Between January 1990 and August 1991, 103 patients with intracranial aneurysms were admitted to our hospital and underwent microsurgical operations. Of the 103 patients, 6 had juxta DURAL-RING aneurysms. Kobayashi and his collaborators classify Juxta DURAL-RING aneurysms into 3 types: infraclinoid type, carotid cave type and intradural type. Of the present 6 cases, 3 cases were carotid cave type and 3 intradural type.
We applied Dolenc' pterional combined epi- and subdural approach to these aneurysms.
Surgical procedures are as follows: (1) a standard pterional craniotomy; (2) in the epidural approach, removal of the orbital roof together with the sphenoid wing, removal of the dorsal wall of the optic canal and the anterior clinoid process. Following these procedures, the anterior loop of the internal carotid artery (IC) can be traced through the thin membrane (Dolenc' anteromedial trangle); (3) in the subdural approach, complete opening of the dural ring, and the exposure of the surgical genu and axilla of the IC. (4) Utilizing these procedures, clipping is relatively easy with the use of Sugita's curved-blad ring (fenestrated) clip.
Postoperative carotid angiograms revealed that all 6 aneurysms were completely obliterated by the clips.
There were 2 complications: l is transient CSF leakage due to opening of the ethomoid sinus; the other is transient oculomotor nerve paresis presumably due to packing the oxycel into the cavernous sinus. All patients returned to their preoperative occupations without any neurological deficits.
From these results, we conclude that the pterional combined epi- and subdural approach is the procedure of choice for the juxta-Dural Ring aneurysms.

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Endovascular treatment of large and giant intracranial aneurysms of the anterior circulation, are now being treated by detachable silicone balloons, coils, and electrolytic platinum coils in selected cases. From a transfemoral approach, under local anesthesia, a catheter is navigated through the intracranial vessels to the aneurysm. For fusiform, ectatic aneurysms, without a well defined neck, test occlusion followed by parent artery occlusion can be performed with detachable balloons. For aneurysms with a well defined anatomical neck, detachable balloons and/or coils can be placed directly into the aneurysm to exclude it from the circulation. Angiography is performed immediately after the procedure and long term follow-up is obtained at 6-12 months post- treatment, to document exclusion of the aneurysm from the circulation.
Of the 321 cases treated by endovascular techniques by our group, 74 patients were treated for a giant aneurysm (>2.5cm) involving the anterior circulation. The presenting symptoms were mass effect in 65/74 cases (87.8%), subarachnoid hemorrhage in 6/74 cases (8.1%), and thromboembolic symptoms in 3/74 cases (4.1%). The embolic materials utilized were balloons in 67 cases, electrolytic coils in 6 cases, and balloons and coils in combination in 1 case. In 51 cases (68.9%) parent vessel occlusion was performed and in 23 cases (31.1%) direct aneurysm occlusion was achieved. Complications related to treatment included 9 cases (12.2%) of stroke, 4 cases (5.4%) of transient, reversible, cerebral ischemia, and 5 deaths (6.8%).
Endovascular treatment appears to be a feasible alternative to surgery for giant anterior circulation intracranial aneurysms in selected cases. As improvements in these techniques evolve, the morbidity associated with therapy should improve.

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Asymptomatic aneurysms of the C₂-C₃ portion of the internal carotid artery were discovered in 13 cases. Before surgical intervention for these lesions is decided on, the following factors should be considered: 1) Surgical technique is more difficult than in the other lesions. 2) Surgical outcome is not always good. 3) The relationship between aneurysm and cavernous sinus is complicated. 4) The incidence of rupture is not yet clear. 5) It is sometimes difficult to confirm whether the aneurysm is located in the cavernous sinus or not. Thirteen cases were analyzed with special reference to the angiographical findings and prognosis.
Seven patients underwent surgery for clipping. In this group, 4 patients had C₂ aneurysm and 3 patients had C₃ aneurysm. Intraoperative findings suggested that the C₃ aneurysm was located in the cavernous sinus and C₂ in the subarachnoid space. Surgical outcome was as follows: 4 in ADL 1, 1 in ADL 2 and 2 in ADL 3. Two patients developed ipsilateral blindness postoperatively.
Six other patients were followed without treatment for 1 to 8 years (mean, 3.6 years). In the followed patients, 2 had C₂ aneurysm and 4 had C₃ aneurysm. Two aneurysms seemed to be located in the subarachnoid space, 4 in the cavernous sinus. None of the unoperated patients have developed a symptom due to C₂-C₃ aneurysm.
These results indicate that surgery is not always recommended. Surgical intervention for intracavernous aneurysm should be especially limited.

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This is a report of 6 adult patients of moyamoya disease. We discuss the effects of the indirect cerebrovascular anastomosis.
Two of these patients, presented with ischemia and the other 4 presented with hemorrhage.
The postoperative follow-up ranged from 18 months to 105 months. Two hemorrhagic patients showed rebleeding. In patients who presented with ischemia, adequate neovascularization and prevention of recurrence were obtained with indirect cerebrovascular anastomosis. However, in patients who presented with hemorrhage, this indirect operative method gave unsatisfactory results.

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Cerebral aneurysms are difficult to treat by neck clipping if their size is too small, or if they are fusiform or have branches from their dome. What therapeutic methods should we select for such cases? If wrapping or coating is to be done, what material should be selected? In recent years, complications such as granuloma or optochiasmal arachnoiditis following wrapping with gauze have been reported by several investigators. We encountered a case in which a small anterior cerebral artery aneurysm and an infundibular dilatation later enlarged and hemorrhaged when they were left untreated. Recognizing the necessity of treatment of these types of small aneurysms, we have been developing and assessing new wrapping and coating materials.
Of the 620 patients who underwent a direct operation on cerebral aneurysms, 10.8% received wrapping or coating independently or after clipping. The reason for the use of wrapping or coating was the presence of a broad neck in 56.7% and small aneurysms in 22.4%.
Histologically, the tissue wrapped with gauze showed infiltration of inflammatory cells, accompanied by fragile granulation. Bemsheets were found to form a firm reinforcing wall as a result of a fibrous tissue reaction with little cell infiltration. Thus, Bemsheets appear to be an excellent wrapping material.
Conventional coating materials such as cyanoacrylate adhesives have been reported to involve problems such as vasotoxicity, late thrombosis, neurotoxicity and deterioration in vivo. We have developed an ethyl acetate solution of ethyl cellulose as a new coating material, and named it“liquid cellulose.”It has a pH of 7-8, a membrane-forming time of 60 seconds, and distensibility of 2-24%.
These physical properties make this material easy to manipulate. It is also very tough (490kg/cm²) and flexible and has a viscosity of 1000-2000 cp, which varies depending on the cellulose consentration and the degree of polymerization.
Scanning electron microscopy of this“liquid cellulose”revealed a multiple laminar structure, suggesting formation of flexible and strong walls.
The development and assessment of new wrapping and coating materials for the treatment ofsmall cerebral aneurysms is very important. Bemsheets and“liquid cellulose”seem to be excellent wrapping and coating materials.

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Eleven patients with supra-aortic artery stenoses were treated with percutaneous transluminal angioplasty (PTA). These cases included 8 vertebral arteries, 3 internal carotid arteries, and 2 subclavian arteries. Minor complications occurred in 3 cases. One internal carotid artery and 1 femoral artery suffered from intimal dissection; bradycardia and mild hypotention due to carotid sinus reflex occurred in another case. No permanent complications were experienced. Except for one stenosis at the origin of vertebral artery and one case of subclavian artery, stenoses were dilated with good results. During the follow-up of 3 to 12 months (mean: 9 months) in 10 patients, 3 stenoses at the origin of vertebral aretry were involved with restenosis. All the patients with stenoses of internal carotid arteries and trunk of vertebral arteries have been treated with satisfactory dilatations. In only 1 stenosis at the origin of vertebral artery, recurrent cerebellar infarction appeared 6 months after PTA.
According to pathological and hemodynamic studies, the stenoses of vertebral and subclavian arteries can be treated by PTA safely. However, for fear of embolism, the application of PTA in the stenoses of internal carotid arteries is still controversial. To prevent embolism, balloon-mounted guiding catheters were used in our internal carotid lesions. On the basis of our own results, PTA is a useful method for supra-aortic artery stenoses.

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Surgical experience focussed on the details of pre- and intraoperative management is presented, based on a consecutive series of 247 patients underwent early surgery for ruptured intracranial aneurysms. Recent trend favors early surgery for ruptured aneurysms. However, it is very likely that swollen brain is easily contused and lacerated, and the pial banks and small vessels, especially the veins, are injured more during an early surgery. Furthermore, subarachnoid blood tends to obscure anatomical details, and aneurysms are prone to rupture during the exposure. To prevent surgical complications, one has to obtain a slack brain and should achieve atraumatic removal of subarachnoid clot, and must try to prevent premature rupture of the aneurysms. It is concluded that surgery for ruptured aneurysms is“surgery of the cisterns”, and surgical outcome may be improved if one appreciate how to handle tight, fragile brain with clot in the subarachnoid cisterns.

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Six adults with spontaneous dissection of the vertebrobasilar system are reported. Clinically, 2 patients presented with subarachnoid hemorrhage and 4 with brain-stem ischemia. In all patients, angiography demonstrated fusiform dilatation and constrictions of the involved vessel, which were called “pearl and string”sign. Among these, 2 patients of subarachnoid hemorrhage and one patient with definite dissecting aneurysm that did not improve in spite of angiographic monitoring were surgically treated. Three other patients were treated conservatively with rather good clinical results. Ischemic type of vertebrobasilar dissection must be angiographically monitored, because of spontaneous healing of dissection. In dealing with dissection of vertebrobasilar arteries, because only severe headache develops before ischemic symptoms appear, great care must be taken for these patients. MRI is one of the most reliable neuroimaging methods for detecting dissection.

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A case of basilar-superior cerebellar junction (BA-SCA) aneurysm associated with Moyamoya disease is reported. The patient was 60-year-old woman stricken by right intracerebral and intraventricular hemorrhage. Consequently, she complained of left hemiplegia and right oculomotor palsy. Operation was performed with orbitozygomatic temporopolar approach (OZT).
In the operation for aneurysm associated with Moyamoya disease in the end part of the basilar artery, it is necessary to keep the following in mind: 1) Difficulty in clipping, because of the interference by complicatedly intertwined abnormal vessels. 2) The necessity of employing an approaching method that protects the surrounding brain, which is essentially very weak against ischemia and compression.
In the approach used in our present case (OZT), it was possible to see, from below, all the blood vessels in the anterior half of the circle of Willis, including the“moyamoya”vessels. It was almost unnecessary to apply the spatula to the frontal lobe, and besides, it minimized contacts with abnormal vessels. At the same time, it makes it possible to have a wider operative space, thereby making the clipping easier.
We report on the usefulness of orbitozygomatic temporopolar approach for BA-SCA aneurysm associated with Moyamoya disease, in comparison with the other approaching methods (subtemporal and pterional).

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We report a case of severe stenosis of bilateral external carotid arteries. The patient was a 58-year-old male who had noticed repeated blackouts, nausea and drop attack-like weakeness of extremities resulting in immobility for several hours. Marked bruit was heard over the bilateral carotid arteries. The angiography revealed multiple ulcer formation, wall irregularity and peculiar stenosis in the entire course of the bilateral common carotid arteries from their origin to bifurcation, sparing the extra- and intracranial internal carotid artery. Collateral flow through the anterior communicating artery was abundant and he well tolerated Matas test, but the collaterals from vertebrobasilar system were poor and he lapsed into unconsciousness in 5 seconds by Alcock test. He underwent subclavian-dacron graft-internal carotid bypass. A 6mm dacron graft was used. An end-to-side anastomosis was done first on the subclavian artery and then on the internal carotid artery. The carotid bifurcation was resected for the histological examination, which revealed that this rare condition was caused by atherosclerosis selectively affecting the common carotid artery. The operative result was successful, and the postoperative angiography revealed good graft patency. He has experienced no further attack and has been reinstated in his former office. We discuss the pathogenesis and operative procedures for this condition.

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There are serious cerebral ischemic problems in carotid endarterectomy (CEA) due to ICA cross clamping and embolism. We performed 110 CEA's using an internal shunt system. Preoperatively Matas test was evaluated with rCBF and intraoperatively ICA stump pressure and SEP were monitored. Meticurous postoperative neurological examinations revealed 10 cases showing transient deterioration of preoperatively observed symptoms and 2 other cases presenting new serious deficits. The former would be due to cerebral ischemia by ICA cross clamping, but the later might be due to embolism; the symptoms were observed at 6 months after surgery. In most of these 12 cases, rCBF in Matas test were below 30ml/100g/min. ICA stump pressure varied from 22 to 90mmHg and evident change in SEP was observed in 6 cases. Cross clamping time over 30 minutes was seen in 3 cases. Patients presenting low rCBF in Matas test with stump pressure below 35mmHg and/or prominent SEP change during ICA cross clamping are susceptible to brain damage. Therefore, intraoperative brain protection by application of shunt system, heparinization, shortening of ICA cross clamp and blood pressure control must be prerequisite for establishing a safety procedure of CEA.

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