Endarterectomía carotídea con medición de presión de muñón, manejo hemodinámico y uso selectivo de shunt / Carotid Endarterectomy with routine carotid stump pressure measurement, intraoperative hemodynamic management and selective use of shunt

Resumen Introducción En la endarterectomía carotídea (EC) durante el clampeo, la perfusión cerebral se mantiene por circulación contralateral a través del Polígono de Willis, que se relaciona con la presión de muñón carotídeo (PM). Si ésta es menor a 50 mmHg existe riesgo de Accidente Cerebrovascular (ACV) por hipoperfusión y está indicado uso de shunt para asegurar suficiente circulación cerebral, pero también se puede elevar transitoriamente la presión arterial sistémica haciendo innecesario el uso de shunt. Objetivo Mostrar los resultados de EC con medición de PM para evaluar la perfusión cerebral del hemisferio clampeado con manejo hemodinámico intraoperatorio minimizando el uso de shunt. Material y Métodos Estudio retrospectivo de 73 pacientes sometidos a EC bajo anestesia general con medición de PM, manejo hemodinámico intraoperatorio y uso selectivo de shunt. Se analizaron variables demográficas, clínicas y morbimortalidad perioperatoria. Resultados 73 pacientes, edad promedio 71,1 años, 69,9% sintomáticos. En 54 pacientes la PM fue superior a 50 mmHg y no se usó shunt, en 19 la PM fue menor a 50 mmHg y con manejo hemodinámico intraoperatorio se elevó en 16 que no requirieron shunt. Sólo en 3 casos la PM no alcanzó los 50 mmHg y se usó un shunt de Pruitt-Inahara. Dos pacientes sintomáticos presentaron déficit neurológico central transitorio postoperatorio y 2 pacientes fallecieron por infarto cardíaco. Conclusión La EC con medición de PM y manejo hemodinámico minimizó el uso de shunt transitorio y fue un procedimiento seguro para tratar los pacientes con estenosis carotídea con indicación quirúrgica.

Introduction During carotid endarterectomy (CEA) clamping cerebral perfusion is maintained by contralateral circulation through the Circle of Willis and it is correlated to the stump pressure (SP). If it is below 50 mmHg there is risk of stroke due to hypoperfusion and a shunt must be used, but systemic blood pressure can be temporarily elevated making the use of shunt unnecessary. Aim Results of CEA with SP measurement to evaluate cerebral perfusion in cross-clamped hemisphere and hemodynamic intraoperative management reducing the use of shunt. Material and Methods Retrospective study of CEAs performed in 73 patients under general anaesthesia with SP measurement, hemodynamic management and selective use of shunt. Demographics, clinical and perioperative morbimortality variables were analized. Results 73 patients, average age 71.1 years, 69.9% symptomatic. In 54 patients SP was above 50 mmHg and shunt was not used, in 19 SP was below 50 mmHg, it was elevated through intraoperative hemodynamic management and shunt was not needed. In only 3 cases SP did not reach 50 mmHg and a Pruitt-Inahara shunt was used. Two patients presented postoperative transient central neurological deficit and 2 died due to myocardial infarction. Conclusion CEA with SP measurement and hemodynamic management reduced the use of carotid shunting and it was a safe procedure to treat patients with severe carotid stenosis who need surgical intervention.

Cerebral vasomotor reactivity assessment using Transcranial Doppler and MRI with apnea test

Differently from previous studies that used Transcranial Doppler (TCD) and functional MRI (fMRI) for cerebral vasomotor reactivity (CVR) assessment in patients with carotid stenosis (CS), we assessed CVR using an identical stimulus, the Breath-Holding Test (BHT). We included 15 patients with CS and 7 age-matched controls to verify whether fMRI responded differently to BHT between groups and to calculate the agreement rate between tests. For TCD, impaired CVR was defined when the mean percentage increase on middle cerebral artery velocities was ≤31% on 3 consecutive 30-s apnea intercalated by 4-min normal breathing intervals. For fMRI, the percent variation on blood oxygen level-dependent (BOLD) signal intensity in the lentiform nucleus (LN) ipsilateral to the CS (or both LNs for controls) from baseline breathing to apnea was measured. The Euclidian differences between the series of each subject and the series of controls and patients classified it into normal or impaired CVR. We found different percent variations on BOLD-signal intensities between groups (P=0.032). The agreement was good in Controls (85.7%; κ=0.69) and overall (77.3%; κ=0.54). We conclude that BHT was feasible for CVR assessment on fMRI and elicited different BOLD responses in patients and controls, with a good overall agreement between the tests.

Hemodynamic Significance of Internal Carotid or Middle Cerebral Artery Stenosis Detected on Magnetic Resonance Angiography

PURPOSE: We evaluated hemodynamic significance of stenosis on magnetic resonance angiography (MRA) using acetazolamide perfusion single photon emission computed tomography (SPECT). MATERIALS AND METHODS: Of 171 patients, stenosis in internal carotid artery (ICA) and middle cerebral artery (MCA) (ICA-MCA) on MRA and cerebrovascular reserve (CVR) of MCA territory on SPECT was measured using quantification and a 3-grade system. Stenosis and CVR grades were compared with each other, and their prognostic value for subsequent stroke was evaluated. RESULTS: Of 342 ICA-MCA, 151 (44%) presented stenosis on MRA; grade 1 in 69 (20%) and grade 2 in 82 (24%) cases. Decreased CVR was observed in 9% of grade 0 stenosis, 25% of grade 1, and 35% of grade 2. The average CVR of grade 0 was significantly different from grade 1 (p<0.001) and grade 2 stenosis (p=0.007). In quantitative analysis, average CVR index was -0.56+/-7.91 in grade 0, -1.81+/-6.66 in grade 1 and -1.18+/-5.88 in grade 2 stenosis. Agreement between stenosis and CVR grades was fair in patients with lateralizing and non-lateralizing symptoms (kappa=0.230 and 0.346). Of the factors tested, both MRA and CVR were not significant prognostic factors (p=0.104 and 0.988, respectively), whereas hypertension and renal disease were significant factors (p<0.05, respectively). CONCLUSION: A considerable proportion of ICA-MCA stenosis detected on MRA does not cause CVR impairment despite a fair correlation between them. Thus, hemodynamic state needs to be assessed for evaluating significance of stenosis, particularly in asymptomatic patients.

Hemodynamic Instability during Carotid Angioplasty and Stenting-Relationship of Calcified Plaque and Its Characteristics

PURPOSE: During carotid angioplasty and stenting (CAS), hemodynamic instability (HDI) can occur, possibly causing post-procedural ischemic complications. The goal of this study was to investigate the risk factors of HDI focusing on characteristics of plaque. MATERIALS AND METHODS: Thirty nine CAS patients were retrospectively evaluated for HDI. Prolonged HDI that lasted over 30 minutes was analyzed in relation to characteristics of calcified plaque. RESULTS: Nineteen (48.7%) patients had HDI. Ten of the 19 had both bradycardia and hypotension, and nine had only bradycardia. All bradycardia was treated well with a transcutaneous temporary cardiac pacemaker. But eight patients presented with prolonged hypotension in spite of recovery of bradycardia. Calcified plaque was a related factor associated with HDI (odds ratio, 8.571; 95% confidence interval, 1.321-55.62; p=0.024). Extensive and eccentric type calcified plaques were associated with prolonged hypotension (p=0.04, and p=0.028, respectively). CONCLUSION: The calcification of plaque is a predictable factor of HDI during CAS, and its extensive and eccentric calcified plaques may be related to prolonged HDI.

The modified 2VO ischemia protocol causes cognitive impairment similar to that induced by the standard method, but with a better survival rate

Permanent bilateral occlusion of the common carotid arteries (2VO) in the rat has been established as a valid experimental model to investigate the effects of chronic cerebral hypoperfusion on cognitive function and neurodegenerative processes. Our aim was to compare the cognitive and morphological outcomes following the standard 2VO procedure, in which there is concomitant artery ligation, with those of a modified protocol, with a 1-week interval between artery occlusions to avoid an abrupt reduction of cerebral blood flow, as assessed by animal performance in the water maze and damage extension to the hippocampus and striatum. Male Wistar rats (N = 47) aged 3 months were subjected to chronic hypoperfusion by permanent bilateral ligation of the common carotid arteries using either the standard or the modified protocol, with the right carotid being the first to be occluded. Three months after the surgical procedure, rat performance in the water maze was assessed to investigate long-term effects on spatial learning and memory and their brains were processed in order to estimate hippocampal volume and striatal area. Both groups of hypoperfused rats showed deficits in reference (F(8,172) = 7.0951, P < 0.00001) and working spatial memory [2nd (F(2,44) = 7.6884, P < 0.001), 3rd (F(2,44) = 21.481, P < 0.00001) and 4th trials (F(2,44) = 28.620, P < 0.0001)]; however, no evidence of tissue atrophy was found in the brain structures studied. Despite similar behavioral and morphological outcomes, the rats submitted to the modified protocol showed a significant increase in survival rate, during the 3 months of the experiment (P < 0.02).

Morphological and hemodynamic patterns of carotid stenosis treated by endarterectomy with patch closure versus stenting: a duplex ultrasound study

OBJECTIVES: A duplex ultrasound study was performed to investigate morphological and hemodynamic patterns of carotid stenoses treated by endarterectomy with patch closure versus stenting. MATERIALS AND METHOD: Twenty-nine carotid stenoses were treated with stenting and 65 with patch closure. Duplex ultrasound parameters (luminal diameter, mm; peak systolic velocity and end-diastolic velocity, cm/s) were measured 24 hours after the procedures and also at 12 months post-procedure. Residual stenoses (immediately postprocedure) and restenoses (within 12 months of procedure) were defined as narrowings of >50 percent on duplex ultrasound examination. RESULTS: In stented patients, the luminal diameter of the proximal internal carotid artery increased in the interval between the 24-hour and 12-month post-procedure studies, while in the patch closure patients, the diameter decreased. Carotid hemodynamics normalized immediately after both patching and stenting and remained relatively stable thereafter up to 12 months. No statistically elevated flow velocities (in the absence of residual stenosis or restenosis) were observed in the patched or stented carotid arteries. No significant differences in residual stenosis rates were observed between the stenting group (3 cases, 10.34 percent) and the patch closure group (1 case, 1.53 percent, P = 0.08). At 12 months, 2 stenting patients (6.88 percent) and 2 patch closure patients (3.07 percent) had $50 percent restenosis (P = 0.58). One case of late stroke due to restenosis was observed in the stenting group; the patient died 12 months postoperatively, before receiving new intervention. CONCLUSION: Measurements over time in luminal diameter signalized differences in arterial remodeling mechanisms between patched and stented carotids. Both stenting and patch closure were associated with carotid patency and flow restoration. This study does not support a general approach to new velocity criteria indiscriminately applied to stented or patched carotids.

Estudio con ultrasonido doppler color en la caracterización de la enfermedad aterosclerotica carotidea oclusiva sintomática / Study with color doppler ultrasound in the characterization of symptomatic carotid atherosclerotic occlusive disease

Objective: To determine the association between risk factors and atherosclerosis in the carotid arteries in occlusive cerebrovascular disease. Method: A prospective, descriptive, cross-sectional study in 274 patients with clinical and CT diagnosis ofischemic ictus was conducted. Examination by the means of carotid artery color Doppler ultrasound was performed in the study Group. Results and Conclusions: The mean age of patients was 68.7 years anda male predominance (54.1 percent) was reported. Arterial hypertension, which was present in 214 patients (78.1 percent), constituted the most prevalent atherogenic risk factor, followed by age over 60 years (75.9 percent), and smoking (58 percent). The atherothrombotic and cardioembolic origins were predominant (54 percent and 19.7 percent, respectively), followed by lacunar (13.9 percent), and undetermined origin (11.3 percent). Atherosclerotic involvement occurs bilaterally with a predominance of the right axis, appearing low shear stress areas as the sites of the greatest severity.

Objetivo: Determinar la asociación entre los factores de riesgos y la aterosclerosis de las arterias carótidas, en la enfermedad cerebrovascular oclusiva. Método: Se realizó un estudio prospectivo, descriptivo y transversal en 274 pacientes con diagnóstico clínico y tomográfico de ictus isquémico, realizándoles estudio con ultrasonido Doppler color carotídeo. Resultados y Conclusiones: La edad media de los pacientes fue 68,7años. Se observó predominio de sexo masculino (54,1 por ciento). EI factor de riesgo aterogénico que predominó fue HTA, presente en 214 (78.1 por ciento), seguido por edad mayor de 60 (75.9 por ciento) y tabaquismo (58 por ciento). El origen aterotrombótico y cardioembólico fueron predominantes (54 y 19.7 por ciento respectivamente), seguidos por el lacunar (13.9 por ciento) y el origen indeterminado (11.3 por ciento). La afectación aterosclerótica ocurre bilateralmente, con un predominio del eje derecho, siendo las zonas de bajo shear stress los sectores de mayor severidad.

Outcomes of carotid artery stenting in patients with symptomatic and asymptomatic carotid artery stenosis.

OBJECTIVE: Carotid endarterectomy is superior to medical therapy in patients with significant extracranial carotid artery stenosis. This modality of treatment has its own complications. The principal objective of this study is to assess efficacy, feasibility and outcomes of carotid artery stenting in both symptomatic and asymptomatic carotid artery stenosis. METHODS: Our study is a retrospective analysis of 45 consecutive patients with 56 lesions who underwent carotid angioplasty with stenting from January 2000 to June 2007 for carotid artery stenosis of more than 70%. All patients underwent detailed neurological examination and carotid Doppler evaluation by using Sonos 5500. Computed tomography of brain was done in those patients who were symptomatic in the past. RESULTS: The mean age of the study population was 65 +/- 9.2 years. There were 34 (79%) patients with coronary artery disease and out of them 31 (68%) patients had undergone coronary artery bypass grafting. All patients with common carotid artery, 13 (81%) patients with right internal carotid stenosis and 12 (66%) patients with left internal carotid artery stenosis had ostioproximal stenosis. Contralateral lesion was found in 9 patients and 2 patients had total occlusion. There were no post-procedural neurological events. Only one patient died in our study population due to non-cerebral cause. CONCLUSION: Carotid artery stenting is a safe procedure. The 30 days' outcomes are similar in both symptomatic and asymptomatic patients with significant carotid artery stenosis.

Orbital infarction syndrome in nephrotic syndrome patient with extensive carotid arteries occlusion.

Orbital infarction syndrome is defined as ischemia of global intraorbital structures such as extraocular muscles, optic nerves, and retina. The most common cause of this syndrome is carotid arterial occlusion. Other causes include vasculitis, vasospasm, and compression of intraorbital circulation. There has never been reported a case of orbital infarction syndrome in nephrotic syndrome patient. We present a case of 42-year-old Thai man with underlying disease nephrotic syndrome presented with abrupt onset of headache at left temporal area, horizontal diplopia, limitation of eye movement in all directions, ptosis, and blurred vision on the left eye. He was treated with pulse methylprednisolone intravenously for 3 days. Leg edema was improved however, the eye symptoms persisted. There was no evidence of hypercoagulable state. Magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) revealed loss of signal intensity at left internal carotid artery from base of skull to intracavernous part. Cerebral angiography demonstrated complete occlusion of left common carotid artery. After the anticoagulant treatment, his symptoms were gradually improved. The cause of extensive carotid arterial occlusion in this patient is most likely from hypercoagulable state. Although it was negative for hypercoagulable state evidence, the authors assume that the high dose steroid treatment could lead to remission of nephrotic syndrome and resulting in the resolution of hypercoagulable state.

Avaliação hemodinâmica em portadores de estenose de carótida com Doppler Transcraniano / Hemodynamic study in stenotic carotid artery patients by Transcranial Doppler

O manejo terapêutico de portadores assintomáticos ou com estenose menor que 70 por cento da carótida é ainda debatido na literatura.Estudos anteriores não se utilizaram de parâmetros funcionais na randomização de seus pacientes.Realizamos este estudo com o objetivo de avaliar a integridade hemodinâmica intracerebral por meio da da reatividade cerebrovascular(RCV) e correlacionar os resultados com o grau de estenose e com a sintomologia clínica.The management of asymptomatic and <70 per cent carotid stenosis patients is still debatable.Previous studies did not use functional parameters to randomize these patients.In order to find out the relationship among the degree of carotid stenosis, symptoms and reserve capacity we performed a study using cerebrovascular reactivity(CVR)as an index of cerebral hemodynamic integrity...

Enfermedad carotídea arterioesclerótica: estudio de 22 casos de alto riesgo intervenidos con anestesia local

Se presenta un estudio descriptivo de 22 casos de endarterectomía carotídea con anestesia local en la Fundación Santa Fe de Bogotá. Se analizan los resultados que muestran una aceptable morbilidad postoperatoria y ausencia de mortalidad relacionada con el procedimiento. En pacientes de alto riesgo quirúrgico y anestésico, esta técnica es sencilla de practicar y el manejo intra y postoperatorio no presenta mayores dificultades