Embolic Lesions Research Articles

Síndrome del dedo azul

Blue digit syndrome (or sign) is a cutaneous manifestation of multiple diseases that produce acute or subacute ischemic compromise in one or more fingers or toes. The most frequent cause of this syndrome is a reduction in arterial blood flow due to compromise or occlusion of small peripheral vessels, with preservation of the distal pulses. The reduction in blood flow may be caused by a variety of pathogenic mechanisms including thrombosis, embolism, severe vasoconstriction, or inflammatory or non-inflammatory lesions of the vascular wall. The finger or toe affected by ischemia turns blue or violet and may develop necrosis. Independently of the cause, blue digit syndrome is a medical emergency requiring rapid diagnosis and specific treatment, given the risk of progression to irreversible necrosis.

Ultrasonographic Character of Carotid Plaque and Postprocedural Brain Embolisms in Carotid Artery Stenting and Carotid Endarterectomy

To investigate ultrasonographic character of carotid plaques, and incidences of brain embolism in carotid angioplasty and stenting (CAS) and carotid endarterectomy (CEA). CEA (22/25 symptomatic lesions) and CAS (17/20 symptomatic lesions) between 2007 and 2010. Embolic protection devices (15 occlusion and 5 filtering devices) were used during CAS. Carotid plaques were classified into three categories (I: calcificated, II: intermediately echogenic, III: echolucent). Magnetic resonance imaging (MRI) was used to investigate brain emboli. Ultrasonographic character of the plaques in CEA cases (I: 4%, II: 88%, III: 8%) was different from the one in CAS cases (I: 10%, II: 90%, III: 0%). The incidence of brain embolism in the CAS cases was 52.6% while 0% in the CEA cases (p = 0.00037). CAS had high incidences of brain embolism in any plaques (I: 100%, II: 43.8%). In the most recent 9 procedures of CAS using occlusion devices, averaged number of embolic lesion was 1.0 (0 post operative day; 0 POD). The number increased as 1.4 (1 POD) and 2.0 (7 POD). CEA should be currently the first choice for most patients with a high-grade and symptomatic carotid artery stenosis.

Primary hepatic neuroendocrine carcinoma with nonbacterial thrombotic endocarditis: A case report

Nonbacterial thrombotic endocarditis (NBTE) is occasionally found in patients with carcinoma (lung or gastrointestinal) or debilitating diseases. Definite diagnosis of NBTE should be performed by autopsy. It is difficult to diagnose NBTE if patients have no clinical signs of thromboembolism. Here, we present a case of primary hepatic neuroendocrine carcinoma with NBTE as proven by autopsy.

Identification of Carotid ‘Vulnerable Plaque’ by Contrast-enhanced Ultrasonography: Correlation with Plaque Histology, Symptoms and Cerebral Computed Tomography

Introduction Indication to carotid revascularisation is commonly determined by percent of stenosis as well as neurological symptoms and clinical conditions. High plaque embolic potential is defined as ‘vulnerability’; however, its characterisation is not universally used for carotid revascularisation. We investigated the role of contrast-enhanced ultrasonography (CEUS) to identify carotid vulnerable plaque. Methods Patients undergoing carotid endarterectomy were preoperatively evaluated by cerebral computed tomography (CT) scan and CEUS. Contrast microbubbles detected within the plaque indicated neovascularisation and were quantified by decibel enhancement (dB-E). Plaques were histologically evaluated for five features: (microvessel density, fibrous cap thickness, extension of calcification, inflammatory infiltrate and lipid core) and blindly scored 1–5 to assess plaque vulnerability. Analysis of variance (ANOVA), Fisher’s and Student’s t-test were used to correlate patients’ characteristics, histological features and dB-E. Results In 22 patients, dB-E (range 2–7.8, mean 4.85 ± 1.9 SD) was significantly greater in symptomatic (7.40 ± 0.5) vs. asymptomatic (3.5 ± 1.4) patients ( p = 0.002). A higher dB-E was significantly associated with thinner fibrous cap (<200 μm, 5.96 ± 1.5 vs. 3 ± 1, p = 0.01) and greater inflammatory infiltrate (3.2 ± 0.9 vs. 6.4 ± 1.2, p = 0.03). Plaques with vulnerability score of 5 had significantly higher dB-E compared with those with vulnerability score of 1 (7.6 ± 0.2 vs. 2.5 ± 0.6, respectively, p = 0.001). Preoperative ipsilateral embolic lesions at CT were correlated with higher dB-E (5.96 ± 1.5 vs. 3.0 ± 1.0, p = 0.01). Conclusion CEUS with dB-E is indicative of the extent of plaque neovascularisation. It can be used therefore as a marker for vulnerable plaque.

Lemierre’s syndrome complicated by an infected branchial cyst

We present a case of a young man with Lemierre's syndrome characterised by suppurative thrombophlebitis of the internal jugular vein and multiple septic embolic lesions with cavitations in both lungs resulting from an infected branchial cyst which was previously undiagnosed. Lemierre's syndrome is a rare presentation, especially with pulmonary cavitations, but remains a serious illness with a high mortality rate. Early recognition and prompt treatment have significant impact on prognosis. We believe this to be the first case of Lemierre's syndrome complicated by a previously undiagnosed, infected branchial cyst.

Radiofrequency Catheter Ablation of Atrial Fibrillation: A Cause of Silent Thromboembolism?

Background— Radiofrequency left atrial catheter ablation has become a routine procedure for treatment of atrial fibrillation. The aim of this study was to assess with preprocedural and postprocedural cerebral magnetic resonance imaging the thromboembolic risk, either silent or clinically manifest, in the context of atrial fibrillation ablation. The secondary end point was the identification of clinical or procedural parameters that correlate with cerebral embolism. Methods and Results— A total of 232 consecutive patients with paroxysmal or persistent atrial fibrillation who were candidates for radiofrequency left atrial catheter ablation were included in the study. Pulmonary vein isolation or pulmonary vein isolation plus linear lesions plus atrial defragmentation with the use of irrigated-tip ablation catheters was performed. All of the patients underwent preprocedural and postablation cerebral magnetic resonance imaging. A periprocedural symptomatic cerebrovascular accident occurred in 1 patient (0.4). Postprocedural cerebral magnetic resonance imaging was positive for new embolic lesions in 33 patients (14). No clinical parameters such as age, hypertension, diabetes mellitus, previous history of stroke, type of atrial fibrillation, and preablation antithrombotic treatment showed significant correlation with ischemic cerebral embolism. Procedural parameters such as activated clotting time value and, in particular, electric or pharmacological cardioversion to sinus rhythm correlated with an increased incidence of cerebral embolism. Cardioversion was also associated with an increased risk of 2.75 (95 confidence interval, 1.29 to 5.89; P =0.009). Conclusions— Radiofrequency left atrial catheter ablation carries a low risk of symptomatic cerebral ischemia but is associated with a substantial risk of silent cerebral ischemia detected on magnetic resonance imaging. Independent risk factors for cerebral thromboembolism are the level of activated clotting time and, in particular, the electric or pharmacological cardioversion to sinus rhythm during the procedure.

Neuropsychological decline after catheter ablation of atrial fibrillation

Cerebral embolic events represent recognized side effects after catheter ablation in the treatment of recurrent atrial fibrillation (AF). The study was performed to analyze the neuropsychological outcome and to detect new embolic ischemic brain lesions after therapeutic left atrial catheter ablation of AF. We enrolled 23 patients with recurrent AF who underwent elective circumferential pulmonary vein isolation. The primary endpoint was the neuropsychological outcome 3 months after intervention in contrast to the results of non-AF controls (n = 23) without ablation and in covariance of baseline performance. Cerebral diffusion-weighted magnetic resonance imaging (DWI) was performed in 21 AF patients at baseline, 2-4 days, and 3 months after intervention. In 3/21 patients (14.3%), new ischemic lesions were detected on DWI shortly after intervention. In one patient, a territorial middle cerebral artery infarct occurred with severe clinical symptoms. The other two patients represented clinically silent small lesions. In contrast to the control group and in covariance of baseline performance, the ablation group showed worse neuropsychological outcome in verbal memory (one of five cognitive domains) with an effect size of d = 0.93[t (.05; 42) = -3.53; P < .001; false discovery rate (FDR)(crit) ≤ .01]. Adverse neuropsychological changes after left atrial catheter ablation are verifiable in verbal memory and, conjoined with ischemic brain lesions on DWI, might represent cerebral side effects of this procedure.

Atherosclerotic plaque composition assessed by virtual histology intravascular ultrasound and cerebral embolization after carotid stenting

Previous studies have investigated the predictive value of clinical and morphologic parameters for distal embolization during carotid interventions. The composition of the atherosclerotic plaque, using virtual histology intravascular ultrasound (VH-IVUS) imaging obtained with an IVUS catheter that is advanced through the lesion after a filter has been placed distally, has not been evaluated as a marker for cerebral embolization. The purpose of this study was to assess the relationship between atherosclerotic plaque composition determined with VH-IVUS and the occurrence of cerebral embolization after carotid artery stenting (CAS). During a 10-month period, 24 patients undergoing CAS procedures using a filter device for embolic protection were prospectively evaluated. All patients underwent VH-IVUS exams at the time of the intervention, transcranial Doppler (TCD) monitoring during CAS, and pre- and 24-hour postprocedural diffusion-weighted magnetic resonance imaging (DW-MRI) exams. Using VH-IVUS, plaque components were characterized as fibrotic, fibrofatty, dense calcium, and necrotic core. The frequency of Doppler-detected microembolic signals (MES) during CAS and the incidence and location of acute postprocedural embolic lesions detected with DW-MRI were assessed to determine cerebral embolization. Univariate and correlation analyses were used to assess the association between plaque composition and frequency of cerebral embolization. No periprocedural transient ischemic attacks, strokes, or deaths occurred within 30 days. Seventeen patients (71%) demonstrated new acute cerebral emboli in DW-MRI. Of these, all revealed ipsilateral lesions and 12 (50%) had contralateral lesions. For the entire study group, the median number of ipsilateral DW-MRI lesions was 1 (range, 0 to 3), and TCD MES counts were 227 (interquartile range, 143-315). Volumetric VH-IVUS analysis revealed that there was a trend for larger median dense calcium volume in patients with ipsilateral subclinical cerebral embolism detected with DW-MRI (33.2±24.5 mm3 vs 11.4±6.1 mm3; P=.08). Scatter plots of plaque components revealed statistically significant correlation between fibrofatty plaque volume (Spearman r=0.49; P=.016) and number of new ipsilateral lesions in DW-MRI. Degree of cerebral embolization during CAS measured with TCD correlated with plaque burden, necrotic core, fibrofatty, and fibrous volumes. Plaque composition, as determined by VH-IVUS, only weakly correlates with the degree of cerebral embolization after carotid stenting. Specifically, there is a trend for larger dense calcium volume in patients with distal embolization. Of note, the proportion of necrotic core, which has traditionally been considered the main component of a vulnerable or unstable plaque, is not definitely associated with subclinical cerebral embolization after CAS when a filter device for embolic protection is used. The role of VH-IVUS in evaluating plaque composition during CAS remains unestablished and warrants further investigation.

The Benefits of Internal Thoracic Artery Catheterization in Patients With Chronic Abdominal Aortic Occlusion

Occlusion of the abdominal aorta may be caused by an embolic lesion, but more commonly by thrombotic disease at the aortoiliac area, progressing retrograde. However, the visualization of the distal run-off via internal thoracic-epigastric inferior artery collateral channel may be a very important diagnostic tool, especially in countries with poor technical equipment. This study was designed to show the benefit of the selective internal thoracic angiography in cases with complete aortic occlusion. We present 30 patients with chronic aortic abdominal occlusion who were submitted to the transaxillary aortography and selective ITA angiography with purpose of distal run off evaluation. Angiographic evaluation was performed by two independent radiologists according to previously defined classification. Good angiographic score via internal thoracic angiography by first observer was achieved in 19 (63.3%) patients and in 18 (60%) by a second observer. Transaxillary aortography showed inferior results: good angiographic score by the first observer in six (20%) patients and by the second observer in three (3%) patients. Low extremity run-off is better visualized during internal thoracic angiography than during transaxillary aortography.

Alterações patológicas em potros infectados por Actinobacillus equuli subsp. haemolyticus

Neste trabalho, são descritos dois casos fatais de septicemia com lesões embólicas causadas por Actinobacillus equuli subsp. haemolyticus em potros recém-nascidos. Em um dos animais, foram observados, na necropsia, pequenos nódulos esbranquiçados de aproximadamente 0,2cm de diâmetro na cortical dos rins e no outro havia uma área de coloração acinzentada no lobo diafragmático esquerdo do pulmão. As principais alterações microscópicas observadas no primeiro animal foram rins com infiltrado inflamatório multifocal a coalescente acentuado, com predomínio de neutrófilos, associado com áreas basofílicas levemente granulares compostas por grumos bacterianos. No segundo animal, o pulmão apresentava infiltrado inflamatório neutrofílico, edema, congestão e colônias bacterianas intravasculares. Em ambos os casos, colônias bacterianas foram encontradas disseminadas por vários órgãos incluindo capilares cerebrais. Nos dois casos foi isolado e identificado A. equuli subsp. haemolyticus.

Risk and Fate of Cerebral Embolism After Transfemoral Aortic Valve Implantation: A Prospective Pilot Study With Diffusion-Weighted Magnetic Resonance Imaging

The aim of this study was prospective investigation of silent and clinically apparent cerebral embolic events and neurological impairment after transfemoral aortic valve implantation (TAVI). TAVI is a novel therapeutic approach for multimorbid patients with severe aortic stenosis. We investigated peri-interventional cerebral embolism with diffusion-weighted magnetic resonance imaging (DW-MRI) and its relationship to clinical and serologic parameters of brain injury. Cerebral DW-MRI was performed before, directly, and 3 months after TAVI with the current third-generation self-expanding CoreValve (Medtronic, Minneapolis, Minnesota) prosthesis. At the timepoints of the serial MRI studies, focal neurological impairment was assessed according to the National Institutes of Health Stroke Scale (NIHSS), and serum concentration of neuron-specific enolase (NSE), a marker of the volume of brain tissue involved in an ischemic event, were determined. Thirty patients were enrolled; 22 completed the imaging protocol. Three patients (10%) had new neurological findings after TAVI, of whom only 1 (3.6%) had a permanent neurological impairment. Of the 22 TAVI patients with complete imaging data, 16 (72.7%) had 75 new cerebral lesions after TAVI presumed to be embolic. The NIHSS and NSE were not correlated with DW-MRI lesions. The incidence of clinically silent peri-interventional cerebral embolic lesions after TAVI is high. However, in this cohort of 30 patients, the incidence of persistent neurological impairment was low. (Incidence and Severity of Silent and Apparent Cerebral Embolism After Conventional and Minimal-invasive Transfemoral Aortic Valve Replacement; NCT00883285).

Ecthyma gangrenosum caused by Pseudomonas aeruginosa in a patient with astrocytoma treated with chemotherapy

Ecthyma gangrenosum, presenting as embolic lesions caused by Pseudomonas aeruginosa infection, has distinct pathognomonic features and a high mortality rate in patients with bacteremia, but when recognized early is easily treated. In this case report we describe this disseminated infection in an adult patient treated with chemotherapy for an astrocytoma.

脳アミロイドアンギオパチーによる多発性皮質微小梗塞が認知症の進行に影響したと考えられる１剖検例

A Japanese male showed gradually progressing dementia with psychiatric symptoms including abnormal behavior, night and day reversal, nocturnal delirium, loud shouting, agitation, resistance to care, and loud soliloquy. The patient had a history of right cerebral embolism due to atrial fibrillation 1 month before the onset of dementia. Head CT revealed widespread cerebral infarction in the right cerebral hemisphere with bilateral lateral ventricular dilatation. The patient died at the age of 83, 10 months after the onset of cerebral embolism. The clinical diagnosis was mixed-type dementia. On autopsy the brain weighed 1,160 g. Widespread cerebral amyloid angiopathy (CAA) was observed, with distribution most severe in the cerebral cortical vessels and slightly milder in the leptomeningial and subarachnoid vessels. The artery, arteriole, and capillary walls were thickened by the deposition of amorphous, eosinophilic and beta-protein immunopositive amyloid. Abeta-deposition was more severe in capillaries and CAA tended to be more severe in the occipital regions. Multiple cortical microinfarcts were found, particularly in the crests of the cerebral gyri of watershed zones. Cerebral white matter, basal ganglia, thalamus, brainstem and spinal cord were relatively preserved from CAA. Infarction was not apparent, except for an embolic lesion in the right cerebral hemisphere and the cortical microinfarcts. We did not observe fibrinoid necrosis, granulomatous angiitis or giant cell reaction associated with CAA-vasculopathies. Rare instances were observed of neurofibrillary tangles and senile plaques corresponding to Braak stages II and A, respectively. We thought the multiple cortical microinfarcts occurred due to chronic hypoperfusion associated with CAA-associated vasculopathies of capillaries in the cerebral cortex. We suspected that the dementia was influenced by the CAA with multiple cortical microinfarcts. Pathologic findings of the patient suggest that CAA without AD-related Abeta-deposition might exist and that capillary Abeta-deposition might be an important factor of hemodynamic perturbation.

Atherosclerotic Plaque Composition and Cerebral Embolization after Carotid Stenting

Background: Previous studies have investigated the predictive value of clinical and morphologic parameters for distal embolization during carotid interventions. The composition of the atherosclerotic plaque using virtual histology intravascular ultrasound (VH IVUS) imaging at the intervention site has not been evaluated as a marker for cerebral embolization. The purpose of this study was to assess the relationship between atherosclerotic plaque composition determined with VH IVUS and the occurrence of cerebral embolization after carotid angioplasty and stenting (CAS). Methods: During a 10-month period, 24 patients undergoing CAS procedures using a filter device for embolic protection (Accunet Filter, Abbott Vascular, Santa Clara, Calif) were prospectively evaluated. All patients underwent VH IVUS imaging before the intervention, transcranial Doppler (TCD) monitoring during CAS, and preprocedural and 24-hour postprocedural diffusion-weighted magnetic resonance imaging (DW-MRI). VH-IVUS characterized plaque components as fibrotic, fibrofatty, dense calcium, and necrotic core. The frequency of Doppler-detected microembolic signals (MES) during CAS and the incidence and location of acute, postprocedural embolic lesions detected with DW-MRI was assessed to determine cerebral embolization. Univariate and linear regression analyses were used to assess the association between plaque composition and the frequency of cerebral embolization. Results: No periprocedural transient ischemic attacks, strokes, or deaths occurred at 30 days. DW-MRI demonstrated new acute cerebral emboli in 14 patients (58%). All revealed ipsilateral lesions, and eight (32%) had also contralateral lesions. For the entire study group, the median number of DW-MRI lesions was two (range, 0-173) and the TCD MES counts were 222 (interquartile range, 152-322) .Of the plaque components, DW-MRI determined that only dense calcium was significantly associated with cerebral embolization. The proportion of dense calcium was significantly larger in patients with cerebral embolization (5.7% ± 2.2% vs 1.2% ± 0.3%, P = .04). Findings on postprocedural DW-MRI did not correlate with the proportion of fibrotic, fibrofatty, and necrotic core. Degree of cerebral embolization during CAS measured with TCD did not correlate with plaque composition. Conclusions: Plaque composition, as determined by VH IVUS, correlates with the degree of cerebral embolization after CAS but not during the intervention. Specifically, the proportion of dense calcium is strongly associated with the occurrence of cerebral embolization after CAS. Of note, the proportion of necrotic core, which has traditionally defined the presence of a vulnerable or unstable plaque, does not correlate with the degree of distal embolization after CAS when a filter device for embolic protection is used. Optimal management and strategies to prevent distal embolization after CAS of lesions with significant dense calcium warrant further investigation.

Evaluation of Angiographic and Technical Aspects of Carotid Stenting with Diffusion-Weighted Magnetic Resonance Imaging

The detection of clinically silent ischemic lesions on postprocedural diffusion-weighted magnetic resonance images has become a preferred method for the description of embolic risks. The purpose of this single-center study was to evaluate whether diffusion-weighted imaging (DWI) could determine material related or technical risk factors of filter-protected carotid stenting. Eighty-four patients with symptomatic severe (> or = 60%) carotid artery stenoses received filter-protected carotid stenting. Standard DWI (b = 1000) was performed within 48 h before and after carotid stenting. The occurrence and load of new postinterventional DWI lesions were assessed. Multivariate analysis was performed to determine risk factors associated with DWI lesions, with emphasis on technical factors such as use of different access devices (guiding catheter method vs. long carotid sheath method), type of stent (open-cell nitinol stent vs. closed-cell Wallstent), and protective device (filters with 80-microm vs. 110-120-microm pore size). Markers for generalized atherosclerosis and for degree and site of stenosis were assessed to allow comparison of adequate risk profiles. Access, protective device, and stent type were not significantly associated with new embolic DWI lesions when we compared patients with equivalent risk profiles (long carotid sheath method 48% [11 of 23] vs. guiding catheter method 44% [27 of 61], Wallstent 47% [15 of 32] vs. nitinol stent 44% [23 of 52], and small pore size filter 61% [11 of 18] vs. large pore size filter 41% [27 of 66]). Single-center DWI studies with a moderate number of cases are inadequate for proper assessment of the embolic risk of technical- or material-related risk factors in carotid stenting. Larger multicenter studies with more cases are needed.

Überwachung der zerebralen Integrität

In vascular surgery, intraoperative monitoring of the brain is recommended when the internal carotid artery (ICA) is clamped, because brain damage by ischemia and embolism is possible. Clamping of the ICA results in embolic or ischemic brain lesions in about 7 % of all patients undergoing the procedure. Prophylactic routine insertion of an intraluminal shunt can cause brain embolism and does not reduce the occurrence of complications. Consequently, a shunt should only be inserted, if critical reduction of cerebral perfusion is evident after clamping the ICA. Measurement of carotid stump pressure is an invasive method to estimate perfusion of the brain hemisphere at the clamping side. Transcranial doppler sonography (TCD) measures the mean blood flow velocity in the ACI, but practicability is suffering from technical problems in 20% of all patients. However, TCD is useful for detecting intraoperative embolism and postoperative hyperperfusion. Changes of oxyhaemoglobine and desoxyhaemoglobine concentration in brain tissue can be measured using near-infrared spectroscopy (NIRS) with wavelengths between 700 and 1000 nm. NIRS measurement is easily performed and reacts quickly to changes of brain tissue oxygenation, but there is still lacking evidence and at present a general recommendation of its application in vascular surgery is not justified. Use of somatosensory evoked potentials (SEP) is the most widespread cerebral neuromonitoring during vascular surgery due to its high reliability and simple application. Sensitivity and specifity for ischemic lesions are 100% and 94%-99%, respectively. SEP are regarded as the gold standard for cerebral neuromonitoring in anaesthetized patients.

Cerebral Ischemic Lesions Detected With Diffusion-Weighted Magnetic Resonance Imaging After Carotid Artery Stenting: Comparison of Several Anti-embolic Protection Devices

Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm(3) vs. 86.9 mm(3), respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm(3)) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm(3) and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions.

Induction of severe Staphylococcus aureus sepsis in pigs

Organ dysfunction is an integrated part of severe sepsis, and severe sepsis is one of the major causes of death in ICUs. Lately Gram-positive bacteria accounted for more than one-half of the overall sepsis cases reported in the USA, with Staphylococcus aureus being the most commonly isolated bacterium. Effective treatment of sepsis is still not optimal and good animal models are needed for research in pathogenesis and treatment. S. aureus infections are also common in pigs and are isolated from approximately 40% of embolic lesions found in slaughter-pigs.

Atherosclerotic aortic lesions increase the risk of cerebral embolism during carotid stenting in patients with complex aortic arch anatomy

Carotid artery stenting (CAS) leads to frequent embolic brain lesions; their source has not been clearly identified yet. In order to investigate this phenomenon, we have evaluated embolic brain lesions (BL) after CAS and correlated them with aortic arch (AA) characteristics. The AAs of 59 patients undergoing CAS under distal protection were evaluated by angiography and transesophageal echocardiography (TEE). AAs were stratified according to morphology (type I and II "simple" vs type III and bovine "difficult"), atherosclerotic arch lesions (complicated: >5 mm or with mobile debris vs uncomplicated: <5 mm), and tortuosity index (TI; sum of all angles diverging from ideal carotid axis, <150 vs >150). Diffusion weighted imaging (DWI) was performed before and within 24 hours from CAS. New BL were considered ipsilateral (IL) if ipsilateral to the site of CAS and non-ipsilateral (CL) if contralateral to it or bilateral. Normality distribution was by Shapiro-Wilk test (variables reported as medians +/- interquartile range) and statistical significance (P < .05) by Wilcoxon and Fisher's exact test. Difficult arches were present in 17 patients (28.8%), complicated aortic plaque in 21 (35.5%), and TI > 150 in 34 (57.6%). New BL appeared in 34 or 57.6% patients (6 or 18% IL and 28 or 82% CL). The mean number of BL was 5.7 (range, 0 to 20), 4.7 IL, and 5.7 CL, with a median volume of 560.95 +/- 1677.7 mm(3). Type of arch and TI were not correlated with mean number of BL. Mean volume of BL were greater in patients with difficult AA, complicated plaques, and TI > 150 (258 (572) mm(3) vs 15.6 (353) mm(3), P = .2; and 86 (828) mm(3) vs 85.9 (352) mm(3), P = .4 172 (766) mm(3) vs 0 (228) mm(3), P = .06, respectively). In patients with all three AA characteristics, mean number and volume of BL was significantly greater compared with other patients. Specifically, this increase was due mainly to CL (IL 0 (117) mm(3) vs 0 (172) mm(3), P = .9; CL 564 (687) mm(3) vs 0 (133) mm(3), P = .001). None of the technical details considered was correlated with either IL or CL. BL are frequent after protected CAS and are correlated with AA characteristics, thus underlining the role of catheterization maneuvers in determining embolic events. TEE may be useful in patient's selection for CAS.

2071 Perioperative monitoring of microembolic cerebral events in patients undergoing different types of aortic valve replacement by magnet resonance imaging

Methods We examined 24 patients (20 female, 4 male) at an average age of 82 years suffering from an aortic valve stenosis before (mean = 3 days) and after (mean = 8 days) different types of AVR by Magnet Resonance Imaging (MRI) using a Philips Intera 1.5 T system. We acquired FLAIR-, T2and diffusion weighted transversal images with the following parameters: TR = 10000; 5000; 6230 ms, TE = 140; 100; 73 ms, FOV: 230–250 mm, matrix = 205*256; 307*512; 90*256. Different types of AVR were surgical AVR via sternotomy (3 patients), microinvasive transapical (11 patients), as well as transfemoral catheter based AVR (10 patients). New lesions between the two examinations were counted by two observers in consensus. Results The sequences using diffusion weighted imaging (DWI) detected most of the new embolic lesions (90) in 14 patients (58%). While with the post-operative FLAIR images only 37 new lesions in 13 patients (54%), with the T2-weighted images only 14 new lesions in 10 (41%) patients were identified. Figure 1 shows an example of positve findings in the different sequences.