Hiroshi Kawaji

Evaluation of tumor blood flow after feeder embolization in meningiomas by arterial spin-labeling perfusion magnetic resonance imaging.

Preoperative embolization changes the amount of blood flow and pattern of flow distribution in meningioma. Tumor blood flow was investigated in eight meningioma patients before and after embolization using arterial spin-labeling (ASL) perfusion imaging. Although blood flow was significantly reduced in the whole tumor after embolization, changes in flow distribution patterns varied from one case to another. The findings suggest that evaluation of post-embolization tumor blood flow by ASL perfusion imaging would be useful in the surgical planning of meningioma.

Intraosseous schwannoma of the cervical vertebral body: A case report and review of the literature

Intraosseous schwannomas (IOS) of non-sacral vertebra are extremely rare; only 14 cases were reported previously. We described a case of IOS involving a cervical vertebral body, successfully treated by surgical resection, with a review of the literature and discussion of this extremely rare tumour.

Supratentorial subdural hematoma following microvascular decompression: a report of four cases

IntroductionMicrovascular decompression has become an accepted surgical technique for the treatment of trigeminal neuralgia, hemifacial spasm, and other cranial nerve rhizopathies. However, critical complications still exist, and postoperative hemorrhage is one of the most life threatening complications following microvascular decompression. Most of the hemorrhages occur in the infratentorial region, and we found only four reports of supratentorial acute hemorrhages following microvascular decompression. Here, we report four cases of such hematomas and discuss the potential underlying mechanisms. Moreover, we discuss methods for handling such complications.Case descriptionBetween 2004 and 2015, four patients developed postoperative hemorrhages, all of which were supratentorial subdural hematomas. The hematomas occurred ipsilaterally in two cases and contralaterally in two cases. All of the patients were treated conservatively and discharged without clinical symptoms.Discussion and evaluationAlthough several intracranial hematomas have been reported distant from the craniotomy site, few reports of remote subdural hematomas after microvascular decompression exist. Draining large amounts of intraoperative cerebrospinal fluid may induce brain shifts and tearing of the small bridging veins. Of our four cases, two were ipsilateral and two were contralateral, and the side of the hemorrhage may suggest possible mechanisms of remote subdural hematomas in microvascular decompression. Although a lateral position for microvascular decompression mainly extends ipsilateral bridging veins, a postoperative supine position can extend bilateral veins equally. Therefore, we assumed that, supratentorial subdural hematomas occurred when the patients were returned to the supine position at the end of the microvascular decompression surgery. We may be able to prevent supratentorial subdural hematomas with the application of sufficient amounts of artificial cerebrospinal fluid immediately after a microvascular decompression.ConclusionWe suggest that it is important to avoid excessive CSF aspiration and to compensate for the cerebrospinal fluid loss with artificial cerebrospinal fluid adequately in order to avoid subdural hematomas after microvascular decompression. In addition, immediate postoperative CT scan is recommended even if the MVD has performed uneventfully.

Dissecting Aneurysm at the Proximal Segment of the Anterior Cerebral Artery Associated with Infraoptic Course Anterior Cerebral Artery

A 48-year-old man presented a subarachnoid hemorrhage caused by a rupture of a dissecting aneurysm at the proximal segment (A1 segment) of the right anterior cerebral artery (ACA). He also had an anomalous artery named infraoptic course ACA and an agenesis of the contralateral ACA A1 segment. Balloon occlusion test at the bifurcation of the right internal carotid artery demonstrated that the distal segments of the bilateral ACAs were perfused through the infraoptic course ACA. Therefore, we surgically trapped the A1 segment including the aneurysm. The patient got discharged without any neurological deficit. Natural course of ACA dissecting aneurysms is unclear because of rarity of the disease and treatment strategy is still controversial. Most of the dissecting aneurysms in the A1 segment are surgically treated, because they often present with massive hemorrhage and poor prognosis. In the present case, the contralateral A1 segment was absent but trapping of the dissecting aneurysm could be achieved without vascular reconstruction (e.g., bypass surgery) because of the presence of the infraoptic course ACA.

Genetically Engineered Multilineage-Differentiating Stress-Enduring Cells as Cellular Vehicles against Malignant Gliomas

Malignant glioma, the most common malignant brain tumor in adults, is difficult to treat due to its aggressive invasive nature. Enzyme/prodrug suicide gene therapy based on the herpes simplex virus thymidine kinase (HSVtk)/ganciclovir (GCV) system is an efficient strategy for treating malignant gliomas. In the present study, we evaluated treatment with multilineage-differentiating stress-enduring (Muse) cells, which are endogenous non-tumorigenic pluripotent-like stem cells that are easily collectable from the bone marrow as SSEA-3+ cells, as carriers of the HSVtk gene. Human Muse cells showed potent migratory activity toward glioma cells both in vitro and in vivo. HSVtk gene-transduced Muse cells (Muse-tk cells) at a cell number of only 1/32 that of U87 human glioma cells completely eradicated U87 gliomas in nude mouse brains, showing a robust in vivo bystander effect. Pre-existing intracranial U87 gliomas in nude mouse brains injected intratumorally with Muse-tk cells followed by intraperitoneal GCV administration were significantly reduced in size within 2 weeks, and 4 of 10 treated mice survived over 200 days. These findings suggest that intratumoral Muse-tk cell injection followed by systemic GCV administration is safe and effective and that allogeneic Muse-tk cell-medicated suicide gene therapy for malignant glioma is clinically feasible.

The efficacy of resection of an intradural extramedullary foramen magnum cavernous malformation presenting with repeated subarachnoid hemorrhage: a case report

BackgroundIntradural extramedullary cavernous angiomas of the central nervous system are a rare type of cavernous angioma, but they can cause fatal subarachnoid hemorrhage. The efficacy of resection for this type of cavernous malformations remains uncertain. This is the first report to recommend surgical resection of these types of lesions regardless of the fatal condition.Case presentationOur patient was a 70-year-old Japanese man who experienced a sudden onset of an occipital headache, followed by bilateral abducens nerve palsy. Magnetic resonance imaging revealed a small amount of hemorrhage in both of the lateral ventricles and an intradural extramedullary mass lesion in the left side of his foramen magnum. Two weeks after the appearance of initial symptoms, he became comatose. A computed tomography scan showed an increase in the subarachnoid intraventricular hemorrhaging and of the acute hydrocephalus. Following ventricular drainage, total tumor resection was performed using the lateral suboccipital transcondylar approach in conjunction with a first cervical hemilaminectomy. We observed a grape-like vascular-rich tumor with calcification that was adhering tightly to the wall of his left vertebral artery. A histopathological examination of the surgery specimen identified it as a cavernous angioma. After placement of a ventriculoperitoneal shunt and 2 months of rehabilitation, he recovered completely.ConclusionsAn intradural extramedullary foramen magnum cavernous malformation is quite rare. The fragile surface of our patient’s lesion was causing repeated subarachnoid hemorrhage and consequently progressive fatal neurological deterioration. Surgical resection of the lesion to prevent repeated hemorrhage was performed and he recovered fully. Therefore, we recommend surgical resection of the lesion regardless of the potentially fatal condition.