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H Iseki

Publications and source records attributed to H Iseki.

At least 55 records · Page 3Linked to original sources
PubMed1994

An image-guided stereotactic system for neurosurgical operations.

A new simulation system utilizing digital images (CT/MRI/SPECT) and an ultrasound/laser navigation system has been developed for image-guided surgery. Preoperative CT/MRI imaging does not always indicate the actual location of the lesion during intracranial operation, because the lesion may be displaced or distorted by operative procedures or CSF flowout. The authors developed an image integration system including an intraoperative ultrasonogram, which provides accurate information not only on the location of the deep-seated lesions but also surrounding anatomical structures during operation. The rationale of the system is to coordinate the three-dimensional axes of each image with the aid of a stereotactic subframe. Our simulation system has two ways. One simulation system works on a SUN workstation. At the preoperative simulation study: the entry point on the brain surface and the access route to the lesion are decided on from the three-dimensional CT/MRI images on the computer display. Then the configuration of the lesion from the operative view is displayed as an expected ultrasound image by reconstructing the CT and/or SPECT image. Another simulation system (HyperCAS) works on the HyperCard of a MacIntosh. The target point, the entry point and the trajectory are decided on and the three-dimensional location of these points is measured from serial CT images on the LCD display. At the time of operation, stereotactic craniotomy is performed using the laser navigator. The extent of the lesion at every depth in the surgical process is predicted from these images, and the access route to the lesion is easily corrected with the intraoperative ultrasound navigator.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Simulation↗
PubMed1994

[A case of partial atrioventricular canal with discrete subvalvular aortic stenosis worsened 3 years after the replacement of the mitral valve].

The extension of the left ventricular outflow tract is provoked by a partial atrioventricular canal, and is easy to cause stenosis after a radical operation and/or a replacement of the left atrioventricular valve because of its anatomical structure. This report shows a case of a partial atrioventricular canal with a discrete subvalvular aortic stenosis which was worsened three years after the replacement of mitral valve. In this case the left ventricular outflow tract obstruction (LVOTO) had been found before the replacement of mitral valve but it was kept observing without surgical treatment because the degree was judged slight. Subvalvular aortic stenosis was worsened three years after the replacement. It was suspected that the stenosis developed because of the proliferation of heterologous tissue by a turbulent flow of a site of stenosis. For this diagnosis, the transesophageal echocardiography was very effective, and in this case the cause of LVOTO is uncertain, so a careful observation is necessary for it.

Adult↗
PubMed1993

A simple system for stereotactic volumetric resection.

Stereotactic volumetric resection of deep-seated intracerebral lesions is generally believed to require expensive and complex facilities. The authors report a simple system for stereotactic craniotomy, in which the software in the computed tomographic scanner and a personal computer are used for preoperative planning and intraoperative orientation.

Brain Neoplasms↗
PubMed1992

Unexpected movement disorders in neurosurgical practice: report of three cases.

Hyperkinetic movement disorders may develop as a complication of stereotactic thalamotomy or pallidotomy. However, such movement disorders are uncommon after nonsterotactic intracranial operations. The authors report three cases of involuntary movement disorders unexpectedly developing after intracranial operations. The patients had undergone clipping of an internal carotid aneurysm, removal of an intracerebral hematoma, and resection of a tentorial meningioma. Two patients developed choreic movements and a dystonic posture of the unilateral upper extremity. One patient showed a tremor that had features of both parkinsonism and essential tremor. The symptoms of these patients were medically uncontrollable, and they were successfully treated with stereotactic ventrolateral thalamotomy.

Aged↗
PubMed1992

Stereotactic mesencephalotomy for pain relief. A plea for stereotactic surgery.

Rostral mesencephalic reticulotomy (RMR) for pain relief was performed in 34 patients with intractable pain. Most of these patients have been followed for a long period of time postoperatively, the longest follow-up period being 11 years. Contrary to the commonly prevailed bias in the past that mesencephalotomy may be a surgical intervention with potential risk, these patients of RMR have continued to substantial improvement postoperatively in terms of their preoperative intractable painful dysesthesia after a long period of time. The results of pain relief for denervation pain as well as for nondenervation pain are surprisingly good even after unilateral procedures. There was no operative mortality. Postoperative disturbance of ocular motility has been reduced. RMR has its scientific basis in that the medial part of the reticular formation rather than the classical lateral spinothalamic tract has more significance in the central conduction of nociceptive impulses through the midbrain level, which was verified by intraoperative neuronal recording with a tungsten microelectrode. The present report emphasizes that stereotactic mesencephalotomy, if performed meticulously and precisely, is a safe surgical procedure for pain relief. Results of MRI and sensory manifestations of a patient 11 years after RMR are also presented.

Follow-Up Studies↗
PubMed1992

[A modified technique in total cavopulmonary connection].

We have used an alternative technique in Total Cavopulmonary Connection without using any prosthetic material. The technique is a modification of Senning operation in which a flap of right atrial wall is used to create a tunnel between inferior vena cava and superior vena cava. We used this modified technique in two cases, and they showed excellent postoperative convalescence.

Blood Vessel Prosthesis↗
PubMed1991

An ultrasound-guided stereotactic apparatus for intracranial mass lesions.

One of disadvantages of conventional stereotactic operation for intracranial mass lesions is that it is basically a blind procedure even if the operation is performed in a gantry of a CT scan. High resolution ultrasound image gives real-time information on intracranial pathology such as bleeding, remaining cyst fluid or haematoma. The authors report an ultrasound guided stereotactic apparatus which gives real-time images of the lesion during operation.

Biopsy, Needle↗
PubMed1991

Bilateral versus unilateral percutaneous high cervical cordotomy as a surgical method of pain relief.

The present report is concerned with the results of bilateral percutaneous high cervical cordotomy (60 patients) compared with those of unilateral cordotomy (161 patients). The result of pain relief is classified into 4 grades based on Hitchcock's criteria; grade 1: complete pain relief, grade 2: almost complete pain relief with slight residual pain, grade 3: persisting pain, but tolerable, grade 4: persisting pain, untolerable. In cases of bilateral cordotomy (60 patients), 76% of the cases showed grade 1, 19% being grade 2, 3% being grade 3 and 2% being grade 4. On the contrary, the unilateral cordotomy (161 patients) showed less impressive results, particularly in grade 1, namely, grade 1 being 64%, grade 2 being 18%, grade 3 being 14% and grade 4 being 4%. Clinically acceptable results (grade 1 plus grade 2) were, therefore, obtained in bilateral cordotomy (95%) as compared with unilateral cordotomy (82%). The difference in pain relief between bilateral and unilateral procedure observed in the present investigation is contrary to that reported previously by others. The possible explanation for less impressive result in regard to grade 1 of unilateral cordotomy is that unilateral cordotomy was performed in this series to alleviate the major side of patient's pain, followed by latent pain on the other side postoperatively, which is not uncommon phenomenon in cancer pain. Whereas all of the bilateral cordotomies were done either for midline pain or bilateral pain, unilateral cordotomy gave satisfactory pain relief in some cases of midline pain. Midline pain, therefore, does not necessarily require bilateral cordotomies from a clinical point of view.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[CT-guided stereotactic surgery of brain abscess].

Seven patients with brain abscess underwent CT-guided stereotactic aspiration using Iseki's stereotactic apparatus. Three of them were under the age of fifteen and four were older than thirty. The lesions were single and round in four cases, multilobular in two and multiple in one patient. Operations were performed after systemic administration of antibiotics for more than two weeks and after capsule formation was confirmed on CTs. Preoperative volume of the abscesses was estimated from CTs. The target point chosen was the center of the ring of the largest diameter in the enhanced lesion. Abscess was aspirated under monitoring with intraoperative CT scan. No continuous drainage was performed and no antibiotics were given directly into the abscess cavity. In all cases the center of the abscess was punctured with a single trial. Average volume of the preoperative brain abscesses was 18.8ml. Aspirated volume at the time of the operation averaged 16.9ml and all the abscesses decreased to unmeasurable size on CTs. In five of seven patients abscesses were cured after a single aspiration, and in one case after the second operation. One case required extirpation of the lesion. During the follow-up period of four months to five and a half years six patients showed no recurrence. One patient died of unrelated cause four and a half years after the operation. No operative complication was noted. There was no operative morbidity or mortality. Using a CT guided stereotactic method, brain abscess is punctured so accurately, regardless of its location and size, that damage to the surrounding brain during operation can be minimized. Therefore it is highly possible to aspirate abscesses completely.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Late results after open repair of tetralogy of Fallot: a 13-24 year follow-up].

Late results in 139 patients undergoing open repair of tetralogy of Fallot from 1965 to December 1975 were analyzed. Their ages ranged from 1 year to 35 years. All patients were repaired through a right ventricular approach. One hundred two patients had infundibulectomy alone (non-patch group) and 14 required right ventricular outflow patch (RV-patch group) and 23 trans-annular patch. The hospital mortality rate was 18.7% (26 cases) and 103 patients were discharged and have been followed until death or for 13-24 years. Cardiac catheterizations were performed in 80 patients an average of 1.8 years after correction. Right ventricular systolic pressure was 49.8 +/- 22.4 mmHg in non-patch group, 41 +/- 16.5 mmHg in RV-patch group and 54.5 +/- 14.2 mmHg in PA-patch group. Seven in 11 patients of PA-patch group had over an 8 mmHg of right ventricular end diastolic pressure. Six patients died during the follow up: four deaths in the first 5 years, 2 between 5 and 15 years. The causes of death were congestive heart failure (3), sudden (1), pneumonia (1) and accidental (1). Late complications were 3 arrhythmias and 2 reoperations. Event free rate at 24 years was 74.8 +/- 3.8%.

Adolescent↗
PubMed1990

[A case report of combined composite valve graft replacement of the aortic root and graft replacement of the abdominal aorta].

A 55-year-old man who had both aortic root aneurysm with severe aortic regurgitation and enlarging abdominal aortic aneurysm was admitted to our hospital. We employed the combined composite valve graft replacement of the aortic root and Y-graft replacement of the infrarenal abdominal aorta at one stage operation. At the operation, median sternotomy was made and the composite graft replacement of the aortic root was performed under cardiopulmonary bypass prior to the abdominal procedure. After cardiopulmonary bypass was removed, abdominal incision was made. Although ventricular arrhythmias and mild hypotension transiently occurred when the abdominal aorta was clamped, the Y-graft replacement was also completed uneventfully, and no complication occurred postoperatively. We conclude that the combined operation of the aortic root and the abdominal aorta is clinically feasible in certain situation.

Aorta↗
PubMed1989

[A new apparatus using the Micro Ultra-Sonic Aspirator (MUSA) system for microneurosurgery].

Matsumoto was the first to present the NIIC UltraSonic Aspirator for CT guided stereotactic aspiration of intracerebral hematoma. Based on the NIIC Aspirator, the authors have developed a useful tool for microsurgery by adapting conventional ultrasonic aspirators. This was done by making the aspirator lighter and more handy for use during microsurgical procedures. A newly devised apparatus using the Micro Ultra-Sonic Aspirator (MUSA) was applied clinically to surgical treatment for brain tumors, arterio-venous malformations (AVMs) and intracerebral hematomas. Using the MUSA system, it became easier to remove successfully tumorous mass and the nidus of AVM, because it minimized the risk of injury to the normal structures such as the surrounding brain tissue, vascular systems and the cranial nerves.

Brain Diseases↗
PubMed1988

Origin of lingual proprioceptive afferents in Japanese monkey, M. fuscata fuscata. Studied by HRP-labeling technique.

The peripheral course of the axon of the lingual proprioceptive neurons in 5 Japanese monkeys was studied by injecting HRP into the distal part of the hypoglossal nerve through the proximal stump. The present authors confirmed that the HRP-labeled cell bodies appeared ipsilaterally in the C2, C3 and C4 spinal ganglia. The afferents to the C2, C3 and C4 ganglia pass through the ansa hypoglossi and direct neuronal anastomosis existing between the first cervical nerve and the hypoglossal nerve. It was confirmed that in the Japanese monkey, having abundant muscle spindles in the tongue, the lingual proprioceptive neuron soma exist in the C2, C3 and C4 spinal ganglia, their peripheral axons passing through the ansa hypoglossi and the direct neuronal anastomosis.

Animals↗
PubMed1988

Degeneration of the primary snout sensory afferents in the cervical spinal cords following the infraorbital nerve transection in some mammals.

To obtain the neuroanatomical information on the role of the snout sensory input in mastication, the present study was conducted on young and adult mice, young Wistar rats and adult Japanese shrew-moles. The animals were subjected to unilateral and bilateral infraorbital nerve transection. Transganglionic degeneration was studied by the Nauta method and electron microscopy including HRP application to the neck muscles. Transganglionic degeneration was found in every experimental case. 1. Transganglionic degeneration of the fibers was found not only in the main sensory nucleus and spinal tract nucleus of the trigeminal nerve but throughout the cervical and the upper part of the thoracic spinal cord. 2. These transganglionically degenerated fibers descended bilaterally through the cuneate nucleus and then caudally through the posterior funiculus at the obex level. They then entered the dorsal and ventral horns to make a synaptic contact with the degenerated synapses on the dorsal horn cells and with the multipolar cells in the ventral horns. This neuroanatomical information suggests: 1) that the trigemino-neck muscle reflex will be generated monosynaptically by the primary neurons arising from the snout sensory organs and 2) that these primary neurons may play a large role as a neuronal bridge in connecting the masticatory reflex system and the cranio-neck reflex system.

Animals↗
PubMed1988

[Identification of location of electrode tip during percutaneous retrogasserian glycerol injection (PRGI) with blink reflexes elicited by direct stimulation of trigeminal complex (DBR)].

In order to identify the location of the electrode tip during percutaneous retrogasserian glycerol injection (PRGI), the blink reflex (DBR) following direct stimulation of the trigeminal complex (the gasserian ganglion, trigeminal rootlets, or the 3rd division of the trigeminal nerve) was obtained from 6 patients with trigeminal neuralgia. 1) The waveform of the DBR was very similar to that of the blink reflex (BR) elicited by percutaneous stimulation of the 1st division of the trigeminal nerve. However, the latency of early reflex (R1) as well as late reflex (R2) of the DBR was approximately 2 msec shorter than that of the conventional BR. 2) When the electrode tip was introduced into the gasserian ganglion, the DBR showed the largest response under the same recording condition, whereas the DBR was not recorded when the tip of the electrode was placed into either the arachnoid space or the subdural space. The each DBR response, however, showed the same configuration when the electrode tip was situated at the territory of the 1st, 2nd or 3rd division of the trigeminal nerve within the gasserian ganglion or the trigeminal cistern. 3) The DBR always appeared under the anesthesia with the intravenous administration of 10 mg diazepam and 30 mg pentazocine. 4) Based on the present study, the DBR proved to be an usuful parameter in determining whether the electrode tip is introduced into the trigeminal complex or not, particularly in the case of patients having no reliable sensory response to electrical stimulation.

Aged↗
PubMed1988

Degenerative changes of the primary trigeminal axons and neurons following infraorbital nerve transection.

The sensory input of the Vth cranial nerve might play a great role in the feeding activity of the mammals, especially of the Japanese shrew-moles. After the transection of the pure sensory infraorbital nerve, a drastic structural disorder was observed in the rat masseter muscle. In order to give anatomical evidence as to whether the interference of the sensory input affects the peripheral effector, electron microscopic investigations were performed on the primary axons and neurons of the Japanese shrew-moles. The results obtained are as follows: The preganglionic part of the transected nerves showed drastic degenerative changes of the myelinated fibers, characterized by a prominent decrease in the large- and medium-sized myelinated axon fibers, a gradual numerical increase of the clustered or isolated unmyelinated axons, and the frequent appearance of macrophages. The ganglion cells exhibited displacement of the nucleus with infolding of the nuclear membrane, the appearance of a large amount of lipofuscin granules, and an increase of neurofilaments and reduced Nissl bodies. The transganglionic part of the sensory root exhibited mainly a predominant axonal destruction, accompanied by myelinated disintegration.

Animals↗