の治療指針の確立のため国立病院機構の脳神経外科で初めてのEBM作成のための研究が12施設の国立病院を中心に始められている. 5mm以下のが発見された場合手術などの処置を行わず自然経過を観察するという前方視的研究である. 2000年9月から540個(446例)が登録され, うち92個(89例)が除外されたため448個(373例)が経過観察され, その合計824.5 Aneurysm・Years (718 Person・Years) で平均22.8ヵ月の観察がなされている. これまで5個の破裂が認められ, また動脈瘤サイズ増大のため6個が処理された. Kaplan-Meier法で年間破裂率は0.5%であり単発性と多発性に分けるとそれぞれ0%と1.1%であった. 女性, 多発性, 70歳以上の高齢, 前交通動脈瘤などの因子が破裂因子の傾向は認めたが, 統計学的有意差は認めなかった. これまでの結果から5mm以下の単発性のは手術の適応は非常に慎重でなければならない.

抄録全体を表示

Most neurosurgeons regard cerebral vasospasms as one of the most significant prognostic factors for patients with ruptured intracranial aneurysms.
Its etiology and pathogeneis are still unknown, though there have been many clinical and experimental studies.
In this report we assessed the clinical value of sequential measurement of CSF uric acid level in patients with ruptured aneurysm. CSF was investigated postoperatively in controls and 31 cases with ruptured aneurysm.
The initial CSF uric acid level in patients with unruptured aneurysm was decreased but normalized within a few days after operation.
In the patients with ruptured aneurysm associated with or without mild vasospasm, the CSF uric acid level was within normal or increased slightly and transiently.
In the patients with ruptured aneurysm associated with severe vasospasm, the CSF uric acid level was increased markedly.
The sequential measurement of uric acid in CSF in patients with ruptured aneurysm is important for evaluating intracranial tissue damage and for predicting their prognosis.

抄録全体を表示

Elective surgery for asymptomatic small (<5 mm) unruptured intracranial aneurysms (UIAs) remains controversial. To reveal the current trend and outcomes in the management of (UIAs) in daily clinical practice, we retrospectively analyzed treatment options and surgical morbidity of small UIA cases in our institute (Group A: 129 aneurysms) and from the Nagasaki UIA Registry (Group B: 610 aneurysms) over the four recent years (2006–2009). After discreet discussions including recent prospective data of rupture risk and guidelines for treatment of small UIAs as part of informed consent procedure, only 7% (9 aneurysms) of the patients in Group A chose surgical treatment of either clipping or coiling, on which no intra- or post-surgical morbidity was observed. Direct surgical or endovascular interventions were performed in 267 aneurysms in Group B, in which a significant number of complications were reported (mRS≥2=5.9%; mRS 1=7.7%, at three months after the surgery).
In view of recent studies suggesting low annual rupture rates (0.3–0.5%/yr) with significant morbidity rates (2–7%) of small UIAs, more conservative management should be considered, especially for UIAs smaller than 5 mm.

抄録全体を表示

This analysis indicates the results of a prospective study of 102 patients with 124 asymptomatic unruptured aneurysms without operation from 1993. The patients (M: 33, F: 69) were followed from 2 to 83 months (mean 38.2). The ages at diagnosis ranged from 21 to 78 years (mean 64.1) The locations were ICA: 48, MCA: 37, AcomA: 23, the vertebrobasilar artery: 9, ACA: 6 and PCA: 1. The average aneurysmal diameter was 4.3 mm, a range of 2 to 12 mm. They were followed up radiologically using MRA, MRI and 3D-CT angiography. Among the 102 patients, five had suffered subarachnoid hemorrhage (SAH) due to rupture of the aneurysms (MCA: 3, BA-SCA: 1, IC-PC: 1) The maximal diameter of the aneurysms at diagnosis ranged from 4.5 to 8 mm. The period from discovery to SAH was from 4 to 69 months and the cumulative rate of rupture of the aneurysms was 1.5 percent per year. The present study demonstrates that five asymptomatic unruptured aneurysms less than 10 mm in diameter subsequently ruptured. We ought to consider the data that unrup-tured aneurysms less than 10 mm in diameter have a very low probability of subsequent rupture published the New England Journal of Medicine (1998) very seriously.

抄録全体を表示

In this study, we discuss the indications for surgery for unruptured cerebral aneurysm and the role of Japan, with special reference to the features of the Japanese medical system based on the data of ruptured cerebral aneurysm. We investigated 506 clipping cases of cerebral aneurysms from 1999 to 2011 in Shimane Prefectural Central Hospital: 182 unruptured cerebral aneurysms and 324 ruptured cerebral aneurysms.
There were four cases (2.2%) of postoperative major complications of unruptured cerebral aneurysm, including two hemiparesis of symptomatic internal carotid artery aneurysm and two visual disturbance of paraclinoid aneurysms. There were two minor complications of transient memory disturbance and two complications of olfactory disturbance of anterior communicating artery aneurysms. There were 13 (7.1%) transient neurological deficits. Postoperative parenchymal abnormality on CT and/or MRI was seen in 14 (7.7%).
Data show ruptured aneurysms occur most frequently in males in their 50’s and in females in their 70’s. The mean size of ruptured cerebral aneurysm according to site was 7±3.4 mm, 6.9±4.0 mm, and 5.7±2.5 mm in internal carotid artery posterior communicating artery aneurysms, middle cerebral artery aneurysms and anterior communicating artery aneurysms, respectively. Small aneurysms under 5 mm were 101 (31.1%).
According to the OECD health data, Japan had the most acute care beds per 1,000 population and the most CT scan and Magnetic Resonance Imaging Units per million population.
The treatment indication of unruptured cerebral aneurysm should be considered more precisely based on sex, age and site. In Japan, we have the most follow-up data on unruptured cerebral aneurysms and should share that data with the world.

抄録全体を表示

Currently, unruptured cerebral aneurysms (U-Ans) are positively treated in conformity with the guideline for the Japanese Society for Detection of Asymptomatic Brain Diseases. Direct operations are performed after informed consent is obtained in U-Ans cases. However, unfortunate outcomes have occurred even if safe surgery was done. Therefore we examined the characteristics of U-Ans and report surgical treatment in our hospital.
Consecutive operations (n=45) on 43 patients between January 2005 and October 2007 were included in this study. Surgical neck clipping was performed on all patients. The mean age was 67 years. U-Ans were discovered in medical check-ups in 24 cases (56%), during close examinations of headache and dizziness in 10 cases, examination of oculomotor palsy in 5 cases and examination of ruptured cerebral aneurysm in 2 cases, respectively. The mean U-Ans sizes were 6.1 mm in the internal carotid artery, 6.4 mm in the anterior cerebral artery and 6.4 mm in the middle cerebral artery (MCA), respectively. One basilar top aneurysm 7 mm in size was included. Surgical morbidity was recognized in 2 patients (4%). One patient, a 75 year-old male, suffered a left temporal cerebral infarction due to mechanical vasospasm. Another patient, a 67 year-old female, developed a cerebral infarction in the territory of the right MCA due to the compression for MCA during approach for basilar-top UAn.
We experienced 2 cases with unfortunate outcomes. Surgical complications caused by mechanical damage and vessel compression occurred. These complications in clipping for aneurysms are preventable. More care in performing operative procedures is needed.

抄録全体を表示

Recently less invasive diagnostic tools for the brain have been developed rapidly at a time when the population of the elderly has become enormous. Likewise, the number of patients having uAN-associated ischemic complications has grown sharply. For this special category of uAN, risk-benefit analysis is extremely difficult. Higher morbidity/mortality is common but rupture rates are considered more frequent than incidental uAN.
To prevent bleeding from uAN and to reduce complications triggered by precedent ischemic insult, we have performed radical surgery for such special uAN according to the following guidelines: 1) 70 years old and younger, without serious neurological deficits or general complications, capable of independent life, 2) significant interval (3-6 months) required between precedent ischemic insult and radical surgery, 3) meticulous examination for the etiology of ischemic condition and adequate treatment for the causes, 4) acceptance of prophylactic surgery such as CEA/stent (2 stage), and STA-MCA (concurrent with uAN surgery), 5) prevention of dehydration/hypotension and minimal washout of anti-platelet/thrombotic drug through perioperative period, 6) avoiding too much aspiration of CSF, long-time compression of the brain, temporarily occlusion of arteries, and sacrifice veins. We analyze the results of this series and evaluate the strategy in relation to the cause of complications.
Surgical mortality was 0 and morbidity was observed in 3 patients (permanent: 1; 6.25%, transient: 1; 6.25%). Good results were obtained by our strategy. Precedent ischemic insult may not deeply influence the result. Concurrent bypass did not increase risk of ischemic complication during radical surgery for uAN. However, much attention must be paid to sclerotic perforating artery, brain atrophy, and craniocerebral disproportion in patient with uAN and precedent ischemic accident.

抄録全体を表示

Twenty-one patients underwent surgery for unruptured cerebral aneurysms associated with ischemic cerebrovascular disease between 1980 and 1989. In five patients (group A), extracranial-intracranial (EC-IC) bypass or carotidendarterectomy (CEA) was performed at the same time as aneurysm surgery. In five patients (group B), EC-IC bypass or CEA was performed subsequent to aneurysm surgery. In eleven patients (group C), revascularization was not performed. Two patients in group A had ischemic complications (reversible ischemic neurological deficits, RIND), and one patient in group B had a hemorrhagic complication postoperatively. However no permanent deficit developed in any of these patients. Two of these patients had perioperative problems, one in group A had intraoperative hypocapnia and one in group B had been under medication with an antiplatelet drug preoperatively.
The risk of aneurysm surgery for patients who have indications for cerebral revascularization are greater than for patients without such indication. And the risk of surgical complications is greatest when aneurysm surgery is performed concomitantly with revascularization. One reason may be that the brain of these patients is hypoperfused, and is vulnerable to brain retraction, hypocapnia or hypotention. The other reason may be that the temporary arterial occlusion during revascularization or the change of blood flow after revascularization increases the risk of surgical complications.
We conclude that usually, it may better to perform aneurysm surgery without performing revascularization, and when we perform revascularization at the same time, it is more important to pay careful attention to perioperative management including tender operative manipulation of the brain tissue with proper intraoperative monitoring.

抄録全体を表示