hayakawa motoharu

中枢神経は,CTが有利とされる頭蓋内新鮮血腫の検出,石灰化・骨破壊の診断等の一部疾患を除けば,MRIの有用性が高い領域で,マルチスライスCT導入以後もこの点においては変わりはない.しかし,ルーチン検査の容易性に関しては,マルチスライスCTにて一層CTの優位性が増した.CT angiographyは,その精度においてMR angiographyを凌ぐ.CTによる灌流画像は,マルチスライス化によってMRIによるそれと同等の診断能を有するようになった.脊椎・脊髄領域では,CTでの高分解能再構成縦断像が容易に生成可能となり,一部でMRIの適応を代替可能となった

脳血管障害の一っであるくも膜下出血は、全世界的に日本で多く見られる疾患であり、その主要因は脳動脈瘤の破裂といわれている。脳ドック受診者の2-3%に脳動脈瘤が見っかり、最近では医用画像の精度の向上により、6.5%にもなるという報告がある。一方、破裂す確率は、10mm以下の脳動脈瘤で約0.05%といわれており、破裂する瘤と破裂しない瘤の見極めが重要な課題となっている。一般に、脳動脈瘤は特定の部位にでき、発生年齢に片寄りがあり、さらに性差による発生部位が異なるといった特異な特徴を持っている。このように，血管形状に起因する血行力学的な因子の変化が、脳動脈瘤の発生あるいは破裂に関与していると考えられる。そこで、本研究では、医用画像あるいは超音波流速計などの非侵襲に得られたデータを用い、より現実に近い数値シミュレーションを行うことにより、血行力学的な観点からみた脳動脈瘤のメカニズムの解明を行っている。医用画像に基づく数値シミュレーションはImage-based simulationとして、最近注目されている。図1に示されているように、Image-Based Simulationは主に、3つのプロセスから成り立っている。まず、最初にCTなどの医用画像から3次元の血管を抽出する、血管形状のモデリング、そして数値シミュレーション、最後にそれらの結果を可視化し分析するポスト処理のプロセスである。特に、ポスト処理では臨床で行われる疫学調査に計算力学的なアプローチを組み合わせることにより、統計的な考察を行っている。中大動脈および中大脳動脈瘤にっいて、約20例から30例の医用画像に基づくシミュレーションを行った。本研究では、内皮細胞に影響を与える壁面ずり応力に着目し、血管形状をパラメータ化することにより、血管形状の壁面ずり断応力に与える影響を分析・考察している。

17歳男.突然左片麻痺と意識障害が出現,当救命センターに入院,CTで右側頭葉内に脳内血腫を認め,血腫による脳ヘルニアを生じていた.脳血管撮影で血腫による圧排像と中大脳動脈M2からの血管異常を認め,血腫除去と動脈瘤クリッピング術を施行.CTでは血腫によるmass effectは消失した.約1月後,テレビを見ていて再度の頭痛に続く嘔吐を繰り返し意識障害となる.CTで初回と同じ部位から前頭葉上方内に血腫が進展し,mass effectを認め,直ちに再開頭し,Sylvius裂を分けると大量の血腫を認め,動脈瘤のdomeを認めた.親血管を含め動脈瘤を切除した.術後CTでmass effectの減少を認めた

高い解像度での短時間広範囲撮影を可能にしたマルチスライスCTによって,等方性ボリュームデータが取得可能となった.軟部組織の濃度分解能もよく保たれており,多断面再構成法(MPR)や三次元画像(3D-CT)の画質は飛躍的に向上した.従来,描出困難であった微細構造物や微細血管構造も描出可能となった.マルチスライスCTにより,頭頸部及び脊椎領域における臨床応用は大幅に進歩した

Introduction : 3D-CT angiography (3D-CTA) is a non-invasive imaging modality for cerebral aneurysms. 3D-CTA is helpful in evaluating the configuration of the aneurysm, the surrounding vessels and the inside of the aneurysm dome. Clinical application of this technique to complicated large cerebral aneurysms, showed that anatomical details of cerebral aneurysms such as orifice of aneurysm, intraluminal thrombus, and calcification of the wall could be clearly demonstrated by 3D-CT endoscopic imaging. Using the 3D-imaging method of helicl CT, virtual veiws of various surgical approaches can be obtained and compared preperatively. This information was found to be very useful for determining difficult aneurysms for coil embolization or direct surgey, including complicated and broad-based aneurysms. Methods : Helical CT scanners (TOSHIBA X-vigor) are used to image intracranial vascular lesions. At present, nearly stereoscopic images at a pixel size of 0.35×0.35×0.4mm are obtained by reconstruction under the following conditions : slice thickness, 0.8mm ; couch top speed, 1.0mm/sec. ; 130kV ; 220mA ; visual field, 18cm in diameter (11cm after extension) ; pitch, 0.4mm ; and opposed beam interpolation. Results and clinical application : In virtual vascular 3D-CT endscopy, the lumen of the cerebral aneurysm is displayed by the surface rendering method. Its clinical applications include : (1) Determination of the 3D aneurysm morphology, as well as the dome and neck region. The smallest detectable lesion was 1.5mm. (2) Preoperative simulation. (3)Allows the confirmation of parent blood vessels flowing into aneurysms and the sites of blood vessels flowing out of aneurysms and visualization of aneurysmal lumen calcification. Coronal and sagittal sections can demonstrate whether the branches will be derived from aneurysm or aneurysmal neck. One limitation with 3D-CTA is in delineation of perforating arteries which are less than 1.2mm in diameter. A problem with virtual vascular 3D-CT endoscopic images is that endoscopic findings in the vascular wall are incomplete because of the partial volume effect and pulsation of the aneurysm and vascular wall. Conclusions : Helical scanning CT is an excellent and non invasive diagnostic modality for cerebral aneurysm detection. 3D-CT angiography has distinct advantages for evaluating an aneurysm and for determining og the most appropriate therapeutic modality. More precise and useful images will be obtained by recently developed half-second, submillimeter, real multirow helical CT.

過去5年間の直達手術例307例及びコイル梗栓術例40例を対象に治療選択について検討した.直達手術と血管内外科コイル塞栓術の振り分けは,原則として脳内血腫例や動脈瘤の形態からネック付近にblebを有したり,いびつな形状のものや広頸のものは直達手術を第1選択とした.後頭蓋窩動脈瘤及び75歳以上の高齢者と全身状態不良例は血管内外科コイル塞栓術とした.直達手術例はGR219例(71.3%),veg+D40例(13%)であった.一方コイリングの転帰は不変22例(55%),悪化13例(72.5%)であった.このうち梗栓術に起因する合併症は術中出血1例,minor leak 7例,embolism 6例,coil migration 2例(このうち悪化原因となったもの9例)である.GRが11例(27.5%),veg+D21例(58.7%)であった

Since the development of endovascular treatment, mangement of intracranial aneurysms has been changing. There are several merits and demerits in either mode of treatment. However, in cases of ruptured aneurysms, subarachnoid hemorrhage itself makes the patient's condition critical and not due to the existence of aneurysms.<BR>Retrospective study of 437 cases of cerebral aneurysms including 345 SAH cases over 4 years period has been reported. Out of 345 cases, surgical clipping was performed in 254 cases and endovascular treatment was done in 26 cases. No treatment was performed in 65 cases. In direct surgical treatment group, morality rate was 9.8% and good recovery was seen in 75% of cases. In endovascular intervention group morality rate was 42.3% mainly because of severity of their neurological grading and older age. Six out of 26 cases had complications such as leakage of contrast medium (ruptured) in 4 cases, embolic infarction 2 cases. We have discussed which type of treatment suitable for the aneurysm cases, considering permanent cure.

1)安静時CBFとCBVによる分類では,70%以上の症例は循環予備能が保たれており(I型),代謝予備能の低下した状態(いわゆるmisery perfusion)と推定される症例は5%以下であった. 2)Diamox負荷によるCBF増加率測定は,CBFが保たれ循環予備能が低下した軽度の状態の検出に有用と考えられたが,血管反応性や代謝が既に低下した状態では予備能を必ずしも反映していない. 3)SPECTによるCBV測定は,主幹部脳動脈高度閉塞性病変において,血行力学性脳循環不全による虚血発作のhigh risk group,血行再建術の適応評価に簡便で有用な方法と考えられた

We report a series of surgical treatment for anterior communicating artery (Acom. A) aneurysm with fenestration. A preoperative angiogram is a must for demonstrating Acom. A, because around the Acom. A there are many perforating arteries seen crossing. Also when there is an abnormality of Acom. A, for example fenestration, duplication and etc., it is not clearly seen. It is a well-known that fenestration has a lack of arterial media and is potentially weak, so an abnormal blood flow has taken place and an aneurysm has occurred at the point of fenestration. For the cases where aneurysms with fenestration cannot be seen by angiogram we have succeeded in using a 3D-CT to show the point of fenestration.<BR>It is necessary to determine an accurate surgical approach because in Acom. A with fenestration the space for moving is very limited. To get a good operative view when an aneurysm is anteriorly placed, it is better to approach from behind the A2 side.<BR>If an aneurysm is posteriorly placed, it is better to approach from the front of A2.<BR>We treated 5 Acom. A with fenestration and report 4 of them.

Meth-A fibrosarcomaを腹腔内注入されたマウスに対して,低出力レーザー照射を行った場合,体重減少や体重増加の抑制は認められない為,腫瘍縮少効果は認められなかったが,生存日数の延長,即ち延命効果は認められた.これは低出力レーザー,免疫機能賦活化作用によるものと考えられる.しかし,下垂体を摘出したマウス(I群)においては,生存日数の延長は認められなかった

Surgical treatment of internal carotid (IC) artery aneurysms around the carotid siphon is discussed. We present 54 cases including 16 of giant aneurysms. The surgical approaches to the aneurysms in this region are as follows : 1) A frontotemporal approach with the patient in a 45° semi-sitting position to decrease venous pressure, 2) A Dolenc approach with incision of part of the dura mater of the superior orbital fissure to facilitate removal of the anterior clinoid process and unroofing of the optic canal, and 3) Opening of the medial triangle followed by transection of the optic canal and dural sheath. Carotid siphon aneurysms can be divided into three groups anatomically : aneurysms of the ophthalmic segment (C2), of the clinoid segment (C3), and of the horizontal segment (C4). We present 29 cases of aneurysms arising from the C2 or C2/3 segment, 14 cases arising from the C3 or C3/4 segment, and 11 cases arising from the C4 segment. The anatomic locations of the aneurysms were determined preoperatively using angiography and three-dimensional CT imaging. Small aneurysms of the opthal-mic segment projecting inferomedially can be clipped using a contralateral approach via the prechiasmatic route. Aneurysms of the ophthalmic segment projecting superiorly can be clipped following resection of the anterior clinoid process. The clinoid process should be resected intradurally with direct visualization of the aneurysms. Straight side-angled clips are suitable for these aneurysms. Carotid cave aneurysms, which include aneurysms of the ophthalmic segment oriented inferomedially and of the clinoid segment projecting posteromedially, can be clipped using curved fenestrated clips via Dolenc's extradural approach. For accurate clipping, opening of the medial triangle and full mobilization of the IC at the clinoid segment and optic nerve by unroofing of the optic canal are required. Aneurysms of the horizontal portion are clipped after full exposure of the artery in the cavernous sinus only when the aneurysms are large and symptomatic. We used the frontotemporal and Dolenc approaches and applied fenestrated clips to aneurysms oriented posteromedially and straight or oblique clips to aneurysms projecting anterolaterally. Forty aneurysms were clipped using these approaches with 36 cases (90%) resulting in favorable postoperative recovery. There were 3 deaths secondary to complications of vasospasm and 3 cases with postoperative visual loss. The classification of these aneurysms and the surgical techniques we employed are discussed in detail.

We highlighted 2 cases of radical clipping of large aneurysms that were seen in the vertebrobasilar junction accompanied by a vascular deformity, consisting of fenestration of the split basilar artery at the origin of the basilar artery. Information concerning the inner and outer surface of the aneurysm were obtained pre-operatively from neuroradiographic studies by 3-D CT and 3-D CT endoscopy of the position of the neck, parent vessels of the vertebral arteries on both side, basilar artery and split basilar artery as well as its branches. The neck had a broad base in both cases. The height of the neck extended to the internal acoustic meatus, and it was possible to expose the periphery of the aneurysmal neck with an anterior transpetrosal approach. Based on the size of the aneurysm which was placed on the anterior surface of the brain stem, clipping or arterial reconstruction were performed in the first case under cover of barbiturates and deep hypothermia extracorporeal circulation, and in the second case in a state of circulatory arrest. The following provides a report of these 2 cases along with other cases treated so far.

Surgery for high placed basilar bifurcation aneurysm is one of the most difficult neurological operations. There are special approaches for high basilar bifurcation aneurysms such as the temporopolar approach, zygomatic approach, transzygomatic subtemporal approach, transclinoid transsellar transcavernous approach, and transthird ventricular approach. In this paper, we will discuss some technical procedures that we have developed for the transcrista galli translamina terminalis approach in treating a small high basilar bifurcation aneurysm.<BR>Case report<BR>A 73-year-old woman was referred with a diagnosis of SAH Grade IV, and pulmonary effusion. Cerebral angiograms and helical 3D CT demonstrated an aneurysm arising at the bifurcation of the basilar artery. The aneurysm measured 7mm×10mm and the neck of the aneurysm was located 15mm high from the posterior clinoid process. The transcrista galli, interfalcine, translamina terminalis approach was selected because of the patient's old age and the highly placed basilar bifurcation aneurysm in the third ventricle. This approach requires less brain retraction. We will discuss some tactics of approaching this aneurysm, clipping techniques, and the surgical merits and demerits of this approach.

The treatment of large, high-flow cerebral arteriovenous malformations (AVMs) is one of the most difficult operations which a neurosurgeons will encounter, because of the complex surgery and the postoperative effects on the brain. We evaluated 25 patients with AVMs who underwent surgical resection. They were classified into three groups for the purpose of determining a therapeutic approach. They comprised of 9 cases with small AVMs (<3cm), 2 cases of medium AVMs (3 to 6cm) and 14 cases of large AVMs (>6cm). Patients were investigated with contrast-enhanced computed tomography (CECT) and magnetic resonance (MR) imaging, ¹²³I-IMP single photon emission computed tomography (SPECT) studies of cerebral flow and cerebral vasodilatory function, intraoperative Laser Doppler flowmetry, and conventional angiography.<BR>SPECT imaging performed on the first postoperative day showed marked hyperperfusion in the brain tissue surrounding the resected nidus, and these regions were normal on images on the 7th postoperative day. Laser Doppler flowmetry showed sudden, and marked increase in CBF immediately following placement of temporary clips on the main feeding artery. Angiograms done 7-14 days following surgery showed a stagnating artery, fragile vessel, and a prolonged circulation time. Our results indicate that pre- and postoperative SPECT study, especially a dynamic SPECT study done on the first postoperative day, was the most useful examination for ascertaining the postoperative NPPB.