization improved, not treatment outcome, but overall management outcome than those treated clipping only.

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Currently, unruptured cerebral aneurysms (U-Ans) are positively treated in conformity with the guideline for the Japanese Society for Detection of Asymptomatic Brain Diseases. Direct operations are performed after informed consent is obtained in U-Ans cases. However, unfortunate outcomes have occurred even if safe surgery was done. Therefore we examined the characteristics of U-Ans and report surgical treatment in our hospital.
Consecutive operations (n=45) on 43 patients between January 2005 and October 2007 were included in this study. Surgical neck clipping was performed on all patients. The mean age was 67 years. U-Ans were discovered in medical check-ups in 24 cases (56%), during close examinations of headache and dizziness in 10 cases, examination of oculomotor palsy in 5 cases and examination of ruptured cerebral aneurysm in 2 cases, respectively. The mean U-Ans sizes were 6.1 mm in the internal carotid artery, 6.4 mm in the anterior cerebral artery and 6.4 mm in the middle cerebral artery (MCA), respectively. One basilar top aneurysm 7 mm in size was included. Surgical morbidity was recognized in 2 patients (4%). One patient, a 75 year-old male, suffered a left temporal cerebral infarction due to mechanical vasospasm. Another patient, a 67 year-old female, developed a cerebral infarction in the territory of the right MCA due to the compression for MCA during approach for basilar-top UAn.
We experienced 2 cases with unfortunate outcomes. Surgical complications caused by mechanical damage and vessel compression occurred. These complications in clipping for aneurysms are preventable. More care in performing operative procedures is needed.

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We evaluated the effectiveness of assist-systems such as endoscopy, navigation, and motor evoked potential (MEP) monitoring in terms of improving the safety and accuracy of surgery for cerebrovascular diseases.
Since January 2000, the following devices have been used at our institution to assist in surgical procedures: an endoscope (diameter, 2.7 or 4.0 mm; tip angle, 30° or 70°) in 69 surgical procedures to treat cerebral aneurysms, a navigation system (Stealth Station) in 22 operations for cerebral aneurysms and arteriovenous or cavernous malformations, and MEP monitoring (bipolar or mono-polar electrical stimulation of the motor cortex and EMG recording of the face, trunk and upper extremity contralateral to the stimulated side) in 11 operations for cerebral aneurysms or arteriovenous malformations.
Endoscopy allowed visualization of the anatomical relationship between the aneurysm neck and the parent or perforated artery before clipping, and the location of the clip tip, occlusion of the perforated artery, or stenosis of the parent artery could be evaluated after clipping. Postoperative MR and/or CT images revealed an asymptomatic infarction of perforated artery in 4 patients. Navigation allowed prediction of the sites of aneurysms, cavernous malformations, or of the feeding arteries of arteriovenous malformations. This resulted in accurate approaches to these structures, although a brain shift in some patients was recognized by ultrasound imaging linked to the navigation system. Although MEP monitoring should have predicted postoperative motor function, MEP findings after clipping the neck of aneurysms or obliterating the arteriovenous malformation of a feeding artery were normal in all of the analyzed patients. Postoperative convulsive seizures developed in patients as a result of 20 mA of bipolar electrical stimulation.
Endoscopy, navigation, and MEP monitoring are considered helpful for safe and accurate surgical treatment of cerebrovascular diseases, although the disadvantages of these systems should also be considered.

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Our department is located in the Tsugaru area of Aomori Prefecture, which has a population of about 600,000. There are few neurosurgical centers that can treat patients presenting with stroke, head trauma, and other disorders. In this report, we describe the usefulness of telemedicine using an imaging transfer system for aneurysmal subarachnoid hemorrhage.
Imaging transfer systems have been installed at our hospital and 11 regional hospitals in the Tsugaru area. We studied 572 patients with subarachnoid hemorrhage who transferred using the imaging transfer system and admitted directly from January 2001 to August 2007. We studied Hunt and Kosnik grade on admission, treatment, Glasgow outcome scale, and the place of re-rupture. Most patients were transferred and treated with direct surgery and endovascular embolization in the telemedicine group. In the telemedicine group, Hunt and Kosnik grade and Glasgow outcome scale were significantly better than in the direct-admission group. Re-rupture was suspected in 38 cases (6.6%). And 71.4% of re-ruptures occurred in an ambulance in the direct-admission group. On the other hand, in the telemedicine group 42.9% of re-ruptures occurred during transport to the primary hospital and during transfer from the primary hospital to our hospital.
There were not many severe patients in the telemedicine group compared with the direct-admission group. The final outcome in the telemedicine group was better than in the direct-admission group. These findings indicate that telemedicine using an image transfer system is useful in the treatment of subarachnoid hemorrhage.

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We report 5 cases of remote cerebellar hemorrhage (RCH), which occurs rarely after supratentorial aneurysmal clipping. Among 501 consecutive cases, who were operated on for their supratentorial cerebral aneurysms (unruptured 174 cases; ruptured 327 cases) in our facility between 2002 and 2007, 5 (unruptured 4; ruptured 1) were found to have RCH. RCH was not found on the first CT scan taken within an hour after surgery but was detected between 4 hours and 8 days after surgery. Postoperative epidural drainage in RCH cases amounted to more than 200 ml per 4 hours. While several risk factors for this hemorrhage have been reported, hemorrhage along the cerebellar folia and delayed occurrence suggested that the disturbed cerebellar venous drainage caused by excessive CSF drainage during the perioperative period was the cause of this hemorrhage.
While the pathogenesis of RCH has not fully been elucidated, excessive CSF drainage should be avoided during supratentorial aneurysm surgery.

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The surgical management and therapeutic indication for poor-grade patients with subarachnoid hemorrhage (SAH) is controversial. Our hospital has an emergency medical center and admits many poor-grade SAH patients at ultra-early stages. We treated SAH patients with World Federation Neurological Surgeons (WFNS) Grade V who displayed the presence of the light reflex, intra-cerebral hematoma (ICH) or improvement of WFNS grade. We retrospectively evaluated 43 WFNS Grade V patients treated with surgical clipping (SC) or coil embolization (CE) in the period of 1998 to 2008. Forty-two patients (98%) were admitted within 180 minutes after SAH onset. SC was performed in 17 patients (40%), and CE was performed in 26 patients (60%). ICH was observed in 8 patients (18.6%). Rebleeding occurred in 9 patients (20.9%). At the time of surgery, the light reflex was present in 32 patients (74.4%). Grade improvement in the acute stage was observed in 18 patients (41.9%). In 24 patients (55.8%), SC or CE was performed within 24 hours. Symptomatic vasospasm was observed in 5 patients (11.6%), and shunt operation was performed in 14 patients (32.6%). The length of hospitalization ranged from 3 to 233 days (mean: 62.6 days).
The overall outcomes assessed at discharge by the Glasgow outcome scale (GOS) were GR in 11 (25.6%), MD in 12 (27.9%), SD in 10 (23.3%), and dead in 10 patients (23.3%). The percentage of GR was 29.4% in the SC group and 23.1% in the CE group. Similarly, MD was 29.4% and 26.9%; SD was 23.5% and 23.1%. But mortality was 17.6% and 26.9%. Favorable outcomes (GR+MD) were observed in 11 patients (61.1%) with grade improvement, in 22 patients (68.8%) with the presence of light reflex and in 6 patients (75%) with ICH. Patients with pre-operative Glasgow coma scale scores of 3, 4 obtained unfavorable outcomes.
About half of WFNS Grade V patients obtained unfavorable outcomes, but favorable outcomes can be obtained in patients with grade improvement, the presence of the light reflex or ICH.

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We analyzed surgical results and complications of 100 consecutive cases with unruptured intracranial aneurysms of the anterior circulation that were treated by 1 neurosurgeon over a period of 7 years beginning in 2001. Forty-one cases were internal carotid aneurysms, 35 were middle cerebral aneurysms, and 21 were anterior cerebral aneurysms. The size of aneurysms was 3-5 mm in 16 cases, 5-10 mm in 68, 10-15 mm in 8 and more than 15 mm in 8 cases. Neck clipping was performed in 97 cases and bypass plus trapping was selected in 3 cases. Postoperative angiography revealed complete disappearance in 99 cases, and no subarachnoid hemorrhage occurred during post-surgical follow-up. Permanent surgical morbidity and mortality were 2% and 0%, respectively.
Unruptured cerebral aneurysms in anterior circulation can be treated with low morbidity and mortality, but cranial nerve injury and ischemic complication should be avoided particularly in case of anterior communicating artery aneurysms, paraclinoid aneurysms and proximal middle cerebral artery aneurysms.

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We report a case of carotid-ophthalmic aneurysm that caused a transient lower half visual field defect. A 41-year-old man experienced a transient lower half visual field defect in his left eye. Computed tomographic angiography (CTA) and digital subtraction angiography (DSA) showed a left carotid-ophthalmic aneurysm 8 mm in diameter projecting superiorly. The position of the supra-
clinoidal portion and the bifurcation of the left internal carotid artery (ICA) were lower than the other side. Neck clipping was performed with a right-angled clip after anterior clinoidectomy and optic canal unroofing. Intraoperative findings showed the aneurysm was located just under the left optic nerve and stretched it superiorly. The upper surface of the optic nerve was compressed at the edge of the falciform ligament. The postoperative course was uneventful.
We think the aneurysm displaced the optic nerve superiorly against the falciform ligament and the compression of the upper surface of the optic nerve caused the lower half visual field defect. Direct surgery is adequate treatment in this case to avoid further damaging the visual function because coil embolization may enlarge the aneurysm. The low position of the supraclinoidal portion and the bifurcation of the ICA result in optic nerve compression. This radiographical findings of CTA and DSA are characteristic and may help understanding the symptom.

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We report on our surgical technique, “the rubber band and hook method,” for carotid endarterectomy (CEA). Since carotid stenosis is frequently high-positioned in the Japanese population, even a small transposition of the carotid artery downwards makes it safer and easier to manipulate the distal internal carotid artery. With rubber bands and small skin hooks, we mobilize the carotid artery by holding up the carotid sheath. The author (S.O.) performed 60 CEAs from 2001 to 2006 using this method. No perioperative stroke or hematoma formation that required surgical removal was observed. Postoperative angiography confirmed optimal patency in all cases. We observed, however, 1 persistent case (1.6%) and 2 transient cases (3.3%) of hoarseness due to superior laryngeal nerve palsy related to surgical maneuvers.
In this article, we report the effectiveness of our technique in ensuring the operative field along with the potential benefit to reduce bleeding by not separating the backside of the carotid artery. We also underscore the need of meticulous manipulation in securing the distal internal carotid artery and superior thyroid artery to prevent the superior laryngeal nerve palsy.

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Surgical treatment of the cerebral arteriovenous malformations (AVMs) is one of the most difficult neurosurgical practices, because neurosurgeons may not get adequate practice operating on patients with AVMs and because the variation of the characteristics of these lesions makes it difficult to establish a standard technique and skill to effectively resect these complicated vascular tangles in the brain parenchyma. However, it is mandatory for any vascular neurosurgeon to manage patients with AVM who present with severe neurological deficits or moribund condition due to hemorrhage. Here we report on our experiences of AVM cases and suggest that it is possible to remove the AVMs safely if the surgeon can open the cerebral sulci widely without trauma and without any nidal venous compromise using basic arachnoid dissection technique. We present illustrated cases and discuss the importance of the dissection of the cerebral sulci and staged surgery for large AVMs.

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