Kazuo Tokushige

Basilar bifurcation aneurysms associated with persistent primitive hypoglossal artery

We report two cases of ruptured basilar bifurcation aneurysm associated with a persistent primitive hypoglossal artery. Angiograms revealed low-positioned aneurysms; in both cases bilateral vertebral arteries and posterior communicating arteries were hypoplastic or aplastic. Both aneurysms were successfully clipped via subtemporal transtentorial approach through the craniotomy ipsilateral to the side of he primitive hypoglossal artery. The ipsilateral craniotomy and exposure of the cervical carotid artery were helpful for obtaining the proximal control of the basilar artery needed to perform the clipping procedure with safety.

New radiolucent head fixation made of engineering plastics for intraoperative CT scanning

SummaryA newly developed head fixation for intraoperative computerized tomographic (IOCT) scanning is presented. The system is developed based on the head holder of multipurpose head frame and is made of two kinds of advanced engineering material; carbon fiber reinforced plastic for head holder and frames, polyamide-imide polymer for joints, screws, and head pin. Clinical tests including autoclaving and sterilization were performed and revealed all materials had sufficient strength for clinical use. This fixation system enables us to increase the efficacy of IOCT scanning during open-field neurosurgery.

Odontoid compression of the brainstem without basilar impression – “ odontoid invagination”

We report five patients with odontoid invagination, in which the odontoid process bulges upward into the foramen magnum and compresses the brainstem without deformity of the occipital bone. Two patients had a craniovertebral abnormality associated with Chiari malformation without instability of the craniovertebral junction (stable odontoid invagination). The other three patients had dislocation of the craniovertebral junction due to iatrogenic destruction of the occipital condyle, rheumatoid arthritis or an anomaly of C2 (unstable odontoid invagination). Patients with stable odontoid invagination underwent a transoral odontoidectomy followed by occipitocervical fixation. Those with unstable odontoid invagination underwent cervical traction followed by posterior fixation in reducible cases, while in irreducible cases odontoidectomy with subsequent occipitocervical fixation was performed. Decompression of the neuraxis together with symptomatic improvement was achieved in all patients and none became unstable or developed new symptoms during follow-up ranging from 3 to 15 years.

Surgical experience with resection en bloc of intramedullary astrocytomas and ependymomas in the cervical and cervicothoracic region

We performed 8 operations on 7 patients with benign intramedullary astrocytomas and ependymomas in the cervical and cervicothoracic region. All patients initially underwent gross total tumor resection en bloc. One patient with an astrocytoma showed tumor recurrence postoperatively, and underwent a second operation resulting in subtotal removal. The follow-up after the initial surgery ranged from 2.7 to 19.7 years (mean 8.5 years). Symptomatic improvement was observed in 6 patients after the initial operation. Two patients showed postoperative neurological deterioration, one with an ependymoma and the other after the second operation. No operative complications or deaths, nor postoperative respiratory dysfunction occurred. Benign intramedullary astrocytomas and ependymomas of the cervical and cervicothoracic spinal cord can be treated by radical resection en bloc with a low morbidity and recurrence, as well as acceptable outcomes. We describe here the surgical technique for en bloc tumor removal.

Repeat operations in the management of clival chordomas: palliative surgery.

Some chordomas have a very poor prognosis because of their aggressive growth nature, but the efficacy of repeat operations for these cases has not been well documented. This report concerns 3 patients with aggressive chordoma of the clivus, who underwent operations 6 to 12 times over a period of 8 to 17 years because of symptomatic regrowth. Overall mean interval between repeat operations was 18 months with a range from 5 to 57 months and survival times were 9 to19 years after the first surgery. Main symptoms before each operation were diplopia and visual disturbance. Repeat palliative operations by intentional extradural debulking of the tumour to decompress offending neural structures, as well as maximal removal of the tumour, using appropriate skull base approaches, can mitigate progressive symptoms, and may result in better quality and some prolongation of life, although our patients gradually deteriorated neurologically throughout the clinical course.

Simple cervical spine traction using a halo vest apparatus: technical note

BACKGROUND A halo vest apparatus, commonly used for external immobilization and protection of the cervical spine, offers several advantages. We present here a simple, accurate, easy, and safe cervical traction technique using a halo vest apparatus. METHODS The distinguishing feature of our technique is that, after application of a halo vest apparatus, the halo crown is distracted gradually and stepwise by turning the bilateral screw bolts that hold the halo crown over a period of one to several weeks. After each of these steps, care must be taken to check neurologic, radiologic, and skin conditions, as well as cranial pin tightening. CONCLUSIONS This distance control technique can provide a strong and accurate traction force by simply turning the bolts without the risk of overdistraction or the need for bed rest, and can be used in conjunction with radiologic examination and transportation of patients, even those unable to walk. The Sugita head fixation system constitutes a safe and easy way to facilitate surgical management after correction of cervical dislocation.

A newly designed attachment device of multipurpose frame for neuronavigator : technical note

SummaryA newly designed attachment device of the multipurpose head frame (Sugita) for Neuronavigator (Watanabe) is presented with an illustrative case of glioblastoma in an eloquent area. This has extended the usefulness of the neuronavigator for those who prefer and use the multipurpose head frame, while the requirements for keeping a stereotactic combination and the original concept of the multipurpose head frame, as well as that of the neuronavigator have been kept undisturbed.