Hiroshige Kishi

The role of postoperative patient posture in the recurrence of chronic subdural hematoma: a prospective randomized trial

BACKGROUND Chronic subdural hematoma is known to have a significant recurrence rate. In this report, we evaluate the relationship between the recurrence rate of chronic subdural hematoma and postoperative patient posture. METHODS We conducted a prospective randomized study of 46 patients with chronic subdural hematoma treated surgically at the Osaka City General Hospital from January 1997 to December 1999. In Group A, the patients were kept in a supine position for 3 days after the operation. In Group B, the patients assumed a sitting position on the day after the operation. RESULTS The recurrence rates in Group A and Group B were not significantly different. CONCLUSIONS Assuming an upright posture soon after operation in cases of chronic subdural hematoma is not thought to be a risk factor for recurrence.

Gamma knife surgery for skull base meningiomas: The effectiveness of low-dose treatment

BACKGROUND The surgical removal of skull base meningiomas has a high morbidity rate, even by modern microsurgical standards. We evaluated the results of gamma knife surgery for skull base meningiomas using a relatively low radiation dose for the tumor margins. METHODS We reviewed 24 cases of skull base meningiomas during a 30-month period. The locations of the tumors were the petroclival region in 11 cases, the cavernous sinus region in 9 cases, and the cerebellopontine angle region in 4 cases. Eight patients (33%) had been operated on previously and fourteen patients (67%) had been treated by neuroimaging. The marginal doses for the tumors were 8 Gy to 15 Gy (median, 10.6 Gy). A large petroclival tumor 58 mm in diameter was treated with a staged treatment protocol with a 6-month interval between treatments. RESULTS Tumor regression was observed in 46% of the patients imaged during the follow-up period (median, 17.1 months). No patients revealed tumor growth in the follow-up period (100% tumor control rate). Eleven patients (46%) had improved clinically by the time of the follow-up examinations. Preexisting cranial nerve deficit in one patient worsened because of radiation injury. CONCLUSION Although a longer follow-up period is required, the relatively low minimum tumor radiation dose treatment for skull base meningiomas using a gamma knife seems to be an effective treatment with low morbidity.

Bilateral Dissecting Aneurysms of the Vertebral Arteries Resulting in Subarachnoid Hemorrhage: Case Report

OBJECTIVE AND IMPORTANCE We present the case of a patient with bilateral dissecting aneurysms of the vertebral arteries resulting in subarachnoid hemorrhage. CLINICAL PRESENTATION A 44-year-old man suffered a sudden onset of severe occipital headache and nausea and then dysphasia caused by subarachnoid hemorrhage. A computed tomographic scan demonstrated right side dominant subarachnoid hemorrhage mainly in the posterior fossa. Angiography revealed bilateral, vertebral dissecting aneurysms. The right aneurysm was larger and had a bleb-like protrusion, which strongly suggested a causative lesion of the subarachnoid hemorrhage. Six months later, the patient was referred to our hospital for further evaluation and treatment. INTERVENTION The ruptured right aneurysm was trapped surgically through a lateral suboccipital approach. The patients postoperative course was unremarkable, and he was discharged on the 14th day after surgery. However, postoperative angiography demonstrated slight enlargement of the left nonruptured aneurysm. Four months after surgery, the patient developed brain stem ischemic symptoms. The angiography conducted at that time showed further enlargement of the left aneurysm. Five months after surgery, fatal rupture of the left aneurysm occurred. CONCLUSION These results indicate that sacrifice of the unilateral vertebral artery may result in an enlargement of the contralateral nonruptured aneurysm and may thus be dangerous in the case of a patient with bilateral dissecting aneurysms.

Primary intracranial germinoma in the medulla oblongata.

BACKGROUND Primary intracranial germ cell tumor in the medulla oblongata is very rare; only five cases, including our case, have been reported. CASE REPORT Our patient, an 18-year-old woman, was diagnosed with a primary intracranial germinoma in the medulla oblongata by an open biopsy. She was treated successfully with chemotherapy and radiosurgery. CONCLUSION All five tumors in this site were histologically diagnosed as germinomas. The finding of female predominance in germ cell tumors in this region is shown.

Successful treatment of brainstem abscess with stereotactic aspiration

BACKGROUND Brainstem abscess is an uncommon condition associated with a high mortality. We report a case of brainstem abscess in a 51-year-old female with a pulmonary arteriovenous fistula that was cured after appropriate antibiotic therapy following stereotactic aspiration. The value of stereotactic aspiration in the management of brainstem abscess is documented with a review of the relevant literature. CASE REPORT A 51-year-old female with a pulmonary arteriovenous fistula suffered fever, diplopia and weakness on the right side. Magnetic resonance (MR) imaging of the brain showed a large cystic mass with ring-like enhancement in the brainstem. A diagnosis of brainstem abscess as a complication of pulmonary arteriovenous fistula was made. MR imaging-guided stereotactic exploration was carried out via the suboccipital transcerebellar approach and the pathogen of the brainstem abscess was identified. The brainstem abscess was cured after treatment employing antibiotics to which the pathogen was sensitive. CONCLUSIONS Stereotactic aspiration is an effective procedure for brainstem abscesses. This procedure is less invasive than open surgery and can be performed even in patients in poor general condition.

Very poor prognosis in cases with extravasation of the contrast medium during angiography

BACKGROUND The rebleeding of a ruptured intracranial aneurysm in the acute stage has been thought to indicate a very poor prognosis. In our experience, the outcome of patients with extravasation of the contrast medium is worse than that of patients with rerupture under circumstances other than angiography. We demonstrated the poorer outcome of the patients with extravasation, compared to that of the patients developing rerupture under circumstances other than angiography, and examined the factors that contributed to the poorer outcome of the patients with extravasation. METHODS Among the 641 cases of ruptured intracranial aneurysm, we have handled over the past 10 years, 36 (5.6%) patients have rebled before surgery was performed. Thirteen patients rebled during angiography (Group I), and the remaining 23 patients rebled in other circumstances (Group II). We compared the outcome of both groups. RESULTS The rebleeding occurred within 6 hours of the initial rupture in 29 (80%) patients. The outcome of Group I was significantly poorer than that of Group II (p < 0.05). In Group I, SD was achieved in only 1 patient and the remaining 12 patients died, while in Group II, 8 patients were in GR or MD, 2 were in SD, and the remaining 13 patients died. CONCLUSION Because rebleeding during angiography most often occurs in the acute stage and because the outcome of patients with extravasation is very poor, we recommend that the performance of angiography be delayed at least between 3 and 6 hours after the initial rupture.

Direct surgical treatment of intracavernous internal carotid artery aneurysms: Report of four cases

The authors have operated directly on four cases of intracavernous internal carotid artery aneurysms by opening the cavernous sinus. Surgery was performed using a semisitting position, in which the upper half of the patients body was elevated approximately 20 degrees from the horizontal plane. The superior wall of the cavernous sinus was opened through the pterional approach, and an aneurysmal neck clipping was successfully performed on three patients. A coating of the aneurysm was carried out on one patient. The results obtained were excellent in all cases. The authors believe that the operative technique reported is useful for surgical treatment of intracavernous lesions.

Vertebral artery occlusion after subarachnoid hemorrhage from a dissecting aneurysm of the vertebral artery: case report.

BACKGROUND Generally speaking, occlusion of the vertebral artery is a finding of a dissecting aneurysm associated with completed stroke. We present a case of a vertebral dissecting aneurysm that produced subarachnoid hemorrhage (SAH). Angiography on the day of hemorrhage, however, demonstrated complete occlusion of the vertebral artery. CASE PRESENTATION A 44-year-old hypertensive woman suffered a sudden onset of headache and vomiting followed by loss of consciousness due to SAH. Angiography on the day of hemorrhage revealed a complete occlusion of the right vertebral artery just distal to the dissecting aneurysm. This is the first report of such a case. The patient was still considered to be at significant risk of rerupture. Craniotomy and clip occlusion of the right vertebral artery and the origin of the right posterior inferior cerebellar artery were carried out to trap the thin-walled sac. At discharge, the patient had recovered completely except for some left limb ataxia, which subsequently disappeared. CONCLUSIONS Two options are available for the treatment of such a case: surgical or medical treatment. We employed surgery. Which is the preferred approach, however, is a difficult judgment to make at this juncture.