PubMed Health⌕ Search

Biomedical subjects

B C Eikelboom

Publications and source records attributed to B C Eikelboom.

At least 19 recordsLinked to original sources
PubMed2003

MR angiography of the lower extremities with a moving-bed infusion-tracking technique.

PURPOSE: To assess the value of MR angiography (MRA) with automatic table movement in a consecutive series of patients with peripheral arterial disease. METHODS: Seventy-two patients underwent both conventional angiography (CA) and MRA for peripheral arterial occlusive disease. Both techniques were scored in a masked way. Consensus scoring for CA was compared with MRA scoring per observer. If there was a discrepancy in scoring of a segment on MRA and CA, the images were reviewed and a consensus arrived at. RESULTS: Observer A found 7.4% and observer B found 6.5% of the segments could not be analyzed on MRA. Observer A scored 11.4% dissimilar on MRA and CA, observer B 15.2%. In the aortoiliac arteries, this was mainly caused by stents and overestimation of stenoses; in the crural arteries it resulted from underestimation of the stenoses on MRA. Overall sensitivity and specificity for the aortoiliac, femoropopliteal and crural vessels were respectively 90% and 91%, 90% and 96%, 59% and 96% for observer A, and 85% and 91%, 84% and 89%, 68% and 85% for observer B. CONCLUSION: Although MRA of the lower extremities is a promising technique, improvements still need to be made. In particular, MRA below the knee is suboptimal for clinical use.

Adult↗
PubMed2003

Screening for asymptomatic internal carotid artery stenosis and aneurysm of the abdominal aorta: comparing the yield between patients with manifest atherosclerosis and patients with risk factors for atherosclerosis only.

OBJECTIVE: The purpose of this study was to investigate whether screening for internal carotid artery stenosis (ICAS) and aneurysm of the abdominal aorta (AAA) is indicated in patients with either manifest atherosclerotic disease or with only risk factors for atherosclerosis. STUDY DESIGN: Data were obtained for 2274 patients enrolled in the SMART study, an ongoing single-center, prospective cohort study of patients referred to our vascular center with manifest atherosclerotic disease (peripheral atherosclerotic disease [PAD]; transient ischemic attack [TIA], stroke, or ICAS; AAA; angina pectoris; or myocardial infarction [MI]) or with only risk factors for atherosclerosis (diabetes mellitus, hypertension, hyperlipidemia). The presence of ICAS or AAA was determined with duplex scanning and ultrasonography. RESULTS: The prevalence of ICAS 70% or greater is low in patients with risk factors for atherosclerosis only (1.8%-2.3%), intermediate in patients with angina pectoris or MI (3.1%), and highest in patients with PAD (12.5%) or AAA (8.8%). The prevalence of AAA 3 cm or larger is low in patients with risk factors for atherosclerosis only (0.4-1.6%), intermediate in patients with angina pectoris or MI (2.6%), and highest in patients with PAD (6.5%) or TIA, stroke, or ICAS (6.5%). The prevalence of AAA larger than 5 cm is low in all of the considered patient groups. The yield of screening can be optimized through selection on the basis of simple patient characteristics. In patients with PAD, selecting those with advanced age (>54 years) increased the prevalence of ICAS to 21.8%. Selecting patients with lower diastolic blood pressure (<83 mm Hg) increased the prevalence of ICAS to 17.9%. In patients with both advanced age and lower diastolic blood pressure, the prevalence of ICAS increased to 34.7%. Selecting patients with advanced age increased the prevalence of AAA 3 cm or larger to 9.6%. In patients with TIA, stroke, or ICAS, selecting those with advanced age increased the prevalence of AAA 3 cm or larger to 8.2%. Selecting patients with taller stature (>169 cm) increased the prevalence of AAA 3 cm or larger to 9.3%. In patients with advanced age and taller stature, the prevalence of AAA 3 cm or larger increased to 13.1%. CONCLUSIONS: Screening for ICAS should be limited to patients referred with PAD or AAA, especially those with advanced age or with low diastolic blood pressure. Screening for AAA should be limited to patients referred with PAD or with TIA, stroke, or ICAS, particularly those with advanced age or tall stature. In patients referred with angina pectoris or MI and those referred with only risk factors for atherosclerosis, screening cannot be endorsed.

Adult↗
PubMed2002

[One hundred years of the Association of Surgeons in the Netherlands. VII. Vascular surgery].

The Dutch Society for Vascular Surgery was founded in 1981, as the first daughter of the Association of Surgeons in the Netherlands. Twenty years of vascular surgery show a broad perspective. Aside from the traditional handywork--central vascular reconstruction, bypass surgery (especially in the legs), and carotid surgery--, there have been many developments. Operations are less invasive and vascular surgeons are cooperating more and more intensively with other medical disciplines, especially radiology. Examples are the endovascular treatment of abdominal aortic aneurysm, in which an endoprosthesis is inserted via minute incisions in the groin by the vascular surgeon and an (interventional) radiologist together. In addition, interventions such as percutaneous transluminal angioplasty and stenting as well as new diagnostic possibilities (e.g. MRA) strengthen the cooperation with the radiologists. The multidisciplinary approach is also extremely important in other areas. Vascular surgeons team up with internal-medicine specialists (diabetes, hypertension, lipid metabolism disorders, thrombotic syndromes, etc.), rehabilitation specialists and podotherapists (in cases of diabetic foot and amputation), vascular laboratory technicians (diagnostics and follow-up by means of doppler and duplex techniques), and neurologists (cerebrovascular diseases). In the vascular centres, patients are treated effectively by a multidisciplinary team that draws up a plan for diagnosis and treatment. The two-year postgraduate course in vascular surgery is one of the tools used to guarantee and improve the high standard of quality. To this end, cooperation within Europe in the European Society for Vascular Surgery and the development and organisation of European examinations in vascular surgery are also of the essence.

Angioplasty, Balloon↗
PubMed2002

Detection and treatment of claudication due to functional iliac obstruction in top endurance athletes: a prospective study.

BACKGROUND: Endurance athletes often have restrictions in flow in their iliac arteries during exercise. Such restrictions have previously been ascribed solely to intravascular lesions. We postulate that flow could also be restricted by functional kinking in the arteries, and that surgical release of these kinks might be an effective treatment. METHODS: We prospectively studied 80 endurance athletes who had complaints suggestive of flow restriction in the iliac arteries of one (n=74) or both (6) legs (total 92 legs). Using vascular diagnostic tools, we examined athletes while they were doing activities that often provoke flow restrictions. Restrictions were determined by measurement of systolic pressure in the ankle after exercise; peak systolic velocities were measured with echo-doppler. Kinks were detected with echo-doppler and magnetic-resonance angiography. When functional kinking was diagnosed as the cause of the restriction, the athlete was offered surgery to release the iliac arteries, as part of our prospective study. FINDINGS: We recorded flow restrictions in the iliac arteries of 58 of 92 (63%) legs. In 40 of these legs (69%), kinks were the most important cause of the restriction, making these legs suitable for surgical release. We operated on 23 of 58 (40%) legs. All athletes who had an operation subjectively improved. Maximum workload in a cycling test and ankle pressure significantly improved after the operation. 20 (87%) athletes were able to successfully return to their desired high level of competition. INTERPRETATION: Our sports-specific protocol is effective in detecting kinking of the iliac arteries as a cause for flow restriction in athletes who have few intravascular abnormalities when investigated with conventional vascular diagnostic tools. Surgical treatment directed at the kinking was less invasive and therefore a better alternative to vascular reconstruction in these athletes.

Adult↗
PubMed2002

Contaminants from the transplant contribute to intimal hyperplasia associated with microvascular endothelial cell seeding.

OBJECTIVES: seeding prosthetic grafts with fat-derived microvascular endothelial cells (MVEC) results not only in a non-thrombogenic EC layer, but also in intimal hyperplasia. Here we investigated incidence, composition, progression, and cause of this intimal hyperplasia. DESIGN: EPTFE grafts with MVEC were implanted as carotid interpositions in six dogs with 1 month, and in three dogs with 4, 8 and 12 months follow-up. Grafts seeded without cells, implanted in the contralateral carotid, served as a control. In another three dogs labelled cells were seeded to investigate the contribution of the seeded cells (2-3 weeks). MATERIALS AND METHODS: MVEC were isolated from the falciform ligament. Cells were pressure seeded on ePTFE grafts. Labelling was performed using retroviral gene transduction. The grafts were analysed with immunohistochemical techniques. RESULTS: after 1 month, all patent non-seeded grafts (5/6) showed fibrin and platelet deposition, and all patent seeded grafts (5/6) were covered with a confluent endothelial monolayer on top of a multilayer of myofibroblasts, elastin and collagen. After long term follow-up, all non-seeded grafts were occluded, all patent seeded grafts (4 and 12 months) were covered with an EC-layer with intimal hyperplasia underneath. The thickness of the intima did not progress after 1 month. Transduced cells were found in the endothelial monolayer, hyperplastic intima and luminal part of the prosthesis. CONCLUSIONS: MVEC seeding in dogs results in intimal hyperplasia in all patent grafts, which contains myofibroblasts. Contaminants from the transplant contribute to this intimal hyperplasia.

Animals↗
PubMed2002

Reduction of non-endothelial cell contamination of microvascular endothelial cell seeded grafts decreases thrombogenicity and intimal hyperplasia.

INTRODUCTION: fat derived microvascular endothelial cells (MVEC) seeded on prosthetic vascular grafts, improve patency in animals. Results in humans were disappointing, due to thrombogenicity and progressive intimal hyperplasia. Also in animals intimal hyperplasia was found. We postulate that contaminating cells present in the transplant are involved in the intimal hyperplasia. We developed a method to further purify human MVEC from 40-90%. Here we tested the effects of enrichment upon thrombogenicity and seeding-related intimal hyperplasia. METHODS: liposuction fat was enzymatically digested and centrifuged. To enrich MVEC, contaminating macrophages and fibroblasts were removed with dynabeads coated with macrophage- and fibroblast-specific antibodies. Thrombogenicity was assessed by measuring tissue factor and thrombomodulin activity, presence of endothelial nitric oxide synthase and via perfusion of the cells with whole blood. To investigate seeding-related intimal hyperplasia, PTFE grafts were seeded with the cells and cultured for 3 weeks. RESULTS: tissue factor activity of purified cells was reduced compared to nonpurified cells. Purified cells showed thrombomodulin activity and eNOS expression. Fragment 1+2 and Fibrinopeptide A generation after perfusion of purified cells were significantly lower than after perfusion of nonpurified cells, and only nonpurified cells were covered with platelets and fibrin. Prostheses seeded with nonpurified cells showed an EC monolayer above a multilayer of myofibroblasts, prostheses seeded with purified cells only showed a single EC monolayer. Mixing experiments with human umbilical cord EC (HUVEC) and fibroblasts showed that when more than 25% HUVEC were present a confluent EC layer was formed. When the amount of fibroblasts was 25% or less, no development of a subendothelial multilayer of myofibroblasts was found within 3 weeks. CONCLUSION: reduction of non-endothelial cell contamination of microvascular endothelial cell seeded grafts decreases thrombogenicity and might prevent seeding-related intimal hyperplasia.

Cell Separation↗
PubMed2002

The influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery in the Dutch BOA Study.

OBJECTIVE: Hyperhomocysteinemia has been identified as a risk factor for (cardio)vascular disease. Whether hyperhomocysteinemia contributes to graft failure after peripheral bypass surgery remains unclear. The present study evaluated the influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery. DESIGN: The present study was designed as a nested case-control study. METHOD: In this study (nested in the Dutch Bypass Oral anticoagulants or Aspirin Study), 150 patients with graft occlusion were each matched with two randomly selected controls with patent grafts (N = 299) from the same trial. Venous blood samples were drawn from cases and controls, and total plasma homocysteine (tHcy) was determined. Mean serum homocysteine levels and the presence of hyperhomocysteinemia (>95th percentile in healthy individuals) were compared between cases and controls. RESULTS: No significant differences were found between serum levels of homocysteine in patients with and without graft occlusion. The mean plasma homocysteine levels were 14.4 micromol/L and 14.9 micromol/L in the case and control groups, respectively. The resulting mean difference was -0.4 (95% confidence interval [CI], -1.8-0.9). The odds ratio of hyperhomocysteinemia was 0.81 (95% CI, 0.49-1.33). Adjustment for risk factors of graft occlusion did not change these results. CONCLUSIONS: Postoperative raised serum levels of homocysteine proved not to be a risk factor for graft occlusion after infrainguinal bypass grafting.

Aged↗
PubMed2001

[Spiral computed tomographic angiography as a substitute for intra-arterial angiography of aorta and its branches].

Until recently, intra-arterial angiography was the diagnostic method of first choice when pathology of the aorta or its branches was suspected. A disadvantage of this technique is that only the lumen of spaces with blood flow can be visualised and that the soft tissue surroundings remain (partly) invisible. Spiral computer tomographic angiography (CTA) has some major advantages compared with conventional angiography. The technique is less invasive and faster. Also, the soft tissue is imaged by CTA. In addition, computer reconstructions allow viewing from all directions without the limitations of overprojection. Spiral CTA is a suitable technique for imaging the thoracic part of the aorta: in case of dissection if transoesophageal echography is not available, in case of an aneurysm to determine the diameter and in case of rupture as a highly sensitive but not very specific examination technique. For imaging of the abdominal part of the aorta, spiral CTA may be considered. In case of an aneurysm or a possible rupture of this part of the aorta it is then possible to visualize the operation area and to choose the optimal approach. For the exclusion of stenoses in mesenteric arteries or in renal arteries, spiral CTA offers the advantage of non-invasivity. The technique is less suitable for demonstration of these stenoses and does not allow immediate intervention.

Adult↗
PubMed2001

Cerebral blood flow in relation to contralateral carotid disease, an MRA and TCD study.

OBJECTIVE: to describe redistribution of cerebral blood flow in patients with severe internal carotid artery (ICA) stenoses in relation to contralateral ICA disease. METHODS: sixty-six patients scheduled for carotid endarterectomy (CEA) were grouped according to severity of contralateral stenosis (<30% [group I]; 30-69% [group II]; 70-99% [group III]; occlusion [group IV]. Transcranial Doppler (TCD) and magnetic resonance angiography (MRA) investigations were performed preoperatively. RESULTS: TCD demonstrated a reversed flow in the contralateral anterior cerebral artery (A(1)segment) and ophthalmic artery in three-quarters of group IV patients (p <0.0001). Group IV patients also exhibited decreased blood flow velocity in the contralateral middle cerebral artery (p =0.001). MRA showed increased ipsilateral ICA and basilar artery (BA) blood flow volumes (Q-flows) in group IV patients when compared to the other groups (p <0.001). No changes in total Q-flow (ICAs+BA) were found. CONCLUSIONS: in patients considered for CEA, the severity of the contralateral ICA disease is an important determinant of the pattern of blood flow redistribution through the anterior communicating pathway and ophthalmic artery. Significant flow redistribution through the posterior communicating pathway occurs especially in patients with contralateral ICA occlusion.

Adult↗
PubMed2001

Flow redistribution in the major cerebral arteries after carotid endarterectomy: a study with transcranial Doppler scan.

PURPOSE: This open single-center prospective study aimed to determine the redistribution of blood flow within the circle of Willis and through collateral pathways after carotid endarterectomy. Blood flow velocity and flow direction in the major cerebral arteries were determined, both at rest and during CO(2) inhalation. METHODS: Carotid endarterectomy was performed in 148 patients with a 70% or greater diameter stenosis of the internal carotid artery while patients were under general anesthesia. Arteriotomy closure was done with a venous patch. Selective shunting was performed with an electroencephalogram. Baseline blood flow velocity of the basal cerebral arteries was measured by means of transcranial Doppler sonography preoperatively (within 1 week before surgery) and 3 months postoperatively. At the same times, cerebrovascular reactivity was calculated during CO(2) inhalation insonating both middle cerebral arteries. RESULTS: Baseline blood flow velocity in the ipsilateral middle cerebral artery hardly changed 3 months postoperatively, but there was a considerable redistribution of flow in the circle of Willis. This was characterized by a decrease in contribution from the contralateral hemisphere through the anterior communicating artery, reduced cerebropetal flow rates in the ophthalmic artery, and smaller contribution of the posterior collateral sources. The CO(2) reactivity on the side of surgery increased in all patients. In patients with a contralateral occlusion, CO(2) reactivity increased on both sides. The redistribution of flow was most pronounced in patients who needed intraoperative shunting and in patients with a contralateral internal carotid artery occlusion. CONCLUSION: After carotid endarterectomy, flow redistribution, as expressed by changes in blood flow velocity values, occurs in the circle of Willis. The contribution of collateral sources is diminished, and the CO(2) reactivity increases, both of which reflect improvement of the hemodynamic condition. The most improvement occurs in patients with contralateral occlusion.

Aged↗
PubMed2001

Concerns for the durability of the proximal abdominal aortic aneurysm endograft fixation from a 2-year and 3-year longitudinal computed tomography angiography study.

OBJECTIVE: To provide a long-term perspective on the durability of the proximal abdominal aortic aneurysm endograft fixation from a single device series with perpendicular neck measurements in two groups of patients with complete 2- and 3-year follow-up. DESIGN: This was a prospective study of postoperative, radiologic images. SETTING: The study used a referral center, institutional practice, and ambulatory patients. SUBJECTS: From January 1994 until May 1998, 37 endografts were implanted for abdominal aortic aneurysm. In the first postoperative year, there were four unrelated deaths and six conversions, leaving 27 patients with complete 24-month data and 13 with complete 36-month data. MAIN OUTCOME MEASURE: Computed tomography angiograms were processed on a work station to measure the neck perpendicular to the central lumen line of the aorta. The surface area at the proximal endovascular anastomosis was recorded at each follow-up interval and related to the postoperative size at the same level. RESULTS: Significant dilatation of the surface area was found: 20% (16% to 27%) at 24 months (c2 = 30; P < .001, Friedman) and 23% (18% to 28%) at 36 months (c2 = 27; P < .001, Friedman). This increase in neck size was continuous and linear, with a yearly rate of approximately 10% surface area; translated into diameter, this approximates 1 mm/y. CONCLUSION: A continuous aortic enlargement of approximately 1 mm/y at the level of the proximal endovascular anastomosis was found. Because of the practice of oversizing the endograft relative to the infrarenal aortic neck, a loss of the endovascular seal may not become apparent until several years after endovascular abdominal aortic aneurysm repair is performed.

Aged↗
PubMed2001

Optimal oral anticoagulant intensity to prevent secondary ischemic and hemorrhagic events in patients after infrainguinal bypass graft surgery. Dutch BOA Study Group.

OBJECTIVES: The purpose of this study was to determine the optimal intensity of oral anticoagulation in patients who participated in a randomized trial of oral anticoagulants or aspirin after infrainguinal bypass graft surgery. METHODS: The distribution of patient-time spent in international normalized ratio (INR) classes of 0.5 INR unit was calculated assuming a linear change between successive measurements. INR-specific incidence rates of ischemic and hemorrhagic events were calculated as the ratio of the number of events at a certain INR category and the total patient-time spent in that class. The relationship between INR class and event rates was quantified by rate ratios calculated in a Poisson regression model. RESULTS: In 1326 patients (mean age, 69 years) 41,928 INR measurements were recorded in 1698 patient-years. Patients spent 50% of the total time within the target range of 3.0 to 4.5 INR. Most of the patient-time (60%) was spent between 2.5 and 3.5 INR. For each increasing class of 0.5 INR, the incidence of ischemic events (n = 154, INR data on event available in 49%) decreased by a factor of 0.97 (95% CI, 0.87-1.08). The incidence of major bleeding (n = 123, INR data on event available in 65%) increased significantly by a factor of 1.27 (95% CI, 1.19-1.34) for each increasing 0.5 INR category. The optimal target range was 3.0 to 4.0 INR, with an incidence of 3.8 events (0.9 ischemic and 2.9 hemorrhagic) per 100 patient-years. CONCLUSIONS: The target range of 3.0 to 4.0 INR is the optimal range of achieved anticoagulation intensity and is safe for the prevention of ischemic events in patients after infrainguinal bypass graft surgery.

Acenocoumarol↗
PubMed2001

Cost-effectiveness of oral anticoagulants versus aspirin in patients after infrainguinal bypass grafting surgery.

PURPOSE: Several antithrombotic therapies are available for the treatment of patients with peripheral vascular diseases. It is unknown how quality of life and costs of treatment are influenced by different therapies. This study assessed the cost-effectiveness of oral anticoagulants versus aspirin in patients after infrainguinal bypass grafting surgery. METHODS: Clinical outcome events and event-free survival were collected from 2650 patients in 77 centers who participated in the Dutch Bypass Oral anticoagulants or Aspirin trial. Approximately half the patients had critical ischemia; 60% received vein grafts, and 20% had femorocrural bypass grafts. A model that was primarily driven by clinical outcome events was used as a means of determining quality of life (EuroQol EQ-5D) and costs for each patient. The main outcome measure was the incremental health care costs in relation to the additional number of quality-adjusted life years and the additional number of event-free years. RESULTS: The mean costs during the 21 months of follow-up were epsilon 6875 per patient in the oral anticoagulants group versus epsilon 7072 in the aspirin group (difference, 197; 95% CI, -746 to 343). The event-free survival was 1.10 years in the group treated with oral anticoagulants versus 1.09 years in the group treated with aspirin (difference, 0.01; 95% CI, -0.07 to 0.08), whereas the corresponding quality-adjusted life years were 1.06 and 1.05, respectively (difference, 0.01; 95% CI, -0.03 to 0.06). CONCLUSION: Health care costs, event-free survival, and quality-adjusted life years in patients after infrainguinal bypass surgery were not different in patients treated with aspirin and patients treated with oral anticoagulants. The extra costs of monitoring patients treated with oral anticoagulants were limited and play no role in the decision for treatment.

Aged↗
PubMed2001

Distal aortic diameter and peripheral arterial occlusive disease.

OBJECTIVE: Several studies have reported an association between abdominal aortic dilatation and peripheral arterial occlusive disease. Narrowing of aortic diameter, also called abdominal aortic hypoplasia, and peripheral arterial occlusive disease have received insufficient attention. Precise estimates of the relationship between aortic hypoplasia and peripheral arterial occlusive disease are lacking. In this study, we assessed the relationship between abdominal aortic diameter and peripheral arterial occlusive disease. METHODS: In this cross-sectional study, we analyzed 1572 patients 18 to 79 years of age, newly referred to the vascular center of our hospital with clinically manifest atherosclerotic arterial disease or for treatment of cardiovascular risk factors. Diameter measurements were used to subdivide patients according to tertiles of abdominal aortic diameter. Peripheral arterial occlusive disease was assessed by adjusted Rose questionnaire, ankle-brachial pressure index, and the presence of gangrene or leg ulcers. RESULTS: Compared with patients with normal aortic diameter, peripheral arterial occlusive disease was twice as prevalent in patients at both ends of the aortic diameter spectrum. When the lowest tertile was compared with the middle tertile in male patients, the adjusted odds ratio was 1.7 (95% CI, 1.0-3.1). When the highest tertile was compared with the middle tertile, the adjusted odds ratio was 2.1 (95% CI, 1.2-3.4). Similar results were found in female patients. The adjusted odds ratio of lowest versus middle tertile was 2.4 (95% CI, 1.1-5.0) and 1.8 (95% CI, 0.8-4.0) when the highest tertile was compared with the middle tertile. CONCLUSION: The risk of peripheral arterial occlusive disease was increased in the lower and upper distribution of aortic diameter. Apparently, both patients with an aortic diameter too large and patients with an aortic diameter too small are prone to peripheral arterial occlusive disease. This is the first large study that shows that small aortic diameter is associated with peripheral arterial occlusive disease.

Adolescent↗
PubMed2001

Sustained bilateral hemodynamic benefit of contralateral carotid endarterectomy in patients with symptomatic internal carotid artery occlusion.

BACKGROUND AND PURPOSE: We sought to investigate whether in patients with a symptomatic internal carotid artery (ICA) occlusion, endarterectomy of a severe stenosis of the contralateral carotid artery can establish long-term cerebral hemodynamic improvement. METHODS: Nineteen patients were studied on average 1 month before and 6 months after contralateral carotid endarterectomy (CEA). Volume flow in the main extracranial and intracranial arteries was measured with MR angiography. Collateral flow via the circle of Willis and the ophthalmic arteries was studied with MR angiography and transcranial Doppler sonography, respectively. Cerebral metabolism and CO(2) vasoreactivity were investigated with MR spectroscopy and transcranial Doppler sonography, respectively. Twelve nonoperated patients with a symptomatic ICA occlusion and contralateral ICA stenosis, who were matched for age and sex, served as control patients. RESULTS: In patients who underwent surgery, flow in the operated ICA increased significantly (P:<0.05) and flow in the basilar artery decreased significantly (P:<0.01) after CEA. On the occlusion side, mean flow in the middle cerebral artery increased significantly from 71 to 85 mL/min (P:<0.05) after CEA. The prevalence of collateral flow via the anterior communicating artery to the occlusion side increased significantly (47% before and 84% after CEA; P:<0.05), while the prevalence of reversed ophthalmic artery flow on the operation side decreased significantly (42% before and 5% after CEA; P:<0.05). In the hemisphere on the side of the ICA occlusion, lactate was no longer detected after CEA in 80% of operated patients, whereas it was no longer detected over time in 14% of nonoperated patients (P:<0.05). CO(2) reactivity increased significantly in operated patients in both hemispheres (P:<0.01). CONCLUSIONS: Contralateral CEA in patients with a symptomatic ICA occlusion induces cerebral hemodynamic improvement not only on the side of surgery but also on the side of the ICA occlusion.

Aspartic Acid↗
PubMed2000

Increase in alpha rhythm frequency after carotid endarterectomy.

OBJECTIVES: Besides preventing stroke, carotid endarterectomy (CEA) is reported to improve cerebral circulation and brain function. We tested whether this improvement is reflected by changes in the qEEG. METHODS: qEEG changes in 166 patients with a >70% stenosis of the internal carotid artery (ICA) were assessed after subtraction of the preoperative and postoperative spectra (eyes closed condition) before and 3 months after CEA. The mean frequency of the alpha band (MFA), the peak frequency of the alpha band (F alpha), and bands with limits relative to each patient's F alpha were studied in relation to neurological symptoms, patency or occlusion of the contralateral ICA, shunt requirement, and side of surgery. RESULTS: MFA and F alpha significantly increased over both hemispheres. After alignment on F alpha, a decrease of spectral band power was seen below F alpha, and a band power increase above F alpha. The group of patients with a contralateral ICA occlusion showed significantly more improvement than the group without. The group of patients with neurological deficits showed a tendency for improvement. No differences were found concerning shunt requirement or the side of surgery. CONCLUSIONS: After CEA the alpha rhythm frequency increases. In general, patients with a contralateral ICA occlusion improve more than other patients, in agreement with data from the literature on cerebral circulation and brain function.

Aged↗