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Biomedical subjects

T Takemae

Publications and source records attributed to T Takemae.

At least 37 records · Page 2Linked to original sources

Carotid cave aneurysms of the internal carotid artery.

In a series of 32 surgical cases of carotid-ophthalmic artery aneurysm, seven of the lesions were located in the "carotid cave." This special type of aneurysm is usually small and projects medially on the anteroposterior view of the angiogram. At surgery, it is located intradurally at the dural penetration of the internal carotid artery (ICA) on the ventromedial side, appears to be buried in the dural pouch (carotid cave), and is often difficult to find, dissect, and clip. The aneurysm extends into the cavernous sinus space, and the parent ICA penetrates the dural ring obliquely. An ipsilateral pterional approach was used in all 32 cases, and ring clips were used exclusively because the aneurysms were located ventromedially. Clipping was successful in five cases. All patients returned to their preoperative occupation, although vision worsened postoperatively in two cases. The technical steps required for successful obliteration of this aneurysm are summarized as follows: 1) exposure of the cervical ICA; 2) unroofing of the optic canal and removal of the anterior clinoid process; 3) exploration of the ICA around the dural ring and opening of the cavernous sinus; 4) direct retraction of the ICA and optic nerve; and 5) application of multiple ring clips to conform to the natural curvature of the carotid artery; a curved-blade ring clip is especially useful. The relevant topographic anatomy is discussed.

Adult↗

[A tetrapolar circuit method using magnetic field for biological resistivity measurement].

A local impedance and its change were measured using a tetrapolar circuit combined with magnetic eddy current generator. By this method, current distribution can be restricted to a desired part, so as to eliminate errors due to uncertainty of the resistance between the electrode and the skin. The resistivity of a substance in a biological model measured by this method was nearly equal to that of the substance separated from the model. Sensitivity and localization were assessed in the other model composed of a piece of metal plate in a saline pool. The detection sensitivity was validated theoretically. The localization of the impedance pulsatile waveforms, measured at the proximal part of the forearm, was consistent with that of the arteries at this part. These results suggest that this method using eddy current should expand the application area of bio-impedance measurements.

Electric Conductivity↗

Giant aneurysms of the vertebral artery. Report of five cases.

The authors report five cases of surgically treated giant vertebral artery aneurysm. Two giant serpentine aneurysms were managed with aneurysmectomy, a giant semifusiform aneurysm with trapping and partial aneurysmectomy, and the other two saccular giant aneurysms with clipping. Surgical results were satisfactory in all cases. In particular, the two patients who underwent complete aneurysmectomy showed remarkable improvement after the second procedure of a two-stage operation that consisted of initial proximal occlusion and secondary evacuation of clots in the aneurysm when advanced thrombosis was identified. Aneurysmectomy in a two-stage operation was the best treatment for these partially thrombosed giant aneurysms which completely concealed the distal artery under a tight thinned medulla.

Aged↗

Sylvian fissure arteriovenous malformations.

We have operated on 16 cases of arteriovenous malformation (AVM) in and around the sylvian fissure. We call these lesions "sylvian fissure AVMs" and classify them into four subdivisions, namely, pure, lateral, medial, and deep AVMs. By others, they have been variously called AVMs of the basal ganglia, insula, anterior choroidal artery, frontal lobe, or temporal lobe. These sylvian fissure AVMs showed similar angiographic findings: the feeders in all cases were branches of the middle cerebral artery; in some cases, additional feeders from the anterior and posterior choroidal and posterior communicating arteries were present also. We describe the characteristic features of these AVMs from the anatomical and surgical points of view. The surgical results were satisfactory in 15 cases (no additional neurological deficits), and 1 patient died.

Adult↗

Usefulness of ceramic implants in neurosurgery.

The authors have designed various implants made of alumina ceramic for neurosurgical use. They were used for reconstruction of the sellar floor and orbital wall and for cranioplasty to repair bone defects in both the convexity and the suboccipital region. Burr hole and sphenoid buttons were made to prevent postoperative dents in the skin. A ceramic-silicon sponge was developed as a marker prosthesis for neurovascular decompression. There were no untoward side effects such as infection or rejection by recipient tissue in humans or dogs. The advantages and disadvantages of the material are discussed.

Ceramics↗

Aneurysms of the basilar artery trunk.

Ten cases of basilar artery trunk aneurysms are reported; nine were operated on by a middle subtemporal approach and one by a pterional transsylvian technique. The middle subtemporal approach facilitated clipping of aneurysms located as deep as 25 mm below the posterior clinoid process as seen on the lateral views of the angiogram, such that the junction of the vertebral arteries was visible in most cases. The authors emphasize the usefulness of direct retraction of the trigeminal nerve, the pons, and the aneurysm itself; occasionally, drilling off the pyrimidal edge is also valuable. Surgical results were satisfactory in seven cases and poor in one; two patients died.

Adult↗

Aneurysms protruding from the dorsal wall of the internal carotid artery.

Saccular aneurysms arising at locations other than at arterial divisions are extremely rare. The authors describe eight such aneurysms that protruded from the dorsal wall of the internal carotid artery (ICA) and were unrelated to any arterial junction. Radical surgery was performed in all eight cases. The aneurysms were saccular with a fragile wide or semifusiform neck. Intraoperative rupture occurred in three cases. From this experience, it is emphasized that these unusual protruding aneurysms of the dorsal ICA should be clipped with the clip blade parallel to the parent artery. In addition to clipping, complete wrapping with fascia or Bemsheet (cellulose fabric) is often advisable to prevent slippage of clips or postoperative rupture of residual aneurysm.

Adult↗

Retraction system for transsphenoidal surgery. Technical note.

A retraction system has been developed for transsphenoidal surgery to use together with a conventional self-retaining speculum. The system comprises an attachment to the speculum, a self-retaining retractor, and a slim tapered brain spatula and pronged hook. The spatula or hook is secured with the self-retaining retractor and the attachment. The retractor can also be fixed to the Sugita multipurpose head frame. The system may be used to retract the bulging diaphragma sellae and tumor tissues, and to stop bleeding from the dural venous sinus or tumor bed, so the surgeon can continue the procedure with both hands.

Adenoma↗

[Posterior fossa microvascular decompression for hemifacial spasm and trigeminal neuralgia--some improvements on operative devices and technique].

Microvascular decompression has been widely used as a method for the treatment of hemifacial spasm and trigeminal neuralgia. We have experienced 30 such cases in the last 2 years; 25 of them were hemifacial spasm and 5 trigeminal neuralgia. Excellent results were obtained in 26 cases; the remaining two cases, both hemifacial spasm, were partially cured. Mild facial paresis appeared several days after the operation in 3 patients. In all the cases, the facial paresis recovered completely within several weeks. The cause of the facial paresis was not known. In 2 cases a slight hearing deficits were noticed after surgery, which has been gradually improving over several months. As this operation is functional surgery, operative complications must be avoided as much as possible. It has been our policy that we first try medical treatment and/or some kinds of nerve block and if no effects are obtained, we recommend the microvascular decompression. For microvascular decompression, suboccipital craniectomy is performed in lateral position. From the point of view of surgical technique, we stress several important points as follows: The head is elevated about 30 degrees, and it is kept approximately horizontal and should not be excessively rotated. Craniectomy is made as far laterally as the sigmoid sinus; its shape is elongated oval. Retraction of the cerebellum should not be done in the direction of the cranial nerves to avoid post-operative hearing deficit. Two tapered retractors are effectively used for cerebellar retraction. A third slim, tapered retractor is useful for holding an offending artery when exploring the root exit zone or placing a sponge for decompression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Characteristics and use of ultra-long aneurysm clips.

Ultra-long aneurysm clips, 21 to 40 mm in length, are described, and their characteristics and application delineated. These clips have been used in 30 procedures for various kinds of aneurysms. They are useful not only for wide-necked and giant aneurysms but also for deeply located aneurysms such as those on the vertebrobasilar artery.

Adult↗

Intimal proliferation of cerebral arteries after subarachnoid blood injection in pigs.

A model of experimental subarachnoid hemorrhage in young pigs has been created using two subarachnoid blood injections. Cerebral arteries of the pig demonstrate intimal proliferation and medial necrosis 10 days after experimental blood injection; this appears to be a reaction to arterial injury. The similarity between the arterial reaction to subarachnoid blood and the general process of atherosclerosis is noted, and steps have been taken to insure that the vasculopathy described is truly a response to the injected blood. The authors conclude that the intimal proliferation observed between 1 and 2 weeks after experimental subarachnoid blood injection is an indicator of arterial injury and is, therefore, a good end point for further studies.

Animals↗

Mortality study of patients with subarachnoid haemorrhage at University hospitals and their affiliated hospitals in Japan.

This study was undertaken to examine the differences in aneurysm statistics between University hospitals where subacute or chronic patients are primarily treated and University-affiliated hospitals where both acute and chronic cases are also admitted. In each hospital group, the transition of the statistics in the last decade was studied. The purpose of this study was also to see if any conclusion could be drawn regarding the surgical treatment of acute cases. The death rate for all aneurysm cases admitted is 8% at University hospitals, whilst that at affiliated hospitals is roughly 30% during the 1970s. The operative death rate at the University hospitals is 3%, whilst that at affiliated hospitals is 16% which improved at one affiliated hospital to 8% in the 1980-1981 period. Morbidity also improved in the latest series in the affiliated hospital. These improvements are considered to be de to the change of operative and postoperative policies for acute cases to: limited surgical indications for grade IV patients, extensive cisternal clot removal at the time of surgery, and oral administration of Ticlopidine, a new antiplatelet agent.

Hospitals, Special↗