Treatment and outcome of 41 patients with unruptured cerebral aneurysms (11 males, 30 females, 23-74 years, 53 years on average) were evaluated. They were discovered in 24 patients with subarachnoid hemorrhage due to a rupture of the other aneurysm, in 13 patients with neurological deficits and in 4 patients with headache (screening of organic lesions). Surgery was not performed on 7 patients or patients with severe subarachnoid hemorrhage. Two of 4 patients with intradural aneurysms developed a subarachnoid hemorrhage and had a poor outcome, whereas all 3 patients with extradural aneurysms had a good outcome. Surgery was performed on 26 patients. Twenty patients with aneurysm of less than 15mm diameter underwent direct surgery and all had a good outcome. Four patients with aneurysm larger than 15mm diameter underwent direct surgery and 3 had a poor outcome, whereas 2 patients who underwent a trapping with a balloon had a good outcome. From these findings, it is concluded that direct surgery should be done for an unruptured cerebral aneurysm less than 15mm diameter, but an embolization should be chosen at first for larger aneurysm. Direct surgery, if it is performed, requires cautions and through preparations pre- and intra-operatively.

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The best treatment for intracranial aneurysm is neck-clipping. However, direct clipping of some giant aneurysms is difficult and surgical results are not satisfactory. We report a case of internal carotid artery giant aneurysm clipped by birect surgery. The patient is a 60-year-old female with visual field defect. Right carotid angiogram demonstrated a giant aneurysm (34×25×26mm) at the supraclinoid portion and no cross circulation was seen. The balloon occlusion test was performed and regional blood flow (rCBF) was assessed using ^99mTC-HM-PAO SPECT. The neurological signs appeared 10 seconds after the inflation of balloon. A decrease of rCBF was demonstrated in the occluded cerebral hemisphere. Therefore, an interposed long saphenous vein bypass was utilized between the superior thyroid artery and precentral artery to supply high blood flow rapidly. The aneurysmal dome was punctured and the neck was clipped with 4 Sugita's clips under temporary trapping of internal carotid artery. The postoperative course was uneventful. A slight decrease of rCBF in the territory of the middle cerebral artery in the affected hemisphere was demonstrated following SPECT. Thus, there remain questions as to whether the vein graft should be ligated or not after successful neck clipping.

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We report five cases of giant aneurysm in the posterior fossa; arising from the posterior inferior cerebellar artery in 1, the vertebral artery in 2 and the vertebrobasilar artery in 1 patient. The origin of aneurysm was unknown in 1 patient in whom a completely thrombosed aneurysm was located in the cerebellopontine angle. Two patients underwent surgical treatment. One patient who underwent resection of a giant and multiple aneurysms of the distal posterior inferior cerebellar artery had a good result. The other patient who underwent partial aneurysmectomy of a giant thrombosed aneurysm of the vertebral artery had postoperative hemorrhage and died 10 months after the operation. Two patients, 1 with a partially thrombosed giant aneurysm of vertebral artery and the other a giant fusiform vertebrobasilar artery were managed conservatively and died due to progressive brainstem compression and ischemia. Managements of giant aneurysms in the posterior fossa were discussed.

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During a 3-year period, 51 patients (38 men and 13 women, mean age 60.3 years) were diagnosed as having bilateral occlusive carotid disease by angiography. Two patients had bilateral carotid occlusion and 12 patients had unilateral carotid occlusion and contralatral stenotic carotid lesions. Another 37 patients had various degrees of stenotic lesions on bilateral carotid arteries. Presenting symptoms included transient ischemic attacks (TIA) in 7 patients, minor stokes in 34, major strokes in 7 and nonfocal symptoms in 3.
In this series, 11 patients were operated on bilaterally and 19 patients were operated on unilaterally. So totally 41 operations were canducted in 30 patients. Bilateral STA-MCA anastomoses, bilateral endarterectomies and a combined STA-MCA anastomosis and endarterectomy were performed in 6, 3 and 2 patients respectively. All bilateral operations were staged. Unilateral STA-MCA anastomosis, unilateral endarterectomy and external decompression were performed in 11, 7 and 1 patients respectively. There were one perioperative stroke (3.4%) and two deaths (6.7%).
Forty-nine patients were followed up 10 to 42 months. Three of 28 pateints (11.1%) treated by operation(s) suffered recurrent stroke during the follow-up period. Two developed TIA and/or minor stroke referable to the side that underwent carotid endarterectomy. Another one developed minor stroke referable to the side of STA-MCA anasatomosis for carotid occlusion. On the contrary, 5 of 20 patients treated conservatively suffered strokes during the follow-up period.

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In the present study we evaluated cerebrovascular reserve capacity (CRC) during temporal occlusion of the internal carotid artery (Matas test) as a preoperative test in the selection of candidates for permanent carotid ligation from among patients with internal carotid cavernous giant aneurysms. Cerebral blood flow (CBF) during rest (resting CBF), the Matas test (Matas-CBF), and after administration of 1g of acetazolamide during the Matas test (acetazolamide-Matas-CBF) were measured using stable xenon-enhanced CT CBF technique (Xe-CT). This procedure was named as “Acetazolamide loading Matas test.”
The CRC during the Matas test (Matas-CRC) was calculated as the difference between the Matas-CBF and the acetazolamide-Matas-CBF.
In a case of 51-year-old male with left internal carotid cavernous giant aneurysm, CBF study showed resting CBF, Matas-CBF, and Matas-CRC within normal limits. The left internal carotid artery was surgically trapped without complication.
Among patients with internal carotid cavernous giant aneurysms, those with normal Matas-CRC in the“Acetazolamide loading Matas test”were found to be good candidates for a permanent carotid ligation.

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Various kinds of complications may happen in association with the clipping surgery of cerebral aneurysms. The sites at which complications occur relate to the following three anatomical structures; I. aneurysm itself, II. parent artery and branches, III. neural tissues. We classified our techniques to avoid complications as follows: A: techniques useful before application of a clip to gain better visualization of the aneurysm neck and surrounding structures, B: selection of clip, C: application of clip, D: techniques after clipping. Especially in this paper, we describe our methods related to C: application of clip. It includes a) multiple clipping, b) formation clipping, c) booster clipping, d) shank clipping, e) compression clipping, f) rotation advance, g) applicator changing, and h) dissection with clip blade. To know these techniques systematically and beforehand would be more helpful in successfully clipping a given aneurysm than trying to find a method at the time of difficulty.

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Thirteen dural arteriovenous malformations (AVMs) involving the lateral and sigmoid sinuses were treated with a variety of treatment modalities. Three patients underwent surgical isolation of affected sinuses by clipping and ligation of all feeding arteries at the dura mater and tentorium; Two of these patients had complete obliteration of their fistulas and 1 patient, with advanced severe neurological deficits, died of general malaise 6 months after surgery. Three patients, who were treated by surgical removal of the affected sinus, had complete cure immediately after surgery; 1 of these 3 patients was treated by transarterial embolization with polyvinyl alcohol before surgery. Her symptoms improved trasiently but recurred in several days. Three patients were treated by palliative surgery such as the ablation of periosteum from occipital bone, ligation of external carotid artery and/or its branches and venticulo-peritoneal shunt. Their symptoms improved transiently but aggravated at the follow-up periods. Three patients with asymptomatic dural AVM had conservative treatment.
From our experiences, the most effective treatment is thought to be complete removal of the affected sinus in the early stage.
Histopathological profiles of this disease were studied in serial sections of resected lesions from the above 3 patients. The essential lesion was confirmed histologically to be dural arteriovenous fistulas within the wall of the venous sinuses.

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In an attempt to lyse the intracranial hemorrhage, a polymeric delivery system capable of sustained urokinase release was developed. An in vitro study proved that urokinase polymer retained fibrinolytic activity for more than 24 hours. Based on this result, a polymer affixed to the drainage catheter tip was used in the treatment of patients with intracerebral (n=4), intraventricular (n=4) or subarachnoid hemorrhage (n=9), and the hematoma lysis was assessed on CT scan. In subarachnoid hemorrhage patients, the effect of urokinase polymer on the prevention of angiographical vasospasm was also evaluated. In intracerebral hemorrhage patients, the mean hematoma volume reduction on CT scan taken on day 2 of the operation was 62% (range 46% to 75%). In intraventricular hemorrhage patients, a marked reduction in both ventricular size and hematoma volume was observed by day 2 after the operation. In patients with thick subarachnoid hemorrhage, a large part of the subarachnoid clot was resolved within 2 days. Fibrin degradation products in the cisternal fluids taken from patients treated with urokinase polymer were significantly higher than those taken from untreated patients. Seven out of 9 patients showed no or mild angiographical vasospasm, and severe vasospasm was noted onyl in 2 patients. Complications attributable to urokinase polymer, such as postoperative bleeding or infection, were not observed. The present study indicates that urokinase polymer may be of clinical use for the treatment of intracranial hemorrhage.

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This report reviews the clinical courses of 42 adult patients with Moyamoya disease and in whom onset occurred after the age of 16. Twenty-five of the 42 patients presented with hemorrhagic type disease while the remaining 17 had non-hemorrhagic type. Twenty-five percent of the hemorrhagic type patients who underwent bypass surgery experienced rebleeding postoperatively, while 21% of those without bypass surgery had recurrent hemorrhage. There was no significant difference in the rebleeding rates between the groups with and without bypass surgery. Bypass surgery did not demonstrate any effect in preventing a recurrence of intracranial hemorrhage in these cases.
This report also reviews the long-term clinical results of 28 adult Moyamoya patients who had ischemic symptoms in childhood. Fourteen percent of the patients had hemorrhagic attacks as adults. None had undergone bypass surgery before the hemorrhagic attack. On the other hand, 18 patients who underwent bypass surgery in the pediatric period have since shown no hemorrhagic attack until present. The above findings therefore suggest that bypass surgery performed in the pediatric period may possibly prevent future incidences of intracranial hemorrhage.

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Because of the rapid increase of the aged population, arteriosclerosis of the cerebral artery has become one of the most important cerebral pathologies in the adult patients. Unfortunately, a reliable and non-invasive method for estimation of sclerotic changes in the cerebral artery has not yet been established. We developed a new method for this purpose, using an ultrasonic phaselocked echo tracking technique. As we reported in our previous papers, the grade of arteriosclerosis was estimated by the magnitude of pulsatile movement of the arterial wall. In this study, grading of cerebral arteriosclerosis by our method was compared with grading or rating by other methods of investigation.
In our method, a linear scan ultrasonograph (Aloka-SSD610) was used, which contains an ultrasonic phase-locked echo tracking system and is combined with a 10 MHz transducer and a RF-I echo monitor. The common carotid artery, internal carotid artery, carotid sinus and vertebral artery were examined separately by this method. A stiffness parameter, i.e. β value, was calculated from the diameter of an examined artery (Dd), pulsatile changes in a diameter of the artery (ΔD), systolic arterial pressure (Ps) and diastolic arterial pressure (Pd), using the following equation; β = In {(Ps/Pd) / (ΔD/Dd)}. It is apparent, therefore, that a higher β value suggests a less pulsatile deformation of an arterial wall, i.e. a higher hardness of the arterial wall.
On the other hand, a severity of cerebral arteriosclerosis was rated with a five-grade scale (0 to IV) according to angiographical changes such as irregularity of the wall, stenosis, tortuosity and dilatation. Additionally, an arteriosclerotic rating due to the funduscopic findings and evaluation of cerebral perfusion by a single photon emission CT (SPECT) with ¹²³I-IMP were tried. Included in this study were 196 cases of obstructive cerebrovascular disease.
Our data accumulated so far has revealed that: (1) β value become high as an sclerotic change in the arterial wall increased, (2) β value tended to be higher in the hypertensive group than in the non-hypertensive group, (3) β value was proved to correlate well with the angiographic rating of cerebral arteriosclerosis, (4) Keith-Wagener grading based on funduscopic findings also correlate well with β value, (5) β value was elevated in patients with cerebral hypoperfusion demonstrated by SPECT with ¹²³I-IMP.
Our conclusion is that assessment of cerebral arteriosclerosis by our method has a clinical usefulness because of its good correlation with other ratings of cerebral arteriosclerosis and its non-invasiveness.

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We have previously reported that obstructive cerebrovascular disease correlates with stiffness parameter β, which indicates the arteriosclerotic grading in the internal carotid artery under the ultrasonic phase-locked echo tracking system. This statement is based upon the examinations performed by cerebral angiography of more than 200 patients with obstructive cerebrovascular disease. Based upon the results of the SPECT & CT examination, we have also proved that intracerebral ischemic change correlates with the stiffness parameter P. Under this system, a non-invasive screening method, we can recognize to what extent the medical treatments are effective in patients, and predict the existence of non- symptomatic cerebrovascular disease. This system is of great help to present and future treatments. Here we report on the usefulness of this system, especially for outpatients.
We chose 59 cases out of more than 200 with obstructive cerebrovascular disease, all of whom were followed up continuously. The mean period of examination for each patient was 1 year and 10 months. For each patient a SPECT examination was given, and the stiffness parameter β was measured. We made a continual study of the patient's clinical symptoms and resulting changes in the β values.
The cases where the value of β either fell or remained unchanged, were classified by SPECT as either “better” or “remained unchanged,” and these were found to be either “better” or “remained unchanged” by the observation of clinical symptoms. The cases where the β value rose (i.e. indicating a “worse” condition), were also denoted as “worse” by the SPECT method, and indicated as “worse” through clinical observation.
In most cases the value of β paralleled the condition of the patient. (i.e. a rising β value corresponded to a worsening condition of the patient.). The β values “rises” “unchanges” and “falls,” corresponds to clinical conditions of better, unchanged, and worse, respectively, 5.1% of the cases with a rising β value revealed clinical symptoms of “better,” while 18.6% of cases with a rising β value revealed clinical symptoms of “unchanged,” revealing a slight incongruency. These results show that clinical symptoms can be controlled by treatment even if arteriosclerosis advances. However, it is still necessary to study and treat patients with a rise in the β value carefully, for the rise in the β value warns of a very strong possibility of the appearance of obstructive cerebrovascular disease.

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