The major purpose of aneurysm surgery is to completely prevent bleeding from intracranial aneurysm (“complete” surgery), without any neurological deficit due to the surgical procedure (“safe” surgery). We evaluated the achievement of this “complete” and “safe” surgery for intracranial aneurysms by retrospectively analyzing Hunt and Kosnik Grade I and II cases with ruptured aneurysm and also cases with unruptured aneurysm.“Complete” surgery is defined as complete clipping of aneurysmal neck, neck clipping plus neck coating, or complete coating of small hemispherical aneurysm.“Safe” surgery is defined as the absence of new neurological deficits due to surgical procedure. Included in this study were 343 Grade I cases and 130 Grade II cases with ruptured aneurysm (RA), 25 unruptured symptomatic aneurysms (US) and 83 unruptured incidental aneurysms (UI).“Complete” surgery was not performed in 6 in RA, 5 in US and 2 in UI. Vertebrobasilar giant aneurysms tended to be incompletely treated by surgery.“Safe” surgery was not done in 8 in RA, 5 in US and 10 in UI. Large or giant posterior circulation aneurysms and basilar terminal aneurysms with high-positioned neck tended to have experienced post-surgical neurological deterioration.
In these aneurysms,“complete and safe” surgery for aneurysm is often difficult. Surgical manipulation for them should be more carefully performed so as not to injure perforating arteries. Endovascular embolization of aneurysm should be considered as an alternative.

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It is often unavoidable to cut the bridging veins via the frontal base to the superficial sylvian vein (fronto-temporal bridging vein, FTBV) in the pterional approach to the cerebral aneurysms and complications rarely occur. We analyzed approximately 300 cases who underwent the pterional approach over the past 5 years retrospectively, by intraoperative VTR and postoperative CT scan of each case. Eight cases (2.6%) had changes that were considered to be the venous system-related infarction, excluding retraction injury (43 to 78 years old, mean 58; IC-PC: 6 cases; Acomm.: 1 case; basilar tip: 1 case). The area of venous infarction ranges from ipsilateral deep frontal white matter to the basal ganglia, which was presumed to be the area of a first segment of basal vein of Rosenthal. Two of the 8 cases produced intracerebral hematoma in a basal ganglia, one died from pneumonia and heart failure 1 month later, and temporary motor aphasia was observed in the other one. The remaining 6 patients showed an uneventful course or a transient mild disorientation.
We reviewed anatomical variations of cerebral veins and presumed that FTBV in those cases could be anastomotic veins of superficial and deep venous drainage system. We discuss some methods of preventing such complications.

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We assessed the effect of intra-arterial injection (IA) of Papaverine hydrochloride (Papaverine) with/without Ca⁺⁺. antagonist (Nicardipine) on vasospasm following aneurysmal rupture.
We carried out this investigation as an open study on 70 patients. The average age was 52.1 and all underwent early aneurysm surgery within 48 hours after onset of subarachnoid hemorrhage. IA was carried out after development of neurological symptoms due to vasospasm and/or rapid increase of intracranial blood flow velocity on transcranial Doppler sonography (TCD). Vasospasm was graded by the degree of narrowing of main cerebral arteries by reference to angiograms obtained before aneurysm surgery. Intra-arterial injection of Papaverine (40-240mg) with/without Nicardipine (5-10mg) was carried out through a catheter inserted into the C5 portion of the internal carotid artery. Response of spastic arteries to Papaverine with/without Nicardipine was assessed on angiograms before and after drug injections.
The main cerebral arteries were all more or less dilated by IA therapy. When we compared the responses with IA among Day 4-5, Day 7-8, and later than Day 9 to examine the optimal timing of IA, the responses were most prominent in patients of Day 4-5, In most cases, however, efficacy of this therapy did not continue more than 24 hours: TCD usually showed increase of blood flow velocity of the cerebral arteries on the following day. However, only 11 cases required a second injection of drugs or angioplasty.
IA of Papaverine with/without Nicardipine is a safe and easy method for treatment of vasospasm, and timing of IA is most important for this treatment.

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The indication of radical surgery for unruptured cerebral aneurysms (uAN) remains obscure. To prevent bleeding, we have aggressively performed radical surgery for uAN even in elderly patients (over 70 years old) and in patients with cerebral ischemia, with concurrent bypass surgery for ischemic patients if necessary. We evaluated our surgical strategy in this study by analyzing the results of patients, especially the ratio of surgical mortality/morbidity and its causes.
Ninety-six patients (141 aneurysms) were treated. In 34 patients, aneurysms had been diagnosed without neurological symptoms. The remaining patients had been diagnosed at the examination due to precedent neurological diseases: subarachnoid hemorrhage (28 patients), hypertensive intracerebral hemorrhage (12), cerebral infarction (10), and the others (12). Distribution of the aneurysms were 57 internal carotid artery, 48 middle cerebral artery, 11 anterior cerebral artery, 10 anterior communicating artery, 8 basilar artery, 4 vertebral artery, and 2 posterior cerebral artery. Of the 141 aneurysms, 133 were clipped, and one was wrapped. Ligation or trapping of internal carotid artery with high flow EC-IC bypass using saphenous vein graft was done on 7 giant internal carotid aneurysms or symptomatic cavernous internal carotid aneurysms. Surgical mortality was 0 and morbidity was 5 cases (5.2%). Inappropriate handling of spatula and resultant cerebral contusion worsened the result of Case 1. Optic nerve compression with oxycellulose at dural repair after Dolenc approach caused ipsilateral blindness in Case 2. The cause of these morbidity was obviously carelessness. However, there was no apparent causal factor found in the following three cases (3, 4, 5). The three cases had common features as follows: 1) relatively high age (64, 67, 79 years old), 2) IC aneurysms, 3) large aneurysms, 4) not parent artery occlusion/stenosis but perforator injury suspected. One of the 3 patients received reoperation soon after the paresis had presented. But the clip was well placed, parent vessels were patent, and perforators looked healthy. Angiography of the remaining 2 cases showed no remarkable abnormality. Therefore, we cannot explain the neurological deficits in these cases.
Good results were obtained with our strategy. Precedent neurological diseases may not influence the result, even cerebral ischemia if precise and careful preparation is performed. Concurrent bypass surgery may not be avoided. Care should be taken for elderly patients with IC large aneurysms because perforator injury by unknown causes occasionally occurs.

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We investigated cerebral blood flow (CBF), cerebrovascular reserve capacity (CVRC) and metabolism of vertebrobasilar occlusive disease by positron emission tomography (PET) to clarify the effectiveness of extracranial-intracranial bypass. The subjects were 4 patients undergoing superficial temporal artery (STA)-superior cerebellar artery (SCA) anastomosis. In the preoperative studies, reduction of CVRC was observed in the posterior and anterior circulation. The STA-SCA anastomosis procedure is effective in improving CBF and metabolism in patients with vertebrobasilar occlusive disease.

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In basilar bifurcation aneurysm surgery, it is most important to get a wide operative field. The transsylvian approach or subtemporal approach have been performed for basilar bifurcation aneurysms. In the transsylvian approach, perforators from the posterior communicating artery and the internal carotid artery restrict access to the basilar bifurcation aneurysm. The subtemporal approach has the risk of venous damages or contusion of the temporal lobe. We have the anterior temporal approach for basilar bifurcation aneurysms. The anterior temporal approach is a modified distal transsylvian approach and the operators can keep a wide operative field. Superficial sylvian veins are dissected from the temporal lobe and moved to the frontal lobe, and the anterior temporal artery is separated from the medial surface of the temporal lobe completely. Dissection of vessels from the temporal lobe enables retraction of the temporal lobe posteriorly with minimum power. We describe some key operative techniques and some advantages and problems of the anterior temporal approach.

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On the basis of the concept of central salt wasting syndrome, hypotonic dehydration due to sodium-diuresis is considered to be a cause of cerebral vasospasms. To treat hyponatremia found in the acute stage of ruptured cerebral aneurysm, when sodium is solely supplemented, a large volume of infusion is required because of acceleration of sodium excretion. This makes treatment difficult in many cases. Hence, paying attention to the sodium balance in the acute stage of subarachnoid hemorrhage, we examined the effect of fludrocortisone acetate, a mineralocorticoid which accelerates resorption of sodium in the renal tubules on the sodium balance.
The subjects were 25 patients with ruptured cerebral aneurysm who underwent radical operation within 2 days after onset. They were allocated into fludrocortisone acetate (0.3mg/day) administration group (N=10) and no administration group (N=15) and at random. During the course of administration, infusion was performed actively using water balance and CVP as indexes. Sodium in serum and urine was continuously monitored, and a sodium balance sheet was made.
In the no administration group, the sodium balance tended to be negative from the third day after onset, accompanied by urine volume increase. In the fludrocortisone acetate administration group, decreased sodium excretion in urine was observed and the water balance was easily corrected. In addition, the prevalence of symptomatic cerebral vasospasms tended to be low.
In the acute stage of subarachnoid hemorrhage, the water and sodium balances tend to be negative from the third day after onset, and patients become dehydrated. When this state lasts a long time without correction, hyponatremia and symptomatic cerebral vasospasms occur easily. To avoid this state, administration of fludrocortisone acetate appeared to be effective.

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Purpose: With improving quality of images obtained by 3D-CT-Angiography, this procedure may promise to become a powerful tool in intracranial aneurysm diagnostic. We have evaluated this method comparatively between angiographic and intra-operative findings.
Method: Forty-one patients were examined by cerebral angiography and 3D-Angio-CT. Radiological findings were evaluated by neuroradiologists and neurosurgeons. Intra-operative findings were documented by video or photography.
Results: All angiographically proven aneurysms were also visualized by 3D-Angio-CT. In over sixty percent of cases 3D-Angio-CT showed the aneurysmal anatomy equally well to angiography or presented valuable additional information not obtainable by angiography. In complex aneurysms as well as in aneurysms of the posterior circulation, the additional information offered by 3D-Angio-CT was most valuable. Intra-operative anatomical findings showed a high correlation with 3D-images.
Conclusion: In our experience 3D-Angio-CT proved to be a powerful tool in the diagnostic procedure of intracranial aneurysms, either in the acute or non-acute phase. In many cases 3D-images present valuable additional information not otherwise obtainable, especially in complex aneurysms and aneurysms of the posterior circulation. In selected cases neurosurgical therapy can be planned on 3D-images alone. Nonetheless conventional cerebral angiography remains the gold standard in diagnostic management of intracranial aneurysms.

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We report on a patient in whom the right posterior cerebral artery-posterior communicating artery junction (PC-Pcom junction) aneurysm was associated with bilateral carotid occlusion. She had been in good health until when she had admitted to our facility immediately after loss of consciousness. Computed tomography revealed subarachnoid hemorrhage (SAH). Cerebral angiography demonstrated an aneurysm arising from the right PC-Pcom junction. Bilateral carotid arteries were occluded 2-3cm from bifurcations. Anterior circulation was supplied with the vertebro-basilar system. The cerebral aneurysm was located in the posterior circulation where the hemodynamic stress might have occurred. High resolution computed tomography demonstrated the presence of bilateral carotid canals in the skull base. Thirty-seven days after onset, neck clipping of the aneurysm was carried out through the right pterional approach. We could not perform STA-MCA anastomosis because of poor filling of the external carotid artery. Postoperative angiography showed disappearance of the aneurysm and good filling of the posterior communicating artery. The patient returned home 16 days after surgery with no neurological deficits.

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We report the case of a patient with a bacterial intracranial aneurysm treated with endovascular coil embolization. A 16-year-old boy who suffered from endocarditis presented with severe headache. CT scan demonstrated subarachnoid hemorrhage and subsequent cerebral angiogram showed an aneurysm formation at the right angular artery. The endovascular approach was used to obliterate the aneurysm and its parent artery by use of interlocking detachable coil. CAG revealed complete occlusion of the lesion and the patient recovered without neurological deficit. Endovascular coil embolization is thus one good option for the treatment of bacterial cerebral aneurysm.

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We report 2 cases of surgically treated symptomatic mesencephalic vascular malformation. The first patient, a 56-year-old man, suffered from diplopia and gait disturbance on February 10, 1996. He was transferred and admitted to our hospital. The neurological examination showed left abducens nerve palsy, nystagmus and cerebellar ataxia. MRI revealed a mass lesion in the upper pons-midbrain. The mass was successfully removed by transcerebellomedullary fissure approach through suboccipital craniotomy. The histological diagnosis was cavernous hemangioma. The second patient, a 61-year-old man, suffered from diplopia, dysarthria and gait disturbance on August 21, 1996. On admission, the neurological examination showed left abducens palsy, nystagmus, cerebellar ataxia and right hemisensory disturbance. MRI revealed a large hematoma in the upper pons-midbrain. The hematoma was removed by transoccipital transtentorial approach. The histological diagnosis was capillary telangiectasia. We discuss the surgical approach to the mesencephalic vascular malformation.

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