Guidelines for carotid endarterectomy. A multidisciplinary consensus statement from the ad hoc Committee, American Heart Association

Randomized clinical trials: How will results influence clinical practice in the management of symptomatic and asymptomatic extracranial carotid occlusive disease?

Evaluation of the efficacy of carotid endarterectomy and stenting requires careful consideration of clinical trial methodology as applied to the primary clinical end points of the specific trial. Although publication of observational data including registries is helpful in selecting options for further study, these reports are not considered replacements for the randomized clinical trial. This article reviews methodology and results of registries and randomized clinical trials. Pending publication of larger clinical trials on the management of symptomatic and asymptomatic carotid stenosis within the next 1 to 3 years, carotid endarterectomy remains the preferred technique for cerebral revascularization. The only exceptions to this recommendation come from higher risk categories of patients; however, their identification is frequently difficult and controversial.

Carotid intervention 1: who should be treated?

Stroke is a major cause of morbidity and mortality in the modern world. Carotid artery atheromatous disease is responsible for a significant number of these events. The effects of carotid artery disease may be prevented by appropriate treatment. All patients with known atheromatous disease should be treated with medical therapy. Despite this, some patients remain at high risk of stroke, which may be reduced by the selective use of additional therapies such as carotid endarterectomy or carotid stenting. Patients who have had recent neurological symptoms, attributable to their carotid disease, may benefit most from these additional treatments, particularly if the treatment is performed soon after the event. The operation needs to be performed with low complication rates. Some groups of patients who have been free of neurological symptoms may also benefit from these additional therapies, but these patients have a much lower inherent risk of stroke, and so the potential benefits are less. In such circumstances it is even more important that the operations are performed with minimal morbidity. Patients undergoing coronary artery bypass grafts, who also have carotid disease, are at elevated risk of stroke, and it is common practice to treat both conditions. There is no strong data to support this practice.

Insulin-like growth factor-I receptors in atherosclerotic plaques of symptomatic and asymptomatic patients with carotid stenosis: effect of IL-12 and IFN-γ

The balance between apoptosis and survival of vascular smooth muscle cells (VSMCs) in the fibrous cap appears to best correlate with plaque instability or stability and is controlled by growth factors and cytokines. We recently reported the inhibition of insulin-like growth factor (IGF)-I-induced proliferation and increase in apoptosis of VSMCs by atheroma-associated cytokines. Here we assessed the expression of IGF-I receptor (IGF-IR) in atherosclerotic plaques and in plaque VSMCs of asymptomatic and symptomatic patients with carotid stenosis and examined the effect of IGF-I, IL-12, and IFN-γ on the expression of IGF-IR and IGF-binding protein (IGFBP)-3 in plaque VSMCs. We observed significantly lower density of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive apoptotic nuclei and increased positive immunoreactivity to IGF-IR and mRNA transcripts of endogenous IGF-I and IGF-IR in asymptomatic than in symptomatic plaque VSMCs. Positive correlation was found between apoptosis and IGF-IR expression in asymptomatic ( r2= 0.942) and symptomatic ( r2= 0.908) plaque VSMCs. The specific binding of125I-labeled IGF-I was 3.7-fold higher in plaque VSMCs of asymptomatic patients than in symptomatic patients. IGF-I increased both IGF-IR mRNA transcripts and expression of IGFBP-3 in VSMCs of asymptomatic plaques. IL-12 and IFN-γ decreased IGF-IR mRNA transcripts and further increased the expression of IGFBP-3 in asymptomatic VSMCs but had no effect in symptomatic VSMCs. These data suggest that the decreased expression of IGF-IR mRNA and increased expression of IGFBP-3 in carotid plaques of symptomatic patients could be due to atheroma-associated cytokines and this could result in plaque instability.

Low prevalence of significant carotid artery disease in Iranian patients undergoing elective coronary artery bypass

BACKGROUND

Coronary artery bypass grafting ranks as one of the most frequent operations worldwide. The presence of carotid artery stenosis may increase the stroke rate in the perioperative period. Routine preoperative noninvasive assessment of the carotid arteries are recommended in many institutions to reduce the stroke rate.

METHODS

271 consecutive patients undergoing coronary artery bypass grafting at Shaheed Madani hospital of Tabriz, Iran (age, 58.5 Y; 73.1% male) underwent preoperative ultrasonography for assessment of carotid artery wall thickness.

RESULTS

Plaque in right common, left common, right internal and left internal carotid arteries was detected in 4.8%, 7.4%, 43.2% and 42.1% of patients respectively. 5 patients (1.8%) had significant (<50%) and 3 (1.1%) patients had critical (<70%) stenosis in internal carotid arteries. Plaque formation in common carotid was not significantly different between two genders but the stenosis of left internal carotid was more frequently seen among men. Patients with plaques in right or left internal carotid arteries were significantly older.

CONCLUSION

Consecutive Iranian patients undergoing elective coronary artery bypass surgery show a very low prevalence of significant carotid artery disease.

Urgent Endarterectomy Using Pretreatment With Free Radical Scavenger, Edaravone, and Early Clamping of the Parent Arteries for Cervical Carotid Artery Stenosis With Crescendo Transient Ischemic Attacks Caused by Mobile Thrombus and Hemodynamic Cerebral Ischemia-Case Report-

A 68-year-old man with left cervical internal carotid artery stenosis suffered crescendo transient ischemic attacks caused by mobile thrombus detected by carotid echography and secondary impairment of cerebral hemodynamic reserve demonstrated by positron emission tomography. Urgent carotid endarterectomy (CEA) was performed following pretreatment with edaravone and early clamping of the carotid arteries without intraluminal shunting. The postoperative course was uneventful, and postoperative magnetic resonance imaging and single-photon emission computed tomography revealed no new cerebral ischemic lesions and no findings of cerebral hyperperfusion, respectively. The risks associated with CEA are higher for patients with evolving stroke or crescendo transient ischemic attacks than that for patients with stable disease. This case demonstrates that urgent endarterectomy for cervical carotid artery stenosis with crescendo transient ischemic attacks caused by mobile thrombi and hemodynamic cerebral ischemia can be successfully performed following pretreatment with edaravone and early clamping of the carotid arteries.

The Superficial Cervical Plexus Block for Postoperative Pain Therapy in Carotid Artery Surgery. A Prospective Randomised Controlled Trial

OBJECTIVES

Rapid and reliable neurological evaluation soon after carotid artery surgery is feasible with modern methods of general anesthesia, but postoperative pain therapy remains a challenge. Use of opioids can mask neurological deficits. We investigated whether superficial cervical plexus block reduced postoperative opioid consumption after carotid endarterectomy.

DESIGN

Prospective, randomised, double-blinded, placebo controlled trial.

METHODS

46 patients undergoing unilateral carotid endarterectomy under general anesthesia were randomized to either superficial cervical block with ropivacaine (n=23) or placebo (n=23). A patient controlled analgesia device (PCA) delivering morphine was provided for all patients. Subjective pain levels (visual analog scale, VAS) were recorded. The primary outcome was total morphine consumption on discharge from the recovery room. Secondary outcomes included arterial pCO2 (as an indicator of central nervous effects of morphine) and patient satisfaction.

RESULTS

No adverse effects of the superficial cervical plexus block were reported. Four patients in the placebo group were excluded because of other drug use post-operatively. Per protocol analysis compared 23 patients in ropivacaine group and 19 patients in the placebo group. The ropivacaine group had a significant reduction in morphine consumption (3.8+/-2.0 versus 12.9+/-4.0, p<0.001), lower maximal pain scores (2.6+/-2.0 versus 5.8+/-1.6, p<0.001), and paCO2 levels (39.0+/-2.6 versus 41.9+/-3.4, p=0.008) at discharge from the recovery room. Patient satisfaction (1=very good to 6=insufficient) was substantially higher in the ropivacaine group (1.7+/-0.7 versus 3.1+/-1.2, p<00.01).

CONCLUSION

The significant and clinically relevant lower morphine consumption and pain score, as well as the substantially higher patient satisfaction demonstrate that superficial cervical plexus block provides effective pain relief for patients undergoing carotid endarterectomy.

Differential effects of insulin-like growth factor-1 and atheroma-associated cytokines on cell proliferation and apoptosis in plaque smooth muscle cells of symptomatic and asymptomatic patients with carotid stenosis

Morbidity and mortality from atherosclerosis are associated with complicated atherosclerotic lesions due to plaque rupture, which is regulated by a balance between proliferation and apoptosis of vascular smooth muscle cells (VSMC). We examined insulin-like growth factor-1 (IGF-1)-induced survival of plaque VSMC from carotid endarterectomy specimens and investigated the underlying cellular mechanisms in the presence and absence of IL-12 and IFN-gamma. Both IL-12 and IFN-gamma were strongly expressed in symptomatic atherosclerotic plaques as compared with asymptomatic plaques. In asymptomatic plaque VSMC, IGF-1 induced the survival and proliferation of VSMC and accelerated VSMC into S-phase. IL-12 or IFN-gamma inhibited proliferation and VSMC were arrested in the G0-G1 phase. IGF-1 markedly inhibited the expression of p27(kip) and p21(cip) and significantly induced cyclin E and cyclin D. Both cytokines by themselves increased the expression of p27(kip) and p21(cip) and inhibited cyclin E and cyclin D. On the contrary, in symptomatic VSMC there was already increased apoptosis of VSMC and there was no significant effect of IGF-1 or inflammatory cytokines on proliferation, apoptosis or the expression of p27(kip) and p21(cip) and cyclin D and E. These data suggest that IGF-1 is more potent in inducing the survival of VSMC from the endarterectomy specimens of asymptomatic patients as compared to that of symptomatic subjects and cytokines associated with atheroma lesions decrease the activity of IGF-1-induced survival in the VSMC of asymptomatic plaques. The different expression and activity of cell cycle regulatory proteins could be responsible for apoptosis of VSMC and destabilization of atherosclerotic plaques.

Penetrating atheroma in cervical carotid artery stenosis

A 61-year-old male presented with left hand motor weakness associated with cerebral infarction in the right frontal lobe. Right common carotid angiography demonstrated a 66% stenosis and carotid duplex scan demonstrated intermediate echogenic plaque, indicating typical carotid plaque. Carotid endarterectomy was performed 22 weeks after the ischemic onset. During exposure of the carotid artery, a soft and yellowish mass (5 x 5 mm) was observed in the lateral wall of the carotid bulbus, which was not covered with adventitia but with thin connective tissue. The mass was removed en-bloc with a small part of the surrounding arterial wall combined with ordinary endarterectomy. The artery was closed with a collagen-impregnated polyester patch graft (Hemashield patch) to maintain adequate arterial lumen. Histological examination of the removed plaque confirmed that atheroma had protruded from the intima through the media as well as the adventitia and formed an extra-arterial mass. Such a case requires great care to dissect the carotid artery to prevent premature disintegration of the atheroma.

Distal protection in cardiovascular medicine: current status

Iatrogenic and spontaneous downstream microembolization of atheromatous material is increasingly recognized as a source of cardiovascular morbidity and mortality. Devising ways of reducing this distal embolization using a variety of mechanical means--distal protection--is currently under intense and diverse investigation. This review therefore summarizes the present status of distal protection. It examines the problem of distal embolization, describes the available distal protection devices, reviews those areas of cardiovascular medicine where distal protection devices are being investigated, and discusses potential future developments.

Protected carotid stenting in high-surgical-risk patients: The ARCHeR results

BACKGROUND

Carotid endarterectomy is the standard of care for most patients with severe extracranial carotid bifurcation disease. However, its safety and efficacy in patients with significant surgical risk are unclear. The ARCHeR (ACCULINK for Revascularization of Carotids in High-Risk patients) trial was performed to determine whether carotid artery stenting with embolic protection is a safe and effective alternative to endarterectomy in high-surgical-risk patients.

METHODS

The ARCHeR trial is a series of three sequential, multicenter, nonrandomized, prospective studies. Forty-eight sites enrolled 581 high-surgical-risk patients between May 2000 and September 2003. Patients with severe carotid artery stenosis (angiographically defined, symptomatic > or =50%, or asymptomatic > or =80%) had an ACCULINK nitinol stent implanted. The ACCUNET filter embolic protection system was added to the procedure in the final 2 studies (422 patients). The primary efficacy end point was a composite of periprocedural (< or =30 days) death, stroke, and myocardial infarction, plus ipsilateral stroke between days 31 and 365.

RESULTS

The 30-day rate of death/stroke/myocardial infarction was 8.3% (95% confidence interval [CI], 6.2%-10.8%), and that of stroke/death was 6.9% (95% CI, 5.0%-9.3%). Most (23/32) strokes were minor, of which more than half (12/23) returned to baseline National Institutes of Health Stroke Scale scores within 30 days. The 30-day major/fatal stroke rate was 1.5% (95% CI, 0.7%-2.9%). No hemorrhagic strokes were observed in the study. Ipsilateral cerebrovascular accident occurred in 1.3% between 30 days and 1 year, thus giving a primary composite end point of 30-day death/stroke/myocardial infarction plus ipsilateral stroke at 1 year of 9.6% (95% CI, 7.2%-12.0%), which is below the 14.4% historical control comparator. Target lesion revascularization at 12 months and 2 years was 2.2% and 2.9%, respectively.

CONCLUSIONS

The ARCHeR results demonstrate that extracranial carotid artery stenting with embolic filter protection is not inferior to historical results of endarterectomy and suggest that carotid artery stenting is a safe, durable, and effective alternative in high-surgical-risk patients.

Cognitive impairment associated with intraoperative and postoperative hypoperfusion without neurologic deficits in a patient undergoing carotid endarterectomy

BACKGROUND

Neuropsychological testing detects cognitive impairment in 20% to 30% of patients after carotid endarterectomy (CEA).

CASE DESCRIPTION

A 51-year-old man with asymptomatic right cervical internal carotid artery (ICA) stenosis underwent a CEA. Intraoperative transcranial regional cerebral oxygen saturation monitoring revealed ischemia in the right cerebral hemisphere during ICA clamping and transient hyperemia subsequent to ICA declamping. The patient recovered without the appearance of new neurologic deficits. Brain single-photon emission computed tomography performed immediately after CEA showed a decrease in cerebral blood flow in the right cerebral hemisphere. Diffusion-weighted magnetic resonance imaging showed no new abnormal findings. Positron emission tomography performed 2 months after surgery revealed decreased cerebral metabolic rate of oxygen in the right cerebral hemisphere, and neuropsychological testing demonstrated a decline in performance IQ relative to preoperative levels.

CONCLUSIONS

Intraoperative ischemia and postischemic delayed hypoperfusion in CEA can impair cognition even in the absence of development of postoperative neurologic deficit.

Tratamento endovascular da doença obstrutiva carotídea em pacientes de alto risco: resultados imediatos

OBJETIVO: Tratamento endovascular - angioplastia carotídea com stent (ACS) - tem se mostrado como opção atual no tratamento da estenose da artéria carótida em pacientes considerados de alto risco para endarterectomia de carótida (ECA). Este trabalho reporta a experiência do Instituto de Cirurgia Vascular e Endovascular (ICVE) de São Paulo nos casos de ACS em pacientes de alto risco. MATERIAL E MÉTODO: Foi realizado um estudo retrospectivo descritivo baseado na análise dos prontuários de 113 pacientes (84 homens e 29 mulheres) submetidos a 130 procedimentos de ACS pelo ICVE, no período de março de 2000 a junho de 2004. A idade média dos pacientes foi de 74 anos (variando de 51 a 86 anos). Os pacientes assintomáticos (55%) apresentavam estenose > 75%, enquanto nos sintomáticos (45%) as lesões encontradas foram > 70%. Foi indicado ACS nos seguintes pacientes: alto risco para ECA (45%), reestenose pós-ECA (15%), estenose carotídea severa bilateral (14%), oclusão da carótida contralateral (12%), bifurcação alta (no nível ou acima da segunda vértebra cervical) (6%), estenose pós-radioterapia (5%) e pescoço hostil (3%). As lesões encontradas localizavam-se na bifurcação carotídea (46%), carótida interna (32%), origem da artéria carótida comum (9%), tronco braquiocefálico (8%) e artéria carótida comum (5%). RESULTADO: Foi observado um total de sete eventos neurológicos (cinco casos de acidente vascular encefálico e dois pacientes que apresentaram ataque isquêmico transitório). A taxa de óbito foi de 0%. A taxa total de complicações (acidente vascular encefálico, acidente isquêmico transitório, óbito) foi de 5,3%. CONCLUSÃO: ACS demonstrou ser um procedimento com baixa taxa de complicações, sendo uma opção segura e eficaz nos pacientes de alto risco para ECA.

Cerebral monitoring in the operating room and the intensive care unit: an introductory for the clinician and a guide for the novice wanting to open a window to the brain. Part I: The electroencephalogram

While there is an increasing body of knowledge in regard to central nervous system function and/or the mode of action of centrally active agents on neuronal function, little is done to develop new techniques on how to measure such changes. Also, monitoring of the cardiovascular system in the past has made extensive progress especially when it comes to evaluate the failing heart. In contrast monitoring of the central nervous system is only done in rare cases where operative procedures likely impede nervous function integrity. Since in the past decade the aging population undergoing operation has rise considerably, the risk of cerebral malperfusion or minute signs of degradation of the aging central nervous system (CNS) to anesthetics and agents being used in the operation room (OR) or the intensive care unit (ICU), needs continuous monitoring of an organ which presents the highest vulnerability and is likely to deteriorate faster than the cardiovascular system. In spite the rapid improvement in technology regarding the electroencephalogram (EEG) and evoked potential monitoring, physicians still are reluctant to use a technology on a routine base, which will give them insight information into brain function and activity. Such "windows to the brain" now not just are reserved to specialists working in the area of neurology and/or psychiatry. More so, cerebral monitoring is getting an integrated part in the overall therapy in patients undergoing operation or who need ventilatory support in the ICU as it effects the well-being and the outcome. The present book therefore, is intended for the practitioners who work with the patient, guide the clinician in his decision making and outlining those situations where cerebral monitoring presents an integrated part in the diagnosis and therapy of patient care. Without going too much into the technical details, representative cases underline the potential use of cerebral monitoring in the underlying clinical situation where either the patient presents borderline perfusion of the CNS, undergoes vascular surgery, or where monitoring of cerebral function in the intensive care in a head trauma patients is an integrated part in therapy. The book therefore is meant for all those clinicians who have to deal with the CNS in a day-to-day situation. This may be the anesthesiologist, the surgeon, the intensive care therapist, the nurse anesthetist as well as all other medical personal involved in intensive care therapy. The aim of the book therefore is to outline the possibilities, the limitations, and the options for therapy when the windows to the brain are opened, how to interpret the data in the light of other physiological parameters and aid the user in the technical details of how to avoid artifacts in recording which may have an impact on final decision making. Therefore, emphasis is placed on the electrode placement, artifact and electrical noise reduction, as well as data interpretation so that cerebral function diagnosis can be made on reliable grounds. The following serves as an introduction to and as a reference guide for Cerebral Monitoring in the OR and the ICU: Gives complete coverage of EEG power spectra analysis. Describes in detail the EEG machines available to be used in the OR and ICU setting. Describes in detail the major features of EEG power spectra and evoked potential measurements, including amplifiers, filter setting and microprocessor algorithm for data reduction. Gives suggestions for assessing and improving signal quality, including noise and artifact rejection, which usually are encountered in the operation room and the intensive care unit, both of which can be considered as electrically contaminated. Gives examples of EEG power spectra and evoked potential monitoring related to different types of anesthesia, in coma, after head trauma, and for the detection of ischemic events. In addition, gives complete coverage of those machines being available for the OR and the ICU, including a list of parameters regarding latency and amplitude in evoked potential As an introductory, recommendations are given for the novice to start cerebral monitoring and guide the beginner in setting up cerebral monitoring in the clinical environment.

Endovascular therapies for noncoronary atherosclerosis in the elderly: supra-aortic vessels and thoracoabdominal aorta lesions

Due to the aging of the population and the fact that people are living longer, there are increasing numbers of older patients with noncoronary atherosclerosis. Carotid and subclavian arteries are often the first involved vessels in atherosclerosis, and thoracoabdominal aortic involvement is becoming even more frequent. New techniques, such as intra-arterial thrombolysis, protection and thrombo-aspiration devices, and new stent graft designs are becoming available for percutaneous treatment of atherosclerosis in such vessels. In this review, the authors offer geriatric cardiologists an overview and an update of the most recent advances in techniques and results in the field of interventional treatments of atherosclerosis of supra-aortic vessels and thoracoabdominal aorta in the elderly.

Management of asymptomatic carotid stenosis in patients undergoing general and vascular surgical procedures

Current available data do not seem to support the strategy for carotid endarterectomy prior to surgical intervention in patients with asymptomatic carotid stenosis. However, in patients with coronary artery disease, synchronous carotid endarterectomy and coronary artery bypass grafting should be considered where there is a proven surgical risk of <3% with unilateral asymptomatic stenosis >60% or bilateral carotid stenosis >75% on the same side as the most severe stenosis. Clarification of the optimal strategy requires an adequately powered, multicentre, randomised clinical trial.

Clinical and operative predictors of outcomes of carotid endarterectomy

OBJECTIVE

The net benefit for patients undergoing carotid endarterectomy is critically dependent on the risk of perioperative stroke and death. Information about risk factors can aid appropriate selection of patients and inform efforts to reduce complication rates. This study identifies the clinical, radiographic, surgical, and anesthesia variables that are independent predictors of deaths and stroke following carotid endarterectomy.

METHODS

A retrospective cohort study of patients undergoing carotid endarterectomy in 1997 and 1998 by 64 surgeons in 6 hospitals was performed (N = 1972). Detailed information on clinical, radiographic, surgical, anesthesia, and medical management variables and deaths or strokes within 30 days of surgery were abstracted from inpatient and outpatient records. Multivariate logistic regression models identified independent clinical characteristics and operative techniques associated with risk-adjusted rates of combined death and nonfatal stroke as well as all strokes.

RESULTS

Death or stroke occurred in 2.28% of patients without carotid symptoms, 2.93% of those with carotid transient ischemic attacks, and 7.11% of those with strokes (P < .0001). Three clinical factors increased the risk-adjusted odds of complications: stroke as the indication for surgery (odds ratio [OR], 2.84; 95% confidence interval [CI] = 1.55-5.20), presence of active coronary artery disease (OR, 3.58; 95% CI = 1.53-8.36), and contralateral carotid stenosis > or =50% (OR, 2.32; 95% CI = 1.33-4.02). Two surgical techniques reduced the risk-adjusted odds of death or stroke: use of local anesthesia (OR, 0.30; 95% CI = 0.16-0.58) and patch closure (OR, 0.43; 95% CI = 0.24-0.76).

CONCLUSIONS

Information about these risk factors may help physicians weigh the risks and benefits of carotid endarterectomy in individual patients. Two operative techniques (use of local anesthesia and patch closure) may lower the risk of death or stroke.

Diagnosing carotid stenosis by Doppler sonography: state of the art

OBJECTIVE

The goal of this review article is to present the state of the art in the clinical applications and technical performance and interpretation of carotid sonographic examinations.

METHODS

Relevant publications regarding color and duplex Doppler sonography (CDDS) of the carotid arteries extracted from a computerized database (MEDLINE) and from references cited in these articles not appearing on the Internet were reviewed.

RESULTS

The ability to quickly and efficiently identify stenosis in the carotid artery is an important goal for clinicians and vascular surgeons. Identification of potentially treatable carotid stenosis enables selection of appropriate candidates for endarterectomy or stent implantation. Advances in performance and interpretation of carotid sonographic studies over the last 20 years have been driven by technological improvements in gray scale and CDDS examinations and have made carotid sonography an important means to reach this goal. On the basis of CDDS, intima-media thickness measurements and plaque location and characterization on gray scale imaging, flow disturbance and areas of stenosis on color Doppler sonography, and flow velocities on spectral Doppler sonography are obtained. The degree of the diameter of a stenosis of the internal carotid artery is the main parameter used for therapeutic approaches. Advantages and limitations of the method are included.

CONCLUSIONS

Carotid sonography is a unique imaging method for the investigation of carotid abnormalities. Noninvasive, accurate, and cost-effective, it provides morphologic and functional information. It is increasingly becoming the first and often the sole imaging study before endarterectomy, whereas costly and invasive procedures are reserved for special cases.

Selective shunting during carotid endarterectomy

Carotid endarterectomy (CEA) is an effective treatment for significant carotid atherosclerosis. Perioperative stroke, a devastating complication, may be partially circumvented by shunting. However, routine shunt use is not without complications and does not benefit every patient. Our study is designed to determine whether CEA under general anesthesia, without cerebral monitoring, can be safely done with shunting only in the presence of poor internal carotid artery back-bleeding or contralateral carotid occlusion or critical stenosis. The medical records of 995 carotid operations were reviewed. A subset of 117 operations was performed on 112 patients using selective shunting. Data were analyzed and outcomes compared. For the selective shunt group, indications for redo operations (n=13) were recurrent asymptomatic high-grade stenosis in 69% and amaurosis fugax or transient ischemic attack in 31%. Indications for primary CEA (n=104) were asymptomatic high-grade stenosis in 59%, amaurosis fugax or transient ischemic attack in 36%, previous stroke in 3%, and global ischemia in 2%. A selective shunt was used in 29% of all symptomatic and 11% of all asymptomatic patients. No cerebral monitoring was used. There were no perioperative deaths and no permanent cranial nerve injuries, and there was one stroke (0.8%) from postoperative carotid thrombosis in a shunted patient. The average length of stay was 1.6 days for the non-shunt group and 2.2 days for the shunt group. The routine shunt group (n=878) had an overall stroke rate of 0.7%, no permanent cranial nerve deficits, and a mean hospital stay of 2.6 days. CEA under general anesthesia with selective shunting can be performed safely without cerebral monitoring.

Management of transient ischemic attack: 2005

Transient ischemic attack is a common presenting problem to clinicians. Historically, these events were defined by the resolution of new neurologic symptoms within a 24-h time-frame; however, recent data suggests that a 1-h time frame is more appropriate. New imaging techniques and clinical evidence suggests that transient ischemic attacks present a higher risk of impending stroke than previously thought. This has led to a redefinition of what constitutes an attack, and also to a focus on both earlier investigation and treatment of correctable causes. New antiplatelet agents are now available and pose a challenge as to how they should be prescribed. Carotid endarterectomy is the standard of care for a subset of transient ischemic attack patients with significant carotid stenosis. Carotid angioplasty and stenting are more recent developments that may further expand treatment options.

Surgical anatomy of the cervical carotid artery for carotid endarterectomy

Carotid endarterectomy (CEA) is the main treatment for atherosclerotic plaque of the cervical internal carotid artery. The surgical anatomy of the carotid arteries was studied in the carotid triangle of 49 cadavers. The carotid bifurcation was located at the level of the lower third of C-3. The superior thyroid artery arose from the anterior wall of the external carotid artery in 70% of specimens and from the distal portion of the common carotid artery in 30%. The lingual artery arose as a separate trunk between the origins of the superior thyroid and facial arteries in 81% of specimens, with the facial artery from a common trunk in 18%, and with the superior thyroid artery in 1%. The occipital artery arose from the posterior aspect of the external carotid artery above the level of origin of the facial artery in 57% of specimens, between the origins of the facial and lingual arteries in 32%, and below the origin of the lingual artery in 11%. The origin of the occipital artery was positioned low and the distal portion of the occipital artery was crossed by the hypoglossal nerve in 20%. The ascending pharyngeal artery arose from the posterior wall of the external carotid artery above the level of origin of the lingual artery in 66% of specimens, below the origin of the lingual artery in 9%, from the proximal portion of the occipital artery in 19%, from the carotid bifurcation in 2%, and from the internal carotid artery in 2%. The branches of the external carotid artery are the key landmarks for adequate exposure and appropriate placement of cross-clamps on the carotid arteries. It is necessary to understand the surgical anatomy of the carotid arteries to carry out successful removal of plaque and minimize postoperative complications in a bloodless surgical field.

History and current status of endovascular management for the extracranial carotid and supra-aortic vessels

Few procedures in the history of medicine have been more controversial than carotid artery stenting (CAS) for the management of carotid artery occlusive disease. Introduced just as the randomized trials were establishing carotid endarterectomy as the gold standard for carotid interventions, CAS has finally reached the point in its development when dedicated stenting systems are being tested in randomized clinical trials. Assisted by the concomitant use of distal protection devices, CAS has shown equipoise with endarterectomy in terms of safety at 30 days. This review summarizes the completed and ongoing CAS trials and the applications of endovascular techniques in the supra-aortic vessels.

Simultaneous Carotid and Coronary Arteries Disease: Staged or Combined Surgical Approach?

BACKGROUND

Patients suffering from a concomitant coronary and carotid artery occlusive disease represent a high-risk population whose management remains controversial.

METHODS

Between April 1979 and June 2002, 202 patients (163 men and 39 women, mean age 65 +/- 7 years) were admitted at the Department of Cardiovascular Surgery of the University of Bologna for coronary artery bypass graft and carotid endarterectomy (CEA). In Group 1 (140 patients) coronary artery bypass graft and carotid endarterectomy were performed simultaneously while in Group 2 (62 patients) they were performed as two-staged procedures.

RESULTS

The rate of postoperative stroke was 6.4% in Group 1 (9/140) and 4.8% in Group 2 (3/62). Significant univariate predictors of myocardial infarction were smoking history and previous myocardial infarction; for stroke they were older, greater than 70 years, and a smoking history; for death the significant predictors were the operative approach, the low ejection fraction, smoking history, renal failure, and peripheral vascular occlusive disease. The hospital mortality was 6.4% in Group 1 versus 12.9% in Group 2.

CONCLUSIONS

Despite the highly selected populations, the contemporary surgical results indicate that the management of these patients needs careful pre-, intra-, and postoperative assessment and timing aimed at reducing the ischemic injuries, both cerebral and cardiac, therefore we believe that the surgical technique should be individualized for each patient.

The influence of concurrent carotid endarterectomy on coronary bypass: A case-controlled study

BACKGROUND

Concurrent carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) are associated with an increased incidence of stroke and death compared to isolated CABG. It is unclear whether this reflects two concurrent operative procedures or the increased risk in patients with more extensive atherosclerosis.

METHODS

To address this question, a case controlled study was performed using data from the New York State Cardiac Database from 1997 to 1998. Patients who underwent combined CEA-CABG were compared with all isolated CABG patients and a risk-matched cohort of isolated CABG patients.

RESULTS

The 35,539 isolated CABG patients had fewer postoperative complications than the 744 combined CEA-CABG patients, but also had a lower overall risk profile. The isolated CABG patients had a lower incidence of stroke (2% vs 5.1%), death (2% vs 4.4%), and combined stroke and death (3.7% vs 8.1%) compared with the combined group ( P < .001). After risk-factor matching, no differences in stroke (5% vs 5.1%), death (3.9% vs 4.4%), or combined stroke and death (8.5% vs 8.1%) were observed.

CONCLUSIONS

Although increased complications are reported after CEA-CABG, these do not differ from those of a risk-matched cohort of isolated CABG patients. Thus, the major morbidity of combined CEA-CABG is due to inherent patient risk and not the addition of CEA to CABG.

What Proportion of Stroke Is Not Explained by Classic Risk Factors?

Ischemic stroke is a complex entity with multiple etiologies and variable clinical manifestations. The most frequent cause of stroke is atherosclerosis of cerebral vasculature followed by cardioembolism. Two thirds of strokes are explained by identifiable risk factors. Age, hypertension, and nonvalvular atrial fibrillation are by far the most frequent and well documented ones. Approximately 5% of strokes are caused by conditions other than atherosclerosis or heart disease, i.e., cervical arteries dissections, nonatherosclerotic vasculopathies, infectious or systemic vasculitis, and collagen vascular diseases. In spite of a thorough diagnostic evaluation, 30% of strokes remain cryptogenic, i.e., no specific cause is identified and the classic risk factors are not present. Identification of unknown environmental or genetic risk factors should be the subject of further research.

Overview of costs of stroke from published, incidence-based studies spanning 16 industrialized countries

OBJECTIVE

The aim of this review is to summarize published data (based on a search of Medline sources, 1993-October 2003) from the last 10 years on the costs of stroke. With the recent encouraging evidence of interventions that reduce the incidence of stroke, the primary focus is on incidence-based cost of stroke studies to identify important factors for future cost-effectiveness analyses on stroke interventions.

FINDINGS

Lifetime costs per patient were in the range USD 11 787 for 'unclassified' stroke in Australia to USD 3035671 in stroke patients with untreated non-rheumatic atrial fibrillation in a UK setting (costs inflated to 2003 values). For the lifetime costs of ischemic stroke only, the range narrowed to USD 41257 in Australia and USD 104629 in the UK. These data confirm that stroke management is associated with a vast economic burden. No correlation of lifetime cost of stroke with specific cost components or time horizon was identified. The cost of stroke is influenced by severity (more severe strokes cost more due to extended hospitalization), age (costs were greater in younger stroke patients) and gender (direct costs were greater for women, but indirect costs were greater in men).

CONCLUSION

Conducting research according to methodological consensus would markedly improve the quality of data from future studies of stroke and support identification of the main cost drivers in different country-specific settings.

Conventional microsurgical endarterectomy

In the 1990's, carotid endarterectomy (CEA) has matured to a widely performed, standard intervention with well defined successive steps. The key feature of microsurgical CEA is the use of the operating microscope for magnification of the surgical field and microsuture of the arteriotomy. Further measures contributing to the success of microsurgical CEA include intraoperative monitoring of cerebral blood flow, selective shunt placement and neuroprotection during arterial cross-clamping. In experienced hands, the operation is not difficult and goes without complication in the great majority of patients. An overall complication rate of 6-8% combining mortality, major morbidity and minor morbidity is acceptable in view of the often multimorbid patients undergoing the operation. However, a rate of major morbidity/mortality not exceeding 1-2% is a realistic goal for microsurgical CEA. On the long-term, the rate of restenosis needing treatment should not exceed 1-2%. To preserve objectivity and quality control of CEA, the clinical results should be assessed independently of the surgeon by a neutral observer, ideally a neurologist.

Frequency and management of recurrent stenosis after carotid artery stent implantation

Object. To determine the rate of hemodynamically significant recurrent carotid artery (CA) stenosis after stent-assisted angioplasty for CA occlusive disease, the authors analyzed Doppler ultrasonography data that had been prospectively collected between October 1998 and September 2002 for CA stent trials.

Methods. Patients included in the study participated in at least 6 months of follow-up review with serial Doppler studies or were found to have elevated in-stent velocities (> 300 cm/second) on postprocedure Doppler ultrasonograms. Hemodynamically significant (≥ 80%) recurrent stenosis was identified using the following Doppler criteria: peak in-stent systolic velocity at least 330 cm/second, peak in-stent diastolic velocity at least 130 cm/second, and peak internal carotid artery/common carotid artery velocity ratio at least 3.8. Follow-up studies were obtained at approximate fixed intervals of 1 day, 1 month, 6 months, and yearly. Angiography was performed in the event of recurrent symptoms, evidence of hemodynamically significant stenosis on Doppler ultrasonography, or both. Treatment was repeated because of symptoms, angiographic evidence of severe (≥ 80%) recurrent stenosis, or both of these.

Stents were implanted in 142 vessels in 138 patients (all but five patients were considered high-risk surgical candidates and 25 patients were lost to follow-up review). For the remaining 112 patients (117 vessels), the mean duration of Doppler ultrasonography follow up was 16.42 ± 10.58 months (range 4–54 months). Using one or more Doppler criteria, severe (≥ 80%) in-stent stenosis was detected in six patients (5%). Eight patients underwent repeated angiography. Six patients (three with symptoms) required repeated intervention (in four patients angioplasty alone; in one patient conventional angioplasty plus Cutting Balloon angioplasty; and in one patient stent-assisted angioplasty).

Conclusions. In a subset of primarily high-risk surgical candidates treated with stent-assisted angioplasty, the rates of hemodynamically significant restenosis were comparable to surgical restenosis rates cited in previously published works. Treatment for recurrent stenosis incurred no instance of periprocedure neurological morbidity.

Patient selection for revascularization in cervical carotid artery disease: angioplasty and stenting vs. endarterectomy

Cervical carotid stenosis is a major cause of stroke and disability. Although carotid endarterectomy is an established and effective treatment for some patients with carotid artery stenosis, angioplasty and stenting has emerged in recent years as a viable alternative, particularly for patients who may be less suited for surgery. This article reviews patient selection for the two alternative approaches. The authors review the findings of the major clinical trials of carotid endarterectomy, summarize the development of carotid angioplasty and stenting, and identify patient characteristics that may guide selection of surgical or endovascular treatment.

Endovascular treatment of carotid artery stenosis: retrospective study of 79 patients treated with stenting and angioplasty with and without cerebral protection devices

We evaluate the results of stenting and angioplasty on carotid bifurcation stenotic lesions using protection systems, emphasizing the indications and technical aspects. Seventy-nine patients, mean age 64.5 years were treated from February,1998 to March, 2003. All patients were included in NASCET study criteria. Forty three patients were treated without the protection systems and thirty six were treated with carotid protection filtering system (Angioguard, EPI). Technical success and 6-months carotid Doppler ultrasound follow-up showing stent patency were achieved in all patients. One major stroke and one death due to intracranial reperfusion bleeding occurred in patients treated without cerebral protection devices. Only one patient presenting hyper perfusion syndrome improving after 7 days, was found in the group treated with the cerebral protection filter mechanism, no other neurologic symptom or death occured in this group. Stenting and angioplasty with protection systems for thromboembolic debris is a safe endovascular method to treat stenotic lesions in the carotid bifurcation with low morbidity and mortality.

Comparison of angioplasty and stenting with cerebral protection versus endarterectomy for treatment of internal carotid artery stenosis in elderly patients

PURPOSE

Carotid angioplasty and stenting (CAS) is being evaluated as an alternative to carotid endarterectomy (CEA) for treatment of severe carotid artery stenosis. Because CAS does not require general anesthesia and is less traumatic, it might be especially advantageous in older patients, but data comparing these 2 treatment methods in older patients are scarce.

METHODS

The periprocedural complication rates in 53 patients aged 75 years or older who had undergone protected CAS between June 2001 and April 2004 were compared with those in a group of 110 patients aged 75 years or older who had undergone CEA between January 1997 and December 2001, before widespread introduction of CAS procedures at our institution. All patients were evaluated by a neurologist both before and after surgery. According to the criteria set forth by the large trials the occurrence of minor, major, or fatal stroke, and myocardial infarction within 30 days was determined.

RESULTS

The demographic characteristics and indications for an intervention were similar in both treatment groups. Thirty patients (57%) in the CAS group had symptomatic carotid stenosis, compared with 69 patients (63%) in the CEA group. In neither group was there any fatal stroke or myocardial infarction. The 30-day stroke rate was significantly higher in the CAS group (4 minor, 2 major strokes; 11.3%) than in the CEA group (no minor, 2 major strokes; 1.8%; P < .05). Although the 30-day major stroke rate between CAS and CEA groups was comparable (3.8% vs 1.8%; P = 0.6), this effect was mainly attributable to a significantly higher rate of minor stroke in the CAS group (7.5% vs 0%; P < .05).

CONCLUSION

Despite the use of cerebral protection devices the neurologic complication rate in patients aged 75 years and older associated with CAS was significantly higher than with CEA performed by highly skilled surgeons at our academic institution. Although this finding is mainly based on a significantly higher rate of minor stroke in the CAS group, the common practice of preferentially submitting older patients to CAS is questionable, and should be abandoned until the results of further randomized trials are available.

A new approach to carotid angioplasty and stenting with transcervical occlusion and protective shunting: Why it may be a better carotid artery intervention

OBJECTIVE

The purpose of this study was to evaluate the effectiveness and demonstrate the advantages of a new technique for carotid angioplasty and stenting (CAS) with proximal cerebral protection through a direct transcervical approach, as compared with a percutaneous transfemoral approach.

METHODS

CAS procedures were carried out in 25 consecutive patients, 4 with the femoral approach and 21 through a 2-cm incision at the base of the neck, with the patient under local anesthesia. For transcervical occlusion and protective shunting (TOPS), a short 9F sheath was inserted directly into the common carotid artery and connected to a 6F sheath placed percutaneously in the ipsilateral internal jugular vein. After clamping the common carotid artery proximal to the 9F sheath, internal carotid artery blood flow reversal was confirmed or an occluding external carotid balloon was placed. A filter interposed between the arterial and venous sheaths collected embolic debris from transcarotid manipulations. The arterial puncture was directly repaired with suture. Neurologic status was assessed with the National Institutes of Health stroke scale by an independent neurology consultant before and after the procedure.

RESULTS

One of the four percutaneous femoral approaches that failed because of tortuous anatomy was successfully treated with TOPS. Angiographic confirmation demonstrating resolution of asymptomatic (>80%; n = 12) stenosis or symptomatic (>60%; n = 12) stenosis was achieved in all patients with stents. A 0% technical failure rate and 0% combined 30-day stroke or mortality rate were achieved in all CAS attempted with TOPS. There were no hematomas in the cervical group, despite pretreatment with clopidogrel bisulfate and heparin, and one hematoma in the femoral group after failure of a Perclose arterial closure device. In one of the patients in the femoral group bilateral cholesterol emboli to the toes developed.

CONCLUSION

TOPS solves problems of access, embolization into the cerebral and peripheral circulation, and specialized cerebral protection devices, and enables secure closure of the access vessel in patients given anticoagulation therapy. TOPS may provide a safer, more effective, economical means for performing CAS.

Endarterectomy for symptomatic carotid stenosis in relation to clinical subgroups and timing of surgery

BACKGROUND

Carotid endarterectomy reduces the risk of stroke in patients with recently symptomatic stenosis. Benefit depends on the degree of stenosis, and we aimed to see whether it might also depend on other clinical and angiographic characteristics, and on the timing of surgery.

METHODS

We analysed pooled data from the European Carotid Surgery Trial and North American Symptomatic Carotid Endarterectomy Trial. The risk of ipsilateral ischaemic stroke for patients on medical treatment, the perioperative risk of stroke and death, and the overall benefit from surgery were determined in relation to seven predefined and seven post hoc subgroups.

RESULTS

5893 patients with 33000 patient-years of follow-up were analysed. Sex (p=0.003), age (p=0.03), and time from the last symptomatic event to randomisation (p=0.009) modified the effectiveness of surgery. Benefit from surgery was greatest in men, patients aged 75 years or older, and those randomised within 2 weeks after their last ischaemic event, and fell rapidly with increasing delay. For patients with 50% or higher stenosis, the number of patients needed to undergo surgery (ie, number needed to treat) to prevent one ipsilateral stroke in 5 years was nine for men versus 36 for women, five for age 75 years or older versus 18 for younger than 65 years, and five for those randomised within 2 weeks after their last ischaemic event, versus 125 for patients randomised after more than 12 weeks. These results were consistent across the individual trials.

INTERPRETATION

Benefit from endarterectomy depends not only on the degree of carotid stenosis, but also on several other clinical characteristics such as delay to surgery after the presenting event. Ideally, the procedure should be done within 2 weeks of the patient's last symptoms.

Routine use of cerebral protection during carotid artery stenting: results of a multicenter registry of 753 patients

PURPOSE

To evaluate the short-term outcome of patients who underwent carotid stenting with the routine use of cerebral protection devices.

METHODS

In five centers, 808 successful stent procedures (of 815 attempted) were performed in 753 patients (557 [74%] men; mean [+/- SD] age, 70 +/- 8 years). Cerebral protection involved distal filter devices (n=640), occlusive distal balloons (n=144), or proximal balloon protection (n=24).

RESULTS

The protection device was positioned successfully in 793 (98.2%) of the 808 attempted vessels. Neurologic complications occurred within 30 days after 46 procedures (5.6%), including seven major strokes, 17 minor strokes, and 22 transient ischemic attacks. There were four deaths (one following a major stroke). The 30-day incidence of stroke and death was 3.3% (27/815). The rate of stroke or death was 3.8% (8/213) for symptomatic lesions and 3.2% (19/602) for asymptomatic lesions (P=0.87), and 3.4% (25/729) in patients aged <80 years and 2% (2/86) in those aged > or =80 years (P=0.81). Protection device-related vascular complications, none of which led to neurologic symptoms, occurred after nine procedures (1.1%).

CONCLUSION

In this uncontrolled study, routine cerebral protection during carotid artery stenting was technically feasible and clinically safe. The incidence of major neurologic complications in this study was lower than in previous reports of carotid artery stenting without cerebral protection.

A guideline for the treatment of dementia in Japan

Worldwide energetic efforts have provided several clues for the management of Alzheimer's disease and related dementias in elderly people, although the history of dementia treatment is not long. Various pharmacological or non-pharmacological treatments are carried out in daily medical practice, but evidence for the validity of these treatments is limited. In United States and Europe, several pharmacological and a few non-pharmacological treatments have been proven effective and a few drugs are approved by various governments and used in practice. In contrast, only one acetylcholinesterase inhibitor, donepezil has been proven effective and used for patients with mild or moderate Alzheimer's disease in Japan. Anti-hypertensive or anti-platelet therapy has been shown to reduce the incidence or recurrence of stroke, probably preventing vascular dementia. Effectiveness of drugs and types of care awaits to be validated in the light of scientific procedures.

Japan Carotid Atherosclerosis Study: JCAS

The recent randomized trials, North American Symptomatic Carotid Endarterectomy Trial, European Carotid Surgery Trial, and Asymptomatic Carotid Atherosclerosis Study, have demonstrated the effectiveness of carotid endarterectomy to reduce the incidence of cerebral infarction in patients with symptomatic and asymptomatic high-grade carotid artery stenosis. However, no studies on Japanese patients have been done until now, and recent progress in endovascular stent treatment has been made. The present prospective, multicenter (not randomized) trial, the Japan Carotid Atherosclerosis Study, has started to analyze present practice and propose treatment guidelines for Japanese patients. Here, the protocol and early results of 565 patients registered until the end of January 2004 are presented.

Imaging of carotid artery disease: from luminology to function?

There have been tremendous advances in our ability to image atheromatous disease, particularly in the carotid artery, which is accessible and large enough to image. The repertoire of methodology available is growing, giving anatomical information on luminal narrowing which is approaching the level at which conventional carotid angiography will become very uncommon as CT and contrast-enhanced MR angiographic techniques become the norm. More exciting is the tentative ability to perform functional plaque imaging addressing enhancement patterns and macrophage activity using MR or positron-emission tomography techniques. These techniques, once rigorously evaluated, may, in addition to complex mathematical modelling of plaque, eventually allow us to assess true plaque risk. Time will best judge whether we will be able to move from the use of simple luminology to assessment of plaque function.

Inability of vascular smooth muscle cells to proceed beyond S phase of cell cycle, and increased apoptosis in symptomatic carotid artery disease

OBJECTIVE

Microemboli passing through the cerebral artery downstream from high-grade carotid artery stenosis produce transient ischemic symptoms and may result in stroke. Rupture of carotid artery plaque is the main source of microemboli in high-grade internal carotid artery stenosis. However, the mechanisms underlying plaque rupture are unclear. We hypothesized that vascular smooth muscle cells (VSMC) from plaque in patients with symptoms of carotid artery stenosis undergo increased apoptosis and decreased proliferation, compared with VSMC in patients without symptoms.

METHODS

VSMC were isolated by means of enzymatic dissociation from plaque removed at carotid endarterectomy in patients with symptoms of carotid artery stenosis, eg, hemispheric transient ischemic attacks, amaurosis fugax, or stroke, and patients with high-grade stenosis without symptoms. VSMC were cultured and immunostained with smooth muscle alpha-actin and caldesmon antibodies to ensure purity. TUNEL assay and annexin V labeling were performed to identify VSMC undergoing apoptosis. Proliferation assay with [(3)H] thymidine incorporation was performed in VSMC stimulated with fetal bovine serum (FBS), and cell cycle profile was analyzed with DNA staining with Vindelov reagent.

RESULTS

We isolated VSMC from symptomatic plaque that showed gross ulceration, and asymptomatic plaque. Apoptosis, as measured with the TUNEL assay, in VSMC from symptomatic plaque was 5.45% +/- 0.8%, and in asymptomatic plaque was 1.20% +/- 0.2%. Annexin V labeling revealed that 26.8% +/- 3.8% cells were labeled for phosphatidylserine in VSMC in symptomatic plaque, compared with 4.8% +/- 0.3% cells in asymptomatic plaque. VSMC in asymptomatic plaque showed significantly increased uptake of [(3)H] thymidine at all concentrations of FBS, compared with symptomatic plaque. In the presence of 10% FBS, VSMC from asymptomatic plaque progressed through the S phase of the cell cycle, whereas significantly increased numbers of VSMC from symptomatic plaque were arrested in the S phase.

CONCLUSION

Increased numbers of VSMC from symptomatic plaque undergo apoptosis, compared with VSMC from asymptomatic plaque. This could be due to inability of VSMC from symptomatic plaque to progress beyond the S phase of the cell cycle. Decreased proliferation and increased loss of VSMC as a result of apoptosis in symptomatic plaque may result in plaque rupture, leading to development of symptoms.

Cerebrovascular disease

PURPOSE OF REVIEW

Carotid endarterectomy remains the preferred surgical intervention for the prevention of stroke among patients with extracranial cerebrovascular disease. Subgroup analyses of the results of several multicentre trials have contributed substantially to our understanding of the appropriate selection of patients and the perioperative risk associated with this procedure.

RECENT FINDINGS

This review describes recent advances in our understanding of the appropriate use of carotid endarterectomy, and outlines recent developments and strategies that are likely to influence the perioperative care of these patients.

SUMMARY

As current clinical guidelines for the use of carotid endarterectomy unfold, anaesthesiologists can expect to care more frequently for older patients and those at increased risk of complications. The perioperative management of co-existing diseases, particularly the control of hypertension and the strategies aimed at reducing the risk of cardiac complications, will contribute substantially to reducing perioperative morbidity and mortality.

An appraisal of different cardiac risk reduction strategies in vascular surgery patients

OBJECTIVES

to summarize existing evidence regarding the benefits and the risks of all available interventional and medical means aimed at cardiac risk reduction in patients undergoing vascular surgery.

DESIGN

review of the literature.

MATERIALS AND METHODS

a critical review of all studies examining the impact of various prophylactic cardiac maneuvers on perioperative outcome following vascular surgery was performed. Overall mortality, cardiac mortality and myocardial infarction rate were used as the outcome measures.

RESULTS

coronary artery bypass grafting is associated with a 60% decrease in perioperative mortality in patients undergoing vascular surgery, but in most of the cases this decrease does not outweigh the combined risk of the cardiac and the subsequent noncardiac vascular procedure. Data supporting the cardioprotective effect of percutaneous transluminal angioplasty in the perioperative setting are insufficient. beta-blockade has been shown to decrease perioperative mortality and cardiac morbidity in both high-risk (strong evidence) and low-risk (weak evidence) patients.

CONCLUSIONS

coronary revascularization is rarely indicated to simply get the patient through vascular surgery and should be reserved for patients who would need it irrespective of the scheduled vascular procedure. Among all available pharmacological agents, including beta-blockers, alpha-agonists, calcium channel blockers and nitrates, only beta-blockers have been proven to reduce the cardiac risk of vascular surgery.

Management of carotid artery stenosis: comparing endarterectomy and stenting

Stroke ranks as the third leading cause of death, behind diseases of the heart and cancer. It is also the most important cause of disability. Approximately 750,000 people experience a stroke annually, costing an estimated $40 billion in direct and indirect costs. Approximately 25% of these ischemic events are related to occlusive disease of the cervical internal carotid artery. Carotid atherovascular stenosis increases the risk of ischemic stroke by acting as an embolic source, and causing hypoperfusion of the ipsilateral cerebral hemisphere. With some limitations, the North American Symptomatic Carotid Endarterectomy Trial (NASCET), European Carotid Surgery Trialists' Collaborative Group (ECST), and Asymptomatic Carotid Atherosclerosis Study (ACAS) have shown that carotid endarterectomy (CEA) substantially reduces the risk of stroke associated with certain grades of carotid stenosis. During the past few years, carotid angioplasty and stenting (CAS) has evolved as an alternative to CEA, particularly in patients who are known to have a higher complication rate with CEA.

Diffusion Tensor Imaging in Patients With Major Cerebral Artery Occlusive Disease

Diffusion tensor (DT) imaging provides quantitative information about the magnitude and the directionality (anisotropy) of water diffusion in vivo and can detect pathologic changes in brain ischemia. This study tried to detect ischemic brain damage using DT imaging in patients with symptomatic chronic major cerebral artery occlusive disease. DT imaging was performed using a 3.0 Tesla magnetic resonance (MR) scanner in 50 patients with unilateral internal carotid artery or middle cerebral artery stenosis or occlusion, who had no obvious infarct lesions on conventional MR imaging. Thirty-three patients underwent DT imaging before and after vascular reconstruction surgery. Fractional anisotropy (FA) was calculated in the middle cerebral artery territory. Preoperative FA values in the ipsilateral side were significantly lower than those in the contralateral side. After surgery, the FA value was significantly increased. DT imaging may indicate ischemic brain damage, not visualized by conventional MR imaging, in patients with major cerebral artery occlusive disease.