Hungarian Radiology

[Transcranial Doppler monitoring of distal embolism during of carotid stenting]


MARCH 20, 2007

Hungarian Radiology - 2007;81(01-02)

[INTRODUCTION - Reducing the risk of embolisation during endovascular treatment of internal carotid artery stenosis is very important. The rate of embolisation is affected by the different steps of stenting manipulation. Using transcranial Doppler equipment we studied the embolic signals during the different phases of carotid dilatation and stenting. MATERIAL AND METHOD - 50 patients (33 male, 17 female; mean age 64 years) were intraproceduraly monitorized with transcranial Doppler. Predilatation was necessary in nine cases, postdilatation was performed in 39 cases. The number of emboli were measured in seven different steps of endovascular treatment of carotid stenosis. Different type of commercial available endovascular devices were used. RESULTS - Intraprocedural embolisation was observed in every case. In different phases of carotid stenting the rate of embolisation showed marked differences in each phase of carotid stenting. Crossing the stenosis with stent delivery system were accompanied by a low rate of embolism (5.3) compared to the level during stent opening (9.16) and balloon dilatation (9.96). The highest level of embolisation was observed during predilatation (15.9) without the protection of the stent. CONCLUSIONS - We detected embolisation in all of the cases, however the number of embolic signals varied in different phases of carotid artery stenting. Embolisation can be reduced if the most dangerous steps (i.e. pre- and postdilatation) are avoided. Using TCD monitorisation the physician can be informed by the degree of embolisation that may alarm the interventionalist to perform the procedure more carefully, furthermore it can be employed during the training of carotid stenting.]



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[Scientific conference of Transylvanian Society and Museum]


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[Diagnostic and therapeutical possibilities in constipation]


[Constipation is a common gastrointestinal problem. The prevalence of symptoms related with constipation fluctuates from 3 to 20 per cent. Constipation occurs more frequently in the elderly people and in females and more frequent in case of inactivity and less fiber intake. Assesment of patients with severe constipation includes specialized investigations. Exclusion of primary organic causes has to be the first step, then metabolic, neurological and iatrogenic causes (such as medicament side effects, etc) have to be excluded. After these considerations special functional gastroenterological investigations are needed which contribute to the diagnosis and differential diagnosis of the cause of the constipation. Anorectal manometry, ballon expulsion test, defecography and colon transit studies allow us to distinguish between slow colon transit, colon inertia, different subtypes of outlet obstruction, and the constipation predominant irritable bowel syndrome. The evaluation of these specific studies leads to the exact diagnosis and appropriate treatement for their problem can be given to the patients, which always has to be individually planed in all cases.]

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Related contents

Clinical Neuroscience

The applications of transcranial Doppler in ischemic stroke


Background: This overview provides a summary of the applications of transcranial Doppler (TCD) in ischemic stroke. Results: A fast-track neurovascular ultrasound protocol has been developed for detecting occlusion or stenosis. The technique is more reliable in the carotid area than in the posterior circulation. By monitoring the pulsatility index the in­crea­sed intracranial pressure can be diagnosed. TIBI score was developed for grading residual flow. TCD has been shown to accurately predict complete or any recanalization. Regarding recanalization, TCD has a sensitivity of 92%, a specificity of 88%, a positive predictive value of 96%, a negative predictive value of 78% and an overall accuracy of 91%, respectively. Sonothrombolysis seemed to be a promising application but randomized controlled trials have shown that it does not improve clinical outcome. TCD examination can detect microembolic signals (MES) which are associated with an increased risk of stroke. Micro­em­boli were detected in symptomatic and asymptomatic carotid artery stenosis and during carotid endarterectomy. The number of microemboli can be decreased by antithrombotic therapy. Contrast en­chan­ced examination and Valsalva maneuver with continuous TCD monitoring can accurately screen for right-to-left shunt.

Hungarian Radiology

[Stroke prevention: Experience with endovascular therapy of carotid artery stenosis]


[INTRODUCTION - Carotid artery stenting as an alternative to carotid endarterectomy is still not accepted by many Hungarian vascular surgeons. The purpose of our study was to prove that carotid artery stenting is effective in the treatment of primary atherosclerotic lesions and it carries a low risk of complications. PATIENTS AND METHODS - 149 patients (86 men, 63 women, 33-82 years old, mean age 57.5 years) were evaluated angiographically. 146 primary atherosclerotic lesions, and 8 post-endarterectomy restenoses were considered for carotid artery stenting. All patients had significant, over 60% stenosis according to NASCET criteria. Atherosclerotic plaques were classified as smooth, irregular and ulcerated. Subtotal occlusions (stenoses over 95%) were noted. The necessity of pre- or postdilation and the types of stent used were registered. Procedural success and periprocedural complication rates were noted. Followup colour Doppler sonography was performed at 1, 6 and 12 months. RESULTS - Subtotal occlusions were detected in 28% of the lesions. Procedural success rate was 149/150 (99%). Stenting was carried out in 86% with Monorail Carotid Wallstent. Predilation or use of protecting device was avoided in 96%. Postdilation was avoided in 6 cases of ulcerated plaques to prevent distal embolisation. Residual stenosis was always less than 30%. Stroke occured in 2.6%, TIA in 0.7%. Two of our patients developed restenosis. CONCLUSION - Carotid artery stenting is a safe alternative to carotid endarterectomy for most patients with primary atherosclerotic stenosis, as it can be carried out with clinical complication rate as low as published in the ACAS.]

Clinical Neuroscience

[Effect of mental arithmetic and verbal fluency on the flow velocity in the middle cerebral arteries]


[Introduction - Using transcranial Doppler sonography (TCD), changes in blood flow velocity (BFV) can be measured in the Medial Cerebral Artery (MCA) during cognitive effort. Our goal was to define the time-course and laterality of BFV in healthy vo-lunters during arithmetic and verbal fluency tasks according to handedness. Methods - Twelve subjects (8 right-handed, 4 left-handed) were assessed. The TCD registered BFV in both MCA simultaneously. Heart rate was also recorded using TCD. Finally we included a 16-channel EEG. BFV laterality index (LI) was calculated. Participants were asked to count silently and generate words beginning with a specified letter. To estimate hemispheric differences in BFV, two-tailed Wilcoxon tests were utilized along with correlational analyses. Results - During cognitive effort the BFV changed in a triphasic manner in all participants. A 6-8% elevation of BFV was observed in MCAs without latency at the time of the evoking signal. Laterality of BFV developed after 5-13 seconds during cognitive effort in right-, and several seconds later in left-handed subjects. During tasks the BFV increased in the dominant hemis-phere up to 2.6-4.7% compared to the subdominant one. We also calculated the LI. During the verbal task the LI agreed with the handedness in 9 out of 12 subjects. During the mental arithmetic task, agreement was found in 6 out of 12 subjects. According to LI results we found a discrepancy between verbal and arithmetic tests in 3 out of 12 subjects. Conclusion - Cognitive effort elicites significant bilateral BFV increases in the MCAs, which suggests fast neurogenic regulation. The course of BFV during mental arithmetic proved to be different from course BFV assessed during the word fluency task. Based on the laterality of the BFV, the word-generation task was more sensitive in determining the dominant hemisphere when compared to the mental arithmetic task. The use of LI may help to estimate hemispheric functions even in pathologic circumstances.]

Lege Artis Medicinae

[Efficacy of maximal dose rosuvastatin therapy in significant carotis stenosis]


[The main role of atherogenic dyslipidemia is known for decades. Several studies have proven the beneficial effect of statin therapy on cardiovascular morbidity and mortality. The following case report demonstrates the efficacy of high dose statin therapy regarding lipid goals and clinical signs. The presented 65 year-old female patient had a history of dyslipidemia and hypertension for over 15 years and positive cardiovascular family history. Carotid ultrasound examination showed 15-20% bilateral stenosis in 2008 whereas four years later, control ultrasound showed significant progression with 65% left-sided asymptomatic stenosis. At this time, LDL-cholesterol level was above the target; we managed to reach the recommended level with high-dose statin treatment in combination therapy with ezetimibe. Besides the lipid levels, regression of the carotid stenosis could be observed without statin-associated side effects.]

Hungarian Radiology

[Forces exerted on the plaques during in vitro measurements by various carotid stent delivery systems and embolic protection devices]


[PURPOSE - During the endovascular treatment of internal carotid artery stenosis, one of the most important aspects is reducing of embolic complications. Degree of embolization may be influenced by the force exerted by stent delivery systems and embolic protection devices. We assessed the force emersion produced by various devices on vessel walls and plaques. MATERIAL AND METHOD - Six different commercially available devices were investigated. The force load on vessel wall was measured in a carotid model with vessel angulations of 25, 50 and 75 degree, respectively. The IDTE 2000 CE marked measurement system was used. A transparent, flexible PVC tube was used as a model of the carotid bifurcation, which was 6 mm in width, 1.5 mm wall thickness and 12 mm length. 75-85% stenosis were created in it. The measured data were evaluated and different conclusions were drawn. RESULTS - Forces exerted on vessel walls varied widely among different stent delivery systems. The magnitude of force exertion caused by stent delivery systems significantly exceeded that caused by protecting devices. Protecting devices showed only 30% increase in vessel load at angulation of 75 degrees compared to those at 25-50 degrees. Above 50 degrees of vessel angulation the forces exerted by stent delivery systems considerably increases. CONCLUSIONS - Our results showed that selection of the most proper stent can contribute to decrease in the load of vessel wall. Protecting devices exert significantly lower forces than stent delivery systems, therefore, it seems to be a better choice to advance a protecting device before introducing a stent delivery system. If the vessel angulation exceeds 50 degrees, endarterectomy should be considered, because the vessel wall load will increase radically in that case.]