We report identical twins presenting subarachnoid hemorrhage with intracranial aneurysms. These female twins were 52 and 64 years old, respectively at the onset of subarachnoid hemorrhage. The former, the younger sister, had 3 aneurysms in the right middle cerebral artery (MCA), the right internal carotid-posterior communicating artery (IC-PC) junction and the left C3 portion, and her sister, had 4 aneurysms in the IC-PC junction and the C3 portion of both sides.
The incidence of aneurysms in identical twins is very rare, and only 7 pairs have been previously reported. The features characteristic of twins' aneurysms can be summarized as follows. The age of the twins at onset is apt to approximate each other. The aneurysms of twins tend to be located in the same or mirror sites. And the incidence of multiple aneurysms is much higher (10/16, 62.5%) compared with those in sporadic cases. These features support previously reported data of the familial aneurysms and are very important as those of representative aneurysms cases on which the strongest genetic factors should be considered.

抄録全体を表示

Together with current advances in neuroimaging techniques, the chance for incidental discovery of unruptured cerebral aneurysms has greatly increased, and the selection of their appropriate management remains controversial, especially for the unruptured aneurysms arising from the posterior circulation. To provide current data about the management for such patients with unruptured vertebrobasilar artery aneurysms, we reviewed 36 consecutive patients with such aneurysms treated either by surgical or conservative means. Sixteen patients were treated surgically. Twelve aneurysms (including 5 large or giant aneurysms) were clipped, and the remaining 4 aneurysms (2 giant aneurysms and 2 vertebral artery aneurysms) were treated by the endovascular approach. There were no surgical mortality but 2 poor results in this series. These 2 poor outcomes were attributable to perforator vessel injuries during direct clipping of the large basilar bifurcation aneurysms. Twenty patients were managed conservatively. Three (15%) of the 20 conservatively managed patients died from the aneurysm rupture during the follow-up period, which averaged 4.6 years. It was confirmed, however, that none of the 7 tiny aneurysms smaller than 5mm in diameter had ruptured. The authors conclude that the unruptured aneurysms of posterior circulation should be considered for surgical treatment, if the aneurysm can easily be approached surgically and the patient's age and medical conditions do not contraindicate surgery. Even for surgically high-risk patients with the giant aneurysms of posterior circulation aneurysms, the surgical indications are now being expanded with the development of the neurosurgical and endovascular surgical techniques.

抄録全体を表示

Since the first report of revascularization of the vertebrobasilar system by Ausman in 1976, there have been various reports of posterior circulation bypass grafts for the treatment of vertebrobasilar insufficiency. However, the definitive role of surgery and medical therapy for vertebrobasilar ischemic disease have not been clearly defined.
This report focuses upon 12 patients with vertebrobasilar occlusive disease and our experiences with extracranial to intracranial (EC-IC) microvascular anastomoses.
Twelve patients underwent intracranial microvascular surgical procedures in the treatment of thromboocclusive disease of the vertebral artery and basilar arteries. There were 10 men and 2 women. The median age was 55 years (range 34 to 75 years).
Patients presented with transient ischemic attacks (TIA) in 3 cases, brain-stem infarction in 6 and cerebellar infarction in 3.
All but 1 (Case 1) of the 12 patients showed intracranial vertebrobasilar occlusive disease on angiography.
Various methods of EC-IC bypass were adopted due to location of the occlusive disease. Postoperatively, 2 patients developed infarction of the anterior circulation and 1 patient a small temporal lobe hematoma. One of 2 patients who developed infarction postoperatively died of pneumonia 10 months after EC-IC bypass, but there were no repetitive TIA's and infarction in a follow-up period with a mean of 48 months. Our results and other reports show that revascularization of vertebrobasilar system might be useful therapy for ischemia due to bilateral intracranial vertebrobasilar occlusive disease.

抄録全体を表示

We present 3 cases of dural arteriovenous malformation (DAVM) in the posterior fossa and discuss strategies for these lesions.
The first case, a 26-year-old man who complained of headache, pulsatile tinnitus and occasional double vision, had to be treated several times by transarterial embolization (TAE), sinus isolation of bilateral transverse-sigmoid sinuses and superior sagittal sinus (SSS) over the course of 3 years because of the development or recanalization of DAVM.
The patient was successfully treated by craniotomy and packing of involved sinuses with platinumcoils, Surgical and Biobond. DAVM and cortical venous reflux disappeared angiographically and it became apparent that the venous angioma existed in the posterior fossa, which drained to the vein of Galen. He resolved all symptoms except for slightly dysarthric speech. However, he was readmitted to our hospital 6 months later, suffering from right hemiparesis. The patient's neurological state gradually deteriorated to brain stem death. The patient died 8 months after the last operation. The cause of deterioration might be the change of venous return related to the venous angioma in the posterior fossa.
The second case, a 56-year-old woman who had a history of epileptic seizure, was treated three times by TAE followed by craniotomy, sinus isolation and packing of left transverse-sigmoid sinuses with Surgical and Biobond. She is free from postoperative symptoms.
The last case, a 64-year-old man who had a history of DAVM treated with liquid emboli 10 years before in our hospital, was referred from another hospital. Although he was treated by almost the same strategies of the above two cases, the last operation was carried out trepanation, direct puncture and packing of SSS with coils.
DAVMs disappeared angiographically in all 3 cases. Follow-up CT scans show only slight ventricular dilatation in all cases.
It was difficult to treat these lesions only by transarterial embolization because of the existance of embryonal arteriovenous shunts around the sinuses. Liquid embolus was superior to particles and coils with respect to permanent occlusion of the feeding arteries.
However, it could not be used for the arteries with positive provocative test. The particles and coils could be used for these arteries, which were recanalized sooner or later.
On the other hand, intraoperative sinus packing was safely performed with coils, Surgical and Biobond in the T-S sinuses and SSS. We concluded that these lesions may be treated safely and completely by direct sinus exploration and packing with coils following transarterial embolization.

抄録全体を表示

In cases of intracranial arteriovenous malformation (AVM) associated with aneurysms, one-stage surgery may be preferable. However, in some cases, it is not easy to determine whether to treat the aneurysms or the AVM first. We present a case of upper vermian hematoma due to a ruptured large AVM of this site associated with two unruptured basilar top aneurysms. These two lesions were successfully treated in 2 separate operations. A 40-year-old female was transferred to our hospital on the 5th day after the onset. On arrival, she was alert, and cerebellar symptoms were minimal. The AVM was fed mainly by the bilateral superior cerebellar arteries (SCA) and drained into the vein of Galen and straight sinus. Two unruptured aneurysms were located at the basilar top and at the origin of the right SCA, respectively. First, the aneurysms were successfully clipped via the right zygomatic approach on the 15th day after the ictus. The postoperative course was uneventful, but right ophthalmoplegia developed. This showed improvement approximately 2 months postoperatively. On the 36th day, a second operation was performed for the AVM via the right occipital transtentorial approach. This approach was suitable for removal of the nidus at this region, but meticulous procedure was needed to preserve perforating arteries feeding the thalamic region, because the patient showed mild hemiparesis and CT and MRI revealed a small infarcted area at the right thalamus.

抄録全体を表示

Eleven cases with acute occlusion of vertebrobasilar artery were treated by local fibrinolysis (LF). Ten were male and one was female, ranging in age from 46 to 85 years. The occlusive site was the basilar artery in 10 cases and bilateral vertebral arteries in one. Glasgow Coma Scale before treatment was 13 or more in 3 cases, from 8 to 12 in 2 cases, and 4 in 6 cases. Collateral circulation via a posterior communicating artery was good in 1, fair in 3, and poor in 6, and unknown in 1. LF was performed by the superselective technique using a microcatheter. The thrombolytic agent used was urokinase in 3 cases and tissue plasminogen activator in 8. Angiographic results: Successful recanalization was achieved in all cases, with residual stenosis of 50% or less in 8 cases, and with severe stenosis in 2. The time delay from the onset to recanalization was from 1.5 to 17 hours. The recanalized artery occluded again in 2 cases after 3 weeks and 7 weeks, respectively. Clinical result: Clinical symptoms improved immediately after treatment in 6 of 11 cases. Two of these 6 died in the follow-up period because of reocclusion. The other 5 cases developed a severe brain stem infarction resulting in death. Glasgow Outcome Scale was GR in 3 cases, MD in 1, and D in 7.
It is concluded that LF is a potential therapy for acute vertebrobasilar arterial occlusion. Clinical improvement will be achieved in patients with a good collateral circulation via a posterior communicating artery. Some revascularizing technique for the residual stenotic lesions after LF therapy may improve the clinical outcome.

抄録全体を表示

Microsurgical anatomy of skull base surgeries for aneurysms of the vertebral and basilar artery were studied using 3 cadavers treated by arterial and venous injection of the mixture of silicon with dye and barium sulfate. The suboccipital and lateral suboccipital approach (LSOA) are useful for VA-PICA and VA union aneurysms that are located laterally. Extradural resection of the jugular tubercle is necessary for approach to midline VA aneurysms. For this procedure, an emissary vein in the condylar fossa is a key anatomical landmark. For lower BA trunk aneurysms, the presigmoid retrolabyrinthine approach (PRA) via the Trautmann's triangular space is useful. This approach, however, does not permit enough working space to access aneurysms between Vth, VIIth-VIIIth and XIth nerves. Additional division of the sigmoid sinus, which might be risky in some patients, and cerebellar tentorium to PRA, namely the retrolabyrinthine transsigmoid approach and combined supra- and infratentorial approach permit more space. The (subtemporal) transpetrosal approach might have some problems of a narrow working space (even with a severe retraction of the temporal lobe) and of a difficult exposure of the proximal parent artery. The petrosal approach (PA), which consists of PRA and division of the tentorium and superior petrosal sinus, permits both the subtemporal and suboccipital routes with a minimal brain retraction. PA or the combined approach of (L)SOA and PA might be useful for BA trunk and midline VA aneurysms such as our case, in which multidirectional viewing was allowed through a working space large enough for the aneurysmal clipping and observation of the distal VA or BA behind an aneurysm.

抄録全体を表示

Fourteen patients underwent intracranial to extracranial bypass anastomosis procedures for intracranial vertebrobasilar occlusive diseases.
There were 4 patients with occipital artery (OA) to posterior inferior cerebellar artery (PICA) anastomosis, 3 patients with superficial temporal artery (STA) to superior cerebellar artery (SCA), and 7 patients with interposed saphenous vein graft from external carotid artery (ECA) to SCA. Venous graft might be considered as a successful substitute for the SCA if the STA is not sufficiently long and large. We describe the technique interposing venous graft bypass from the external carotid to the superior cerebellar artery.
Postoperative angiograms demonstrated good patency of anastomosis in all patients. In this series, the mortality rate was 0%, transient morbidity including IVth nerve palsy occurred in 2 patients and CSF wound collection in 2 other patients.
The STA-SCA anastomosis and interposed vein graft from ECA to SCA were both well tolerated and technically easier than OA-PICA anastomosis procedure. Surgical revascularization should be offered in the ischemia of the rostral brain stem. STA-SCA anastomosis or interposed vein graft from ECA to SCA might play a favorable role in the management of intracranial vertebrobasilar occlusive diseases.

抄録全体を表示

We report a case of large dissecting aneurysm of vertebro-basilar (VB) artery with brain stem ischemia and subarachnoid hemorrhage. This 58-year-old man was admitted because of sudden onset of left hemiparesis and left hemisensory disturbance. The initial CT scan was normal except for a large high-density spot anterior to the brain stem, and angiography revealed a dolichoectatic VB artery and large irregular shaped dissecting aneurysm that extended from the right vertebral to the basilar artery. MRI showed double lumen and intimal flap in the aneurysm. Although ischemic symptoms had disappeared within 2 days, the patient suddenly became comatose 4 days after admission and massive subarachnoid hemorrhage was confirmed on CT scan. Follow-up angiography at 6 months showed disappearance of double contrast of the VB artery detected at onset. Ten months later, on MRI, the false lumen had been enlarged and thrombus of variable phase had been piled in many layers within it. The brain stem was compressed and distorted markedly. The patient died after being a vegetative state for a year and 4 months.

抄録全体を表示

A case of dolichoectatic basilar artery with a mass effect to the brainstem structure was treated by reducing hemodynamic stress. In this case, angiograms showed the dolichoectatic basilar artery creating a turbulent flow in the vertebrobasilar junction. We therefore clipped the unilateral vertebral artery and performed posterior fossa decompression. The postoperative course was uneventful. Two years and 6 months after the operation, the patient died due to multiple brain stem infarction as a result of involvement of many important perforating arteries to the brainstem. Proximal ligation of the right vertebral artery resulted in reduction of turbulent flow but caused intraaneurysmal thrombosis.
Macroscopic examination showed distention and elongation of the vertebrobasilar artery like dolichoectasia, and microscopic examination revealed dissection of the vessels between the intima and medial smooth muscle. We therefore conclude that dolichoectasia of this case was caused by dissection of the basilar artery.

抄録全体を表示

Over the past 10 years we have experienced 8 operative cases of basilar artery trunk aneurysm. Among the operative cases, 3 were males and 5 were females. Their ages ranged from 20 to 73, with a mean age of 53.3 years. Preoperative grade of Hunt and Kosnik included 5 cases of Grade II, 2 cases of Grade III, and 1 case of Grade IV. The maximum diameter of the aneurysms ranged from 5 mm to 18mm, with a mean of 11mm. Two cases were operated on by the pterional approach, 5 cases by subtemporal approach, and 1 by subtemporal approach without successful clipping and finally treated by presigmoid approach. Concerning the Glasgow Outcome Scale, 6 cases had good recovery (75%) and 1 case was severely disabled. One patient died due to uremia caused by severe bilateral renal tuberculosis. Autopsy findings of this case showed successful obliteration of the ruptured aneurysm, but the other small unruptured aneurysm was left unclipped due to narrow operative space. There was no definite temporal contusion on the approached side. The other autopsied case was a 74-year-old male who was DOA at the emergency center. Autopsy revealed the presence of 2 aneurysms between the SCA and AICA, of which the smaller one facing the brain stem had ruptured fatally. From the operative and autopy findings, the following can be concluded: 1) Preoperative angiography should focus on the possibility of the presence of multiple aneurysms, and if any are found, any ruptures should be determined. Angiography without subtraction should be performed in reveal the relationship between the (proximal) neck of the aneurysm and bony landmarks.
2) If the proximal neck of the aneurysm is below the posterior crinoid process and above the upper margin of the pyramis, the procedure of choice might be subtemporal approach without drilling of the pyramis. If it situated below the upper margin of the pyramis, small drilling of the pyramis might be necessary. If it is at the same level or below the external auditory meatus, some modified suboccipital approach should be selected for successful clipping.
3) For successful in clipping, meticulous knowledge of the microsurgical anatomy should be obtained, and some special clips or clip applicator should be prepared. Our preference is the use of fenestrated clip to secure the aneurysmal neck with good visibility and without untoward manipulation of the surrounding structures.

抄録全体を表示