We analyzed the outcome when high-grade arteriovenous malformations (AVMs), i.e., Spetzler and Martin Grades III, IV, and V, were managed by multimodal therapy to clarify the appropriate treatment for these patients.
Seventy-six patients with high-grade AVM were enrolled for this study and followed for a mean of 3.1 years. Initially, surgical treatment was recommended for all patients if it would not cause or worsen a neurological deficit. Fifteen patients were treated conservatively, while 41 patients underwent surgery, and the remaining 20 patients were treated with stereotactic radiosurgery.
(1) Conservative management: Seven episodes of bleeding occurred during the follow-up period, and the hemorrhage rate was 6.39%/year. (2) Surgical treatment: To prevent neurological complications, techniques such as preoperative embolization of the feeding artery, strict blood pressure control, brain function mapping, and intraoperative angiography were employed during surgery and perioperatively. None of the patients developed a permanent neurological deficit after surgery. A poor outcome (i.e., a modified Rankin scale score >2) was seen in older patients (more than 65 years old), patients with bleeding episodes, patients with large lesions (diameter >3 cm), and patients with deep or posterior fossa lesions. (3) Stereotactic radiosurgery: MRA showed more than 80% obliteration of the AVM in 14 patients at 6 months later. During the follow-up period, there were 3 complications (hemorrhage, brain tumor, and middle cerebral artery stenosis).
If surgery is unlikely to cause or worsen neurological symptoms, surgical resection is an appropriate treatment for high-grade AVM.

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Stereotactic radiosurgery (SRS) is widely accepted as the optimum treatment strategy for small arteriovenous malformations (AVMs) of less than 3 cm diameter. However, the treatment of large and high grade AVMs classified as Grades III, IV, and V by the Spetzler-Martin system remains controversial, partly because SRS is not so effective, so many technologies have been developed to assist surgical removal of the nidus. Furthermore, the treatment may be influenced by individual variations caused by the complexity of the drainer-nidus-drainer system and the effects on the natural history of pedicle aneurysms, and deep or superficial, and eloquent or non-eloquent location. We have employed 2 different treatment strategies: intravascular embolization with liquid material to decrease AVM size followed by SRS during 1998-2000; and intravascular embolization to control feeders followed by nidus resection since 2001. Here we analyze the outcomes for patients treated by these protocols.
Seven patients were treated by intravascular embolization: 2 patients received only intravascular embolization and 5 patients received intravascular embolization followed by CyberKnife irradiation in 4 patients and gamma knife followed by CyberKnife irradiation because of the poor initial response in 1 patient. One of the 2 patients treated by intravascular embolization had modified Rankin Scale (mRS) of 5, and the other patient died of bleeding from the AVM. Only 2 of the 5 patients treated by intravascular embolization followed by irradiation had complete obliteration of the nidus. Furthermore, the patient who received SRS twice later suffered from radiation necrosis.
Nine patients were treated by intravascular embolization followed by surgery. The feeders far from the operative field were also embolized to decrease arteriovenous shunting and intraoperative bleeding, and to shorten the operative time, and the nidus was removed within 1 week to avoid newly formed fragile feeders. The hematoma wall adjacent to the nidus was fully utilized as a part of the dissection plane in patients with bleeding episodes. At the end of the operation, intraoperative angiography was performed to confirm complete resection of the nidus. Pre- and post-operative CBF studies were essential to predict NPPB, and this complication was never experienced in this series. The nidus of all 9 patients was completely removed, but 1 patient developed postoperative cerebellar ataxia.
Embolic complication caused by intravascular embolization was observed in only one of the 16 patients in the entire study period.
The present study suggests that large and high grade AVMs should not be treated by intravascular embolization to decrease the AVM size followed by SRS. Recently, recanalization of embolized nidus that was located out of the SRS irradiation field has been reported. Therefore, the low obliteration rate of our first strategy may have resulted from the presence of viable but angiographically occult nidus. In contrast, the second strategy achieved a high success rate.
This study is limited by the small number of patients and large bias introduced by referral and the fact the patients with bleeding, but the findings indicate that intravascular embolization followed by surgery may be the optimum treatment for large and high grade AVMs. A new grading system for AVMs is needed to assess surgical feasibility based on the character of feeders, history of bleeding, and AVM location.

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Carotid endarterectomy (CEA) is surgical treatment for cervical carotid stenosis according to medical evidence. Indications of STA-MCA anastomosis has been established recently based on the Japanese EC-IC Bypass Trial (JET Study). However, surgical management of multiple stenosis and/or occlusion of the internal carotid artery (ICA) remains controversial. In the present study, we investigated the surgical indication and order for the bilateral lesions.
Bilateral ICA stenotic and/or occlusive lesions were divided into 2 groups: ICA occlusion and contralateral severe stenosis (Group 1) and bilateral ICA occlusion except moyamoya disease (Group 2). Nine patients in Group 1 and 6 patients in Group 2 were treated between March 2002 and February 2006 in our institute. In Group 1, in principle, we performed STA-MCA anastomosis on the occlusion side first, followed by separate contralateral CEA. In case of repeated stroke caused by the carotid stenosis, CEA was the first treatment, followed by STA-MCA anastomosis on the contralateral side. In Group 2, we gave priority of surgical treatment (STA-MCA anastomosis) over a symptomatic side.
Based on these treatment strategies, all of the cases in both groups had a good outcome without postoperative complications. However, we needed to control blood pressure strictly in some cases because of contralateral un-treated lesions, particularly in cases with hyperperfusion after the first surgical treatment.
Treatment guidelines should be established for the multiple ICA lesions, which have various and complicated pathological conditions. Patients with these lesions can be treated safely by adequate perioperative management.

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Determining the treatment strategy of severe SAH (Hunt and Kosnik Grade 4 and 5) requires objective evaluation to represent severity. In the present study, we investigated the role of diffusion-weighted imaging (DWI) in the acute stage as an objective tool.
DWI was performed within 48 hours after the onset and preoperatively in 36 patients who fulfilled following the inclusion criteria: admission Hunt and Kosnik Grade 4 or 5, and Fischer Group 3.
Twelve of 14 patients without abnormal findings in DWI underwent surgery in the acute stage. Although 2 of 14 patients with high age were supposed to undergo surgery in the chronic stage, 1 patient died in aneurysmal re-rupture. Glasgow outcome scales (GOS) were GR in 5, MD in 6, SD in 1 and D in 2 patients. Thirteen of 22 patients with DWI abnormality had small lesions less than 10 mm in diameter. Twelve of 13 patients underwent surgery in the acute stage, and 1 died of aneurysmal re-rupture while waiting for surgery in the chronic stage. GOS were GR in 3, MD in 4, SD in 3 and D in 3 patients. Although 5 patients with diffuse DWI lesions underwent surgery in the acute stage, 2 were SD and 3 were D. Four patients were supposed to undergo delayed surgery. However, 2 of them died of recurrent hemorrhage while waiting. GOS were SD in 2 and D in 2 patients.
The present study indicates that DWI may provide objective evaluation of brain damage in severe SAH. However, since there were varieties of DWI findings and clinical courses, careful decisions must be taken in management of severe SAH patients.

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The use of carotid endarterectomy (CEA) for near occlusion (NO) of the internal carotid artery (ICA) has not been evaluated with respect to the diagnostic procedures required, the risks, the appropriate timing, or the benefit of revascularization. Some reports note that the operative risks of CEA in NO patients and in some atherosclerotic total occlusion (TO) patients are not greater than those in patients with ordinary ICA stenosis. However, it is generally accepted that the rate of restenosis after CEA in NO/TO is very high.
In the treatment of atherosclerotic ICA stenosis, it is important to consider not only the stenosis rate but also the plaque characteristics; in recent years, many reports that have used these criteria have demonstrated the usefulness of carotid MRI.
We report the therapeutic results of CEA done in cases with NO/TO, particularly with respect to the relationship between the MRI plaque findings and the postoperative patency of the distal ICA.
Seven CEAs were done in carotid NO/TO cases between March 2003 and October 2005 in our hospital. The morphology of the ICA stenosis and the characteristics of the carotid plaque were evaluated with digital subtraction angiography (DSA) and carotid black-blood (BB) MRI, respectively. Plaques were excised as single masses during CEA and then processed for histology.
One asymptomatic case with de novo small infarction was confirmed on diffusion-weighted MRI images. In our study, neither hemorrhagic complications nor hyper-perfusion syndromes were observed. The overall safety of CEA for NO/TO was acceptable. The BB-MRI findings on T1-weighted images included: an extremely high signal in 3 cases; a slightly high signal in 2 cases; an isosignal in 1 case; and a low signal in 1 case. On histology, there was massive fresh intra-plaque hemorrhage (IPH) in 3 cases, subacute IPH in 1 case, chronic IPH in 1 case, and recanalization of occlusive thrombosis in 2 cases. One patient had asymptomatic thrombotic occlusion. Another patient had a poorly dilated distal ICA. These patients' pre-operative DSA showed NO with a string-like lumen, the BB-MRI revealed iso/low signals and histology demonstrated chronic IPH/recanalization.
CEA for “chronic” NO/TO is of little benefit, since satisfactory post-operative patency of the distal ICA cannot be obtained. BB-MRI appears to be a useful modality for differentiating “acute” from “chronic” NO/TO.

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We retrospectively evaluated computed tomographic angiography (CTA) as the first choice of imaging for diagnosing ruptured cerebral aneurysms among 219 consecutive patients with non-traumatic subarachnoid hemorrhage (SAH) at our hospital between January 2001 and December 2004.
We found ruptured cerebral aneurysms in 203 patients, and the first diagnostic method was Digital Subtraction Angiography (DSA) in 34 patients and CTA in 169. Complementary DSA was indicated in 27 of the latter group (CTA+DSA group), and the remaining 142 patients (CTA group) were treated based solely on CTA findings. We found that 22% of the CTA+DSA group (n=6) and 4.9% of the CTA group (n=7) (P<0.01) had aneurysms at the distal portions of major vessels. The outcomes of the 2 groups did not significantly differ, and the diagnosis was incorrect in only 1 patient in the CTA group.
These findings indicated that the probability of misdiagnosing multiple aneurysms is higher when they are barely visible on CTA images, and thus physicians should strive to acquaint themselves with progress in diagnostic modalities and select the most appropriate strategy for individual patients with aneurysmal SAH.

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It is sometimes difficult to make a diagnosis of the ruptured site in the case of multiple intracranial aneurysms. We retrospectively analyzed 21 ruptured cases with multiple aneurysms, focusing on the following 4 factors.
1. SAH localization: A CT scan was available for localizing the ruptured site in 13 (62%) patients.
2. Size of aneurysm: The ruptured aneurysm was larger than the unruptured aneurysm in 12 (57%) patients.
3. Shape of aneurysm: The ruptured aneurysm was irregularly shaped in all patients, whereas the unruptured aneurysm in 10 (34%) was irregularly shaped and in 19 (66%) was round.
4. Aspect ratio of aneurysm: The aspect ratio of ruptured aneurysms was larger than that of unruptured aneurysms in 20 (95%) patients.
To identify the ruptured aneurysm in the patient of multiple aneurysms, it is important to consider many factors, especially the aspect ratio of the aneurysm.

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We evaluated the management of patients with subarachnoid hemorrhage (SAH) after arrival for surgical intervention in the ultra-acute stage. Immediately after brief neurological and systemic examination, patients were deeply sedated to prevent aneurysmal rerupture. Principally they were intubated with intensive control of systolic blood pressure below 120 mmHg by radial arterial monitoring. Buprenorphine, midazolam, and vecuronium were rontinely intravenously administered; and propofol, barbiturate, nicardipine, or prostaglandin was added to lower blood pressure if necessary. A total of 163 consecutive patients with SAH (59 men and 104 women, mean age of 61.1 years) arrived between 2003 and 2005 were enrolled.
The majority of patients were in poor grade: 26 with Grade IV, 54 with Grade V by grading scale of the World Federation of Neurological Society, and 32 with cardiopulmonary arrest. Eighty-seven patients (53%) arrived within 1 hour after onset of SAH and 127 patients (78%) arrived within 3 hours. Most of the poor-grade patients were intubated before initial brain CT scan. Mean systolic blood pressure was around 170 mmHg at the time of arrival, which was controlled around 120 mmHg or less during resuscitation and angiography. A total of 117 patients had DSA, 111 of them (68%) within 3 hours, and 111 patients underwent surgery, 81 of them (85%) within 6 hours. Despite intensive resuscitation, 36 episodes of rebleeding were detected in 32 patients, 24 before and 12 after arrival. Extravasation of contrast media was seen in 6 patients during cerebral angiography. Favorable outcome (good recovery and moderate disability) was obtained in 69% of Grade IV and 24% of the Grade V patients.
The risk of ultra-early rebleeding is highest for patients with poor grades. Deep sedation and strict blood pressure control followed by urgent obliteration of the ruptured aneurysm have a strong rationale to prevent rerupture and to achieve better overall outcome.

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An analysis of postoperative complications in 637 cases of aneurysm surgery that were performed at 3 associated institutions during 10 years between October 1, 1995, and September 30, 2004, revealed 4 cases of postoperative blindness. We present the etiology, patient background, and course of these cases. The 4 cases comprised 3 men and 1 woman, aged 40 to 63 years. Patients had a history of hypertension (n=3), and diabetes (n=1). Aneurysms were located at the distal ACA (n=2), A-com. (n=1), and MCA (n=1), and comprised ruptured (n=3), and unruptured (n=1) aneurysms. All patients became blind on the side that craniotomy was performed on. Although cerebral angiography was performed postoperatively for 2 patients, no vascular occlusion was detected as a possible cause. After follow-up of 2 to 9 years, patients currently have blindness (n=1), light perception (n=1), and hand movement vision (n=2).
Blindness was thought to have been caused by an increase in intraorbital pressure during reflection of the skin flap, which led to ocular hypertension and caused circulatory insufficiency in the central retinal and short posterior ciliary arteries, which are responsible for nourishing the retina and optic nerve.

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We surgically clipped an IC-PC aneurysm in an 82-year-old woman after opening the oculomotor cistern. The internal carotid artery was sclerotic and tilted to the anterior clinoid process. The aneurysm was very small and embedded beneath the tentorial edge. To expose enough space for aneurysm neck clipping without a temporary carotid artery clamp, the oculomotor cistern was opened along the oculomotor nerve from the oculomotor porus to just lateral to the tip of the anterior clinoid process, and the roof of the cavernous sinus was resected medially to the oculomotor nerve. The aneurysm neck was clipped with neither cavernous sinus opening nor oculomotor nerve injury.

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Acute subdural hematoma (ASDH) due to ruptured cerebral aneurysm is relatively rare. In our institution, of the 210 patients with subarachnoid hemorrhage (SAH) seen between 2000 and 2006, only 6 (2.9%) revealed ASDH in association with cerebral aneurysm. The Hunt & Kosnik grade on admission was Grade III in 1, Grade IV in 3, Grade V in 2. Four patients with Grade III or IV underwent emergency hematoma removal and aneurysmal neck clipping. The outcome was good recovery in 3 and moderately disabled in 1 with Glasgow Outcome Scale. Two patients with Grade V treated conservatively died. We discuss the present cases with reference to a review of the literature.

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