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. A randomized trial of intraoperative autotransfusion during aortic surgery. Neuropsychologic and quality-of-life outcomes after coronary artery bypass surgery with and without cardiopulmonary bypass: a prospective randomized trial. Effects of hypothermic and normothermic cardiopulmonary bypass on brain oxygenation. Long-term follow-up in 257 ICA occlusion: comparison between EIAB-treated and untreated patients. Retinal and cerebral microembolization during coronary artery bypass surgery: a randomized, controlled trial. Comparison of the clinical results of STA-MCA anastomosis and the medical treatment in the cerebral low perfusion patients with viable brain tissue. STA-MCA bypass surgery for internal carotid artery occlusion--comparative follow-up study. Assessment of neurocognitive impairment after off-pump and on-pump techniques for coronary artery bypass graft surgery: prospective randomised controlled trial. Off-pump coronary bypass operations significantly reduce S100 release: an indicator for less cerebral damage?
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. The net benefit of routine intraoperative autotransfusion (IAT) in patients undergoing elective infrarenal aortic surgery was studied.
                One hundred patients undergoing abdominal aortic aneurysm (AAA) repair (n = 50) or aortofemoral bypass (AFB) for occlusive disease (n = 50) were randomized to IAT and control groups. This experience accounted for 58% of patients undergoing aortic surgery during the 16-month study period.
                IAT and control groups were balanced for preoperative demographics, disease (50:50 split of AFB:AAA in each group), and risk factors. There were no significant differences between patients randomized to IAT and control patients in estimated blood loss (EBL), allogeneic blood transfusion (units administered intraoperatively, postoperatively, and total), proportion of patients not receiving allogeneic blood (34% of patients randomized to IAT and 28% of control patients), postoperative hemoglobin/hematocrit levels, and complications. IAT did not reduce allogeneic blood transfusion among all patients undergoing aortic surgery nor in any subgroups that might be more likely to benefit, such as those undergoing AAA repair, those with 1000 mL or more EBL, and those receiving larger volumes of IAT-processed blood.
                We could find no net benefit of IAT in patients undergoing elective, infrarenal aortic surgery. The objective of this study was to compare neuropsychologic and quality-of-life outcomes of patients undergoing off-pump coronary artery bypass surgery to those undergoing coronary artery bypass graft surgery using conventional cardiopulmonary bypass.
                A prospective randomized trial of coronary artery bypass graft surgery with and without the use of cardiopulmonary bypass.
                A cardiothoracic surgery unit at a tertiary hospital.
                Sixty-six patients undergoing coronary artery bypass graft surgery and a control group of 50 participants not undergoing cardiac surgery.
                Patients were randomized to receive coronary artery bypass graft surgery with cardiopulmonary bypass or randomized to coronary artery bypass graft surgery without the use of cardiopulmonary bypass.
                The proportions of neuropsychologic deficits and improvement in quality-of-life were comparable regardless of whether patients were randomized to receive off-pump coronary artery bypass graft surgery or conventional coronary artery graft surgery with cardiopulmonary bypass.
                Patients receiving coronary artery bypass grafts without cardiopulmonary bypass did not show fewer cognitive deficits or greater improvement in quality of life. In this study, we assessed the effects of normothermia and hypothermia during cardiopulmonary bypass (CPB) both on internal jugular venous oxygen saturation (SjvO2) and the regional cerebral oxygenation state (rSO2) estimated by near infrared spectroscopy (NIRS).
                Thirty patients scheduled for elective coronary artery bypass graft surgery (CABG) were randomly divided into two groups. Group 1 (n = 15) underwent surgery for normothermic (> 35 degrees C) CPB, and group 2 (n = 15) underwent surgery for hypothermic (30 degrees C) CPB, and alpha-stat regulation was applied. A 4.0-French fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor the SjvO2 value. To estimate the rSO2 state, a spectrophotometer probe was attached to the mid-forehead. SjvO2 and rSO2 values were then collected simultaneously using a computer.
                Neither the cerebral desaturation time (duration during SjvO2 value below 50%), nor the ratio of the cerebral desaturation time to the total CPB time significantly differed (normothermic group: 18+/-6 min, 15+/-6%; hypothermic group: 17+/-6 min, 13+/-6%, respectively). The rSO2 value in the normothermic group decreased during the CPB period compared with the pre-CPB period. The rSO2 value in the hypothermic group did not change throughout the perioperative period.
                These findings suggest that near infrared spectroscopy might be sensitive enough to detect subtle changes in regional cerebral oxygenation. 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. We sought to compare the effects on ophthalmic function of coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) and off-pump (OPCAB) grafting and to investigate whether retinal microvascular damage is associated with markers of cerebral injury.
                Retinal microvascular damage was assessed by fluorescein angiography and color fundus photography. Ophthalmic function was tested by the logarithm of the minimum angle of resolution visual acuity (VA), and cerebral injury, by transcranial Doppler ultrasound-detected emboli and S100 protein values. Twenty patients were randomized. Fluorescein angiography and postoperative VA could not be obtained for 1 CABG-CPB patient. Retinal microvascular damage was detected in 5 of 9 CABG-CPB but in none of 10 OPCAB patients (risk difference, 55%; 95% confidence interval [CI], 23% to 88%; P=0.01). Color fundus photography detected microvascular damage in 1 CABG-CPB patient but in no OPCAB patients; this lesion was associated with a field defect, which remained after 3 months of follow-up. There was no difference in postoperative VA. Doppler high-intensity transient signals (HITS) were 20.3 times more frequent in the CABG-CPB than in the OPCAB group (95% CI, 9.1 to 45; P<0.0001). Protein S100 levels were higher in the CABG-CPB than in the OPCAB group 1 hour after surgery (P<0.001). HITS were 14.7 times more frequent (95% CI, 3.5 to 62; P=0.001) and S100 level 2.1 times higher (95% CI, 1.3 to 3.5; P=0.005) when retinal microvascular damage was present.
                The relative frequency of retinal microvascular damage between groups shows the extent to which the risk of cerebral injury is reduced with OPCAB. Imaging of part of the cerebral circulation provides evidence to validate markers of cerebral injury. 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) 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. To assess neurocognitive impairment after the off-pump and on-pump techniques for coronary artery bypass graft surgery in patients with triple vessel disease.
                Randomised controlled trial.
                University Hospital of Wales, Cardiff. Participants: 60 patients undergoing coronary artery bypass graft surgery for triple vessel disease prospectively randomised to the off-pump or on-pump technique.
                Change in scores in nine standard neuropsychometric tests administered preoperatively and at 1 and 10 weeks postoperatively.
                The on-pump group showed a significantly greater deterioration in scores for two and three tests at 1 week and 10 weeks postoperatively, respectively, than the off-pump group. The on-pump group also showed a significantly higher incidence of major deterioration in one of the tests both 1 week and 10 weeks postoperatively. The incidence of neurocognitive impairment at 1 week postoperatively was 27% (8 out of 30) in the off-pump group and 63% (19 out of 30) in the on-pump group (P=0.004); and at 10 weeks postoperatively was 10% (3 out of 30) in the off-pump group and 40% (12 out of 30) in the on-pump group (P=0.017).
                Off-pump coronary artery bypass graft surgery results in less neurocognitive impairment than the on-pump technique. Cardiac operations using extracorporeal circulation bear a risk of cerebral complications. The aim of our study was to investigate if off-pump operations without heart-lung machines can reduce cerebral injury.
                S100, a protein specific for cerebral tissue, was used as a marker for cerebral impairment in 108 randomized patients undergoing coronary bypass operation: 67 patients (group A) were operated on with extracorporeal circulation and cardioplegic cardiac arrest, and 41 patients (group B) underwent off-pump beating heart revascularization. Both groups were similar regarding age, sex, ejection fraction, and number of anastomoses. S100 levels were measured from induction of anesthesia until 24 hours after the operation.
                Data collection was 100% complete. There was no in-hospital death. Nonfatal myocardial infarctions occurred in 2 patients in group A, and 1 patient in group B required resternotomy for bleeding. There was no neurologic deficit in either group. S100 levels increased only slightly in the off-pump patients (group B), whereas in group A there was a sharp rise in S100 concentration during extracorporeal circulation, only returning to baseline 6 hours after the end of the operation. Peak S100 levels were four times higher in group A than in group B (2.1 microg/L versus 0.5 microg/L; p < 001).
                The results of our study suggest that perioperative cerebral impairment is reduced in cardiac operations without the use of extracorporeal circulation. Further large-scale studies are needed to show whether this result is reflected by fewer neurologic deficits.
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.