Jun Nomoto

Anatomical Reproducibility of a Head Model Molded by a Three-dimensional Printer

We prepared rapid prototyping models of heads with unruptured cerebral aneurysm based on image data of computed tomography angiography (CTA) using a three-dimensional (3D) printer. The objective of this study was to evaluate the anatomical reproducibility and accuracy of these models by comparison with the CTA images on a monitor. The subjects were 22 patients with unruptured cerebral aneurysm who underwent preoperative CTA. Reproducibility of the microsurgical anatomy of skull bone and arteries, the length and thickness of the main arteries, and the size of cerebral aneurysm were compared between the CTA image and rapid prototyping model. The microsurgical anatomy and arteries were favorably reproduced, apart from a few minute regions, in the rapid prototyping models. No significant difference was noted in the measured lengths of the main arteries between the CTA image and rapid prototyping model, but errors were noted in their thickness (p < 0.001). A significant difference was also noted in the longitudinal diameter of the cerebral aneurysm (p < 0.01). Regarding the CTA image as the gold standard, reproducibility of the microsurgical anatomy of skull bone and main arteries was favorable in the rapid prototyping models prepared using a 3D printer. It was concluded that these models are useful tools for neurosurgical simulation. The thickness of the main arteries and size of cerebral aneurysm should be comprehensively judged including other neuroimaging in consideration of errors.

A neurosurgical simulation of skull base tumors using a 3D printed rapid prototyping model containing mesh structures.

BackgroundDeep regions are not visible in three-dimensional (3D) printed rapid prototyping (RP) models prepared from opaque materials, which is not the case with translucent images. The objectives of this study were to develop an RP model in which a skull base tumor was simulated using mesh, and to investigate its usefulness for surgical simulations by evaluating the visibility of its deep regions.MethodsA 3D printer that employs binder jetting and is mainly used to prepare plaster models was used. RP models containing a solid tumor, no tumor, and a mesh tumor were prepared based on computed tomography, magnetic resonance imaging, and angiographic data for four cases of petroclival tumor. Twelve neurosurgeons graded the three types of RP model into the following four categories: ‘clearly visible,’ ‘visible,’ ‘difficult to see,’ and ‘invisible,’ based on the visibility of the internal carotid artery, basilar artery, and brain stem through a craniotomy performed via the combined transpetrosal approach. In addition, the 3D positional relationships between these structures and the tumor were assessed.ResultsThe internal carotid artery, basilar artery, and brain stem and the positional relationships of these structures with the tumor were significantly more visible in the RP models with mesh tumors than in the RP models with solid or no tumors.ConclusionsThe deep regions of PR models containing mesh skull base tumors were easy to visualize. This 3D printing-based method might be applicable to various surgical simulations.

Early Cerebral Circulation Disturbance in Patients Suffering from Different Types of Severe Traumatic Brain Injury: A Xenon CT and Perfusion CT Study

INTRODUCTION Traumatic brain injury (TBI) is widely known to cause dynamic changes in cerebral blood flow (CBF). In particular, secondary brain insults have been reported to decrease CBF. The purpose of this study was to clarify the cerebral circulation in different types of TBI. METHODS Sixty-nine patients with TBI were divided into four groups, the subdural hematoma group, the contusion/intracerebral hematoma group, the diffuse axonal injury group, and the diffuse brain swelling group. In these patients, we simultaneously performed Xe-CT and perfusion CT to evaluate the cerebral circulation on post-injury days 1-3. We measured CBF using Xe-CT and mean transit time using perfusion CT and calculated the cerebral blood volume using the AZ-7000 W98 computer system. RESULTS There were no significant differences in the Glasgow Coma Scale score on arrival or the Glasgow Outcome Scale score between the groups. The patients who had suffered focal TBI displayed more significant cerebral circulation disturbances than those that had suffered diffuse TBI. We were able to evaluate the cerebral circulation of TBI patients using these parameters. CONCLUSION Moderate hypothermia therapy, which decreases CBF, the cerebral metabolic rate oxygen consumption (CMRO2), and intracranial pressure might be effective against the types of TBI accompanied by cerebral circulation disturbance. We have to use all possible measures including hypothermia therapy to treat severe TBI patients according to the type of TBI that they have suffered.

Basal encephalocele in an adult patient presenting with minor anomalies: a case report

IntroductionBasal encephalocele is rare in adults. Congenital and acquired cases have been reported with regard to the developmental mechanism, and the pathology has not been elucidated in detail.Case presentationWe encountered an adult with basal encephalocele strongly suggesting congenital development because of the presence of minor anomalies: strabismus and ocular hypertelorism. The disease manifested as persistent spontaneous cerebrospinal fluid rhinorrhea and repeated meningitis in a 66-year-old Japanese man. On computed tomography, brain tissue protruded through a part of the ethmoid bone of his right anterior skull base, and it was diagnosed as transethmoidal-type basal encephalocele. Regarding his facial form, the distance between his bilateral eyeballs was large compared to his facial width, and his canthal index (defined as inner to outer inter canthal ratio × 100) was calculated as 38.5, based on which it was judged as ocular hypertelorism. In addition, his right eyeball showed strabismus. A right frontotemporal craniotomy was performed for spontaneous cerebrospinal fluid rhinorrhea, and the defective dura mater region was patched with temporal fascia.ConclusionsMild minor anomalies that require no treatment are overlooked in adults, but the presence of several anomalies increases the possibility of congenital disease. Therefore, it may be necessary to examine minor anomalies in cases of adult basal encephalocele when considering the possibility that the disease may be congenital.

Hydroperoxide in Internal Jugular Venous Blood Reflects Occurrence of Subarachnoid Hemorrhage-Induced Delayed Cerebral Vasospasm

BACKGROUND To investigate the association between subarachnoid hemorrhage-induced delayed cerebral vasospasm (DCVS) and oxidative stress, an oxidation product, hydroperoxide, was measured in 3 specimens: peripheral arterial blood, cerebrospinal fluid (CSF), and internal jugular venous blood (IJVB). METHODS Hydroperoxide was measured using the diacron reactive oxygen metabolites (d-ROMs) test. The hydroperoxide levels were evaluated based on the rate of change in the d-ROMs test value on day 6 relative with that on day 3 (d-ROMs change rate). RESULTS The subjects were 20 patients. The d-ROMs change rate in IJVB was significantly higher in patients with DCVS on day 6 than in those without it (P < .01). When the patients were classified into the following 3 groups: Group A (no DCVS occurred throughout the clinical course); Group B (DCVS occurred, but no cerebral infarction [CI] was induced); and Group C (DCVS occurred and caused CI), the d-ROMs change rate in IJVB was the highest in Group C, followed by Group B then A (P < .01). The d-ROMs change rates in peripheral arterial blood and CSF were not related to the development of DCVS. CONCLUSIONS It was concluded that the more severe DCVS occurs and is more likely to progress to CI as the IJVB hydroperoxide level rises early after the development of subarachnoid hemorrhage.

Ruptured Aneurysm of the Superior Cerebellar Artery Associated With Cerebellar Hemangioblastoma: A Case Report and Review of Literature

Aneurysms associated with hemangioblastoma are very rare. We encountered a patient in whom an aneurysm of the distal superior cerebellar artery, the main feeding vessel of cerebellar hemangioblastoma, ruptured and caused hemorrhage. On the basis of the computed tomography findings, the superior cerebellar artery aneurysm was identified as the source of hemorrhage, and embolization using a Guglielmi detachable coil was performed in subsequent endovascular surgery. Endovascular embolization was applied to the artery feeding the tumor at 4 weeks after admission, and the tumor was removed using an occipital transtentorial approach. A favorable therapeutic outcome may be expected when using a combination of endovascular therapy and surgical craniotomy for aneurysms associated with hemangioblastoma.

The study of systemic general circulation disturbance during the initiation of therapeutic hypothermia: Pit fall of hypothermia

Aims: Neurointensive care has reduced the mortality and improved the outcome of patients for severe brain damage, over recent decades, and made it possible to perform this therapy in safety. However, we have to understand the complications of this therapy well. The purpose of our study was to determine the systemic circulation disturbance during the initiation of therapeutic hypothermia by using this continuous neurointensive monitoring system. Materials and Methods: Ten severe brain damage patients treated with hypothermia were enrolled. All patients had Glasgow Coma Scale (GCS) less than or equal to 8, on admission. Results: We verified that heart rate, cardiac output, and oxygen delivery index (DO2I) decreased with decreasing core temperature. We recognized that depressed cardiac index (CI) was attributed to bradycardia, dehydration, and increased systemic vascular resistance index (SVRI) upon initiation of hypothermia. Conclusion: Although the hypothermia has a therapeutic role in severe brain damage patients, we have to carry out this therapy while maintaining their cardiac output using multimodality monitoring devices during hypothermia period.

Cerebral Mass Lesion in Medulla Oblongata Causing Intractable Hiccups: A Report of 2 Cases and Review of the Literature

Intractable hiccups caused by an intracranial mass lesion are rare. We encountered surgical cases of cavernous angioma and hemangioblastoma in the medulla oblongata, which manifested with intractable hiccups. Herein, we report on 2 cases: case 1, a 30-year-old woman with a past medical history of surgery for cerebellar hemangioblastoma. The disease manifested with intractable hiccups, and a mass lesion was observed in the medulla oblongata on magnetic resonance imaging (MRI). During surgery, a vascular-rich tumor was localized near the obex of the mid-dorsal portion of the medulla oblongata. The hiccups were resolved immediately after total tumor excision, no event occurred thereafter, and the patient was discharged. The pathologic diagnosis was hemangioblastoma. Case 2, in a 22-year-old man, a lesion was observed in the dorsal portion of the medulla oblongata on computed tomography and MRI was performed to investigate the cause of intractable hiccups. During surgery, a mass lesion was present in the right dorsolateral aspect of the medulla oblongata. The hiccups resolved immediately after total excision of the lesion. No neurological deficit occurred, and the patient was discharged. The lesion was pathologically diagnosed as a cavernous angioma. In conclusion, a search for a dorsal medullary lesion using MRI is necessary when investigating intractable hiccups. To resolve intractable hiccups, the active application of surgical excision of the mass lesion is recommended.

Original ArticleHydroperoxide in Internal Jugular Venous Blood Reflects Occurrence of Subarachnoid Hemorrhage-Induced Delayed Cerebral Vasospasm

BACKGROUND To investigate the association between subarachnoid hemorrhage-induced delayed cerebral vasospasm (DCVS) and oxidative stress, an oxidation product, hydroperoxide, was measured in 3 specimens: peripheral arterial blood, cerebrospinal fluid (CSF), and internal jugular venous blood (IJVB). METHODS Hydroperoxide was measured using the diacron reactive oxygen metabolites (d-ROMs) test. The hydroperoxide levels were evaluated based on the rate of change in the d-ROMs test value on day 6 relative with that on day 3 (d-ROMs change rate). RESULTS The subjects were 20 patients. The d-ROMs change rate in IJVB was significantly higher in patients with DCVS on day 6 than in those without it (P < .01). When the patients were classified into the following 3 groups: Group A (no DCVS occurred throughout the clinical course); Group B (DCVS occurred, but no cerebral infarction [CI] was induced); and Group C (DCVS occurred and caused CI), the d-ROMs change rate in IJVB was the highest in Group C, followed by Group B then A (P < .01). The d-ROMs change rates in peripheral arterial blood and CSF were not related to the development of DCVS. CONCLUSIONS It was concluded that the more severe DCVS occurs and is more likely to progress to CI as the IJVB hydroperoxide level rises early after the development of subarachnoid hemorrhage.

Double Plombage Using Abdominal Adipose Tissue for Posterior Transpetrosal Approach–induced Liquorrhea

Objective:To prevent posterior transpetrosal approach–induced liquorrhea, we developed a method involving the double application of abdominal adipose tissue in the subdural and epidural spaces. Materials and Methods:The method was applied to 8 patients who underwent surgery under a posterior transpetrosal approach: 4 with petroclival meningioma and 1 each with tentorial meningioma, jugular foramen neurinoma, trigeminal neurinoma, and metastatic brain tumor. The combined transpetrosal approach was used for 6 patients and the combination with the lateral suboccipital approach was used for the other 2 patients. After tumor resection, the divided dura mater of the presigmoid space was closed as follows: first, a fat mass excised from the abdominal region was divided into 2 parts, and several excisions were made in each part to flatten them. The exposed brain surface was covered with the flattened fat, and the fat margin was circumferentially inserted under the dura mater. The division was then closed by suturing the dural stumps at several sites, loading tension to some extent. Finally, the other part of the adipose tissue was spread in the epidural space in the dural-defective region for double closure inside and outside the dura mater. Results:Liquorrhea was prevented in all patients. Conclusions:It was concluded that this method is useful to prevent postoperative liquorrhea induced by a posterior transpetrosal approach.