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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to clarify the effectiveness of extracranial- intracranial bypass in cases of vertebro-basilar occlusive disease, we investigated the operative complication, clinical course and follow-up study of 30 cases undergoing superficial temporal artery-superior cerebellar artery (STA-SCA) bypass surgery. Postoperative angiogram showed the patency of the anastomoses in all cases. No serious surgical complications were observed. The outcome on discharge was excellent, with no morbidity and one mortality which was due to cardiac infarction. In the follow-up study, there were four cases with ischemic symptoms, two with transient ischemic attack and two with completed stroke, one of which was a supratentorial infarction due to internal carotid artery occlusion and the other was a small infarction of pons. There were also two deaths due to cardiac infarction and diabetes mellitus. Favorable outcomes were obtained for the remaining cases. The present study suggests that, STA-SCA bypass, can be performed without surgical and systemic complications and used as an effective therapy for vertebrobasilar ischemia.
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PMID:Clinical analysis of STA-SCA bypass for vertebrobasilar occlusive disease. 175 11

In a series of patients with unilateral supratentorial ischemia, clinical scores and parameters derived from computer analysis of the EEG and from measurement of the CBF were determined in the first several weeks after the stroke. Seventeen of these patients underwent a carotid-endarterectomy and 15 a STA-MCA bypass operation. Matched control patients were selected from the remaining cases. All patients, including the controls, were eligible for vascular surgery. The measurements were repeated respectively 3 months and 3 years after the first examination. Clinical improvement occurred in all groups. The degree of these clinical changes was similar for operated and non operated cases. EEG changes indicated more improvement in the cases without surgery. Finally, the CBF was remarkably stable in all patients. The overall effects of reconstructive vascular surgery on the recovery after cerebral ischemia appeared to be negligible.
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PMID:Long-term clinical and neurophysiological effects of reconstructive vascular surgery for cerebral ischemia. 272 55

Regional cerebral blood flow (rCBF), using a single photon emission CT with Xe-133 inhalation method, was measured before and after the operation in 30 patients who underwent a superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. The purpose of this study is to assess the effect of STA-MCA anastomosis from the standpoint of hemodynamics and the results obtained were as follows: rCBF at rest increased after the operation, which was approximately 10% alterations and was localized in temporal region of operated hemisphere and frontal region of non-operated hemisphere respectively. rCBF during STA compression test after surgery decreased only in temporal region (anastomotic site) of operated hemisphere. This findings might indicate that blood flow via the bypass artery become to provide mainly to the confined area. CO2 reactivity was disturbed in 6 patients before operation, but it restored in 4 patients after operation. Autoregulation was also abolished in 8 patients before operation, but it restored in 6 patients after operation. In the group of severe degree of ischemia, however, autoregulation did not show the tendency to recover after the operation, whereas CO2 reactivity somewhat recovered. Angiographical retrograde filling which indicates collateral circulation reduced or disappeared in 12 out of 14 patients, in which postoperative rCBF in temporal region increased, in addition autoregulation and CO2 reactivity tended to recover after the bypass operation. These data mentioned above probably indicated the influences of CBF increase via the bypass artery. In summary, it might be concluded that the hemodynamic change such as disappearance of collateral circulation seen on angiography, additionally postoperative rCBF increase in anastomotic site seemed to be related to the restoration of these vascular responses such as CO2 reactivity and autoregulation in ischemic brain.
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PMID:[A study of regional cerebral blood flow before and after superficial temporal artery-to-middle cerebral artery anastomosis]. 310 86

Regional cerebral blood flow (rCBF) was measured with radiolabeled microspheres in a canine model of superficial temporal artery-middle cerebral artery (STA-MCA) bypass and acute ischemia. Ischemic zone flows in seven dogs with the bypass first closed and then open showed no significant contribution of bypass flow in the intact vascular system. Following acute proximal occlusion, rCBF was preserved by bypass flow. A significant flow decrease ensued when the bypass was then clipped, confirming the adequacy of the lesion and the protective effect of the bypass. Reopening the bypass after 15 minutes of ischemia restored 76% of the previous flow. This was a significant increase from the global ischemia values, and was not statistically different from preocclusive values. Preocclusion somatosensory evoked potentials (SSEP's) in these animals showed a consistent biphasic wave at 8 to 10 msec after stimulation. This wave, with some decrease in amplitude, was preserved by bypass flow following creation of the arterial lesion. Bypass clipping abolished these ipsilateral SSEP's. Variable return of SSEP's occurred following reopening of the graft, but the recordings never reached preischemic amplitudes. This experimental study shows that, in this model, a prophylactic bypass subjected to immediate demand (with no time for "maturation") can adequately augment cortical rCBF and is superior to delayed revascularization. The data lend theoretical support to placement of a prophylactic STA-MCA bypass prior to elective carotid artery sacrifice or in surgery where the risk of acute vascular injury is high.
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PMID:Effects of preexisting bypass graft on rCBF and SSEP's following acute stroke in dogs. 361 74

The retinal circulation of 35 patients (age, 30 to 71 years) with symptomatic internal carotid occlusion (22 cases) or severe inaccessible stenosis (13 cases) was studied both before and after superficial temporal to middle cerebral artery (STA-MCA) bypass surgery using ophthalmodynamometry (ODM) and intravenous fundus fluorescein angiography (IVFA). Ninety-four per cent of the patients were found preoperatively to have funduscopic findings or symptoms indicative of ocular ischemia. ODM values were abnormal preoperatively in 32 of 35 patients (91%), and improvement in ODM values for the ipsilateral eye was noted postoperatively in 25 patients (71%). ODM values obtained during the early (less than 3 months) and late (greater than 3 months) postoperative periods were significantly improved when compared to the preoperative values. IVFA values were abnormal in 25 of 29 patients (86%) preoperatively, and significant improvement was noted in 22 of 25 patients (88%) postoperatively. Preoperative patients with normal fundus examinations (10 cases) had significantly better values for IVFA and ODM than patients with venous stasis retinopathy. The findings of the study showed that STA-MCA anastomosis is beneficial in treating retinal ischemia secondary to ipsilateral severe inaccessible carotid artery stenosis or occlusion.
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PMID:Improvement in the retinal circulation after superficial temporal to middle cerebral artery bypass. 399 Sep 31

Regional cerebral blood flow and vasomotor reactivity were measured in 33 patients with surgically remediable hemispheric ischemia by the 133Xe inhalation method prior to superficial temporal to middle cerebral artery (STA-MCA) by-pass. Thirteen patients also underwent LCBF and L lambda measurements by the stable xenon CT method for comparison. Twenty-four had proximal occlusion of one or both internal carotid arteries, 9 had intracranial occlusive disease (4 internal carotid, 5 middle cerebral). Measurements were repeated at intervals up to 30 months following surgery and compared to measurements in a similar group (N = 13) treated medically. In the surgically treated group 22 patients had recurrent TIAs, of whom 12 also had minor residual neurological deficits from recent small cerebral infarctions with potential for recovery (RINDs) while the remaining 11 had RINDs without TIAs. After surgery 28 improved with cessation of TIAs and/or neurological recovery, 3 remained unchanged, 2 cases worsened. Compared to age-matched normal hemispheric F1 (gray matter) values, pre-operative F1 values in the STA-MCA group were reduced in both ischemic and opposite hemispheres. Ischemic regions showed imparied vasomotor reactivity to 5% CO2 or 100% O2 inhalation. After surgery, mean hemispheric F1 values increased + 12.8% on the by-pass side and + 10.5% on the contralateral side. Mean F1 increases reached a maximum 3 months after by-pass, most evident in ipsilateral frontal regions (+ 24.2%). Vasomotor reactivity did not significantly improve. Medically treated cases did not show similar F1 increases. Thirteen with carotid occlusive disease (8 with TIAs, 5 with small recent infarcts) underwent CT LCBF and L lambda measurements before and after STA-MCA by-pass. Cases with recent infarcts showed reduced LCBF and L lambda values which increased significantly after STA-MCA by-pass, however the total group operated upon showed only trends for CBF increases, probably due to large standard deviations encountered in serial measurements.
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PMID:Redistribution of cerebral blood flow following STA-MCA by-pass in patients with hemispheric ischemia. 714 91

We experienced a case of successful acute revascularization using a long vein graft. A 68-year-old man was admitted to our department due to transient ischemic attack of the left hemiparesis. CT scan showed no infarction, but PAO-SPECT revealed moderate hypoperfusion in the right ACA and MCA area. Cerebral angiography demonstrated right IC occlusion at its origin and moderate collateral circulation via leptomeningeal anastomosis from the PCA area, and via the external carotid system, especially directly from STA. But the STA was very narrow. Three days after admission, left hemiparesis appeared again and deteriorated severely. This time the hemiparesis persisted. Although MRI demonstrated little infarction in the right frontal lobe, we decided to carry out revascularization on the same day. Right saphenous vein was harvested for a graft because of the narrow STA. The facial artery and angular artery was selected as a donor and a recipient respectively, to avoid a clamp of the EC and a craniotomy of the STA running area. Finally we performed a facial artery-vein graft-angular artery (M4) bypass. The patient showed no complication and the left hemiparesis improved enough to allow the patient to walk by himself. Revascularization using vein graft is dangerous for acute ischemia due to the possibility of a complication such as brain edema and hemorrhagic infarction. The usual style of vein graft bypass is an EC-vein graft-M2 or M3 bypass. Using this style, high pressure inside the EC is carried intracranially.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A case of successful acute revascularization using a long vein graft]. 775 28

The accuracy of three-dimensional CT angiography (3D-CTA) for delineating atherosclerotic carotid stenosis was examined in comparison with digital subtraction angiography (DSA) in symptomatic patients. In cases undergoing carotid endarterectomy (CEA), the clinical usefulness of 3D-CTA for surgical planning was also evaluated in the light of intraoperative findings. From July 1992 to June 1995, 52 patients suffering from internal carotid ischemia and/or presenting carotid bruit were evaluated to detect carotid bifurcation stenosis by 3D-CTA. Shaded surface reconstruction (SSR) for three-dimensional display and maximum intensity projection (MIP) were employed in multiple projection to evaluate sites of stenosis. DSA was performed in 18 out of 31 patients having atherosclerotic carotid stenosis shown by 3D-CTA. MIP reconstructions accurately delineated sites of stenosis close to DSA and allowed precise depiction of ulcerated plaque and intramural calcification. The percentage of carotid stenosis was determined by comparing the narrowest point to the internal carotid artery (ICA) beyond the bulb on both 3D-CTA and DSA. Assessment of carotid stenosis was highly correlated between 3D-CTA and DSA (r = 0.987, p < 0.0001). In this series, 9 carotid arteries in 8 patients underwent CEA for severe stenosis. 3 patients with ICA occlusion and 1 patient with elongated severe stenosis underwent STA-MCA anastomosis. Using MIP reconstructions and two-dimensional original images it was found that ICA occlusion was apparently distinguished from high grade ICA stenosis. SSR provided valuable informations during CEA for atherosclerotic plaque regarding anatomical relationship with the internal jugular vein and bony structures. This advanced means of 3D-CTA can be adequate as a screening method to detect carotid stenosis in symptomatic patients and useful for surgical planning of CEA and post-operative follow-up examination.
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PMID:[Evaluation of carotid artery stenosis with three-dimensional CT angiography and surgical revascularization]. 893 67

Although parietal EDAS or STA-MCA anastomosis are effective in pediatric moyamoya disease, they do not adequately prevent ischemia in the frontal and occipital lobes. Some additional methods that can prevent ischemia in the frontal and occipital lobes are sometimes needed. We investigated whether EDAS using a frontal branch of the superficial temporal artery (frontal EDAS) or EDAS using the occipital artery (occipital EDAS) is preferable. Frontal or occipital EDAS was performed at 15 sites in seven patients with pediatric moyamoya disease. The outcome was estimated by angiography 3 months later, CT findings 3 months later, neurological findings during the follow up period and perioperative complications. The mean follow up period was 14 +/- 6 months after frontal or occipital EDAS. As results, good revascularization from frontal or occipital EDAS was shown in ten of fourteen surgical sites (71%) in angiography. None of the patients showed deterioration of symptoms after frontal or occipital EDAS during the follow up period. None of the patients developed surgical complications. In conclusion, multiple EDAS using the frontal branch of STA and the occipital artery is an effective and safe method for preventing ischemia in the frontal and occipital lobe in pediatric moyamoya disease.
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PMID:Multiple EDAS (encephalo-duro-arterio-synangiosis). Additional EDAS using the frontal branch of the superficial temporal artery (STA) and the occipital artery for pediatric moyamoya patients in whom EDAS using the parietal branch of STA was insufficient. 920 58

The Japanese EC-IC bypass trial (JET study) was established to evaluate the validity of MCA-STA anastomosis in intracranial arterial occlusive disease aiming at stroke prevention. This study must use an objective method to reliably estimate hemodynamic brain ischemia. We devised a method of objectively classifying the severity of hemodynamic ischemia using quantitatively analytical and display software, stereotactic extraction estimation for stereotactic brain coordinates and three-dimensional stereotactic surface projections (3D-SSP). We analyzed data from 16 patients registered in the JET study. Our method offers quantitative information and 3-dimensional displays of the CBF at rest and after Diamox challenge, vascular reserve and the severity of the hemodynamic brain ischemia. We compared the maximal projection counts with ROI data from tomographic images in the anterior commissure-posterior commissure plane. The maximal counts data correlated closely with the ROI data of rest and with Diamox SPECT images (both p < 0.0001). The slopes of the linear regression line were 1.15 and 1.12, respectively. The results of this study indicated that our method could simply and objectively evaluate the severity of impaired brain circulation. This procedure should support the evaluation of hemodynamic ischemia in the JET study although validation is required by several institutions using more study subjects.
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PMID:Three-dimensional display in staging hemodynamic brain ischemia for JET study: objective evaluation using SEE analysis and 3D-SSP display. 1507 79


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