Long-term follow-up in 257 ICA occlusion: comparison between EIAB-treated and untreated patients. Surgical and nonsurgical treatment of total carotid artery occlusion. Medical versus surgical treatment of patients with cerebrovascular insufficiency. A retrospective comparative study. Long-term assessment of cerebral perfusion following STA-MCA by-pass in patients. Comparison of the clinical results of STA-MCA anastomosis and the medical treatment in the cerebral low perfusion patients with viable brain tissue. Evaluation of vasomotor reactivity by transcranial Doppler and acetazolamide test before and after extracranial-intracranial bypass in patients with internal carotid artery occlusion. Superficial temporal artery--middle cerebral artery anastomosis for acute cerebral ischemia: the effect of small augmentation of blood flow. Measurements of regional cerebral blood flow in patients following superficial temporal artery-middle cerebral artery anastomosis. Clinical results of extracranial-intracranial bypass surgery in patients with hemodynamic cerebrovascular disease. STA-MCA bypass for symptomatic carotid occlusion and haemodynamic impairment. Treatment of the totally occluded carotid artery. Overall management of vascular lesions considered treatable with extracranial-intracranial bypass: part 1. Internal carotid occlusion. Long-term clinical and neurophysiological effects of reconstructive vascular surgery for cerebral ischemia. Evaluation of extracranial-to-intracranial bypass surgery using iodine 123 iodoamphetamine single-photon emission computed tomography. Failure of extracranial-intracranial arterial bypass to reduce the risk of ischemic stroke. Results of an international randomized trial. The EC/IC Bypass Study Group. STA-MCA bypass surgery for internal carotid artery occlusion--comparative follow-up study. [JET study (Japanese EC-IC Bypass Trial)]. Perfusion MRI before and after acetazolamide administration for assessment of cerebrovascular reserve capacity in patients with symptomatic internal carotid artery (ICA) occlusion: comparison with 99mTc-ECD SPECT.
The purpose of this paper is to estimate the real value of the Extra-Intracranial Arterial Bypass (EIAB) in preventing or reducing further and more catastrophic ischaemic events in patients suffering from an Internal Carotid Artery (ICA) occlusion. 257 patients, suffering from ICA occlusion, are considered retrospectively: 122 of them submitted to EIAB and 135 medically treated or untreated. In both groups, homogeneous by sex, age, neurological grading distribution and length of follow-up, the following parameters were considered: the incidence of ischaemic recurrences during the follow-up period; the characters of the recurrences with particular reference to the fatal stroke; the rate of ischaemic events per year. The comparison between the outcome in surgically treated patients and in "untreated" ones indicates that the EIAB can be effective in preventing or reducing the ischaemic recurrences and the frequency of fatal stroke in TIA-, RIND, or stroke-patients suffering from ICA occlusion. The natural history of totally occluded internal and common carotid arteries was studied in 102 patients (109 arteries) with a 97 percent follow-up (mean 39.7 months.) Symptomatic occlusions occurred in 72.6 percent of the patients, the reconstructed group (46 patients) having a greater number of symptomatic vessels than the nonreconstructed group (63 patients) (p less than 0.05). Contralateral disease was encountered in 46 percent. Initial mortality was 5 percent. Twenty patients (19.6 percent) were dead at the time of follow-up. Half of these deaths were from strokes and three fourths from atherosclerotic causes. Persisting neurologic symptoms were present in 14 percent of the patients and new events occurred in 5 percent. Fifteen percent of initially asymptomatic vessels were symptomatic at last follow-up. Twenty-one percent of the symptomatic occluded vessels were symptomatic on follow-up, 16 percent being in the reconstructed group and 26 percent in the nonreconstructed group. Report on a series of patients suffering from cerebrovascular insufficiency caused by stenosis and/or occlusion of one or several major cerebral vessels. The patients were divided in two groups, one being medically treated with anticoagulants, the other operated on either a carotid artery thrombosis by thromboendarterectomy or occlusion treated with an extracranial-intracranial arterial bypass. Results after a follow-up period of 1-3 years are compared and discussed in view of the recent literature. A prospective study of mean hemispheric cerebral blood flow (CBF) correlated with clinical status has now been completed for the past 54 months. Thirty-eight patients underwent superficial temporal to middle cerebral artery (STA-MCA) by-pass. They were compared with 22 patients with similar arteriographic lesions and clinical symptoms, treated medically throughout the same interval of time. Assignment to either treatment group was not randomized but depended solely on choice of patient or treating physician. Both groups were matched for age, clinical symptoms, angiographic abnormalities, and CBF values. All patients had proximal occlusion of one internal carotid artery or intracranial occlusive disease of the internal carotid or middle cerebral arteries. CBF measurements and clinical evaluations were repeated at regular intervals up to 54 months following surgery or institution of medical treatment. Mean follow up interval after STA-MCA by-pass was 28.7 months and for medical treatment was 29.7 months. Mean hemispheric CBF values for STA-MCA patients became significantly increased 2 weeks after operation. After that, CBF flow values decreased. At 24 months after surgery, flow values for surgically treated patients were significantly higher than among those treated medically, although there were no differences in flow values between the two groups at 3, 6, 12, 36 and 48 months. Prospective clinical evaluations after STA-MCA by-pass were as follows: 12 (32%) improved with cessation of TIAs and/or neurological improvement, 16 (42%) remained unchanged, 7 (18%) deteriorated (due to new or recurrent strokes) and 3 (8%) expired. Clinical results were the same for medical treatment: 6 (27%) improved, 10 (46%) unchanged, 4 (18%) deteriorated due to new or recurrent stroke, and 2 (9%) expired. The long-term clinical results of STA-MCA anastomosis as well as the medical treatments were compared in cases that were confined as having a focal cerebral perfusion deficit with viable brain tissue, based on either the drug induced EEG and evoked potential test (DEE test) and/or by positron emission tomography (PET). The criteria for viable cerebral tissue was determined by the following four conditions: (1) functional reversibility could be confirmed by the DEE test; (2) a haemodynamic process could be found in the DEE test; (3) a haemodynamic compromise could be confirmed in the PET study; (4) misery perfusion could be confirmed in the PET study. From 1975 to 1989, 55 cases were confirmed as having viable brain tissue according to the DEE test and the PET study. Of the 55 cases, bypass surgery was performed on 35. Conservative treatment was given to the other 20 cases. There were 3 cases of perioperative neurological deterioration. One was permanent and the other 2 were transient. Results of the long-term follow up are as follows, Ipsilateral attack: 1 case (2.0%) received surgery, and 7 cases (35%) received conservative treatment. Re-attack in the contralateral or posterior circulation: 6 cases (17.2%) received surgery, and 1 case (5%) received conservative treatment. Seventy-seven per cent of the surgical cases improved or had no change in the final functional status, while only 55% of the conservative group either improved or showed no change. The incidence of ipsilateral cerebral ischaemia was significantly low in the surgical group. Contralateral and/or posterior circulation ischaemia tended to be high in this group, however.(ABSTRACT TRUNCATED AT 250 WORDS) The aim of this trial was to evaluate the effectiveness of extracranial-intracranial bypass with respect to vasomotor reactivity in patients with internal carotid artery occlusions and absent vasomotor reactivity, comparing them with a control group treated conservatively.
                To test vasomotor reactivity in 104 patients with unilateral occlusion of the internal carotid artery, we measured blood flow velocity in the middle cerebral artery by transcranial Doppler sonography both at rest and after injection of acetazolamide. Among the 39 patients who failed to show increased mean blood flow velocity after the acetazolamide test distal to an occluded internal carotid artery by greater than or equal to 10%, 14 subjects subsequently underwent extracranial-intracranial bypass surgery (group A) and 14 age- and sex-matched subjects in whom no such procedure was done composed the control group (group B). Follow-up examinations were performed 3-6 months postoperatively and in the control group 3-6 months after initial examination.
                Baseline values of the mean blood flow velocity at rest on the affected side were reduced in both groups compared with the contralateral healthy side (group A, 46.0 +/- 15.1 cm/sec; group B, 48.1 +/- 16.7 cm/sec) and revealed only a marginal increase after acetazolamide. The contralateral side showed a normal blood flow velocity at rest and an adequate response to acetazolamide in both groups. On the follow-up examination group A demonstrated a normalized vasodilatory capacity. Blood flow velocity increased significantly after acetazolamide from 41.9 +/- 13.1 cm/sec to 53.5 +/- 16.0 cm/sec (p less than 0.002). In group B, the compromised vasomotor reactivity remained unchanged.
                Our results demonstrate that transcranial Doppler sonography together with the acetazolamide test can identify subjects with reduced vasomotor reactivity distal to an occluded internal carotid artery, who may improve hemodynamically by an extracranial-intracranial bypass. In order to evaluate the effectiveness of acute cerebral revascularisation, we conducted a review of 70 patients with acute arterial occlusion or severe stenosis. Of these, 35 underwent emergency superficial temporal artery--middle cerebral artery (STA-MCA) anastomosis (surgical group) and the other 35 were treated conservatively (non-surgical group) at different times. Statistical analysis indicated that the two groups were homogeneous for the prognostic indicators. Seven days after admission, neurological symptoms and signs improved in 43% of patients in the surgical group and in 29% of the non-surgical group, however, this difference was not significant. The ratios of independent life at 3 months were 51% and 31%, respectively (not significant). Subgroup analyses indicated that final outcomes for patients with mild to moderate paresis on admission were significantly better in the surgical group than in the non-surgical group (94% vs. 53%, p < 0.01). The ratios of haemorrhagic infarction, neurological worsening, and mortality were comparable between the two groups. Time of ischaemia is a less important factor in the criteria for surgical selection. Acute revascularisation in selected patients does improve a natural course and could be a therapeutic option for acute cerebral ischaemia. Regional cerebral blood flow (rCBF) was measured using the inhalation xenon 133 technique in 25 patients undergoing superficial temporal artery-middle cerebral artery anastomotic surgery. rCBF was measured once before and 3 times after operation, up to one year. Data were compared to rCBF-measurement in 16 patients with similar diagnosis, age distribution and medical treatment except that they were not operated on. Mean rCBF increased in some patients 4-8 weeks after surgery on the ipsilateral side. Compared to the non-surgical patients mean rCBF at this time was higher over both hemipheres. However, taking a flow increase of at least 15% as being significant only one third of all patients presented with a significant flow increase. Regional flow data indicated that the amount of hypoaemic areas in the operated side decreased significantly. Areas with normal flow increased in number from CBF 1 to the 4-8th week. There were no significant changes in flow distribution over the contralateral side. It was concluded that extracranial-intracranial bypass improves flow in patients with TIA or PRIND respectively only in some cases. Also a return to normal flow distribution can be achieved in only a few cases. The importance of hemodynamic factors in the pathogenesis and treatment of cerebrovascular disease remains uncertain. The extracranial-intracranial (EC-IC) bypass trial has been criticized for failing to identify and separately analyze those patients with chronic reduction in regional cerebral perfusion pressure (rCPP) who might be most likely to benefit from surgery. Positron emission tomography (PET) measurements of regional cerebral blood flow (rCBF) and blood volume (rCBV) were performed on 29 patients with symptomatic occlusion or intracranial stenosis of the carotid arterial system prior to undergoing EC-IC bypass surgery. Twenty-four patients had evidence of reduced rCPP (increased rCBV/rCBF ratio) distal to the arterial lesion. Of 21 patients who survived surgery without stroke, three suffered ipsilateral ischemic strokes during the 1st postoperative year. A nonrandomized control group of 23 nonsurgical patients' with similar clinical, arteriographic, and PET characteristics experienced no ipsilateral ischemic strokes during the 1st year following PET. Based on these results in 44 patients, the probability that successful surgery reduces the occurrence of ipsilateral ischemic stroke 1 year later was calculated. This probability ranged from 0.045 for a 50% reduction to 0.168 for a 10% reduction. Thus, there was little evidence to suggest that measurements of cerebral hemodynamics can identify a group of patients who would benefit from EC-IC bypass surgery. Patients with carotid artery occlusion and haemodynamic insufficiency have a high risk of stroke. Cerebral revascularization surgery improves cerebral blood flow, but it remains unclear whether this reduces the risk of stroke. This study assesses the long-term outcome of patients undergoing superficial temporal artery to middle cerebral artery (STA-MCA) bypass for symptomatic carotid occlusion. The long-term clinical follow-up and haemodynamic reserve, measured by (99)Technetium single photon emission computed tomography (Tc99 SPECT) scan with acetazolamide challenge, were reviewed for 19 consecutive patients before and after STA-MCA bypass. The stroke rate after bypass surgery was 8% per year. In patients waiting for surgery, the stroke rate was 18% per year. Cerebral perfusion assessed with SPECT scan improved in 88% of patients. These results are consistent with the high risks of haemodynamic infarction in untreated patients and a benefit from revascularization surgery. The percentage annual stroke risk compares favourably with an 18% rate reported for patients with internal carotid artery occlusion and impaired cerebrovascular reserve. Thirty-four patients, each with a totally occluded common or internal carotid artery, were treated over a 15-year period. Seventeen patients were treated nonsurgically, 17 underwent surgery. There were four patients in the nonsurgical group and six patients in the surgical group who were followed up until death. The average time span from diagnosis of carotid occlusion until death was 4.75 years in the nonsurgical group and 4.52 years in the surgical group. In the nonsurgical group, recurrent symptoms of cerebrovascular accident (CVA) developed in 60% of the patients available for extended follow-up. In contrast, 14% of the patients operated on and available for follow-up had recurrent symptoms, and no CVAs occurred postoperatively. From our data, we concluded that the stroke-free interval is improved, whereas survival is unaffected in the surgically treated patient. Endarterectomy of a contralateral stenotic carotid artery is particularly successful in achieving this reduction in morbidity. From 1973 to 1979, 49 patients with internal carotid occlusion were evaluated and treated. Eighteen of 49 (37%) presented with transient ischemic attack/prolonged reversible ischemic neurological deficit, 14 of 49 (29%) presented with mild completed stroke, 13 of 49 (27%) presented with severe completed stroke, and 4 of 49 (8%) were asymptomatic. Surgical treatment consisting of extracranial-intracranial (EC-IC) bypass, internal carotid stump reconstruction and endarterectomy to open the occlusion, contralateral endarterectomy for carotid stenosis opposite the occlusion, and iatrogenic carotid occlusion with EC-IC bypass was carried out on 22 (45%) patients considered at risk for ischemia based on angiographic evidence of poor collateral circulation and potential sources of emboli. Medical treatment consisting of anticoagulants or anti-platelet aggregation agents was used in 27 (55%) patients with good collateral circulation. By 6 weeks after the initiation of treatment, 10 of 49 (20%) reached end points of new strokes and death. By an average of 3 years after treatment began, 30 of 49 (61%) reached the same end points. The results suggest that new ischemic events in the distribution of the occluded carotid artery occur infrequently if the angiographic study shows adequate collateral circulation to the ischemic territory at risk. Surgical revascularization should be reserved for patients with (a) recurrent ischemic events after the diagnosis of carotid occlusion or (b) poor collateral circulation. 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. Eleven patients with occlusive cerebrovascular diseases were imaged with N-isopropyl-p-I-123 iodoamphetamine. Preoperative and postoperative single-photon emission computed tomography was performed in 10 patients undergoing extracranial-to-intracranial bypass procedures. New images were reconstructed from the two images obtained on the different days by superimposition and division in each pixel to get the ratio of cerebral perfusion change. All patients with bypass procedures had an increase in cerebral blood flow in the affected areas, and nine of 10 had an increase in cerebral blood flow in the contralateral cortex. There was no increase in cerebral blood flow in one case with no operation. Neither our procedure nor the results in this small series prove that recovery of function is due to an increase in blood flow, but we believe this is the case. To determine whether bypass surgery would benefit patients with symptomatic atherosclerotic disease of the internal carotid artery, we studied 1377 patients with recent hemisphere strokes, retinal infarction, or transient ischemic attacks who had atherosclerotic narrowing or occlusion of the ipsilateral internal carotid or middle cerebral artery. Of these, 714 were randomly assigned to the best medical care, and 663 to the same regimen with the addition of bypass surgery joining the superficial temporal artery and the middle cerebral artery. The patients were followed for an average of 55.8 months. Thirty-day surgical mortality and major stroke morbidity rates were 0.6 and 2.5 per cent, respectively. The postoperative bypass patency rate was 96 per cent. Nonfatal and fatal stroke occurred both more frequently and earlier in the patients operated on. Secondary survival analyses comparing the two groups for major strokes and all deaths, for all strokes and all deaths, and for ipsilateral ischemic strokes demonstrated a similar lack of benefit from surgery. Separate analyses in patients with different angiographic lesions did not identify a subgroup with any benefit from surgery. Two important subgroups of patients fared substantially worse in the surgical group: those with severe middle-cerebral-artery stenosis (n = 109, Mantel-Haenszel chi-square = 4.74), and those with persistence of ischemic symptoms after an internal-carotid-artery occlusion had been demonstrated (n = 287, chi-square = 4.04). This study thus failed to confirm the hypothesis that extracranial-intracranial anastomosis is effective in preventing cerebral ischemia in patients with atherosclerotic arterial disease in the carotid and middle cerebral arteries. Sixty-three patients with internal carotid artery occlusion manifesting as transient ischemic attack or minor stroke received superficial temporal artery-middle cerebral artery bypass surgery and medical treatment (n = 27) or medical treatment only (n = 36). Long-term follow-up showed that there was no significant difference in the outcomes. However, positron emission tomography studies suggested that patients with misery perfusion in the chronic stage benefited from extracranial-intracranial bypass surgery. nan Impaired cerebral vascular reserve (CVR) in patients with symptomatic internal carotid artery (ICA) occlusion is regarded as a possible indication for performing extra-/intracranial (EC/IC) bypass surgery. As perfusion MR imaging (MRI) can demonstrate cerebral haemodynamics at capillary level, our hypothesis was that perfusion MRI could be used in these patients for the evaluation of CVR following acetazolamide challenge in a similar way to single photon emission CT (SPECT) and might provide additional information.
                Enrolled in the study were 12 patients (mean age 61.3 years; 11 male, 1 female) with symptomatic unilateral ICA occlusion proven by angiography. Both perfusion MRI and 99m-technetium-ethyl-cysteinate dimer ((99m)Tc-ECD) SPECT were performed before and after injection of acetazolamide (Diamox ,1000 mg i.v.). CVR parameters including regional cerebral blood flow (rCBF) and volume (rCBV), and mean transit times (MTT) were measured by perfusion MRI.
                The patients with impaired CVR proven by SPECT (n = 9) had a negative mean rCBF increment (-46.52%), negative rCBV increment (-13.5%) and delayed MTT (mean +2.98 s), respectively, on the occluded side (Student's t-test all P < 0.05). The patients with sufficient CVR (n = 3) had a mean rCBF increment of 1.2%, a decrement of rCBV of 10.46%, and a mean MTT shortening of 0.27 s following the acetazolamide injection.
                Perfusion MRI before and after acetazolamide administration compares favourably with (99m)Tc-ECD SPECT for the detection of impaired CVR. The impact that perfusion MRI studies (before and after acetazolamide administration) might have on the treatment decision in patients with ICA occlusion has yet to be determined by a prospective study.
EC/IC bypass surgery in patients with sCAO disease was neither superior nor inferior to medical care alone. However, most studies included patients irrespective of their cerebral haemodynamics. Participation in an ongoing RCT, which is restricted to patients with impaired haemodynamics, is recommended as these patients might benefit from bypass surgery.