Search Results

You are looking at 1 - 10 of 47 items for

  • Author or Editor: Hiroshi Abe x
  • Refine by Access: all x
Clear All Modify Search
Restricted access

Yutaka Sawamura and Hiroshi Abe

✓ This report describes a new surgical technique to improve the results of conventional hypoglossal—facial nerve anastomosis that does not necessitate the use of nerve grafts or hemihypoglossal nerve splitting.

Using this technique, the mastoid process is partially resected to open the stylomastoid foramen and the descending portion of the facial nerve in the mastoid cavity is exposed by drilling to the level of the external genu and then sectioning its most proximal portion. The hypoglossal nerve beneath the internal jugular vein is exposed at the level of the axis and dissected as proximally as possible. One-half of the hypoglossal nerve is transected: use of less than one-half of the hypoglossal nerve is adequate for approximation to the distal stump of the atrophic facial nerve. The nerve endings, the proximally cut end of the hypoglossal nerve, and the distal stump of the facial nerve are approximated and anastomosed without tension. This technique was used in four patients with long-standing facial paralysis (greater than 24 months), and it provided satisfactory facial reanimation, with no evidence of hemitongue atrophy or dysfunction.

Because it completely preserves glossal function, the hemihypoglossal—facial nerve anastomosis described here constitutes a successful approach in patients with long-standing facial paralysis who do not wish to have tongue function compromised.

Full access

Yutaka Sawamura and Hiroshi Abe

This report describes a new surgical technique to improve the results of conventional hypoglossal-facial nerve anastomosis that does not necessitate the use of nerve grafts or hemihypoglossal nerve splitting.

Using this technique, the mastoid process is partially resected to open the stylomastoid foramen and the descending portion of the facial nerve in the mastoid cavity is exposed by drilling to the level of the external genu and then sectioning its most proximal portion. The hypoglossal nerve beneath the internal jugular vein is exposed at the level of the axis and dissected as proximally as possible. One-half of the hypoglossal nerve is transected: use of less than one-half of the hypoglossal nerve is adequate for approximation to the distal stump of the atrophic facial nerve. The nerve endings, the proximally cut end of the hypoglossal nerve, and the distal stump of the facial nerve are approximated and anastomosed without tension. This technique was used in four patients with long-standing facial paralysis (greater than 24 months), and it provided satisfactory facial reanimation, with no evidence of hemitongue atrophy or dysfunction.

Because it completely preserves glossal function, the hemihypoglossal-facial nerve anastomosis described here constitutes a successful approach in patients with long-standing facial paralysis who do not wish to have tongue function compromised.

Restricted access

Yutaka Sawamura, Hiroshi Abe, Toshimitsu Aida, Masuo Hosokawa, and Hiroshi Kobayashi

✓ The present investigation was conducted in order to examine the feasibility of isolating and growing gliomainfiltrating lymphocytes in vitro as possible effector cells for use in new adoptive immunotherapy. Eight surgical specimens obtained from patients with malignant astrocytomas were treated by enzyme dispersion; the cells were separated on a density gradient and grown in the presence of human recombinant interleukin-2. The cultured lymphocytes were tested for cell-surface markers by using monoclonal antibodies in a flow cytometric analysis. In all cases the glioma-derived lymphocytes were grown in culture for several weeks with substantial increases in cell numbers (at least 5 × 108 cells). The mature T cell population (CD3, 89%) was found to have an increased proportion of the cytotoxic/suppressor phenotype CD8 (55%) as compared to peripheral blood lymphocytes (PBL's). Eighty-six percent of the cultivated lymphocytes expressed HLA-DR. The IL-2 receptor was predominantly expressed on the helper subset (CD4-positive). Otherwise, anti-CD16, which specifically reacts with natural killer (NK) cells, did not stain significantly more of the cultured glioma-derived lymphocytes compared with lymphocyte-activated PBL's. These results corroborate the observations made with conventional immunohistochemical examination. It has been demonstrated that T lymphocytes isolated from human cancers are enriched for specific reactivity to their autochthonous tumor cells. These experiments support the possible use of glioma-infiltrating lymphocytes as a new treatment for patients with malignant glioma.

Full access

Toshiro Katsuta, Hiroshi Abe, Koichi Miki, and Tooru Inoue

OBJECT

The authors experienced an intriguing phenomenon in 2 adult patients with moyamoya disease. Mouth opening caused reversible occlusion of the donor superficial temporal artery (STA), and the patients exhibited transient cerebral ischemic symptoms. The aim of this study was to assess the incidence of such occlusion and the mechanism of this phenomenon.

METHODS

Twelve consecutive adult patients with moyamoya disease (15 affected sides) who underwent STA–middle cerebral artery anastomosis were included in this study. Ultrasound examination was performed more than 3 months postoperatively to determine whether mouth opening affected blood flow of the donor STA and led to any ischemic symptoms within 1 minute. Computed tomography angiography was performed during both mouth opening and mouth closing, when blood flow changes of the donor STA were recognized.

RESULTS

Under wide mouth opening, steno-occlusion of the donor STA occurred in 5 of 15 sides (33.3%). On 1 side (6.7%), complete occlusion induced ischemic symptoms. Steno-occlusion occurred by at least 2 mechanisms: either the stretched temporalis muscle pushed the donor STA against the edge of the bone window, or the redundant donor STA kinked when the muscle was stretched.

CONCLUSIONS

Even with temporary occlusion of the donor STA, ischemic symptoms seem to rarely occur. However, to avoid the “big bite ischemic phenomenon,” the authors recommend securing a sufficient distance between the donor STA and the edge of the bone window and avoiding a redundant course of the donor STA within the muscle layer.

Restricted access

Takatoshi Sorimachi, Hiroshi Abe, Shigekazu Takeuchi, and Ryuichi Tanaka

Object. The purpose of this study was to investigate the possibility of preventing cumulative neuronal damage after repetitive severe ischemia.

Methods. The authors monitored ischemic depolarization in the gerbil hippocampus, which has recently been shown to be a good experimental model of the effects of brief ischemia on the brain, and evaluated neuronal damage in the CA1 subregion 7 days after the ischemic insult. In a single-ischemia paradigm, the results indicate that induction of ischemia-induced neuronal damage depended on the duration of ischemic depolarization. Neuronal damage can be detected in the CA1 subregion after a period of depolarization lasting 210 seconds. Using a double-ischemia paradigm in which the animals were subjected to two periods of ischemia, there was apparently no accumulation of neuronal damage from the first ischemic episode to the second, provided the duration of the first period of ischemic depolarization did not exceed 90 seconds. Neuronal damage accumulated when the duration of the first ischemia episode exceeded 90 seconds, regardless of the duration of the reperfusion interval between the two ischemic insults. Finally, when the ischemic insult was spread over four separate episodes, each lasting 90 seconds (with a reperfusion interval of 5 minutes), neuronal damage was not found when the total depolarization period was less than 420 seconds.

Conclusions. The authors conclude that cumulative neuronal damage may be avoided by adopting an intermittent ischemia approach. The implications of these results for human surgery requiring temporary occlusion of the cerebral arteries are discussed.

Restricted access

Kiyohiro Houkin, Hiroshi Abe, Tetsuyuki Yoshimoto, and Akihiro Takahashi

✓ Whether a diagnosis of moyamoya disease is justified in patients with typical angiographic evidence of moyamoya disease unilaterally and normal angiographic findings contralaterally remains controversial. In this study the authors analyzed longitudinal angiographic change, familial occurrence, and basic fibroblast growth factor (bFGF) concentration in the cerebrospinal fluid (CSF) of patients with “unilateral” moyamoya disease. Over a 10-year period, 10 cases of unilateral moyamoya disease were followed using conventional angiography or magnetic resonance angiography. Basic FGF in CSF, obtained from the subarachnoid space of the cerebral cortex during revascularization surgery, was measured in five cases. Among the 10 cases of unilateral moyamoya disease, only one pediatric case showed obvious signs of progression to typical bilateral disease. The other nine cases (including six adults and three children) remained stable throughout follow-up radiological examinations (magnetic resonance angiography) with a mean observation period of 3.5 years. There was no familial occurrence in these cases of unilateral moyamoya disease. Levels of bFGF, which are high in typical moyamoya disease, were low in these patients. The progression from unilateral moyamoya disease to the typical bilateral form of the disease appears to be infrequent. The low levels of bFGF in the CSF of these patients and the lack of familial occurrence strongly suggest that most cases of unilateral moyamoya disease, especially those found in adults, are distinct from typical bilateral moyamoya disease.

Restricted access

Yutaka Sawamura, Yoku Nakagawa, Toshio Ikota, and Hiroshi Abe

✓ Neurinomas arising from the peripheral branch of the acoustic nerve distal to the internal auditory canal in the temporal bone are rare. Two advanced skull-base neurinomas are described which were situated mainly in the temporal petrous bone, and extended to the parapharyngeal space anteriorly, to the lateral cervical portion inferiorly, into the sphenoidal sinus medially, and into the middle and posterior cranial fossae compressing the brain stem. Both patients had been deaf for several years without other neurological deficits. The operative findings revealed that the fifth, seventh, and caudal cranial nerves were intact; therefore, it was suspected that these neurinomas originated primarily within the cochlea or the vestibule in the temporal bone. The tumors were completely removed via an extradural approach, with good results. Since the surgical treatment of such advanced skull-base neurinomas is difficult, the operative infratemporal fossa approach is described in detail.

Restricted access

Takatoshi Sorimachi, Hiroshi Abe, Shigekazu Takeuchi, and Ryuichi Tanaka

Object. The authors investigate whether depolarization monitoring is an accurate index of ischemic damage in a gerbil model of unilateral ischemia and assess the effects of brief cerebral ischemia on protein synthesis in this model.

Methods. The authors evaluate the relationship between the duration of ischemic depolarization caused by unilateral carotid artery occlusion and ischemia-induced neuronal damage in the CA1 subregion 7 days after ischemia. When the depolarization period exceeded 210 seconds, some neuronal damage was detected, and almost complete neuronal damage was observed when the period exceeded 400 seconds. Uptake of [14C]valine was evaluated in ischemic and nonischemic CA1 subregions. Disturbances in protein synthesis were seen in all animals subjected to sublethal ischemia (≤ 210-second depolarization) after a 10-minute recirculation, and after 2 and 6 hours of recirculation in animals with 90 seconds or more of depolarization. Inhibition of protein synthesis was proportional to the length of the depolarization period. After 1 and 3 days of recirculation, protein synthesis returned to near normal, and some animals with depolarizations greater than 180 to 210 seconds showed an increase in protein synthesis. Protein synthesis in all animals returned to normal levels after 7 days of recirculation.

Conclusions. In this study the authors demonstrate that monitoring of ischemic depolarization is a useful method to predict neuronal damage in the hippocampal CA1 in this model, and they identify subtle changes in protein synthesis after brief ischemia. Sublethal ischemia was divided into three categories by its depolarization period (< 90 seconds, 90–180 seconds, and > 180–210 seconds) with regard to changes in protein synthesis.

Restricted access

Yoshinobu Iwasaki, Hiroshi Abe, Toyohiko Isu, and Kazuo Miyasaka

✓ The authors describe seven cases of cervical spondylosis in which small high-density areas were detected in the spinal cord on delayed computerized tomographic (CT) myelography. These high-density areas are believed to represent cavities or areas of cystic necrosis. In all seven cases the cervical spinal canal was narrow, and the spondylosis was located at multiple levels, causing a so-called “pincer effect.” On the CT scans the high-density areas resembled fried eggs in the gray matter. These areas were localized near the abnormal cervical discs. In two cases in which the Brown-Séquard syndrome was noted, the symptoms could be attributed to the morphology of the high-density area on the affected side of the cord. Following decompressive surgery, most of the symptoms improved except for numbness of the upper extremities and motor weakness of hands.

Restricted access

Kouhei Echizenya, Masaharu Satoh, Hiroshi Murai, Hiroo Ueno, Hiroshi Abe, and Takashi Komai

✓ The mineralization and biodegradation of cerebrospinal fluid shunting systems were studied using material from 25 shunts that had been implanted for between 6 days and 10 years. New unused materials were also examined for comparison. Surface changes in six systems could be observed under an operating microscope. Substantial quantities of a white deposit had adhered to the tubing in four of the shunts. These changes were most advanced in the galeal penetrative portion of the shunts and are believed to have been caused by mechanical stress. Scanning electron microscopic analysis revealed surface wrinkles, microscopic holes, and tiny particles, suggesting deterioration of the material itself. An energy-dispersive analysis using x-rays demonstrated that the surface deposits were due to mineralization of calcium phosphate and that the tiny particle growth was aluminum. These changes may be a consequence of the degradation of silicone rubber. A discriminant analysis of the mineralization was carried out; thus, the age of the host and the duration of system implantation could be correlated with the incidence of mineralization (p < 0.1). A measurement of the physical properties showed progressive change with a remarkable deterioration in systems implanted for more than 5 years.