Feasibility and reliability of on-line automated microemboli detection after carotid endarterectomy. A transcranial Doppler study

AbstractObjectives: recently, a new algorithm for transcranial Doppler (TCD) ultrasound detection of microembolic signals (MES) was developed. In the present study, we investigated its on-line performance in TCD monitoring after carotid endarterectomy (CEA) and assessed off-line its accuracy in detecting MES. Materials and Methods: first, the feasibility of MES detection in TCD monitoring after CEA in a routine clinical setting was evaluated in 50 patients. Second, to test the reliability of the software a 2-h digital audio study tape was made and analysed by the algorithm and five human experts. The “gold standard” was defined as the agreement between human experts: a MES was considered to be present if at least three human observers agreed. Results: TCD monitoring for emboli detection after CEA was well tolerated by the patients and could be performed reliably. In the study tape, the human gold standard detected 107 MES, with 93 MES having an intensity of ≥7 dB. The software detected 81 and 77 MES, respectively. Using the 7 dB intensity threshold, the software had no false positives and 16 false negatives. The κ value between the human gold standard and the software was 0.91, the proportion of specific agreement was 0.83. Conclusions: the tested algorithm provides a reliable method for automated on-line microemboli detection after CEA. This makes monitoring of the effectiveness of antiplatelet agents in the prevention of stroke after CEA more practicable.Eur J Vasc Endovasc Surg 25, 262–266 (2003

Cognitive functioning and quality of life of atherosclerotic patients following carotid endarterectomy.

Background: Carotid endarterectomy (CEA) is a surgical procedure to remove atherosclerotic plaque from one of the carotid arteries in patients with severe stenosis. The purpose is to prevent future cerebral ischemic attacks. Whether patients, in addition, improve in cognitive functions and quality of life (QoL) was investigated in this study. Methods: Patients with severe carotid stenosis were assessed on cognitive functions one day before and three months after CEA. The test battery included tests of memory, attention, psychomotor function, and laterality. Besides, the Cognitive Failures Questionnaire, the RAND 36-item Health Survey, and a mood questionnaire were administered. A comparison group was composed of patients undergoing peripheral vascular surgery of comparable duration and anesthesia. Results: So far, CEA patients showed significant postoperative cognitive improvement on a few tests, namely of short-term memory (Digit span forward), verbal laterality (Dichotic listening), attentional switching (Visual elevator), motor function (Finger tapping, Motor planning), and a trend for delayed verbal recall (15 Words). Peripheral vascular patients showed slight improvements on tasks of visual memory (Doors B), attention (Trailmaking B, Dichotic listening), and motor function (Motor planning). Concerning QoL, CEA patients showed postoperative improvements in physical functioning, mental health, and health perception, while peripheral vascular patients reported positive changes for physically related scales only. Furthermore, CEA patients noticed less fatigue, anger and tension, but these changes already existed on the day before surgery. Peripheral patients only reported less fatigue. Conclusions: This study suggests that, in addition to its medical aim, CEA improves subjective physical and mental QoL and negative mood states in severe atherosclerotic patients. In addition, some indications were found for improved cognitive functioning

The possible benefits of carotid endarterectomy for cognition and wellbeing in patients with a severe stenosis

Carotid endarterectomy (CEA) is indicatively undertaken in patients suffering from severe symptomatic or asymtomatic atherosclerotic stenosis. CEA restores blood flow to the brain, and prevents future stroke. Atherosclerotic stenosis results in a decline of attentional and memory functions, although effects from normal aging are difficult to rule out. Restoration of blood flow predicts improvement of cognitive functions, according to many authors in this field. Despite of the existence of collaterals by way of the Circle of Willis, this may especially hold for those functions that are localized in the hemisphere ipsilateral to the side of operation. Evidence for improvement however is controversial, even if valid instruments for assessment of hemispheric functions are applied. Improvement of function, if found, seems to be nonspecific and not ipsilaterally bound. Moreover, perioperative embolism after CEA may result in cognitive deterioration. This has also been concluded from cognitive evaluation after open heart surgery, such as coronary artery bypass graft (CABG). Nevertheless, unlike other studies, our research has shown that, following CEA, there are clear positive effects of quality of life. The role of quality of life and micro-embolism as possible predictors for postoperative cognitive change is discussed

Kwaliteit van leven vóór en na carotis endarteriëctomie

Carotid endarterectomy (CEA) is a surgical procedure to remove atherosclerotic plaque from the inside of one of the carotid arteries. The aim is to prevent a future cerebral ischemic attack. Besides this medical purpose, patients are expected to improve in mental functioning and have an increased quality of life (QoL). Twenty-two patients with severe stenosis of the carotid artery but without long-lasting neurological symptoms were questioned about their QoL several weeks before and three months after CEA. Measurements included the RAND 36-item Health Survey and the Cognitive Failures Questionnaire. In addition, the Profile of Mood States was administered to evaluate current mood. CEA patients were compared to patients undergoing peripheral vascular surgery (of one of their legs) of similar duration and anaesthesia. Before surgery both CEA patients and comparison patients showed worse QoL compared to norms. Three months after surgery the two groups improved on several QoL variables. Improvements on physically related scales were noticed to be larger for the control patients, as was expected. There was no surgical effect on reported everyday cognitive failures. Furthermore, all patients were less fatigued, less angry, and less tense three months after surgery, but these reductions could already be observed one day before surgery. The findings support the view that both CEA and peripheral vascular surgery increase QoL

Carotid artery plaque composition : Relationship to clinical presentation and ultrasound B-mode imaging

Objective: To correlate B-mode ultrasound findings to carotid plaque histology. Design: European multicentre study (nine centres). Material and Methods: Clinical presentation and risk factors were recorded and preoperative ultrasound Duplex scanning with special emphasis on B-mode imaging studies was performed in 270 patients undergoing carotid endarterectomy. Perioperatively macroscopic plaque features were evaluated and the removed specimens were analysed histologically for fibrous tissue, calcification and 'soft tissue' (primarily haemorrhage and lipid). Results: Males had more soft tissue than females (p = 0.0006), hypertensive patients less soft tissue than normotensive (p = 0.01) and patients with recent symptoms more soft tissue than patients with earlier symptoms (p = 0.004). There was no correlation between surface description on ultrasound images compared to the surface judged intraoperatively by the surgeon. Echogenicity on B-mode images was inversely related to soft tissue (p=0.005) and calcification ions directly related to echogenicity (p < 0.0001). Heterogeneous plaques contained more calcification than homogeneous (p = 0.003), however there was no difference in content of soft tissue. Conclusion: Ultrasound B-mode characteristics are related to the histological composition of carotid artery plaques and to patient's history. These results may imply that patients with distant symptoms may be regarded and treated as asymptomatic patients whereas asymptomatic patients with echolucent plaques should be considered for carotid endarterectomy

Recognising stroke prone patients with a poor collateral circulation

The prognosis in carotid disease is extremely variable and is influenced by the availability of collateral circulation. This study investigates the possibility of recognising patients with a poor collateral potential by using non-invasive tests. Preoperative OPG and EEG were compared with intraoperative EEG during test clamping in 208 carotid endarterectomies. Clamping ischaemia occurred in 29 patients (14%). Preoperative EEG had a sensitivity of 62% and a specificity of 82%. OPG showed a sensitivity of 96% and a specificity of 54%. Combined OPG and EEG resulted in a sensitivity of 93% and a specificity of 73%. Both tests are safe and easy to perform and interpret. These techniques can be used to identify those patients with carotid stenosis who have an increased risk of stroke due to a poor collateral circulation and may help to refine the indications for carotid endarterectomy

Perioperative Microembolism is not Associated with Cognitive Outcome Three Months after Carotid Endarterectomy

AbstractObjectiveTo investigate the association between perioperative microembolism and cognitive outcome 3 months after carotid endarterectomy (CEA).DesignProspective study.Materials and methodsPatients 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.ResultsForty 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.ConclusionsThe 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

Ultrasonic duplex scanning in atherosclerotic disease of the innominate, subclavian and vertebral arteries. A comparative study with angiography

Ultrasonic duplex scanning of the vertebral artery has a sensitivity of 0.80 and a specificity of 0.83 for the detection of an obstructive lesion of 50% or more at the site of the ostium. For the subclavian arteries these values are respectively 0.73 and 0.91. For both vessels the test has a very high negative predictive value of respectively 0.96 and 0.97. Therefore duplex ultrasound scanning is a reliable test in screening patients suspected of multi-level atherosclerotic disease of the extracranial cerebral vessels. The problem remains in classifying the degree of stenosis. In the case of the vertebral artery the sample volume of the pulsed Doppler is usually too large in relation to the vessel diameter. In the case of the subclavian and innominate artery one of the main problems is the range of the pulsed Doppler system. A subclavian steal syndrome is easily diagnosed without any special test