Kobayashi S

Dorsal internal carotid artery aneurysms with special reference to angiographic presentation and surgical management.

SummaryAneurysms arising from the dorsal wall of the internal carotid artery are rare. The authors surgically treated twenty dorsal internal carotid artery aneurysms. Pre-operative angiographic findings were reviewed and classified into three types. Eleven aneurysms projecting superiorly on the lateral angiogram were found to be adherent to the base of the frontal lobe by the pterional approach. Five aneurysms which had been superimposed with the internal carotid artery on the lateral angiogram were found adhered to the medial surface of the temporal lobe. Four aneurysms not seen on the angiogram had no adhesion. Two aneurysms, which had not been seen on the initial angiograms, were visualized on the angiograms taken during the period of vasospasm. This type of aneurysms can be the source of a subarachnoid haemorrhage of unknown origin and requires repeated examinations. Premature rupture occured intra-operatively in five cases and postoperative bleeding was encountered in two. Clipping technique is discussed from the viewpoint of preventing intra- and postoperative rupture.

Results of Direct Surgery for Aneurysmal Subarachnoid Haemorrhage: Outcome of 2055 Patients who Underwent Direct Aneurysm Surgery and Profile of Ruptured Intracranial Aneurysms

Summary Background and Purpose. The purpose of this study is to evaluate the therapeutic value of our surgical treatment of subarachnoid haemorrhage in a large series with standardized surgical principles. Methods. Results of 2055 direct operations on ruptured intracranial aneurysms, treated in our institutions, where surgical indications, instruments and techniques were standardized, between 1988 and 1998, were retrospectively evaluated and outcome of the patients was discussed; cases treated by intravascular procedures were excluded. Results. According to the evaluation at discharge, 1083 (52.7%) patients were excellent, 324 (15.8%) good and 223 (10.9%) fair. There were 160 (7.8%) patients of poor outcome and the remaining 265 (12.9%) died. There were no differences in the outcome between pre-operative Hunt & Kosnik grade I and II, Fisher Scale 1 and 2, anterior circulation aneurysms and posterior circulation aneurysms except those at and around the basilar bifurcation, men and women, and those clipped and not clipped. Conclusions. The factors related to poor outcomes were, age of 60 years or over, pre-operative Hunt & Kosnik grade II or more, Fisher Scale 3 or more, aneurysm size over 15 mm in diameter, and location at and around the basilar artery bifurcation. The results presented in this study show the status of our direct surgical management of subarachnoid haemorrhage in a large series with standardized surgical principles and procedures.

Development of the operating computerized tomographic scanner system for neurosurgery

SummaryA computerized tomographic (CT) scanner system for intraoperative imaging is presented. The system consists of the following: 1) CT scanner with a mobile gantry, 2) digitally controlled operating table with central processing unit (CPU) and encoder unit; the table can be controlled by the scanner computer as accurately as the scanner bed, and 3) exclusively designed head fixation devices. It allows us to scan the patient on the operating table in the operating room pre-operatively, intra-operatively and immediately after surgery.

Surgical outcome for multiple intracranial aneurysms

SummaryThe surgical outcome of 221 cases with multiple intracranial aneurysms operated upon during the years 1988 to 1994 were reviewed. The patients were classified into three groups according to the locations of the aneurysms; group 1: multiple aneurysms located unilaterally in the anterior circulation only (147 cases); group 2: multiple aneurysms located bilaterally in the anterior circulation only (44 cases) and group 3: multiple aneurysms located in both anterior and posterior circulation or in the posterior circulation alone (30 cases). In 132 cases of group 1 (89.8%) all aneurysms were treated in one-stage operations. Twenty-eight patients from group 2 (63.6%) received partial treatment, where only the ruptured or the symptomatic aneurysms were treated. In 12 other cases from group 2 (27.3%) all multiple aneurysms were treated in two-stage operations. In group 3 patients, one-stage operations were performed in 18 cases (60%), while 9 patients (30%) received partial treatment only. Of the 221 multiple aneurysm cases, 162 (73.3%) presented with manifestations of subarachnoid haemorrhage (SAH). The remaining 59 multiple aneurysms cases (26.7%) presented with manifestations other than SAH (unruptured aneurysms). In the postoperative follow-up, of the 221 multiple aneurysms cases, 113 (51.1%) were free of neurological deficit (excellent), 48 cases (21.7%) were capable of leading an independent life (good), 32 cases (14.5%) were not independent and needed to be assisted (fair), and 28 patients (12.7%) died. These results were comparable to the results of patients with single aneurysms operated on during the same period.Based on our results, we recommend that whenever possible all multiple aneurysms should be treated in one-stage operations. In unruptured multiple aneurysm cases surgical management is the recommended treatment. In poor grade SAH patients or unruptured multiple aneurysms in old patients, two-stage operations or partial treatment of only the ruptured or the symptomatic aneurysms may be adopted.

Symmetric dumbbell ganglioneuromas of bilateral C2 and C3 roots with intradural extension associated with von Recklinghausen's disease: case report

BACKGROUND Ganglioneuromas are rare benign tumors arising most commonly from the sympathetic nervous system. They occasionally grow in a dumbbell fashion extending into the spinal canal extradurally. However, ganglioneuromas of the cervical spine with intradural extension or multiple locations or in association with von Recklinghausens disease are rare. CASE DESCRIPTION A 35-year-old man with von Recklinghausens disease presented with tetraparesis and respiratory dysfunction. Preoperative neuroimaging revealed an intradural mass extending from the foramen magnum to the C4 vertebral level, as well as bilateral extravertebral extension connecting it with bilateral paraspinal lesions in a dumbbell fashion. Four intradural tumors associated with the bilateral C2 and C3 nerves and located ventrally were removed, leaving the intraforaminal and extradural portion intact. The procedure resulted in postoperative symptomatic improvement. Second, extravertebral tumors of the left neck, which were not related to the cervical sympathetic nerve, were removed. The pathologic diagnosis of the tumors of both the intradural space and cervical neck was ganglioneuroma. CONCLUSION We present an extremely rare case in an adult with von Recklinghausens disease who had bilateral, symmetric and multiple dumbbell ganglioneuromas with intradural extension, and also multiple bilateral ganglioneuromas at the neck. The intradural ganglioneuromas were suspected to have originated from the posterior root ganglions of the bilateral C2 and C3 nerves and to have extended ventrally to the spinal cord involving not only sensory but also motor rootlets; the ganglioneuroma of the neck was suspected to have originated from the cervical nerve itself.

Functionally essential neuronal population of the facial motor nucleus

Cranial nerve impairment is one of the more serious complications in neurosurgery. Nevertheless, the important question of how many neurons are required for cranial nerve functions remains unanswered. The VIIth cranial nerve (facial nerve) in mice was subjected to graded crush injuries. After assessment of the facial function, the number of uninjured, healthy facial motor neurons was quantified with a retrograde neuronal tracer. We report that normal facial function is preserved if intact neurons account for more than 56% of the control value, while complete facial paralysis occurs if intact neurons are reduced to less than 32% of the control value.

Subdural fluid collections following transcortical approach to intra- or paraventricular tumours

SummarySubdural fluid collections appeared in 15 cases (39%) after removal of 38 intra- and paraventricular tumours in the third or lateral ventricle through 18 frontal and 20 parietal transcortical approaches. Transient fluid collections which disappeared within 2 weeks occurred in 6 cases (16%) and persistent ones in 9 cases (24%). Four of the 9 cases (11%) of collections required surgical treatment because of positive clinical signs and symptoms. Two cases had expansive fluid collections and the other two contained subdural haematomas at surgery. The risk factors likely to contribute to a persistent collection were preoperative ventriculomegaly (frontal horn index > 0.38) and a frontal transcortical approach. A symptomatic collection should be considered as a potential complication of the transcortical approach to intraventricular tumours and some methods should be devised to prevent it when intra- or paraventricular tumours with ventriculomegaly are removed.

Histological Study on Local Invasiveness of Clival Chordoma. Case Report of Autopsy

Summary.Summary.Background: It is well known that clival chordomas invade bony structures; however, their invasiveness of other structures has rarely been reported. We report an autopsy case of clival chordoma in a 61-year-old woman, who underwent surgery 6 times for a period of 8 years, with special reference to its local invasiveness.Method and Findings: The histological studies showed that the tumour grew in the loose connective tissue in multilayers or multilobular fashion, invading the submucous layer in addition to the bone; however, it did not invade other soft tissue, particularly vital neurovascular structures or the dura itself, even in the advanced stage.Interpretation: The dura may serve as a strong barrier against tumour invasion into the intradural space, which emphasises the importance of not injuring the dura, when the tumour is removed extradurally. For radical removal of clival chordoma, it will be necessary to remove the tumour extensively including normal bone and soft tissues surrounding the tumour, especially the mucous membrane, because the normal mucous membrane is surgically difficult to preserve by dissecting it from the invaded submucous layer.

Inducible expression of p57KIP2 inhibits glioma cell motility and invasion

To examine the role of p57KIP2 in human malignant glioma cells, we studied its expression in a panel of human malignant glioma specimens by western blot and immunohistochemical analysis. To determine the effects of p57KIP2 expression on the phenotype of glioma cells, we analyzed two inducible stably transfected p57KIP2 expressing glioma cell lines. Expression of p57KIP2 was induced in U373 and U87 malignant gliomacells with doxycycline using the tetracycline repressor system. A phagokinetic track assay on gold particles was used to investigate differences in cell migration between p57KIP2 expressing and non-expressing control cells. The effects of the extracellular matrix (ECM) on U373 motility was determined in p57+ and p57− cells on surfaces coated with 5 μg/cm2 of fibronectin, laminin, type I and type IV collagens. The invasion of p57+ and p57− glioma cells across BD Biocoat Matrigel invasion chambers was then determined. p57KIP2 was weakly expressed in 4/6 glioblastoma (GBM) specimens by western blot. By immunohistochemistry, p57KIP2 immunoreactivity was positive in 8/40 GBMs, and was primarily nuclear in location. The motility of U373 glioma cells was significantly reduced after p57KIP2 induction. The presence of ECM proteins did not further alter the motility of p57+ and p57− glioma cells. The results of the invasion chamber assay showed that p57+ cells exhibited a 35% reduction in their invasive capacity as compared to p57− cells. These data suggest that p57KIP2 is expressed in at least some malignant gliomas. Inducible expression of 57KIP2 in cell lines deficient in this cyclin-dependent kinase inhibitor reduces their motility and invasiveness.

Low anterior interhemispheric approach--a narrow corridor to aneurysms of the anterior communicating artery.

Summary.Summary.Background: Many approaches for clipping anterior communicating artery (ACoA) aneurysms are reported in the literature. We describe here a new approach called “low anterior interhemispheric approach” for clipping of ACoA aneurysms.Materials and Methods: A low anterior interhemispheric approach utilizing a unilateral frontal craniotomy flap with minimal unilateral frontal lobe retraction was used in treating four patients harboring an unruptured ACoA aneurysm. The approach axis is directed to the ACoA area itself with minimal exposure to the anterior cerebral vessels.Findings: In all patients, complete neck clipping was possible with minimal brain retraction, without vascular damage and preserved olfaction.Interpretation: This approach is preferred on anatomical grounds for cases of unruptured small and medium sized ACoA aneurysms projecting anteriorly or posteriorly because the anterior communicating artery complex area can be fully visualized with minimal manipulation of the frontal lobes and anterior cerebral arteries.