Search PubMed⌕ Search

Biomedical subjects

H Okudera

Publications and source records attributed to H Okudera.

At least 37 records · Page 2Linked to original sources
PubMed1998

Color Doppler ultrasound imaging in the emergency management of an intracerebral hematoma caused by cerebral arteriovenous malformations: technical case report.

OBJECTIVE AND IMPORTANCE: Ruptured arteriovenous malformations (AVMs) are important causes of spontaneous intracerebral hemorrhages. This is a report of emergency hematoma removal, avoiding damage to the nidus of the AVM, using intraoperative color Doppler imaging. CLINICAL PRESENTATION: A 38-year-old woman suddenly presented with coma. The patient underwent emergency surgery immediately after admission, without preoperative angiographic examination, because of progressive neurological deterioration caused by a massive hematoma in the right basal ganglia, as diagnosed with computed tomographic scanning. INTERVENTION: A right frontotemporoparietal craniotomy was performed. Intraoperative ultrasound imaging with a color Doppler system (EUP-NS32, 5 MHz; Hitachi Medical, Tokyo, Japan) clearly demonstrated a nidus complex in the hematoma. Based on the imaging, effective decompression of the hematoma was performed without damage to the AVM complex. CONCLUSION: Color Doppler imaging (with real-time availability) of an atypical hematoma provided significant information on the vascular lesion causing the hematoma and could reduce the surgical risks during emergency evacuation of large intracerebral hemorrhages resulting from ruptured AVMs.

Adult↗
PubMed1998

Aneurysm surgery in Asia--Japanese situation.

This report is based on the results of the questionnaires conducted for the Japan Stroke Surgery Meeting 1996 (President: S. Kobayashi). The questionnaires were sent to all neurosurgical training institutions approved by The Japan Neurosurgical Society, numbering 959. The response rate was 54.2% (520 institutions). All statistics dealt with cases from January 1995 to December 1995. The total number of aneurysm surgery performed was 13,166. The average operative case number per institution during the year was 25. About 20% of the institutions exceeded 35 cases. Of all operative cases, 76.3% were ruptured aneurysms and 23.7% were nonruptured. Giant aneurysms were 2.9%; dissecting aneurysms 2.4%. Surgical procedures performed were clipping in 90.3%, wrapping in 5.2%, proximal ligation 1.6%, and bypass in 0.7%. Intravascular surgery was performed for 2.3% of the cases. Sugita clips were mainly used in 80.5% of the institutions, Yasargil clips in 6.6%, and both in 12.9%. For anterior communicating artery aneurysms pterional approach was mainly used in 81.0% of the institutions, interhemispheric in 7.2%, and both in 11.7%. For basilar terminal aneurysms, pterional approach was mainly used in 88.3% of the institutions, subtemporal approach in 6.6%, and both in 5.1%. The nonoperative cases included 24.9% of the ruptured aneurysms, 31.7% of the unruptured aneurysms, 38.4% of the giant aneurysms, and 52.1% of the dissecting aneurysms. The above statistics suggest that aneurysms are treated in Japan in most training institutions and that open surgical treatment is still the main procedure of choice.

Humans↗
PubMed1997

Brain spatula with transparent tip: technical note.

A newly developed brain spatula with transparent tip for brain retraction is introduced. The high-molecular polymer plastic material is used only for the tip of the new spatula whilst rest of the spatula is made up of the ordinary malleable metal. The transparent nature of the spatula tip helps us in observing the retracted brain vessels and cranial nerves in continuity with the main operating area. The extent of distortion as a result of the retraction can be directly observed assisting in prevention of an inadvertent injury. The new brain spatula with transparent tip is helpful for microneurosurgery under high magnification. Various shapes and sizes of the spatula can be used.

Brain↗
PubMed1997

Unexpected nerve gas exposure in the city of Matsumoto: report of rescue activity in the first sarin gas terrorism.

This report describes the rescue activities and the exposure of rescue and hospital personnel from the first unexpected nerve gas terrorist attack using sarin (isopropyl methylphophonofluoridate) in the city of Matsumoto at midnight on June 27, 1994. The details of the emergency activities in the disaster were studied based on the records from emergency departments of the affiliated hospitals and records from the firehouse. About 600 people, including residents and rescue staff, were exposed to sarin gas. Fifty-eight residents were admitted to hospitals, and 7 died. Among 95 rescuers and the duty doctor from the doctor car, 8 had mild symptoms of poisoning. All the rescue activity took place without gas masks or decontamination procedures. In this case of unexpected mass exposure to sarin gas, the emergency rescue system for a large disaster in Matsumoto city, which had been established for a conflagration or a local earthquake, was effective.

Humans↗
PubMed1996

Cadaveric Hands-on Workshop Using a Three-Dimensional High-Definition Television System.

We report the introduction of a three-dimensional high-definition television system in cadaveric microneurosurgical hands-on workshops on skull base technique. The system was found to be a useful means of exact communication between the instructor and the participants and avoided congestion around the instructor's table. The instructions could be refayed to the multiple participants at one time and thus avoided repetitions. More participants could be accommodated in the workshops. The entire proceeding could be recorded three-dimensionally for later use and educational purposes.

Journal Article↗
PubMed1995

Sarin poisoning in Matsumoto, Japan.

A presumed terrorist attack with sarin occurred in a residential area of the city of Matsumoto, Japan, on June 27, 1994. About 600 residents and rescue staff were poisoned; 58 were admitted to hospitals, and 7 died. We examined clinical and laboratory findings of 264 people who sought treatment and the results of health examinations on 155 residents done 3 weeks after the poisoning. Findings for severely poisoned people were decreases in serum cholinesterase, acetylcholinesterase in erythrocytes, serum triglyceride, serum potassium and chloride; and increases in serum creatine kinase, leucocytes, and ketones in urine. Slight fever and epileptiform abnormalities on electroencephalogram were present for up to 30 days. Examination revealed no persisting abnormal physical findings in any individual. Acetylcholinesterase returned to normal within 3 months in all people examined. Although subclinical miosis and neuropathy were present 30 days after exposure, almost all symptoms of sarin exposure disappeared rapidly and left no sequelae in most people.

Acute Disease↗
PubMed1995

Noninvasive cerebral optical spectroscopy: depth-resolved measurements of cerebral haemodynamics using indocyanine green.

To investigate the feasibility of a newly developed, near-infrared optical spectroscopy device, we analysed measurements of the infrared tracer indocyanine green (ICG) using sensors with a single near infrared light source and multiple light detectors. Two ml of ICG dye, 1.0 mg ml-1 in concentration, were injected into the internal carotid artery during cerebral angiography in 14 adult patients. The resultant washout curves were measured bilaterally using sensors with 4 detectors spaced at 10, 20, 30 and 40 mm from the infrared light source on the right side, and 15, 25, 35 and 45 mm from the source for the left side, respectively. Washout curves were analysed to determine the relative amplitude of the ICG absorption signal and deduce each detector's penetration distance. When ICG was injected into the internal carotid artery, relative absorption increased with detector distance from the light source. No substantial difference in attenuation was observed in any of the detectors during external carotid injection of ICG. The resultant information related depth of penetration of the light with source-detector separation distances. The feasibility of the system for measuring cerebral oxygen saturation and haemodynamics noninvasively or monitoring at bedside is discussed.

Adult↗
PubMed1995

Computer-assisted geometric design of cerebral aneurysms for surgical simulation.

This report presents conceptual aspects and the clinical implications of a computer-assisted geometric design of a cerebral aneurysm and surrounding structures. The technique is based on the approximation power of the parametric spline function, which achieves interpolation and surface fitting of the arterial information obtained by conventional angiography. Computer graphic transformations including shifting, scaling, rotation, and putting different colors in different intensities make it possible to obtain the surgical simulation of a cerebral aneurysm. To our knowledge, this is the first report in which the computer graphic simulation of the surgical view of a cerebral aneurysm is made with a personal computer. Using our method, it may be possible to obtain the surgical simulation of a more complicated view by introducing a navigation system of a new style for conventional open neurosurgery. Concepts and the technical details of the method are described.

Basilar Artery↗
PubMed1995

[A case of severe sarin poisoning in the sarin attack in Matsumoto--one-year follow-up of clinical findings, and laboratory data].

A patient severely poisoned with sarin in the Sarin Attack in Matsumoto is described. A 19-year-old man was exposed to sarin at 23:00 on 27 June, 1994. At 1:00 of the following day, a rescue team found and brought him to the hospital. His blood pressure was 150-80mmHg and the heart rate was 120/min with frequent premature ventricular contractions (PVC). His respiration was shallow and copious salivation and excretion from the respiratory tract were observed. Consciousness disturbance, generalized convulsion, severe miosis and fasciculation of tongue, facial muscle and extremities were also marked. Serum cholinesterase was 21 U/l (normal 109-249) and acetylcholinesterase in erythrocyte (E-AchE) was 0.1U/l (normal 1.2-2.0). Electroencephalogram (EEG) 30 hours after exposure showed polispike and wave complexes. Ventilatory assistance, forced urination and injection of diazepam and atropin improved his general condition and he was discharged 18 days after exposure. Three months after exposure, E-AchE was normalized and there was no complaint. But one year after exposure, EEG showed epilecpic discharges during sleep, and Holter electrocardiogram showed frequent PVC. As no clinical cases of severe sarin poisoning like this patient was reported, a longterm follow-up of this patient is very important.

Adult↗
PubMed1994

A newly designed attachment device of multipurpose frame for neuronavigator. Technical note.

A 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.

Aged↗
PubMed1994

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

A 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.

Artifacts↗
PubMed1994

Intraoperative CT scan findings during resection of glial tumours.

Intraoperative computerized tomographic (CT) scan findings in two cases during resection of glial tumor are described. These intraoperative CT images were obtained by an exclusively developed operating CT scanner system for use in the operating room. Repeated intraoperative CT scans taken during tumor removal showed shift of the brain including central structures and displacement of the cortical subarachnoid space in both cases. With contrast medium, the edge of the surrounding brain after resection was enhanced and a round enhanced area was observed in distant white matter. The distant enhancement, which we call 'remote enhancement', probably suggests damage to the blood-brain barrier due to surgical manoeuvre.

Adult↗
PubMed1994

Intraoperative regional and functional thermography during resection of cerebral arteriovenous malformation.

We present the first use of intraoperative thermographical imaging for the surgical resection of a cerebral arteriovenous malformation. For obtaining intraoperative regional and functional thermographical images, a real-time mode infrared camera was installed to an operating microscope with an exclusively developed attachment device. Changes of the surface temperature of the cortical draining vein and the surrounding cortical surface were observed intraoperatively before and after the occlusion of the main feeder. Intraoperative functional thermography with cold physiological saline solution demonstrated a change in the heat clearance of the draining vein after complete obliteration of the feeder.

Adult↗
PubMed1993

Intraoperative computed tomographic scanning during transsphenoidal surgery: technical note.

Intraoperative computed tomographic scanning during transsphenoidal surgery on pituitary lesions is performed and evaluated. A computed tomographic scanner system exclusively developed for the operating room is used for this purpose during transsphenoidal surgery. Ten consecutive patients with pituitary lesions underwent operations by this method, which used a combination of an ordinary fluoroscopy unit and the computed tomographic scanner.

Adenoma↗
PubMed1993

Three-dimensional Hi-vision system for microneurosurgical documentation based on wide-vision telepresence system using one camera and one monitor.

A three-dimensional (3-D) high-definition television (Hi-Vision) system suitable for attachment to a stereoscopic operating microscope allowing 3-D medical documentation using one Hi-Vision camera and one Hi-Vision monitor is described. The system provides 3-D high-definition microneurosurgical recorded images suitable for viewing on a screen or monitor, or for printing.

Documentation↗