Craniopharyngiomas occur in the central, or deep part of the brain and extend to key regions, including the hypothalamus and third ventricle. Access to these tumors is easy and many neurosurgeons are experienced in this surgery. However, total lesion removal is extremely difficult, except in the case of small tumors; accordingly, their recurrence rate is very high. Even surgery by experts in this field show no better results. Operative procedures are selected and combined on the basis of tumor extensions. This paper, based on our own experience, describes the key points and pitfalls of a bifrontal transbasal interhemispheric approach to a large craniopharyngioma extending anteriorly to the anterior skull base and posteriorly to the third ventricle. Also described are key points of sacrificing bridging veins, preserving olfactory nerves, treating perforating arteries, using endoscopy to observe the reverse side of chiasm, and the degree of feasible cut into the stalk.

This report describes the technical considerations required in the infratentorial supracerebellar approach to pineal tumor removal with the patient in the sitting position. Points requiring special attention with respect to air embolism prevention by the application of a cervical tourniquet, the angle formed by the neck and head of the patient placed in the sitting position, and access through the dural sinus are presented, followed by essential requirements for each surgical technique for the successful completion of tumor removal. With due caution, the aforementioned approach is considered a good option associated with easy orientation and with no damage to normal tissues.

The lumbar interbody fusion cage has been newly developed for PLIF. The benefits are easy handing, good disc space holding and early mobilization for the patient. The materials used to make the titanium, or carbonfiber or ceramic. Each material has its merits and demerits. For example, carbonfiber is evaluated highly for fusion, but when it is used, it is difficult to check the migration of lumbar X-P. We use the SDIC and CCD because of good fixation provided for the lumbar spine by this system. We report the result of the SDIC system with CCD (rigid fixation) in this paper. 30 cases of patients with spondylolisthesis were operated on in our institute. Patient age distribution was 38-70 (mean 57.9) y. o. and gender was male, 15 cases; female, 15 cases. Follow up term was 4-57 (mean 35) months. We also measured the FACET SAGITTAL ANGLE by CT to check the indication for the instrumentation. Facet sagittal angle was significantly small in degenerative spondylolisthesis patients compared to the control group. All patients experienced relief of radicular pain of the foot and intermittent claudication but complaints of lower-back pain continued for 2-5 months postoperatively. The results were evaluated using the JOA disability scale and neurological signs showed an 82.5% improvement. No serious complication was observed except in one patient who fell on the floor and fractured the L5 pedicle. He recovered after reoperation to fix the lumbar from L3, 4 to S1. It is reported that the interbody fusion cage by itself is enough to stabilize the lumbar spine, but we observed some cases of kyphosis post operatively when only cage fixation was used. As the follow-up term has not been long enough to evaluate properly the effect of this manipulation, it is important to carefully select which instrumentation system we should use.

The treatment of arteriovenous malformation (AVM) is still a challenging problem in the neurosurgical field. The usual operative procedure has been the removal of the AVM by sucking the gliosis which surrounds it. However, by using such a method in the functional area, especially the sensory and motor cortex, it has been impossible to remove the AVM without postoperative neurological deficit. Recent reports have shown that a 1 mm thickness of the brain around a large AVM is non-functioning;(1,2) therefore, we aimed to remove only the AVM without sucking the brain.

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.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.If an aneurysm is posteriorly placed, it is better to approach from the front of A2.We treated 5 Acom. A with fenestration and report 4 of them.

Embolization using IDC was carried out for 33 aneurysm cases in the last 3 years. The indication for the embolization was that the direct surgery was considered to be difficult, because of 1) technically impossible to do clipping, 2) aneurysm of the posterior fossa, 3) reject of patients. Regarding the location of aneurysm, 27 cases were seen in the anterior circulation, and 6 cases in the posterior circulation. Count of 33 cases, 11 cases were ruptured and 22 cases were non-ruptured. The procedure of embolization of aneurysms are generalized as compared to direct surgery, but there remain some technical problems. 33 cases in our series had no significant complication, except for one which had ruptured again. We emphasize that the weak point of IDC which was so hard, had no variations, especially if it happens to migrate during locking procedure. These complications can be prevented, if we use GDC5,6,7 instead of IDC.

Since the dawn of aneurysm surgery, many aneurysms present a more complex challenge. Large size, intimacy with critical perforator branches, deep location, atherosclerotic walls, ruptured aneurysms in the elderly and incorporation of afferent or efferent arteries in the dome represent factors that singly or in combination preclude safe clipping while high pressure circulation continues in the aneurysm. Despite the relative frequency of many class of aneurysms, there remains in the neurosurgical community some degree of confusion regarding the detailed anatomic features and the technical aspects of the treatment of these lesions in the acute stage. In our study of 1,433 cases, we have enumerated four aspects of the pitfalls in aneurysm surgery which should be considered when planning the operative approach to these lesions. These four aspects will be reviewed in relation to the aneurysm surgery: (1) inadequate pre-operative planning; (2) inappropriate response to unexpected premature rupture; (3) poor clipping techniques and clip selection; (4) unintentional occlusion or injury of perforating branches. This discussion will simply elaborate our own conceptual and microsurgical technical approach in dissecting the aneurysms. Minimal retraction was used during the whole surgical procedure. The intracranial brain tension was reduced through a ventricular tap for hydrocephalus or evacuation of hematoma prior to aneurysm surgery. A venous pathway was established for blood circulation. Sharp dissection, using our newly designed jet irrigation bipolar suction method was employed. Regarding the clipping of the aneurysm, we used the tentative clipping and the dome coagulation method thereby preventing the ischemic changes and shortening of the entire clipping procedure. Although the strategies, discussed represent simply our approach to this problem, the principles included have proven quite successful and have allowed safe and definitive treatment in the overwhelming majority of patients and also options to overcome the pitfalls in aneurysm surgery.

An innovative imaging procedure, computed tomographic (CT) fluoroscopy, was recently developed by Katada and Toshiba Medical Corporation in Japan [1,2]. This procedure permits sequential display of computed tomograms in real time. CT-fluoroscopy has been found to be extremely useful for real-time monitoring, which ensures the safety and accuracy of invasive techniques such as punctures in the neurosurgical field [3]. We recently, attempted targeted needle biopsy at three points, the subcortex near the lesion and the lateral side and center of the lesion, under CT-fluoroscopy. We then attempted to precisely place a marker at the inner border of the lesion near the internal capsule. A round mini-coil was used as the marker. Two weeks later we succeeded in extensively resecting the tumor lesion without producing motor weakness because the marker’s shadow on an ultrasonic image allowed navigation to the bottom of the lesion very precisely by showing where the eloquent area was located. A neuronavigation system using preoperative images was used simultaneously. There was a difference of 10 mm between the point indicated with the navigator and the actual position of the marker. This difference is considered to reflect brain shift caused by intraoperative leakage of cerebrospinal fluid. Thus, the computer-aided neuronavigation system appears to require a feedback technique for intraoperative brain shift that would enhance precision, reliability, and safety. In this respect, CT-fluoroscopy combined with intraoperative CT is considered to play a potentially very important role.

脳動脈瘤の検出には従来脳血管撮影が行われてきた.しかしその検査の侵襲, 所要時間などから近年低侵襲, 短時間で生体を高速, 連続的に検査可能なヘリカルスキャンCT (Helical scanning CT : HES-CT) が普及してきた.我々は動脈瘤の描出能並びに脳神経外科領域への応用の点から脳血管撮影とHES-CTとを対比検討した.対象は64例83瘤で, うち破裂脳動脈瘤は37例である.脳血管撮影の動脈瘤検出率は97.6%でfalse negativeは前交通動脈のblister aneurysmsの1例と血栓化椎骨動脈瘤の2例であった.HES-CTの動脈瘤検出率は96.4%で, false negativeは3瘤で全例, 床突起下の内頸動脈眼動脈分岐部小動脈瘤であった.形状, 瘤内表示, 周囲血管や骨との相互関係からみた動脈瘤の総合的診断価値はHES-CTの方が脳外科治療の観点にたち優れていると思われた.HES-CTの利点は特に前交通動脈領域の血管の重複する部位や椎骨脳底動脈系の動脈瘤診断に優れ, 動脈瘤頸部や瘤内部構造の評価が可能な点にあった.また3-D切削プログラムによる任意, 多方面からの高度な脳神経外科手術の術前シミュレーション像が得られた.以上より脳神経外科治療の立場から, 動脈瘤の形状把握, アプローチの選択, 治療方法の決定にHES-CTは従来の血管撮影に比し総合的な診断価値が高いと思われた.

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.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.