High versus standard clopidogrel loading in patients undergoing carotid artery stenting prior to cardiac surgery to assess the number of microemboli detected with transcranial Doppler: results of the randomized IMPACT trial.

AIM: The aim of this study was to compare the effects of 300 mg or 600 mg clopidogrel loading dose, prior to carotid artery stenting (CAS) on the number of transcranial Doppler (TCD)-detected microembolic signals (MES) and to investigate the relationship between the magnitude of platelet reactivity and MES. METHODS: In this prospective randomized, double-blind study, 35 consecutive asymptomatic patients (17.1% females), scheduled for CAS and cardiac surgery were included. The primary endpoint was the number of TCD-detected MES. The secondary endpoints were the absolute magnitude of on-treatment platelet reactivity and the adverse cerebral events. Negative binomial regression to find predictors for sum of single emboli, the student's t-test to assess the association between platelet function tests and randomized dose of 300 mg or 600 mg clopidogrel, and the R2 calculation for the assessment of the association between platelet function tests and embolic load, were used. RESULTS: No statistically significant difference in the number of TCD-detected MES, in the sum of all the single emboli or showers and platelet aggregation measurements between the two groups was observed (aggregometry: 21.7±18.3 versus 23±18%, P=0.8499 and 45.8±17.5 versus 46.5±14.5%, P=0.9003) (verifyNow P2Y12 assay: 231±93 PRU versus 222±86 PRU, P=0.7704). In one patient a transient ischemic attack occurred. CONCLUSION: A loading dose of 300 mg of clopidogrel in combination with aspirin is as effective as 600 mg of clopidogrel in achieving adequate platelet inhibition and preventing periprocedural events in asymptomatic patients undergoing CAS prior to cardiac surgery.

Prediction of cerebral hyperperfusion after carotid endarterectomy with transcranial Doppler.

OBJECTIVES: To determine the diagnostic value for predicting cerebral hyperperfusion syndrome (CHS) by adding a transcranial Doppler (TCD) measurement in the early postoperative phase after carotid endarterectomy (CEA). DESIGN: Patients who underwent carotid endarterectomy between January 2004 and August 2010 and in whom both intra- and postoperative TCD monitoring were performed were included. METHODS: In 184 CEA patients the mean velocity (V(mean)) preoperatively (V1), pre-clamping (V2), post-declamping (V3) and postoperatively (V4) was measured using TCD. The intra-operative V(mean) increase ((V3 - V2)/V2) was compared to the postoperative increase ((V4 - V1)/V1) in relation to CHS. CHS was diagnosed if the patient developed neurological complaints in the presence of a preoperative V(mean) increase >100%. RESULTS: Sixteen patients (9%) had an intra-operative V(mean) increase >100% and 22 patients (12%) a postoperative V(mean) increase of >100%. In 10 patients (5%) CHS was diagnosed; two of those had an intra-operative V(mean) increase of >100% and nine postoperative V(mean) increase >100%. This results in a positive predictive value of 13% for the intra-operative and 41% for the postoperative measurement. CONCLUSIONS: Besides the commonly used intra-operative TCD monitoring additional TCD measurement in the early postoperative phase is useful to more accurately predict CHS after CEA.

Retinal embolization during carotid angioplasty and stenting: periprocedural data and follow-up.

The purpose of this study was to prospectively evaluate the incidence of retinal emboli during carotid angioplasty and stenting (CAS) and to correlate emboli with clinical findings and transcranial Doppler (TCD)-detected cerebral embolic load. Between 2001 and 2005, 33 CAS procedures in 32 patients (23 [72%] male, 19 [58%] symptomatic, mean age 72.5 years [range 54.6 to 83.9]) scheduled for CAS were included in this study. Bilateral fundoscopy with retinal photography was performed by an experienced ophthalmologist immediately before, immediately after (fundoscopy only), and 1 day after the procedure and again at long-term follow-up (mean 37 months). Visual field testing was performed before CAS and again at long-term follow-up. TCD-detected cerebral emboli were stratified to five procedural phases: wiring, predilatation, stent placement, postdilatation, and cerebral protection device (CPD) use (if applicable). To establish correlation between TCD data and retinal embolization, Mann-Whitney test was used, and P < 0.05 was considered statistically significant. All procedures were performed successfully. In five of 33 procedures (15%), new retinal emboli were found. Two of the procedures with emboli had small retinal infarcts. Three of five were performed using CPDs versus seven of 28 that had no retinal emboli (P = not significant). Two of four patients (50%) with previous radiation therapy to the neck had new retinal emboli versus three of 29 patients (10%) who had no previous radiation therapy (P = 0.038). None of the other patient characteristics was associated with retinal embolization. In 30 (91%) of patients with an adequate acoustic temporal window for TCD monitoring, there was no statistically significant correlation between TCD data and the incidence of retinal emboli. No visual field defects were found. On long-term follow-up, all retinal emboli and retinal infarcts had resolved. Retinal embolization during CAS is not uncommon, and it occurs in both protected and unprotected procedures. Most retinal emboli are clinically silent.

Carotid stenting versus carotid endarterectomy: evidence basis and cost implications.

OBJECTIVE: Carotid Angioplasty combined with Stenting (CAS) is increasingly performed because of its presumed benefits. A study was performed to identify key factors that determine the cost-effectiveness as compared to conventional carotid endarterectomy (CEA). METHODS: The incremental cost-effectiveness of CAS over CEA for different scenarios was estimated using a modeling approach. Treatment costs were based on actual costs of successful procedures whereas costs of complications were taken from the literature. Patient survival was modeled using the endarterectomy patients from the ECST trial. RESULTS: Procedural costs of CAS are higher than those of CEA, mainly as a result of the high material costs. Cost-effectiveness of CAS primarily depends on major stroke rates. One percent increase in the peri-operative major stroke rate causes a cost increase of 1051 euros and a loss of 0.06 quality adjusted life years. CONCLUSIONS: At present CAS is at best non-inferior to CEA in terms of clinical outcome. Cost savings due to shorter admission are offset by the high costs associated with catheter-based interventions. At present CAS should be restricted to controlled settings until clinical trials have shown a substantial clinical benefit.

Introduction of an embolus detection system based on analysis of the transcranial Doppler audio-signal.

A new embolus detection system (EDS) is presented, built with the intention of detecting ongoing cerebral embolization in patients at risk of transient ischaemic attacks or stroke. It is based on the analysis of the audio-Doppler signal of a transcranial Doppler machine. The algorithm of the EDS estimates the intensity, duration and zero-crossing dynamics of the audio signal. The EDS has a multi-layer neural network which classifies events into micro-emboli signals (MES) or artefacts. The decision-making component of the software has been validated against human experts. Data from patients in the post-operative phase of carotid surgery were used for the validation process. The results showed agreement in MES and artefact classification of > 93%. Apart from a monitoring display, the monitoring system includes a verification unit that allows the user to listen and to look at all data of individual MES and artefacts. Moreover, the system allows the user to record, store and re-calculate all data files. Data are stored using European Data Format, which allows data transportation over the Internet. The EDS may have a potential in stroke risk stratification, evaluating the effect of novel anti-thrombotic therapies, and in peri-operative and remote monitoring of carotid endarterectomy.

Will carotid angioplasty become the preferred alternative to staged or synchronous carotid endarterectomy in patients undergoing cardiac surgery?

In the absence of randomized trials, the optimal management of patients who present with concomitant carotid and coronary artery disease remains an enduring controversy, with much of the debate revolving around whether staged or synchronous carotid endarterectomy (CEA) will reduce peri-operative morbidity and mortality after cardiac surgery. Although encouraging results have been reported using either strategy, there remains no consensus as to which is preferable. More recently, however, carotid artery angioplasty with stenting (CAS) has emerged as a potential alternative to CEA. In 'high-risk for CEA' patients, CAS has shown comparable short and long-term outcome rates to CEA. Accordingly, CAS followed by cardiac surgery could offer a less invasive (and safer) therapeutic option in cardiac patients. This paper reviews the evidence to date supporting the use of CAS+CABG, while highlighting potential situations where such a strategy might be harmful. In particular, it will focus on how the need for dual antiplatelet therapy after CAS can be balanced with avoiding unnecessary bleeding complications after cardiac surgery.

Influence of antiplatelet therapy on cerebral micro-emboli after carotid endarterectomy using postoperative transcranial Doppler monitoring.

AIM: To study the effect of different antiplatelet regimens (APT) on the rate of postoperative TCD registered micro-embolic signals (MES) following carotid endarterectomy (CEA). DESIGN: Prospective, randomised, double-blinded, pilot study. METHODS: The study group of 102 CEA patients (76 men, mean age 66.8 years) was randomised to routine Asasantin (Dipyridamole 200mg/Aspirin 25mg) twice daily (group I; n=39), Asasantin plus 75 mg Clopidogrel once daily (group II; n=33), or Asasantin plus Rheomacrodex (Dextran 40) 100g/L iv; 500 ml (group III; n=30). TCD monitoring of the ipsilateral middle cerebral artery for the occurrence of MES was performed intra-operatively and during the second postoperative hour following CEA. Primary endpoints were the rate of postoperative emboli and the occurrence of cerebrovascular complications. Secondary endpoint was any adverse bleeding. RESULTS: There were no deaths or major strokes. We observed 2 intraoperative TIA's (group II and III) and 1 postoperative minor stroke (group I). In comparison with placebo, Clopidogrel or Rheomacrodex in addition to Asasantin produced no significant reduction in the number of postoperative MES. There was no significant difference between the number of postoperative MES and different antiplatelet regimens. The incidence of bleeding complications was not significantly different between the 3 APT groups. CONCLUSION: In the present study, we could not show a significant influence of different antiplatelet regimens on TCD detected postoperative embolization following CEA.

The fate of the external carotid artery after carotid artery stenting. A follow-up study with duplex ultrasonography.

OBJECTIVE: To evaluate the long-term effect of carotid angioplasty and stenting (CAS) of the internal carotid artery (ICA) on the ipsilateral external carotid artery (ECA). SUBJECTS AND METHODS: We prospectively registered the pre- and post-interventional duplex scans obtained from 312 patients (mean age 70 years) who underwent CAS. Duplex scans were scheduled the day before CAS, 3 and 12 months post-procedurally and yearly thereafter, to study progression of obstructive disease in the ipsilateral ECA compared to the contralateral ECA. The duplex ultrasound criteria used to identify ECA stenosis >or=50% were Peak Systolic Velocities of >or=125 cm/s. RESULTS: Preprocedural evaluation of the ipsilateral ECA demonstrated >or=50% stenosis in 32.7% of cases vs 30% contralateral. Both ipsilateral and contralateral 3 (1%) ECA occlusions were noted. After stenting 5 (1.8%) occlusions were seen vs 1% contralateral. No additional ipsilateral occlusions and 2 additional contralateral occlusions were noted at extended follow-up. The prevalence of >or=50% stenosis of the ipsilateral ECA (Kaplan-Meier estimates) progressed from 49.1% at 3, to 56.4%, 64.7%, 78.2%, 72.3%, and 74% at 12, 24, 36, 48, and 60 months respectively. Contralateral prevalences were 31.3%, 37.7%, 41.7%, 43.1%, 46.0%, and 47.2% respectively (p<0.001). Progression of stenosis was more pronounced in 234 patients (75%) with overstenting of the carotid bifurcation (p=0.004). CONCLUSION: Our results show that significant progression of >or=50% stenosis in the ipsilateral ECA occurs after CAS. There was greater progression of disease in the ipsilateral compared with the contralateral ECA. Progression of disease in the ECA did not lead to the occurrence of occlusion during follow up.

Preserved hyperaemic response in supraclavicular ultrasonography demonstrates function on demand of the LIMA to LAD string sign graft after CABG.

AIM: To correlate supraclavicular ultrasonography with angiographically patent and string sign left internal mammary artery (LIMA) to left anterior descending artery (LAD) grafts. METHODS: Sixteen patients with a single LIMA anastomosis to the LAD were prospectively entered in a follow-up study. The supraclavicular ultrasonography of the LIMA origin was studied preoperatively and at 5.3+/-3.6 months and 1.7+/-0.4 year postoperatively. At the late postoperative ultrasonography electrocardiographically controlled hyperemic response was also studied for 6 min. Control angiography was performed at 1.5+/-0.8 year. Differences within groups were tested with a paired t-test and between groups with an unpaired t-test. RESULTS: Control angiography showed in 13 patients (group I) a patent LIMA graft and in 3 patients (group II) a string sign LIMA graft. Preoperative blood velocities were not significantly different between groups. Postoperatively, both groups revealed higher diastolic and lower systolic blood velocities compared to preoperative values. The blood velocities at rest did not change in group I and all velocities decreased in group II in time postoperatively. The blood velocities in maximal hyperemic response increased significantly within the groups and were not significantly different between the groups. No ischemia could be detected electrocardiographically during hyperemic response and no patient presented angina. CONCLUSIONS: Both groups showed a shift towards coronary type diastolic blood velocities at rest and at hyperaemic response. Significant hyperemic response was also present in string sign LIMA grafts and demonstrates response capacity to increased myocardial oxygen demand.

The carotid atherosclerotic plaque and microembolisation during carotid stenting.

Microembolisation is an important issue in carotid artery stenting. During different phases in the stenting process, numerous emboli are dislodged from the atherosclerotic plaque. Embolisation can be measured as microembolic signals detected by transcranial Doppler (TCD) monitoring during the procedure or as new ischemic areas determined by magnetic resonance imaging. This article gives an overview of the principles of emboli detection methods, their clinical relevance, and risk factors associated with microembolisation. In addition, protection devices are discussed in relation to embolisation. Although they potentially protect the brain, particularly filter devices increase the amount of TCD-detected cerebral microemboli. Special attention is paid to the carotid artery plaque, which is subject to ongoing research that may yield important implications for clinical practice in the near future. Evidence is accumulating that unstable, vulnerable plaques are associated with increased microembolisation during carotid interventions. This knowledge of the vulnerable plaque can be translated to the clinical setting by plaque imaging. A first approach has been made by duplex imaging of carotid plaque morphology. More advanced methods such as molecular magnetic resonance imaging and optical coherence tomography could aid in optimal treatment selection based on plaque characteristics thus reducing microembolisation and associated cerebral adverse events.

Intrapatient comparison of restenosis between carotid artery angioplasty with stenting and carotid endarterectomy.

AIM: Comparison of restenosis in patients who underwent both carotid artery angioplasty with stenting (CAS) and contralateral carotid endarterectomy (CEA). METHODS: From our CAS data registry (1998-present) all patients with a history of contralateral CEA at any other time were selected (n = 63). Mean age was 70.6, SD = 6.8 for CAS and 68.2, SD = 6.1 for CEA and symptomatic carotid artery stenosis was present in 24% of patients pre-CAS and 40% pre-CEA. All CEAs were primary interventions, 19% of CAS were secondary to restenosis after previous ipsilateral CEA. All patients were followed up prospectively with duplex at 1 year (CAS: n = 58, CEA: n = 59), 2 years (CAS: n = 44, CEA: n = 53), 3 years (CAS: n = 27, CEA: n = 41), and every year thereafter. Within each patient we compared restenosis (>50%) between CAS and CEA procedures. RESULTS: After a follow-up of 28.7 months for CAS (SD = 16.9) and 54.4 months for CEA (SD = 39.5) the rate of = or > 50% restenosis for CAS vs CEA at 1, 2, and 3 years was 23% vs 10%; 31% vs 19%; and 34 vs 24%, respectively (log rank P = NS). CONCLUSIONS: Our intrapatient comparison of patients who underwent both CAS and contralateral CEA did not reveal significant difference in restenosis between both procedures.

Carotid atherosclerotic plaque characteristics are associated with microembolization during carotid endarterectomy and procedural outcome.

BACKGROUND AND PURPOSE: During carotid endarterectomy (CEA), microemboli may occur, resulting in perioperative adverse cerebral events. The objective of the present study was to investigate the relation between atherosclerotic plaque characteristics and the occurrence of microemboli or adverse events during CEA. METHODS: Patients (n=200, 205 procedures) eligible for CEA were monitored by perioperative transcranial Doppler. The following phases were discriminated during CEA: dissection, shunting, release of the clamp, and wound closure. Each carotid plaque was stained for collagen, macrophages, smooth muscle cells, hematoxylin, and elastin. Semiquantitative analyses were performed on all stainings. Plaques were categorized into 3 groups based on overall appearance (fibrous, fibroatheromatous, or atheromatous). RESULTS: Fibrous plaques were associated with the occurrence of more microemboli during clamp release and wound closure compared with atheromatous plaques (P=0.04 and P=0.02, respectively). Transient ischemic attacks and minor stroke occurred in 5 of 205 (2.4%) and 6 of 205 (2.9%) patients, respectively. Adverse cerebral outcome was significantly related to the number of microembolic events during dissection (P=0.003) but not during shunting, clamp release, or wound closure. More cerebrovascular adverse events occurred in patients with atheromatous plaques (7/69) compared with patients with fibrous or fibroatheromatous plaques (4/138) (P=0.04). CONCLUSIONS: Intraoperatively, a higher number of microemboli were associated with the presence of a fibrous but not an atheromatous plaque. However, atheromatous plaques were more prevalent in patients with subsequent immediate adverse events. In addition, specifically the number of microemboli detected during the dissection phase were related to immediate adverse events.

Identification of patients at risk for ischaemic cerebral complications after carotid endarterectomy with TCD monitoring.

OBJECTIVES: Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated. METHODS: Centres that monitored for MES after CEA were identified by searching Medline. Individual patient data were obtained from centres willing to collaborate. The number of emboli in 1h was computed. Uni- and multivariate logistic regression analyses were performed for the variables gender, age and number of MES. Discriminative ability of MES monitoring was investigated in a ROC curve. RESULTS: Nine hundred and ninety-one patients were monitored in the first 3h after CEA. Two percent developed ischaemic cerebral complications. Univariate analysis revealed statistically significant associations between ischaemic cerebral complications and both gender and MES, but not age. In a multivariate analysis, > or =8 MES/h showed a statistically significant relationship with cerebral complications (OR 8.1, 95% CI 1.8-36), in contrast to gender (OR 2.2, 95% CI 0.9-5.5). The ROC curve yielded an AUC of 0.83 for monitoring of MES. CONCLUSIONS: These results support the use of TCD monitoring for MES shortly after CEA in order to identify patients at risk of developing ischaemic cerebral complications.

Perioperative microembolism is not associated with cognitive outcome three months after carotid endarterectomy.

OBJECTIVE: To investigate the association between perioperative microembolism and cognitive outcome 3 months after carotid endarterectomy (CEA). DESIGN: Prospective study. MATERIALS AND METHODS: Patients were tested 1 day before and 3 months after surgery with neuropsychological tests measuring a wide range of cognitive functions. Number of microemboli was monitored with transcranial Doppler ultrasonography in 58 patients during the operation and in a random subgroup of 27 patients directly following the procedure. RESULTS: Forty patients (69%) had intraoperative embolism, varying from 1 to 33 isolated microemboli and/or 1 to 11 embolic showers. Postoperative emboli were present in 22 of the 27 patients (81%), ranging from 1 to 142 isolated microemboli. More than 10 microemboli (including showers) were detected in 13 patients (22%) intraoperatively and in 6 patients (22%) postoperatively. Twenty-two patients (38%) showed deterioration in three or more cognitive function variables at 3 months. There were no significant associations between any cognitive change or deterioration score and presence or number of intraoperative and/or postoperative emboli. CONCLUSIONS: The degree of microembolism during and immediately following CEA is generally small and seems to be of no significance with respect to postoperative cognitive functioning. Future research should include a larger group of patients to allow reliable subgroup analysis.

Transcranial Doppler monitoring after carotid endarterectomy.

The objectives of this study were to evaluate the feasibility of transcranial Doppler (TCD) monitoring after carotid endarterectomy (CEA) and to investigate whether 1 hr of monitoring is sufficient to detect a clinically relevant change in the number of postoperative microemboli. We also evaluated the association of patient characteristics and procedure-related variables with the number of postoperative microemboli. One hundred and two patients were monitored during the second hour after CEA. The main outcome measure was the number of TCD-detected microemboli. The secondary outcome measure was a procedure-related cerebral complication graded according to the modified Rankin scale. The median number of microemboli during the second postoperative hour was two (interquartile ranges, 0.75-11) and decreased in most the patients during this time. Two patients had a relatively high and increasing number of microemboli and developed a minor stroke after a symptom-free interval. One patient developed a TIA intraoperatively. There was no significant association between patient characteristics and the use of a venous patch and the number of postoperative microemboli. Conversely, a statistically significant negative association was found between shunt use and the number of microemboli (p = 0.02). The majority of patients had no or a small and decreasing number of microemboli. One hour of monitoring appeared to be effective to select those patients in whom the number of microemboli did not spontaneously decrease and who may need additional medical treatment or surgical reexploration. The role of TCD-detected microemboli as a surrogate measure for the risk of stroke after CEA remains to be validated.

The depth of microembolic signal direction change corresponds with vessel anatomy.

BACKGROUND: Analysis of microembolic signals (MES) suggests a change of flow direction (CFD). The aim of the present study was to relate MES direction in an amplitude plot, based on the radiofrequent (RF) signal, to the vascular anatomy as seen with transcranial color-coded duplex (TCCD). METHODS: In 5 patients undergoing heart valve surgery or aortic arch replacement, preoperatively TCCD of the distal part of the internal carotid artery and the middle and anterior cerebral arteries on the right side was performed to determine potential depths of changes in flow direction. Peroperatively, a transcranial pulsed Doppler (TCD) monitoring probe was fixed over the right temporal bone. A customized RF-based system, connected to the TCD device, captured and stored the MES. Off-line, the color-coded amplitude of the clutter-filtered RF signals was plotted as a function of time (sample interval 0.17 ms) and depth (sample interval 0.05 mm). RESULTS: A total of 313 MES were recorded in 4 patients with 66 MES (21%) showing a CFD. All MES with CFD could be assigned to maximally three different depth values, six out of eight CFD depth values as seen with the RF analysis were within 1 mm from a turn in flow direction as estimated with TCCD. CONCLUSIONS: A CFD of MES occurred at a very limited number of depths and corresponded mostly with the intracranial vascular anatomy, namely a turn of the flow direction in the intracranial vessels as observed with TCCD.

Postoperative changes in duplex ultrasound velocity characteristics in the nonmobilized right internal mammary artery in patients with left internal mammary artery bypass grafting.

The internal mammary artery (IMA) is the conduit of choice in coronary revascularization because of its long-term patency. We analyzed the effect of left internal mammary artery (LIMA) harvesting on sternal perfusion. Diameters and velocity parameters of the nonmobilized right internal mammary artery (RIMA) were noninvasively analyzed with duplex ultrasound in 41 patients with LIMA myocardial revascularization pre- (2.6 +/- 5 days) and postoperatively (4.9 +/- 3.9 months). Data of 41 patients were analyzed; 38 patients underwent all examinations with adequate supraclavicular signals. The proximal RIMA diameter and all velocity parameters increased significantly at follow-up (3.1 +/- 0.6 vs. 3.2 +/- 0.5 mm, p = 0.03; diastolic peak velocity [DPV] 15 +/- 7 vs. 27 +/- 9 cm/sec, p < 0.0001; systolic peak velocity [SPV] 90 +/- 24 vs. 105 +/- 29 cm/sec, p < 0.02). This was more pronounced for the diastolic parameters and for all parameters in the proximal part of the RIMA than in the distal part (DPV 11.9 +/- 10.1 vs. 9.5 +/- 10.2 cm/sec, p = NS; SPV 14.9 +/- 33.9 vs. 7.4 +/- 26.0 cm/sec, p = NS). With longer time intervals of follow-up the increase in all diastolic velocity parameters became less pronounced. As demonstrated in the RIMA velocity parameters, patients with skeletonized LIMA grafts (n = 4) had significantly more flow, suggesting hyperemic flow, than patients with pedicled LIMA grafts (n = 34). Only in diastolic velocity integral (DVI) and systolic/diastolic velocity ratio (SDVRA) were there significant differences between diabetics (n = 9) and nondiabetics (n = 29) and only in DVI between female, (n = 8) and male (n = 30) patients. This study indicates that duplex ultrasound is a useful tool for noninvasive RIMA follow-up in LIMA myocardial revascularization.

TCD-detected cerebral embolism in carotid endarterectomy versus angioplasty and stenting of the carotid bifurcation.

PURPOSE: In this article we will review some of the issues surrounding the relationship between TCD-detected emboli and brain function and architecture, both during conventional surgical carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS). MATERIAL AND METHODS: In both procedures, the cerebral embolic load was semi quantitatively assessed and associated with clinical outcome during the procedure and after a symptom free interval within 7 days. RESULTS: In CEA, particulate emboli that occurred during the wound closure stage were associated with intraoperative stroke and stroke related death, odds ratios [OR] 2.3 95% CI 1.2-4.4, p = 0.007. In CAS, showers of microemboli that appeared at postdilatation of the stent (OR 3.2, 95% CI 1.5-6.9, p = 0.002), particulate macroembolism (relative risk [RR] 10.2, 95% CI 5.9-17.3, p < 0.001), and massive air embolism (RR 10.2, 95%CI 5.8-17.7, p < 0.001) were associated with new transient and persistent cerebral deficits. CONCLUSION: In both CEA and CAS, recording of cerebral emboli by TCD ultrasonography provides insight in the pathogenesis of procedure related adverse cerebral outcome. In several centres TCD monitoring during CEA is now accepted as a clinically relevant tool that helps the surgeon to make the operation safer. In CAS more research is needed, particularly with respect to the impact of cerebral protection devices.

Left or right carotid endarterectomy in patients with atherosclerotic disease: ipsilateral effects on cognition?

We evaluated hemispheric functions ipsilateral to the side of carotid endarterectomy (CEA) in patients with a severe stenosis in the left or right carotid artery. Assessments took place 1 day before and 3 months after CEA. Only right-handed males were included. Nineteen patients underwent surgery of the left carotid artery and 17 of the right. Valid instruments for hemispheric function were included, such as verbal dichotic listening, finger tapping, and a lateralised test for motor planning. Results showed that, preoperatively, patients had lower scores compared to norms on the laterality tests, and on a visuoconstructive test. There was no evidence of ipsilateral improvement related to side of surgery. Left ear dichotic listening improved, which was seen in both left and right surgery groups. Also in both groups, left- and right-hand movement speed in the motor planning test decreased. Conclusion is that beneficial ipsilateral cognitive change after CEA in patients with severe stenosis in one of the carotid arteries may not be demonstrated, even if valid instruments for hemispheric function are included.