Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Angioplasty in asymptomatic carotid artery stenosis vs. endarterectomy compared to best medical treatment: One-year interim results of SPACE-2

BACKGROUND

Treatment of individuals with asymptomatic carotid artery stenosis is still handled controversially. Recommendations for treatment of asymptomatic carotid stenosis with carotid endarterectomy (CEA) are based on trials having recruited patients more than 15 years ago. Registry data indicate that advances in best medical treatment (BMT) may lead to a markedly decreasing risk of stroke in asymptomatic carotid stenosis. The aim of the SPACE-2 trial (ISRCTN78592017) was to compare the stroke preventive effects of BMT alone with that of BMT in combination with CEA or carotid artery stenting (CAS), respectively, in patients with asymptomatic carotid artery stenosis of ≥70% European Carotid Surgery Trial (ECST) criteria.

METHODS

SPACE-2 is a randomized, controlled, multicenter, open study. A major secondary endpoint was the cumulative rate of any stroke (ischemic or hemorrhagic) or death from any cause within 30 days plus an ipsilateral ischemic stroke within one year of follow-up. Safety was assessed as the rate of any stroke and death from any cause within 30 days after CEA or CAS. Protocol changes had to be implemented. The results on the one-year period after treatment are reported.

FINDINGS

It was planned to enroll 3550 patients. Due to low recruitment, the enrollment of patients was stopped prematurely after randomization of 513 patients in 36 centers to CEA (n = 203), CAS (n = 197), or BMT (n = 113). The one-year rate of the major secondary endpoint did not significantly differ between groups (CEA 2.5%, CAS 3.0%, BMT 0.9%; p = 0.530) as well as rates of any stroke (CEA 3.9%, CAS 4.1%, BMT 0.9%; p = 0.256) and all-cause mortality (CEA 2.5%, CAS 1.0%, BMT 3.5%; p = 0.304). About half of all strokes occurred in the peri-interventional period. Higher albeit statistically non-significant rates of restenosis occurred in the stenting group (CEA 2.0% vs. CAS 5.6%; p = 0.068) without evidence of increased stroke rates.

INTERPRETATION

The low sample size of this prematurely stopped trial of 513 patients implies that its power is not sufficient to show that CEA or CAS is superior to a modern medical therapy (BMT) in the primary prevention of ischemic stroke in patients with an asymptomatic carotid stenosis up to one year after treatment. Also, no evidence for differences in safety between CAS and CEA during the first year after treatment could be derived. Follow-up will be performed up to five years. Data may be used for pooled analysis with ongoing trials.

Abstract 95: MiRNA-210 Enhances Fibrous Cap Stability in Advanced Atherosclerotic Lesions

In the search for markers and modulators of vascular disease, miRNAs have emerged as potent therapeutic targets. We investigated miRNAs of clinical interest in patients with unstable carotid stenosis at risk of stroke. Utilizing patient material from the Biobank of Karolinska Endarterectomies (BiKE), we profiled miRNA expression in symptomatic versus asymptomatic patients with high-grade carotid artery stenosis. A PCR-based miRNA of plasma, sampled at the carotid lesion site, identified eight deregulated miRNAs (miR-15b, -29c, -30c/d, -150, -191, -210 and -500). miR-210 was the most significantly downregulated miRNA in local plasma material. Laser-capture microdissection as well as in situ hybridization revealed a distinct localization of miR-210 in the fibrous caps of atherosclerotic lesions and showed reduced miR-210 expression in the unstable fibrous cap. We confirmed that miR-210 directly targets the tumor suppressor gene adenomatous polyposis coli (APC), thereby affecting Wnt signaling and regulating vascular smooth muscle cell survival, as well as differentiation, in advanced atherosclerotic lesions. Substantial changes in arterial miR-210 were detectable in two rodent models of vascular remodeling and plaque rupture. Modulating miR-210 in vitro and in vivo improved fibrous cap stability with implications for vascular disease. We discovered that an unstable carotid plaque at risk of stroke is characterized by low expression of miR-210. miR-210 contributes to stabilizing carotid plaques through inhibition of APC, ensuring vascular smooth muscle cell survival. We present local delivery of miR-210 as a therapeutic approach for prevention of atherothrombotic disease.

Morphometry and Classification in Abdominal Aortic Aneurysms: Patient Selection for Endovascular and Open Surgery

Purpose:

To evaluate the anatomic morphology of abdominal aortic aneurysms (AAAs) and compose a classification system to facilitate patient selection for endovascular graft (EVG) repair.

Methods:

Data on 242 consecutive AAA patients evaluated on a nonemergent basis in a 3.5-year period to July 1996 were prospectively entered into a registry. Patients were examined using sequential intravenous spiral computed tomographic angiography and intraarterial digital subtraction angiography. The data collected and analyzed included: diameters of the supra- and infrarenal aorta, aneurysm, aortoiliac bifurcation, and iliac arteries; lengths of the proximal neck, distal cuff, and aneurysm; degrees of iliac artery tortuosity; and occlusion of the visceral, renal, or iliac arteries.

Results:

The 242 aneurysms could be easily grouped into three distinctive categories related to the extent of the aneurysmal disease. Type I AAAs (11.2%) had nondilated, thrombus-free infrarenal (15 mm) necks and distal (10 mm) cuffs appropriate for EVG anchoring. In type II and its subgroups (72.3%), a sufficient proximal neck was present, but the aneurysm extended into the iliac arteries; 56% of these were eligible for a bifurcated endograft. In type III (16.5%), a sufficient proximal neck was missing, independent of distal involvement. In all, 51.7% were good EVG candidates based on AAA morphology. Taking into consideration relevant concomitant vascular diseases, proximal iliac kinking, and iliac, renal, or visceral occlusive disease, only 30.2% of the population were potential candidates for an efficient and secure EVG repair using the devices currently available.

Conclusions:

In contrast to classical open repair, detailed preoperative measurements are recommended for EVG planning. The use of liberal EVG indications may lead to a higher incidence of complications, whereas restrictive morphology-based selection criteria may offer excellent results.

Patient characteristics and outcomes of carotid endarterectomy and carotid artery stenting: analysis of the German mandatory national quality assurance registry - 2003 to 2014

AIM

In Germany, every surgical or endovascular procedure on the extracranial carotid artery is documented in a mandatory quality assurance registry. The purpose of this study is to describe the patient characteristics, the indications for treatment, and the short-term outcomes as well as to analyse the corresponding trends from 2003 to 2014.

METHODS

Data on demographics, peri-procedural measures, and outcomes were extracted from the annual quality reports published by the Federal Agency for Quality Assurance and the Institute for Applied Quality Improvement and Research in Health Care. Data were available from 2003 to 2014 for carotid endarterectomy (CEA) and from 2012 to 2014 for carotid artery stenting (CAS). The primary outcome event of this study is any stroke or death until discharge from hospital. Temporal trends of categorical variables were statistically analysed using the Cochran-Armitage test for trend.

RESULTS

Between 2003 and 2014, 309,405 CEAs and 18,047 CAS procedures were documented in the database; 68.1% of all patients were male. The mean age of patients treated with CEA increased from 68.9 years in 2003 to 70.9 years in 2014. The proportion of patients with ASA stages III to V increased from 65% to 71% in CEA, whereas it decreased from 44% to 41% in CAS patients. 53.1% of all CEAs were performed for asymptomatic patients (group A), 34.4% for symptomatic patients treated electively (group B), and 11.2% a in a collective group including other indications for CEA or CAS (such as recurrent stenosis, carotid aneurysms, emergency treatment due to stroke-in-evolution). The corresponding data for CAS are 49.3%, 26.1% and 26.3% respectively. In group B, the interval between the neurological index event and CEA decreased from 28 to 8 days (P<0.001). In patients treated with CAS, this interval was 9 days in 2012 (no further data available). On average, 67.1% and 48.2% of surgically treated patients as well as 77.8% and 69.8% of CAS patients were neurologically assessed before and after the procedure, respectively. From 2003 to 2014, CEA procedures were performed more frequently in locoregional anesthesia (10.1% to 29.1%, P<0.001). The same trend was observed for the application of the eversion technique (37.0% to 41.6%, P<0.001), the neurophysiological monitoring (49.8% to 61.8%, P<0.001), and the intra-procedural assessment of the treated artery (44.5% to 69.7%, P<0.001). In contrast, shunting was used less frequently (48.1% to 43.0%, P<0.001). Averagely 95.7% of all endovascular procedures were performed using stent-angioplasty. In 54.2% a protection device was used. Nitinol and bare metal stents were used in 74.1% and 21.4% of cases, respectively. The in-hospital rate of any stroke or death decreased from 2.0% to 1.1% in asymptomatic patients treated with CEA without a contralateral stenosis ≥75% or occlusion, P<0.001). In patients treated with CAS this rate did not increase (1.7% to 1.8%, p=0.909). The corresponding rates in CEA and CAS patients with severe contralateral stenosis or occlusion varied between 1.9%-3.1% and 2.2%-2.6%, respectively. In symptomatic patients (group B) with a stenosis of 50 percent or more, the rate of any stroke or death decreased significantly after CEA from 4.2% to 2.4% (P<0.001) and remained stable after CAS (3.9% to 3.5%, P=0.577).

CONCLUSION

This report on 327,452 carotid procedures analysed one of the largest quality registries on CEA and CAS worldwide. Data indicate that treated patients became older and sicker, whereas in contrast, the in-hospital rates of stroke or death are decreasing over time.

Stroke risk in the early period after carotid related symptoms: a systematic review

Current guidelines recommend performing carotid endarterectomy in patients with symptomatic carotid disease as soon as possible after the neurological index event. However, early stroke risk has not been well documented for this patient group. We therefore conducted a systematic analysis of the current literature on the recurrent risk of ischemic events in patients with symptomatic carotid stenosis. Systematic review was performed by searching the MEDLINE® database from 1950 until June 8, 2015 (key words: cerebral ischemia, transient ischemic attack, amaurosis fugax, stroke, symptomatic carotid stenosis, recurrent risk, outcome, prognosis, follow-up, cohort and natural history). All studies reporting stroke risks in patients with symptomatic carotid stenosis after neurologic index events within a period of 7 days were included. Cumulative stroke risks with 95% confidence intervals after a neurologic index event were recalculated at 2-3, 7, 14 and 30 days and a meta-analysis including an analysis of heterogeneity were performed using the statistical package R and Excel for Mac 2003. Ten studies with a total number of 2634 patients were included. Results of an overall stroke risk were as follows: 2.0-17.2% at 2-3 days, 0-22.1% at 7 days, 0-29.6% at 14 days and 0-11.1% at 30 days in patients with a symptomatic extracranial carotid stenosis. The pooled stroke risk in the six studies with active follow-up was 6.0% (95% CI 2.4-14.4) at 2-3 days, 10.9% (6.1-18.7) at 7 days and 17.6% (9.7-29.9) at 14 days. Pooled stroke risk in the three studies with uncensored populations was even higher with 6.4% (1.5-23.8%) at 2-3 days, 19.5% (12.7-28.7) at 7 days and 26.1% (20.6-32.5%) at 14 days. Significant heterogeneity (P<0.001) could be explained by the different inclusion criteria and the study's design. Retrospective studies with passive follow-up had the lowest stroke risk whereas prospective studies with active follow-up and without bias through early intervention by carotid endarterectomy or carotid stenting had the highest stroke risk. The risk of recurrence of cerebrovascular events in patients with symptomatic carotid stenosis within the first days after a neurologic index event is as high as 6.4% (1.5-23.8), 19.5% (12.7-28.7) and 26.1% (20.6-32.5) after 2-3, 7 and 14 days respectively. Patients with a symptomatic carotid stenosis are therefore at a very high risk of a definitive stroke. Recommendations by current guidelines to perform carotid endarterectomy as soon as possible after the neurologic index event are therefore justified.

[Treatment of asymptomatic carotid artery stenosis: improvement of evidence with new SPACE-2 design necessary]

Asymptomatic carotid artery stenosis may be treated with carotid endarterectomy (CEA), carotid artery stenting (CAS) or with best medical treatment (BMT) only. Definitive and evidence-based treatment recommendations for one of these options are currently not possible. Studies showing an advantage of CEA over BMT alone do not meet current standards from a pharmacological point of view. On the other hand, more recent data point to a further stroke risk reduction using BMT according to current standards. Studies on carotid artery stenting as a third alternative treatment are partially insufficient, especially when comparing CAS with BMT. Initiated in 2009, the randomized, controlled, multicenter SPACE-2 trial is intended to answer the question about the best treatment option of asymptomatic carotid artery stenosis; however, to increase recruitment rates as a condition for the successful completion of this important study, the trial design had to be modified.

Chapter VI: Follow-up after revascularisation

Structured follow-up after revascularisation for chronic critical limb ischaemia (CLI) aims at sustained treatment success and continued best patient care. Thereby, efforts need to address three fundamental domains: (A) best medical therapy, both to protect the arterial reconstruction locally and to reduce atherosclerotic burden systemically; (B) surveillance of the arterial reconstruction; and (C) timely initiation of repeat interventions. As most CLI patients are elderly and frail, sustained resolution of CLI and preserved ambulatory capacity may decide over independent living and overall prognosis. Despite this importance, previous guidelines have largely ignored follow-up after CLI; arguably because of a striking lack of evidence and because of a widespread assumption that, in the context of CLI, efficacy of initial revascularisation will determine prognosis during the short remaining life expectancy. This chapter of the current CLI guidelines aims to challenge this disposition and to recommend evidentially best clinical practice by critically appraising available evidence in all of the above domains, including antiplatelet and antithrombotic therapy, clinical surveillance, use of duplex ultrasound, and indications for and preferred type of repeat interventions for failing and failed reconstructions. However, as corresponding studies are rarely performed among CLI patients specifically, evidence has to be consulted that derives from expanded patient populations. Therefore, most recommendations are based on extrapolations or subgroup analyses, which leads to an almost systematic degradation of their strength. Endovascular reconstruction and surgical bypass are considered separately, as are specific contexts such as diabetes or renal failure; and critical issues are highlighted throughout to inform future studies.

Chapter I: Definitions, epidemiology, clinical presentation and prognosis

The concept of chronic critical limb ischaemia (CLI) emerged late in the history of peripheral arterial occlusive disease (PAOD). The historical background and changing definitions of CLI over the last decades are important to know in order to understand why epidemiologic data are so difficult to compare between articles and over time. The prevalence of CLI is probably very high and largely underestimated, and significant differences exist between population studies and clinical series. The extremely high costs associated with management of these patients make CLI a real public health issue for the future. In the era of emerging vascular surgery in the 1950s, the initial classification of PAOD by Fontaine, with stages III and IV corresponding to CLI, was based only on clinical symptoms. Later, with increasing access to non-invasive haemodynamic measurements (ankle pressure, toe pressure), the need to prove a causal relationship between PAOD and clinical findings suggestive of CLI became a real concern, and the Rutherford classification published in 1986 included objective haemodynamic criteria. The first consensus document on CLI was published in 1991 and included clinical criteria associated with ankle and toe pressure and transcutaneous oxygen pressure (TcPO(2)) cut-off levels <50 mmHg, <30 mmHg and <10 mmHg respectively). This rigorous definition reflects an arterial insufficiency that is so severe as to cause microcirculatory changes and compromise tissue integrity, with a high rate of major amputation and mortality. The TASC I consensus document published in 2000 used less severe pressure cut-offs (≤ 50-70 mmHg, ≤ 30-50 mmHg and ≤ 30-50 mmHg respectively). The thresholds for toe pressure and especially TcPO(2) (which will be also included in TASC II consensus document) are however just below the lower limit of normality. It is therefore easy to infer that patients qualifying as CLI based on TASC criteria can suffer from far less severe disease than those qualifying as CLI in the initial 1991 consensus document. Furthermore, inclusion criteria of many recent interventional studies have even shifted further from the efforts of definition standardisation with objective criteria, by including patients as CLI based merely on Fontaine classification (stage III and IV) without haemodynamic criteria. The differences in the natural history of patients with CLI, including prognosis of the limb and the patient, are thus difficult to compare between studies in this context. Overall, CLI as defined by clinical and haemodynamic criteria remains a severe condition with poor prognosis, high medical costs and a major impact in terms of public health and patients' loss of functional capacity. The major progresses in best medical therapy of arterial disease and revascularisation procedures will certainly improve the outcome of CLI patients. In the future, an effort to apply a standardised definition with clinical and objective haemodynamic criteria will be needed to better demonstrate and compare the advances in management of these patients.

Chapter V: Diabetic foot

Ulcerated diabetic foot is a complex problem. Ischaemia, neuropathy and infection are the three pathological components that lead to diabetic foot complications, and they frequently occur together as an aetiologic triad. Neuropathy and ischaemia are the initiating factors, most often together as neuroischaemia, whereas infection is mostly a consequence. The role of peripheral arterial disease in diabetic foot has long been underestimated as typical ischaemic symptoms are less frequent in diabetics with ischaemia than in non-diabetics. Furthermore, the healing of a neuroischaemic ulcer is hampered by microvascular dysfunction. Therefore, the threshold for revascularising neuroischaemic ulcers should be lower than that for purely ischaemic ulcers. Previous guidelines have largely ignored these specific demands related to ulcerated neuroischaemic diabetic feet. Any diabetic foot ulcer should always be considered to have vascular impairment unless otherwise proven. Early referral, non-invasive vascular testing, imaging and intervention are crucial to improve diabetic foot ulcer healing and to prevent amputation. Timing is essential, as the window of opportunity to heal the ulcer and save the leg is easily missed. This chapter underlines the paucity of data on the best way to diagnose and treat these diabetic patients. Most of the studies dealing with neuroischaemic diabetic feet are not comparable in terms of patient populations, interventions or outcome. Therefore, there is an urgent need for a paradigm shift in diabetic foot care; that is, a new approach and classification of diabetics with vascular impairment in regard to clinical practice and research. A multidisciplinary approach needs to implemented systematically with a vascular surgeon as an integrated member. New strategies must be developed and implemented for diabetic foot patients with vascular impairment, to improve healing, to speed up healing rate and to avoid amputation, irrespective of the intervention technology chosen. Focused studies on the value of predictive tests, new treatment modalities as well as selective and targeted strategies are needed. As specific data on ulcerated neuroischaemic diabetic feet are scarce, recommendations are often of low grade.

Evidence-based management of carotid stenosis: recommendations from international guidelines

A 50-99% stenosis of the extracranial internal carotid artery can be in detected in 1-3% of all adults. Embolising plaques or acute carotid occlusions cause cerebral ischemia in 1-5% of all patients with an asymptomatic 50-99% stenosis of the internal carotid artery. The prevention of carotid-related strokes by best medical treatment, carotid endarterectomy, or carotid stenting has been evaluated by several prospective randomized multi-center trials. Under the auspices of the German Vascular Society an interdisciplinary evidence- and consensus-based guideline for the management of patients with an extracranial carotid stenosis was initiated and will be published in 2012. Therefore all recent national and international guidelines for stroke management, stroke prevention and carotid artery disease published between 2008 and 2011 were reviewed. This paper gives an overview about these guidelines and their most important recommendations with respect to carotid artery stenosis.

Prestressing in finite deformation abdominal aortic aneurysm simulation

In abdominal aortic aneurysm (AAA) simulation the patient-specific geometry of the object of interest is very often reconstructed from in vivo medical imaging such as CT scans. Such geometries represent a deformed configuration stressed by typical in vivo conditions. However, commonly, such structures are considered stress-free in simulation. In this contribution we sketch and compare two methods to introduce a physically meaningful stress/strain state to the obtained geometry for simulations in the finite strain regime and demonstrate the necessity of such prestressing techniques. One method is based on an inverse design analysis to calculate a stress-free reference configuration. The other method developed here is based on a modified updated Lagrangian formulation. Formulation of both methods is provided. Applicability and accurateness of both approaches are compared and evaluated utilizing fully three-dimensional patient-specific AAA structures in the finite strain regime.

[General surgery under discussion. From the viewpoint of vascular surgery]

Vascular diseases are common and their frequency is rising. Statistics show that 15% of the German population over 65 display some kind of peripheral arterial pathology. Even aneurysmatic degeneration and cardiac and visceral perfusion disorders are being observed more frequently, while peak age is dropping. Therapeutic surgical options are accordingly being continually advanced and refined. Additionally the range of interventional therapies and new conservative options has substantially increased vascular surgeons' armamentarium. Updates in surgical training have responded to this increase in such disorders, and the diversification of therapeutic modalities has resulted in the elevation of vascular surgery from specialized techniques to a fully accredited specialty equal in standing to the other seven surgical disciplines. Controversy exists however about the new accredition, beginning with the question of advancement from basic surgical training while excluding important elements of general surgery. Since those training for this specialty will branch off immediately after 2 years of basic surgical training, their final accreditation in the new classification would exclude essential skills that remain part of the training as general surgeons.

Fibrinogen and high-sensitive C-reactive protein as serologic predictors for perioperative cerebral microembolic lesions after carotid endarterectomy

BACKGROUND

Neurologic deficit caused by cerebral ischemia defines the outcome of carotid endarterectomy (CEA). Although few patients have clinically evident neurologic deficit, diffusion-weighted imaging (DWI) presents a number of cases with ischemic brain lesions. This study should elucidate preoperative risk factors for perioperative microemboli that cause brain infarction.

METHODS

We studied 183 patients (58 women, 69.2 +/-12.7 years; 125 men, 69.3 +/- 8.9 years) with high-degree carotid artery stenosis. DWI was performed before and after CEA to analyze new cerebral ischemia. Blood samples were obtained before operation to measure fibrinogen and C-reactive protein (CRP), and preoperative high-sensitive CRP (hsCRP) was analyzed in 30 consecutive patients.

RESULTS

Postoperative DWI revealed new ipsilateral ischemic lesions in 41 patients (22.4%), and eight (4.4%) showed new neurologic deficit. Preoperative fibrinogen levels were higher in patients with new lesions (397.6 mg/dL +/- 104.7 mg/dL) than in those without (324.7 mg/dL +/- 74.2 mg/dL, P < .001). Preoperative levels of hsCRP were also higher in patients with new lesions (7.9 mg/dL +/- 5.2 mg/dL) than in those without (2.8 mg/dL +/- 2.6 mg/dL, P = .004). Significant association was found between fibrinogen and CRP (Spearman rho = 0.402; P < .001) as well as hsCRP (Spearman rho = 0.603, P = .003). No association was found between postoperative lesions and CRP (P = .833).

CONCLUSION

The present study demonstrates that preoperative levels of fibrinogen and hsCRP are independent determinants for new periprocedural cerebral ischemic lesions caused by microembolic events. There is still not sufficient evidence to recommend measurement of CRP as a prognostic marker for perioperative cerebral lesion.

Aneurysmen und Dissektionen der thorakalen und abdominellen Aorta

One to four per cent of all deaths in patients over 65 are caused by aneurysmatic diseases of the abdominal or thoracic aorta. For elective surgery in abdominal aneurysms, open surgery and endovascular treatment both demonstrate brilliant overall results. In the thoracic aorta, new endovascular procedures have led to considerable reductions of postoperative morbidity and mortality. Nevertheless, in view of the endovascular procedure's high cost and the still unclear long-term behaviour of the stent device, a second opinion from a specialised centre is an absolute necessity.

Do workshops improved the technical skill of vascular surgical trainees?

AIMS

Adjuncts to conventional surgical training are needed in order to address the reduction in working hours. This purpose of this study was to objectively assess the efficacy of workshop training on simulators.

METHODS

Fifteen consecutive participants of the European Vascular Workshop in 2003 and 2004 were recruited to this study. Participants performed a proximal anastomosis on a commercially available abdominal aortic aneurysm simulator, were then given intensive training on sophisticated models for 3 days and re-assessed. Pre- and post-course procedures were videotaped and independently reviewed by three assessors (tapes were blinded and in random order). The operative end product was similarly assessed. Four measures of technical skill were used: generic skill, procedural skill; a five point technical rating of the anastomosis (assessed using validated rating scales) and procedure time. Non-parametric tests were used in the statistical analysis.

RESULTS

The video assessment scores for aneurysm repair increased significantly following completion of the course (p=0.006 and p=0.004 for generic and procedural skill, respectively). End product assessment scores increased significantly post-course (p=0.001) and participants performed aneurysm repair faster following the course (p<0.05). Inter-observer reliability ranged from alpha=0.84-0.98 for the three rating scales pre- and post-course.

CONCLUSION

Objective improvements in technical performance follow intensive workshop training. Participants' perform better, faster, and with an improved end product following the course. Such adjuncts to training play an important part in a focused integrated programme that addresses reduced work hours.

Operative Therapie extrakranieller Karotisstenosen

The surgical therapy for severe stenosis of the carotid provides a highly effective prophylaxis for carotid dependent ischemic strokes. After carrying out prospective, randomised studies, evidence based indications for carotid thromboarterectomy are available. Here, it is necesary to take into account the degree of stenosis, an initial clinical symptom (amaurosis fugax, TIA, stroke), and postoperative risk. This can not exceed 3% by asymptomatic and 6% by symptomatic stenoses in order not to endanger the carotid thromboarterectomy. Stenting of carotid stenoses provides a possible alternative to surgery. Until the prospective, randomised studies are completed, carotid stenting offers a clinical possibility which can only be carried out through interdisciplinary cooperation.

The Carotid Surgery for Ischemic Stroke trial: a prospective observational study on carotid endarterectomy in the early period after ischemic stroke

OBJECTIVE

The purpose of this study was to examine the safety of carotid endarterectomy (CEA) within 6 weeks after a nondisabling carotid-related ischemic stroke. Endpoints were the perioperative stroke or mortality rate and the incidence rate of cerebral bleedings.

METHODS

This prospective observational multicenter trial was performed in community and university centers. One hundred sixty-four hospitalized patients with nondisabling carotid-related ischemic stroke were included. The patients were identified clinically with the modified Rankin scale (initial neurologic deficit grade >/= 2, n = 160). Four patients with evidence of ischemic territorial infarction on cerebral computed tomographic (CT) scan but no persisting functional deficit were also included. CEA was performed within 6 weeks after stroke. Neurologic examinations were performed initially, before surgery, 3 days after surgery, and 6 weeks after CEA. Worsening of more than 1 grade on the Rankin scale was considered as a new stroke or stroke extension. Unenhanced CT scans of the brain were performed before and after surgery. CT scans were evaluated blind to clinical patient data. Statistical analysis included univariate and multivariate analysis.

RESULTS

The combined stroke or mortality rate within 30 days after CEA was 6.7%. Ten patients had a new ipsilateral stroke or stroke extension, and one patient died after surgery of a myocardial infarction. One patient (0.6%) had parenchymatous cerebral bleeding, and in 10 patients, hemorrhagic transformation within the preexisting ischemic infarction was detected but no infarct extension was observed. In the multivariate analysis, American Society of Anesthesiology (ASA) grades III and IV and decreasing age were significant predictors for an increased perioperative risk. Patients with a higher risk profile (ASA classification grades III and IV) had a high perioperative risk when CEA was performed within the first 3 weeks (14.6% versus 4.8% beyond 3 weeks). Patients without severe concomitant diseases (ASA grades I/II) had a low perioperative risk of 3.4% if CEA was performed within the first 3 weeks.

CONCLUSION

Early CEA within 6 weeks after a carotid-related ischemic stroke can be performed with a perioperative stroke or mortality rate comparable with the results reported in the European Carotid Surgery Trial and the North American Symptomatic Carotid Endarterectomy Trial. The risk of parenchymatous bleeding is low. ASA grades III and IV and decreasing age were predictive of an increased perioperative risk, especially if CEA was performed within the first 3 weeks. Patients at low risk can undergo operation safely within the first 3 weeks. Individual patient selection in an interdisciplinary approach between neurologists, anesthesiologists, and vascular surgeons remains mandatory in these patients.

[Outcome quality in vascular surgery]

INTRODUCTION

For the assessment of outcome quality, the acquisition and evaluation of internal and external treatment data is necessary. Vascular surgery is characterized in main topics of treatment such as carotid stenoses, aortic aneurysms, peripheral arterial disease, and varicose veins by clearly defined outcome indicators. Nevertheless, the determination of the quality of outcome is difficult because of the differing standards.

METHODS

For an external, comparative quality assurance, the quality assurance commission of the German Society for Vascular Surgery has established a program, "Quality Management for the carotid TEA and the BAA" according to section 137 SGB V, and has developed a questionnaire for recording the quality of treatment of varicose veins.

RESULTS

The evaluation of all the questionnaires submitted to an independent institute enables the participating departments to have a comprehensive evaluation of their own quality of outcome and provides a tool to compare it with defined quality levels (benchmarking).

CONCLUSION

For every physician, the perception of his own quality of outcome represents a fundamental requirement, which continues to gain importance within the context of future health policies.

Perfusion-weighted magnetic resonance imaging in patients with carotid artery disease before and after carotid endarterectomy

OBJECTIVE

The purpose of this study was to investigate the potential of perfusion-weighted magnetic resonance imaging for preoperative and postoperative evaluation of cerebral hemodynamics in patients undergoing carotid endarterectomy for carotid artery stenosis.

METHODS

We examined 26 patients with angiographically proven stenoses (60%-99%) of the internal carotid artery preoperatively. Perfusion imaging studies were performed by bolus-tracking of a dosage of 0.2 mmol/kg body weight of gadolinium diethylenetriaminepentaacetic acid on a 1.5-T scanner using a T2*-weighted fast low-angle shot sequence. The observed signal intensities were converted pixel by pixel into concentration-time curves. In each patient, the hemispheres were compared and the difference between the normalized first moments (NFMs) and the percentage changes of the regional cerebral blood volume (CBV) were calculated. Three months postoperatively, perfusion-weighted magnetic resonance imaging was performed in 13 patients.

RESULTS

In patients with <80% stenosis (n = 10), there was no significant alteration of NFM and regional CBV compared with the contralateral hemisphere (-0.16 +/- 0.7 s, +5.9 +/- 24.6%). In patients with stenoses >or=80% (n = 16), we found an increase in NFM ipsilateral to the stenosis of 1.2 +/- 0.92 s (P < .001) and an increase of CBV of 16.8 +/- 15.2% (P < .005). Three months postoperatively, perfusion parameters were normal in all 13 patients examined.

CONCLUSIONS

Perfusion-weighted magnetic resonance imaging is well suited to evaluate the preoperative and postoperative hemodynamic changes in patients with carotid artery stenosis. This noninvasive, semiquantitative magnetic resonance technique could prove to be a valuable adjunct in identification of patients who might benefit from carotid endarterectomy.

Immunophenotypic characterisation of carotid plaque: increased amount of inflammatory cells as an independent predictor for ischaemic symptoms

OBJECTIVES

To investigate the inflammatory response within intact carotid plaques from carotid eversion endarterectomy (CEE) to determine the relationship between immunohistological plaque morphology and ischaemic cerebrovascular symptoms.

MATERIAL AND METHODS

Intact CEE plaques from 71 patients with high-grade (>70%) stenosis undergoing CEE (group I, symptomatic, n=42; group II, asymptomatic, n =29) and 12 normal postmortem arteries (control group) were analysed with specific antibodies to inflammatory cells (T-Lymphocytes (CD3, CD4), cytotoxic T-cells (CD8), B-lymphocytes (CD20), natural killer cells (CD57), macrophages (CD68)), endothelial adhesion molecules (ICAM-1 (CD54), P-selectin (CD62P), E-selectin (CD62E), VCAM-1 (CD106) and T-lymphocyte co-stimulatory molecule (CD40)) and procoagulatory modulators (thrombomodulin (CD141), tissue factor (CD142)). Both groups were matched for gender, age, risk factors, degree of carotid artery stenosis. Plaques were measured using a semiquantitative score system in a blinded fashion by two observers. Statistical analysis of the group differences were performed by using the Kruskal-Wallis test and the Multitest Procedure with Permutation-Testing. Significance was taken as a p<0.05.

RESULTS

There were significantly more inflammatory cells, an overexpression of P-selectin and the procoagulatory markers thrombomodulin and tissue factor in symptomatic compared to both asymptomatic plaques and the ones of the control group. In both groups there was no significance for ICAM-1, VCAM-1, macrophages and co-stimulatory molecule CD40. There was also no significance for any factor between the asymptomatic and the control group. However, the differences between the symptomatic and the asymptomatic group were highly significant for all factors.

CONCLUSION

These data suggest that structural changes and inflammatory damage within the individual plaque seems to be a critical step in promoting plaque rupture with embolic sequelae.

Grading of Internal Carotid Artery Stenosis: Validation of Doppler/Duplex Ultrasound Criteria and Angiography Against Endarterectomy Specimen

OBJECTIVES

duplex ultrasound has replaced angiography prior to carotid endarterectomy (CEA) in many institutions. However, the indications for CEA are based on angiographically controlled studies and widely accepted ultrasound criteria do not exist. Consequently, the reliability of Doppler and/or duplex ultrasound to predict a high-grade ICA stenosis has to be proven.

DESIGN

prospective validation study.

MATERIALS

one hundred and fifty carotid bifurcations assessed by ultrasound and selective angiography and 68 acrylat outcasts of carotid specimen after eversion CEA.

METHODS

ICA stenosis was measured angiographically according to the ECST criteria. Combined Doppler acoustic standard criteria (CDASC), peak systolic frequency (PSF), peak systolic velocity (PSV) and end-diastolic velocity (EDV) served as criteria for the ultrasound assessment. These criteria and the results of angiography were compared to the degree of ICA stenosis determined by specimen measurements.

RESULTS

the median degree of ICA stenosis as assessed by angiography (82%, range 56-97%) and CDASC (83%, range 50-99%) corresponded well to the specimen measurements (80%, range 50-95%). The sensitivity of angiography and CDASC to predict a 70-90% ICA stenosis (ECST criteria) compared to the specimen measurements was 88% and 95%, respectively. The positive predictive value (PPV) reached 92% and 96%, respectively. CDASC were equivalent to angiography and were superior to the best single frequency or velocity parameters. If CDASC do not indicate a >/=70% ICA stenosis in spite of a PSV >/=180 cm/s and/or an EDV >/=50 cm/s, angiography may detect patients with a >70% ICA stenosis.

CONCLUSIONS

CDASC are valid in the quantification of high-grade ICA stenosis. They are more reliable than single velocity and/or frequency measurements. However, if velocity criteria and CDASC do not agree, angiography should be performed.

[Carotid surgery in patients 80 years old or older]

BACKGROUND AND OBJECTIVE

Because of their high age and markedly increased co-morbidity, physicians and geriatricians are often cautious in their indications for carotid thromboendarterectomy (TEA) in patients 80 years or older. However, it is these very patients who are subject to an exponentially increased risk of ischaemic cerebral vascular accidents (CVA). This study examined the morbidity and mortality rates of TEA in patients of this age group at one institution.

PATIENTS AND METHODS

Between 1994 and 1998, among a total of 912 TEAs, 46 had been performed in patients 80 years or older (15 women, 31 men): indications, diagnosis and associated diseases as well as perioperative complications were entered prospectively into a data-bank.

RESULTS

Only one patient (2.2%) sustained a perioperative CVA and no patient died. Three patients (6.5%) developed transitory neurological deficits. One patient had to have an emergency reoperation because of a postoperative carotid artery thrombosis. One patient had an intraoperative asystole due to a hypersensitive carotid sinus. There were no other serious cardiovascular or pulmonary complications. One patient sustained some oral muscle weakness as a result of intraoperative retractor pull on a branch of the facial muscle.

CONCLUSION

These results indicate that even in patients of this age group carotid TEA can be performed with great safety.

[Urgent and emergency carotid TEA]

Restoration of blood flow to reperfuse ischemic but not infarcted areas of the brain (ischemic penumbra) and the removal of an ongoing embolic source are the therapeutic aims of emergency and urgent carotid endarterectomy (CEA), both in patients with an acute or progressive ischemic stroke and in patients in the early period after a carotid-related stroke. Based on poor results in the 60ies and 70ies, many centers traditionally perform CEA four to six weeks after a carotid-related stroke at the earliest interval. Since natural history is associated with a high risk of an disabling and/or recurrent stroke in several subgroups of patients, some reports were able to show that urgent and emergency CEA could be worthwhile in well-selected patients.

[Measurement of local oxygen parameters for detection of cerebral ischemia. The significance of cerebral near-infrared spectroscopy and transconjunctival oxygen partial pressure in carotid surgery]

The principle of, "selective shunting" during carotid endarterectomy requires a special concept to monitor neuronal function. The valence of the oxymetric methods, "near-infrared" spectroscopy (NIRS) and conjunctival oxygen tension (pcjO2) was determined with the reference method somatosensory evoked potentials (SEP).

METHODS

In 41 patients undergoing reconstructive surgery on the internal carotid artery, recordings of the different methods were obtained under control, during carotid occlusion and during reperfusion. Cerebral ischemia was assumed if a complete loss of SEP appeared and an intraluminal shunt was placed. Conjunctival oxygen tension was measured continuously and simultaneously on the ipsi- and contralateral eye.

RESULTS

In comparison to the reference method (SEP) the sensitivity and specificity of NIRS was 80% and 94%, respectively. The occlusion induced reduction of NIRS appeared 6.5 +/- 3.2 min earlier than the corresponding loss of SEP. Biocular determination of conjunctival oxygen tension was not able to detect hypoperfusion dependent ischemia during carotid occlusion.

CONCLUSION

During carotid endarterectomy the measurement of conjunctival oxygen tension is not useful to detect cerebral ischemia. The use of NIRS as a single neuronal monitor is not appropriate to perform, "selective shunting". In contrast to SEP, however, NIRS is characterized by its rapid changes immediately following carotid occlusion. This non invasive method is likely to complete the standard method SEP in a modified monitoring concept of neuronal function during carotid endarterectomy.

Emergency carotid endarterectomy

OBJECTIVE

Evaluation of the therapeutical efficacy of emergency carotid endarterectomy (CEA) in neurologically unstable patients.

PATIENTS AND METHODS

Three groups of a consecutive series of 71 emergency CEAs performed from 1980 to July 1998 were classified: (1) acute onset of severe stroke (n = 16), (2) progressive stroke/stroke in evolution (n = 34), and (3) crescendo transient ischemic attacks (n = 21). Cerebral coma, cerebral haemorrhage, and major ischemic stroke established in cranial computed tomography scans were contraindications for surgery. The neurological outcome was assessed by the modified Rankin scale. Long-term survival and long-term stroke recurrences were analyzed.

RESULTS

The recovery/minor stroke rates (Rankin 0-3) in acute stroke, progressive stroke, and crescendo transient ischemic attacks were 56.3, 76.4 and 80.9%, respectively; the combined major stroke/mortality rates (Rankin 4-6) were 43.7, 23.6 and 19.1%, respectively. Intraoperative angiography in 39 patients detected early carotid reocclusions in 2 and intracranial embolism in 7 patients. Local application of thrombolytic agents (n = 5) may contribute to a better neurological outcome in emergency CEA. Life table probabilities of major strokefree survival were 74.5, 71.6, and 53.7% after 1, 2, and 5 years, respectively (including perioperative strokes). Life table probabilities to suffer no stroke recurrence during follow-up were 96.7, 96.7 and 85.3%, respectively (perioperative strokes excluded).

CONCLUSIONS

Emergency CEA may be worthwhile in selected patients. Completion angiography is mandatory. Emergency CEA should be included in therapeutic strategies for ischemic stroke.

[Endovascular prostheses: evolution, state-of-the-art and perspectives of a new technology]

The treatment of infrarenal aortic aneurysms by means of transluminally placed endovascular prostheses reflects significant progress in the field of vascular surgery. In the case of infrarenal aortic aneurysm it is possible to achieve technically successful implantation of such a prosthesis in well over 90 % of cases. The rate of clinical success, meaning lasting effective exclusion of the aortic aneurysm, cannot (yet) be definitively determined, since no long-term results are so far available. Secondary leaks are observed in at least 10 % of all patients, making a further therapy necessary (endorepair, conversion, embolization). Further development of endovascular prostheses will include optimization of the aortal/iliac attachment of the prostheses, a better configuration and the development of long-lasting materials that can be used for endovascular prostheses.

Adenosine: a sensitive indicator of cerebral ischemia during carotid endarterectomy

BACKGROUND

For the human brain, there are no data available concerning the significance of adenosine and its metabolites as biochemical indicators of cerebral ischemia. Since adenosine may counteract key pathogenetic mechanisms during cerebral ischemia, its sensitivity and specificity as a marker of cerebral ischemia was investigated in relation to hypoxanthine and lactate.

METHODS

Arterial and jugular venous concentration changes of adenosine, hypoxanthine, and lactate were studied in 41 patients undergoing carotid endarterectomy. Cerebral tissue oxygenation was monitored continuously by somatosensory-evoked potentials. A carotid artery shunt (n = 6) was placed only after complete loss of somatosensory-evoked potentials.

RESULTS

Before carotid artery clamping jugular venous concentrations of adenosine, hypoxanthine, and lactate in subsequently shunted patients were 229+/-88 nM, 1105+/-116 nM, and 0.85+/-0.52 mM, respectively (mean +/- SD). In patients who required shunting, carotid artery clamping induced a significant increase in jugular venous adenosine (389+/-114 nM) and jugular venous hypoxanthine (1444+/-168 nM). In contrast, the increase in jugular venous lactate (0.91+/-0.48 mM) did not reach statistical significance. Focal cerebral ischemia was indicated by jugular venous adenosine with a sensitivity and specificity of 0.83 and 0.71, respectively.

CONCLUSIONS

Carotid artery clamping induced significant increases in jugular venous adenosine and hypoxanthine in patients with inadequate collateral blood flow. In addition, focal cerebral ischemia was reflected by changes in adenosine concentrations.

[Carotid surgery for prophylaxis of ischemic stroke]

Every year more than 250,000 patients suffer from ischemic (80%) or hemorragic (20%) stroke. Some 40,000 of these strokes are induced by stenosis or occlusion of the extracranial carotid artery. Several randomized studies (NASCET, ECST, ACAS, etc.) have proved that operative removal of high-grade carotid stenoses is an effective method in the primary and secondary prophylaxis of ischemic stroke. Operative therapy is significantly better than medical therapy with thrombocyte aggregation inhibitors. The prerequisite for effective operative prophylaxis is a low perioperative stroke rate. Even though the prophylactic value of carotid thrombarterectomy (TEA) is obvious, only about 5% of all carotid-related strokes are prevented by this operation. Essential conditions for increased efficiency in carotid surgery are close cooperation with the neurologist and the internist, screening of patients with a high risk for ischemic stroke, sophisticated, mainly non-invasive diagnostics, and more operative capacity. Interventional methods (stent, PTA) have not yet been proved safe and effective. These methods should be employed only in special cases after interdisciplinary discussions or in randomized studies.

Carotid endarterectomy and intracranial thrombolysis: simultaneous and staged procedures in ischemic stroke

PURPOSE

The feasibility and safety of combining carotid surgery and thrombolysis for occlusions of the internal carotid artery (ICA) and the middle cerebral artery (MCA), either as a simultaneous or as a staged procedure in acute ischemic strokes, was studied.

METHODS

A nonrandomized clinical pilot study, which included patients who had severe hemispheric carotid-related ischemic strokes and acute occlusions of the MCA, was performed between January 1994 and January 1998. Exclusion criteria were cerebral coma and major infarction established by means of cerebral computed tomography scan. Clinical outcome was assessed with the modified Rankin scale.

RESULTS

Carotid reconstruction and thrombolysis was performed in 14 of 845 patients (1.7%). The ICA was occluded in 11 patients; occlusions of the MCA (mainstem/major branches/distal branch) or the anterior cerebral artery (ACA) were found in 14 patients. In three of the 14 patients, thrombolysis was performed first, followed by carotid enarterectomy (CEA) after clinical improvement (6 to 21 days). In 11 of 14 patients, 0.15 to 1 mIU urokinase was administered intraoperatively, ie, emergency CEA for acute ischemic stroke (n = 5) or surgical reexploration after elective CEA complicated by perioperative intracerebral embolism (n = 6). Thirteen of 14 intracranial embolic occlusions and 10 of 11 ICA occlusions were recanalized successfully (confirmed with angiography or transcranial Doppler studies). Four patients recovered completely (Rankin 0), six patients sustained a minor stroke (Rankin 2/3), two patients had a major stroke (Rankin 4/5), and two patients died. In one patient, hemorrhagic transformation of an ischemic infarction was detectable postoperatively.

CONCLUSION

Combining carotid surgery with thrombolysis (simultaneous or staged procedure) offers a new therapeutic approach in the emergency management of an acute carotid-related stroke. Its efficacy should be evaluated in interdisciplinary studies.

[Computer-based training exemplified by the carotid artery]

The purpose of computer-based training (CBT) is interactive use of multimedia components, such as text, graphics, animation, sound, digital slide shows, and videos. This CD-ROM illuminates different aspects of carotid surgery: cerebrovascular insufficiency, sonographic and neuroradiological diagnostics, indications and results of carotid surgery in the literature, perioperative complications and new developments such as interventional procedures. Digital imaging (60 minutes of video sequences and 250 graphics) especially focus on operative standard procedures (conventional and eversion technique) and alternative methods. CBT is an evolving supplement to improve education programs in vascular surgery.

[Indications for urgent carotid reconstruction]

Diagnostic methods and indications for carotid surgery must be coordinated with the individual carotid-related stroke risk. The indication for urgent carotid reconstruction within a few days after the initial event should always be evaluated when a clinical and/or morphological unstable and therefore risky carotid lesion is present and the 30-day stroke risk without surgery is > 5%. Patients with high-grade symptomatic carotid stenoses fulfill these criteria as do patients with recurrent carotid-related TIA, patients with hemipheric TIA, patients with symptomatic carotid stenosis and contralateral carotid occlusion and patients after a non-disabling carotid-related stroke. The clinical significance of sonographic carotid plaque criteria and intracranial emboli detected by TCD must be further evaluated in prospective studies.

[Endovascular infrarenal surgery of abdominal aortic aneurysm in selected patients: 3-years outcome and complication management]

We report a over 3-year single center experience with five different self-expanding or ballon-expandable stent-graft devices used for aneurysm exclusion in the infrarental aorta. All devices appeared to offer a safe, efficacious, and minimally invasive means of excluding the aneurysms from circulation. Key to success is restrictive patient selection due to morphological criteria and improvements in surgical techniques and equipment to reduce the incidence of complications and endoleaks. At the moment, patients who opt for the endovascular method of repair should be aware that the minimally invasive technique carries the disadvantage of a higher failure rate compared to open surgery. Long-term results are required to establish selection criteria, especially for younger patients.

Concentration changes of malondialdehyde across the cerebral vascular bed and shedding of L-selectin during carotid endarterectomy

BACKGROUND AND PURPOSE

Oxidative stress has been postulated to account for delayed neuronal death due to ischemia/reperfusion. We investigated cerebral formation of malondialdehyde as an index of lipid peroxidation in relation to different sources of reactive oxygen species in patients undergoing carotid endarterectomy.

METHODS

In 25 patients undergoing carotid endarterectomy, jugular venous-arterial concentration differences of brain metabolites, malondialdehyde, plasma total antioxidant status, and soluble P-selectin and L-selectin were measured. A carotid artery shunt (n=5) was placed only after complete loss of somatosensory evoked potentials, indicating a focal cerebral blood flow <15 mL/min per 100 g.

RESULTS

As an indication of cerebral lipid peroxidation, jugular venous-arterial malondialdehyde concentration differences were significantly enhanced before reperfusion, and an additional rise was observed 15 minutes after reperfusion. Plasma total antioxidant status significantly decreased during carotid artery occlusion only in patients with carotid artery shunt. This decrease was matched by cerebral formation of adenosine, hypoxanthine, and nitrite/nitrate. While jugular venous-arterial concentration differences of soluble P-selectin showed changes similar to those of malondialdehyde, the concentration difference for soluble L-selectin was enhanced exclusively at 15 minutes after reperfusion.

CONCLUSIONS

Short-term incomplete cerebral ischemia/reperfusion significantly enhanced cerebral lipid peroxidation, as indicated by malondialdehyde formation. The generation of reactive oxygen species by xanthine oxidase or nitric oxide metabolism might be involved in the induction of lipid peroxidation. The additional rise in cerebral release of malondialdehyde was found to coincide with a significant activation of polymorphonuclear leukocytes across the cerebral circulation.

[Carotid endarterectomy in the early phase after a non-disabling stroke: 1980-1995 results]

In 56 patients, carotid endarterectomy (CEA) was performed 14 days (median) after a non-disabling carotid-related stroke with a perioperative minor stroke rate of 3.6%. Even large ischemic brain infarcts on CT scan did not exclude patients from CEA, as long as the patient had reached a neurologic plateau. The data from this study indicate that CEA can be performed safely in properly selected patients, and might reduce the high risk of a recurrent stroke (5%-9.5% within 30 days).

Early carotid endarterectomy after non-disabling ischaemic stroke: adequate therapeutical option in selected patients

OBJECTIVE

To evaluate neurological outcome and long-term results of early carotid endarterectomy (CEA) after non-disabling stroke.

MATERIALS

Retrospective study between 1980 and 1995 of 56 patients undergoing CEA within 4 weeks of a transient (n = 15) or a permanent non-disabling (n = 41) ischaemic stroke.

METHODS

Analyses of preoperative cerebral CT imaging, neurological outcome (mod. Rankin-scale) and long-term results (life-table analyses according to Kaplan-Meier).

RESULTS

Incidence of early CEA increased from 1.7% (27 out of 1636) in the period 1980-1993 to 7.8% (29 out of 374) between 1994 and 1995. CEA was indicated after a neurological plateau phase was established (median interval 14 days). Fifty-seven per cent of the CEA patients had a minor ischaemic infarction (area < 2 cm), 18% showed a large territorial ischaemic infarction (area 2-5 cm) in cerebral CT imaging. Two patients deteriorated postoperatively (minor stroke rate 4%) but no major stroke or death occurred. Life-table probability of stroke-free survival (mean follow-up 42.7 months) was 94%, 90% and 84%, respectively, after 1, 2 and 5 years. Kaplan-Meier survival rates were 96%, 91% and 86% after 1, 2 and 5 years.

CONCLUSIONS

Early CEA after non-disabling stroke is a safe procedure in selected patients.