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Biomedical subjects

K Ebina

Publications and source records attributed to K Ebina.

At least 73 records · Page 4Linked to original sources
PubMed1984

A clinico-experimental study on various wrapping materials of cerebral aneurysms.

In this paper, we discuss the results of a systemic study of various materials so far used for wrapping, using the intracranial arteries of 43 mongrel dogs. The findings obtained are: Muscle, fascia and dura observed began to show necrotic and absorbable change within 1 to 2 months after operation, suggesting their unreliability. Bemsheet was superior in this study in adhesiveness to the vascular wall, highly contributory to constructing a firm reinforced wall by proliferating collagen fibres in the space of stereo-reticular structure of cotton fibre. No change occurred in the cotton fibre itself with the passage of time. Lyodura had a poor adhesiveness to the vascular wall with detectable gap; in addition, it showed necrosis and absorption in the bending site. Coating with Aron alpha A had a relatively poor adhesiveness to the vascular wall and seemed to crack and disappear with time.

Animals↗
PubMed1984

[Gangliocytoma of the pineal body. A case report and general review].

A case of pineal gangliocytoma in a 51 year-old man is presented. He was admitted to the hospital on February 2, 1982, with complaints of headache, nuchal pain, blurred vision, nausea and vomiting of three years' duration. Neurological examination did not show any neurological deficits but bilateral choked disc. Preoperative CT scan disclosed a sharp by circumscribed high density lesion in the pineal region with moderate hydrocephalus. Preoperative 99m Tc-DTPA brain scan revealed a warm activity in the pineal region, and changes of its activity were only little in the course of time. Preoperative Amipaque ventriculogram showed dilation of the lateral ventricles and a shadow of the tumor bulging into the posterior half of the distended third ventricle. A diagnosis of tumor of the pineal region was made and removal of the tumor was performed by biparieto-occipital interhemispheric approach in "sea lion" position. The tumor was a dark reddish solid mass which replaced the pineal body and extended under the cerebellar tentorium. The patient made an uneventful recovery without any neurological deficits. By light microscopy, the neoplasm was composed mostly of mature and immature ganglion cells and small round cells with moderate cellularity and multiform cytologic features. Ganglion cells with large nuclei and prominent nucleoli had characteristic Nissl substance in various amounts. Oligodendrocytes and astrocytes appeared around the tumor but did not show neoplastic growth. GFAP stain did not show glial component in the tumor. According these findings, the tumor was diagnosed as gangliocytoma originated from the pineal body, and this was the first case in Japan.

Brain Neoplasms↗
PubMed1982

Histological change in permanently clipped or ligated cerebral arterial wall. Part I. An experimental study in dogs.

In this paper, we discuss the results of a study by light microscope of the effect of permanent clipping or ligation on the intracranial arteries of 38 operation dogs and 7 control dogs. The findings obtained are: 1. In the cerebral arterial circle, necrosis could easily result from ordinary clipping or ligation because of scarce vasa vasorum. 2. As for the incidence of necrosis, the greatest was found in the case of the Yaşargil clip after electric coagulation, next came the Yaşargil clip alone, next ligation, and last the silver clip. The degree of necrosis correlated with the duration of clipping in the cases treated with a spring type clip, and was influenced more by the closing strength at the time of application in the cases with non-spring type clips or ligation. 3. In some of the cases ligated for long duration, recanalization was caused by the passage of the ligature through the vessel wall, suggesting that ligation is not a certain procedure if it is applied alone. 4. The granulation tissue round the clip and ligature began to grow after one month. As for its degree, the most marked granulation was that caused by the silver clip, next the ligature, than the Yaşargil clip after electric coagulation, and finally the Yaşargil clip used normally; in all of them the correlation with the passage of time was noted. 5. In the group of duration three months or more, concentric intimal proliferation was noted peripheral to the clip, and intimal proliferation was also noted exclusively localized to the side of a branch on the central or truncal side of a clip. This correlated in degree with the passage of time. 6. Clipping and ligation are liable to cause necrosis and fragmentation, but on the other hand it was considered that rupture of the vessel wall did not result because of the reinforcing and reparative effect of the reactive granulation tissue and the intimal proliferation which developed in such a manner as to strengthen the area involved.

Animals↗
PubMed1982

Histological change in permanently clipped or ligated cerebral arterial wall. Part II: Autopsy cases of aneurysmal neck clipping.

An investigation was carried out on clinical autopsy cases into histological changes in the vessel wall and into the surrounding tissue reaction after permanent clipping. 1. There were 17 autopsy cases of cerebral aneurysm, which included seven cases treated with the Yaşargil clip, five with the Heifetz clip, and five control cases. 2. Clipping period ranged from 6 days to 11 months. Both the Yaşargil and the Heifetz clips, even with long duration of clipping, caused no changes, and inflammatory reaction was slight. 3. As for the necrosis of the vessel wall beneath the blade, the Yaşargil clip produced marked necrosis at the blade edge in 4 of 7 cases (57%), while the Heifetz clip caused necrosis under the midconvexity of the blades in all 5 cases (100%). 4. The granulation tissue reaction round the clip began to occur after one month, and was enough to embed the blade of the clip after three months. We considered it very unlikely for a slip-out accident to occur after this stage. 5. Formation of mural red thrombus and deposition of fibrin with irregular intimal thickening were noted in the aneurysmal lumen in cases clipped for less than 13 days. After one month the intimal thickening was diffuse, and organized thrombus was noted. After three months or more, the aneurysmal lumen was found to have been filled almost completely by intimal thickening. Based on the above finding, the optimum condition for temporary and permanent clips was also considered.

Adult↗
PubMed1982

Recurrence of cerebral aneurysm after initial neck clipping.

Neck clipping has generally been believed to be among the most reliable of the operative modalities for cerebral aneurysm. However, recurrences with catastrophic outcome have been known to occur. We recently treated two patients who each had a new aneurysm at the site of the initial clipping. In both cases, the recurrence was found several years after the aneurysm neck had been closed successfully with a silver clip, which had been confirmed by intraoperative inspection and by postoperative angiographic studies demonstrating disappearance of the aneurysm. Histological examination of the recurrent aneurysm showed that the arterial wall had apparently been damaged by the clip edge, which resulted in thinning and disruption of both the muscle layer and the internal elastic lamina. Therefore, local fragility of the arterial wall adjacent to the aneurysm seems to have been the cause of the formation of a new aneurysm. The need to reinforce the thin-walled parent artery and the usefulness of high resolution computed tomography for the early detection of recurrent aneurysms are emphasized.

Cerebral Angiography↗
PubMed1982

[Evaluation of the dopamine induced hypertension therapy for vasospasm (author's transl)].

The purpose of this study is to clarify the usefulness and the limitations of the dopamine induced hypertension therapy (DIH) in the treatment of symptomatic vasospasm secondary to aneurysmal rupture. Twelve patients suffering from ischemic complications of vasospasm were treated with DIH and large quantities of intravascular fluids. All underwent cerebral angiography and CT scan in order to ascertain if their neurological deteriorations were due to vasospasm. In 9 cases, the levels of consciousness and neurological state were improved within a few hours after DIH started. It suggests that their ischemic symptoms were dependent on their systemic blood pressure. In one case, whose vasospasm was extensive and diffuse, DIH was life-saving, however the patient remained bedridden. In 2 cases, vasospasm was too intense for DIH to prevent continued neurological deteriorations. There seems to be a correlation between the effect of DIH and the angiographic grade of vasospasm (Table 1). The ultimate results of these 12 cases were compared with those of 46 cases which suffered from symptomatic vasospasm but were not treated with DIH (Table 3). There was no significant difference between the two groups. One died of severe brain edema, which may have been aggravated by DIH. In such a case where diffuse brain edema and breakdown of blood-brain barrier are observed on CT scan, DIH can be hazardous. However, in a case where CT scan before or during the therapy shows a localized low density area of infarction, DIH can be beneficial by preventing the progression of cerebral ischemia, in spite of a possible risk of bringing about hemorrhagic infarction. Our conclusions are as follows: 1) DIH is useful in many cases involving significant vasospasm. 2) DIH is less useful in such a case whose angiogram shows extensive vasospasm throughout the internal carotid and vertebro-basilar systems, and should be performed carefully in coordination with measures to reduce intracranial pressure. DIH is expected to protect the brain tissue from ischemia by increasing blood flow through the arteries of vasospasm and collateral circulation, but should not dilate the histologically changed arteries. Further clinical studies including cerebral blood flow measurements are necessary to define precisely the effectiveness, the indication and contraindication, and the mechanism of action of DIH.

Adult↗
PubMed1982

[Recurrent cerebral aneurysm after successful clipping of aneurysmal neck].

Neck clipping has been widely believed to be one of the most reliable and typical treatment of the cerebral aneurysm. Recently we experienced two cases of recurrence of cerebral aneurysm several years after surgery, in spite of confirmation of perfect neck clipping not only by intraoperative inspection but postoperative angiographical studies. The histological findings demonstrated that the arterial wall at the clip edge changed into thinning, interruption, and atrophy both of the muscle layer and internal elastic lamina. Therefore, local fragility of the arterial wall adjacent to clip edge seemed to cause formation of a new aneurysm. In addition, we discussed the usefulness of riskless CT in postoperative follow-up study of the cerebral aneurysm.

Carotid Arteries↗
PubMed1981

[Thromboendarterectomy for cervical carotid occlusive lesions--technical note of our method (author's transl)].

In consecutive 13 cases of the carotid occlusive lesions the carotid thromboendarterectomy was performed with some of our devices as follows: 1) Superior cervical ganglionectomy was added to this operation, bringing efficacy to increase cerebral blood flow. 2) Removal of atheroma plaque en block, as far as possible, shortened the operation time and diminished the arterial wall damage. 3) We could approach to the carotid artery without dissection of the common facial vein by antero-medial retraction of the internal jugular vein. 4) The operation without internal shunt made the technique simple and shortened the operation time. 5) Interlacing vascular suture with microsurgical technique prevented narrowing or shortening of the carotid artery. 6) We used a pair of small needle holders with teeth for anterior wall suture. We could pick up the adventitia easily and exactly, and did not need change of the needle holding with these instruments. 7) Others: The clamping time ranged 15-45 minutes without any neurological deficits.

Carotid Arteries↗
PubMed1980

[A study on histological changes of the intracranial arteries after permanent clipping or ligation.--Part II. Autopsy cases of aneurysmal neck clipping (author's transl)].

Local changes after neck clipping of cerebral aneurysms were studied histopathologically with light microscope in 12 autopsy cases. Seven of them were treated surgically with Yaşargil clips and 5 were treated with Heifetz clips. Another 5 aneurysmal cases, who died without surgery, were studied as the control group. At autopsy, the circle of Willis was fully exposed and meticulously dissected, and the clipped aneurysm was removed en bloc and embedded whole into a paraffin block after the aneurysm clip was removed. The specimen was examined histopathologically in longitudinal serial sections. Time interval between the operation and autopsy ranged from 6 days at the shortest to 11 months at the longest. All cases were congenital berry aneurysms, which showed defects of the tunica media and the internal elastic lamina. The arterial wall between the blades of aneurysm clip showed segmental arterial wall necrosis in 4 (47%) out of 7 cases in the Yaşargil clip group, and in all 5 cases (100%) in the Heifetz clip group. The necrotic change was the strongest at both edges of the blades of the aneurysm clip in the Yaşargil clip group, whereas in the Heifetz clip group the worst changes was found at the mid-convexity of the blades. This is probably due to the different shape and width of the blade of these aneurysm clips. The blade of the Heifetz clip is wider than the blade of the Yaşargil clip, and its convex, almost cylindrical surface is turned toward the vessel, causing a wider ischemic area of the arterial wall with the strongest closing force at the mid-convexity. In the Yaşargil clip group, the degree of arterial wall necrosis was well correlated to the time interval after the clipping. The Heiftz clip group showed arterial wall necrosis even within the 7 days following the operation, and the degree of the necrosis did not show a correlation to the time interval. Definite reactive granulation tissue was not observed until 1 month after the operation, and thereafter the degree of granulation in both groups was proportional to the time interval after the operation. After 3 months following the operation, the blades of the aneurysm clips were covered completely with the granulation tissue and it seemed impossible for the aneurysm clip to slip out at this stage. Up to 14 days after the operation, the aneurysmal lumen was filled with mural, red thrombus and irregular intimal proliferation. After one month following the operation, this was filled with diffuse massive intimal thickening and organized thrombus. After 3 months, intimal thickening filled the aneurysmal lumen almost completely.

Adult↗