Clinical results of extracranial-intracranial bypass surgery in patients with hemodynamic cerebrovascular disease. 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 for symptomatic carotid occlusion and haemodynamic impairment. [Spinal cord electric stimulation vs. femoro-distal bypass in critical ischemia of the legs. Preliminary results in a randomized prospective study]. 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. Randomized study of carotid angioplasty and stenting versus carotid endarterectomy: a stopped trial. Cerebral dysfunction after coronary artery bypass grafting done with mild or moderate hypothermia. Risk of retinal microembolism after off-pump and on-pump coronary artery bypass surgery.
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. 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. 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. In the last few years the development of new and improved surgical procedures caused a more aggressive approach, by femoro-distal bypass, to the limb affected by critical ischaemia. A good surgical result is related to the crural vessel patency, the presence of an adequate autologous vein and the possibility to visualize inframalleolar and foot arteries by selective angiograms. Should all these conditions not be present, an outflow procedure might be at high risk for failure. On the other hand, several studies show that SCS relieves rest pain and improves trophic lesion healing although there is no evident increase in peripheral blood flow, but these studies refer to heterogeneous non-randomized patients. In order to evaluate the effectiveness of SCS compared to distal arterial reconstruction, we started this prospective and randomized study. In a period of 15 months, 12 patients affected by critical limb ischaemia at 4th stage of Fontaine with angiographic multilevel distal lesions were randomised for SCS (7 cases: group A) and distal bypass (5 cases: group B). The result of the therapy was judged as good or fair when either complete or evident pain regression and trophic lesion healing were obtained; otherwise the result was considered as poor. Actually the study is in progress, the follow-up is partial (3-12 months), the results are preliminary. In the patients of group A the results were good or fair in 5 cases (72%) and poor in 2 (28%). In the patients of group B the results were good or fair in 2 cases (40%) and poor in 3 (60%).(ABSTRACT TRUNCATED AT 250 WORDS) 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. Carotid angioplasty (CA) has been suggested to be a safer and more cost-effective alternative to carotid endarterectomy (CEA) in the management of symptomatic severe internal carotid artery (ICA) disease.
                The study was conducted as a prospective consecutive randomized trial of CEA versus CA for symptomatic severe ICA disease in a university teaching hospital. All patients were assessed before and after surgery by a neurologist. The study consisted of 23 patients with focal carotid territory symptoms and severe ICA stenosis (> 70%) who were randomized to either CEA or CA. However, only 17 had received their allocated treatment before trial suspension. CEA with patching or CA with stenting were used as interventions. The main outcome measures were death or disabling or nondisabling stroke within 30 days.
                All 10 CEA operations proceeded without complication, but 5 of the 7 patients who underwent CA had a stroke (P=.0034), 3 of which were disabling at 30 days.
                After referral, the Data Monitoring Committee invoked the stopping rule and the trial was suspended. The investigators and the Ethics Committee subsequently concluded that the trial could not be restarted--even in an amended format-primarily because of problems with informed consent. We review many of the ethical dilemmas encountered in the performance of this study. If future trials do suggest a selected role for CA, it is essential that both the inclusion and the exclusion criteria are fully documented. Ninety-nine patients undergoing elective coronary artery bypass grafting were enrolled in a prospective, randomized study to evaluate the incidence of cerebral dysfunction after "mild" or "moderate" hypothermia during cardiopulmonary bypass.
                Patients were evaluated before and after operation before hospital discharge and in some cases at follow-up at least 6 weeks later with a complete neurologic examination (85 patients) and a battery of standard neuropsychometric tests (86 patients).
                Postoperative changes detected by neurologic examination consisted of the appearance of new primitive reflexes in both groups. No statistically significant differences in incidence were found. The neuropsychometric performances of the two groups were statistically similar by either event-rate or group-rate analysis.
                There is no detectable difference in postoperative cerebral dysfunction in patients undergoing coronary artery bypass grafting who are supported by cardiopulmonary bypass with either mild or moderate hypothermia. In order to investigate the neuroprotective efficacy of off-pump coronary artery bypass surgery (OPCAB) over conventional on-pump coronary artery bypass surgery (CCAB), we have performed a prospective randomized study evaluating retinal circulation changes after OPCAB and CCAB.
                Twenty patients were randomized to OPCAB or CCAB. Retinal fluorescein angiography and 60 degrees black-and-white as well as color fundus photographs of both eyes of each patient were taken 1 to 24 h before and 5 to 6 days after the operation.
                Patients undergoing OPCAB had more severely stenosed carotid arteries (P=0.075), higher incidence of slightly diseased ascending aorta (P=0.087) and higher Northern New England Cardiovascular Study Group stroke risk score (P=0.075). Neither stroke nor transient ischemic attack occurred postoperatively in these patients. Inferotemporal retinal arterial embolization and microinfarction was detected in one patient after CCAB, but in none of the OPCAB group.
                The risk of retinal embolism can be minimized by the use of OPCAB and, most likely, by adequate epiaortic ultrasound scanning of the ascending aorta and avoiding clamping in case of severely diseased aorta.
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.