Tomomi Iwashita

Description and first clinical application of AirWay Scope for tracheal intubation.

We have developed a novel airway apparatus, AirWay Scope, which we have used in the orotracheal intubation of 10 consecutive patients requiring general anesthesia before neurosurgical procedures. The characteristic shape of the introducer (INTLOCK), the tube guiding function and the sighting device of the AirWay Scope has possibility to facilitate tracheal intubation. Here, we report the first clinical application of this system and describe potential advantages of the apparatus.

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.

Parameters for contralateral approach to ophthalmic segment aneurysms of the internal carotid artery.

OBJECTIVEThis study was undertaken to define more accurately the feasibility and indications of the contralateral pterional approach to ophthalmic segment aneurysms of the internal carotid artery (ICA). METHODSBetween 1995 and 1999, 46 patients with ophthalmic segment aneurysms of the ICA were surgically treated in our institution. Eleven of the 46 aneurysms were operated using the contralateral pterional approach. All aneurysms were successfully clipped without complications; three patients required bone resection around the aneurysm neck. We studied the 11 patients who were treated with the contralateral approach by defining six parameters to assess the feasibility of the approach and to predict the necessity for bone resection: 1) Parameter A, the distance between the anterior aspect of the optic chiasm and the limbus sphenoidale; 2) Parameter B, the distance between the bilateral optic nerves at the entrance to the optic canal; 3) Parameter C, the interrelation of the optic nerve and the ICA, expressed as a/b in which a is the length from the midline to the optic nerve and b is the length from the midline to the ICA; 4) Parameter D, the size of the aneurysm neck; 5) Parameter E, the direction of the aneurysm from the ICA wall on the anteroposterior angiogram; and 6) Parameter F, the distance from the medial side of the estimated distal dural ring to the proximal aneurysm neck on the lateral angiogram. RESULTSParameters A to F were 8.8 mm (range, 5.4–11.1 mm), 14.5 mm (range, 10.4–22.2 mm), 0.9 mm (range, 0.6–1.3 mm), and 3.0 mm (range, 2.3–4.7 mm), 5 to 160 degrees, and 1.3 mm (range, 0.3–2.4 mm), respectively. All patients had excellent operative outcomes without visual dysfunction. Three patients required drilling of the bone around the optic canal on the craniotomy side; bone drilling was not required when Parameter E was between 30 and 160 degrees and Parameter F was more than 1 mm. CONCLUSIONParameters A to D are important for assessing the feasibility of the contralateral approach to ICA-ophthalmic segment aneurysms, and Parameters E and F are most useful for calculating the difficulty of this approach.

Comparison of three types of laryngoscope for tracheal intubation during rhythmic chest compressions: A manikin study

BACKGROUND If tracheal intubation can be performed during uninterrupted chest compressions, this will sustain circulation during the procedure of intubation and may lead to successful resuscitation. We compared three types of laryngoscope on a manikin as to whether they enabled tracheal intubation while the manikins chest was rhythmically compressed. METHODS A total of 35 persons who had little or no experience in intubation served as examinees. The laryngoscopes employed were a conventional Macintosh laryngoscope (MAC), a new video laryngoscope, Pentax-AWS (AWS) and an optic laryngoscope Airtraq (ATQ). During chest compression on the manikin by an assistant, the examinee attempted to perform intubation. The success rate and the time for successful intubation were measured. RESULTS During rhythmic chest compressions, nine examinees failed in tracheal intubation with the MAC, seven failed with the ATQ, and no one failed with the AWS. The success rates with the AWS were significantly higher than those with the MAC (P<0.01) or ATQ (P<0.05). The time needed for intubation was significantly shorter with the Pentax-AWS than with the others. CONCLUSIONS These results suggest that the use of the Pentax-AWS enables tracheal intubation while the patients chest is rhythmically compressed, and would more often lead to successful intubation, which in turn may lead to more successful resuscitation.

Histological Study on Local Invasiveness of Clival Chordoma. Case Report of Autopsy

Summary.Summary.Background: It is well known that clival chordomas invade bony structures; however, their invasiveness of other structures has rarely been reported. We report an autopsy case of clival chordoma in a 61-year-old woman, who underwent surgery 6 times for a period of 8 years, with special reference to its local invasiveness.Method and Findings: The histological studies showed that the tumour grew in the loose connective tissue in multilayers or multilobular fashion, invading the submucous layer in addition to the bone; however, it did not invade other soft tissue, particularly vital neurovascular structures or the dura itself, even in the advanced stage.Interpretation: The dura may serve as a strong barrier against tumour invasion into the intradural space, which emphasises the importance of not injuring the dura, when the tumour is removed extradurally. For radical removal of clival chordoma, it will be necessary to remove the tumour extensively including normal bone and soft tissues surrounding the tumour, especially the mucous membrane, because the normal mucous membrane is surgically difficult to preserve by dissecting it from the invaded submucous layer.

Malignant astrocytoma of the conus medullaris treated by spinal cordectomy

We present a case of malignant astrocytoma of the conus medullaris in a 48-year-old man treated by spinal cordectomy. Preoperative examination revealed a tumor at the T12 to L1 level, and intraparenchymal invasion up to T8. The spinal cord was amputated caudally to the root entry zones of the T9 sensory roots. Additional cordectomies were repeated three times because of tumor infiltration at the cut end. At each procedure, the cord was segmentally transected just caudal to the root entry zones of the p reserving-aid sensory roots to minimize the neural deficit. The final transected level was between T3 and T4, and the cut end did not pathologically reveal any tumor invasion. However, the patient died from tumor recurrence and dissemination. Although the attempt to control the tumor by long segment cordectomy was unsuccessful, spinal cordectomy with wide margin may be a possible treatment for patients with malignant astrocytoma of the conus medullaris presenting with complete deficit below the lesion a nd no dissemination, if in an early stage.

Traumatic middle cerebral artery aneurysm: case report and review of the literature

Traumatic intracranial aneurysms are rare. A case of traumatic middle cerebral artery aneurysm was presented. A 66-year-old man sustained a severe head injury in a bicycle accident. Serial computed tomography and angiography showed the delayed intracerebral hemorrhage caused by the traumatic middle cerebral artery aneurysm. The aneurysm was trapped and removed. Histological examination clearly revealed the pseudoaneurysm. Traumatic middle cerebral aneurysms were reviewed.

Incomplete Ventricular Septal Rupture Following Blunt Chest Trauma: A Case Report

This report describes a case of traumatic incomplete rupture of the ventricular septum, a rare complication caused by blunt chest trauma. Although a serial ECG progressed its course similar to acute anteroseptal myocardial infarction in this case, there was little clinical clue of septal tear. The diagnosis was established by transthoracic echocardiography. The authors chose a conservative line of management rather than surgical repair for incomplete septal rupture because of the patent’s stable clinical course and hemodynamic status. A sequence of echocardiography during a 32-day stay in the hospital showed no change in the extent of incomplete septal rupture, septal structure, systolic function, and shape of left ventricle and also obtained no evidence of shunting through the rupture. In conclusion, echocardiography is a useful investigation to make a diagnosis as well as for follow-up in case of incomplete ventricular septal rupture. A close follow-up of incomplete septal rupture with serial echocardiography should be performed, because several cases of delayed ventricular septal rupture following blunt chest trauma have been reported.

Subtle computed tomography abnormalities in cerebral deep sinus thrombosis.

A patient with cerebral deep sinus thrombosis, which was not diagnosed on the first examination, is reported. A 46-year-old woman presented with headache and vomiting. Neurological examination and a brain computed tomography (CT) scan showed no obvious abnormal findings. The patient suffered disturbed consciousness on the day after the examination, and was admitted to our emergency centre. A CT scan and magnetic resonance imaging revealed an ischaemic lesion in the left basal ganglia, suggesting deep sinus occlusion. Anticoagulant therapy was administered. One day after admission, a CT scan showed a haematoma and severe brain swelling in the same region. Cerebral angiography demonstrated a straight sinus occlusion. Intracranial pressure was not controlled with hypothermia, and the patient died 25 days after admission. Review of the initial CT scan revealed subtle, early findings of deep venous thrombosis that were missed on first examination.

Aneurysm originating from the fenestration of the posterior cerebral artery: Case report

OBJECTIVE AND IMPORTANCE A rare case of an aneurysm arising at the fenestration of the P2 segment of the posterior cerebral artery is reported. CLINICAL PRESENTATION A 37-year-old man presented with severe headache and disturbance of consciousness. Computed tomographic scanning showed diffuse subarachnoid hemorrhage. Cerebral angiography revealed an aneurysm at the fenestration of the P2 segment of the right posterior cerebral artery. The aneurysm was located at the middle portion of the lower trunk of the fenestration. An unruptured arteriovenous malformation was incidentally found in the right thalamus. INTERVENTION A right frontotemporal craniotomy with orbitozygomatic osteotomy was made, and the aneurysm was successfully clipped. One year after the operation, gamma knife surgery was performed for the right thalamic arteriovenous malformation. CONCLUSION This is the first reported case of an aneurysm originating from the middle portion of a fenestrated posterior cerebral artery.