Animals ; Carotid Arteries ; physiology ; Cerebral Angiography ; Cerebral Arteries ; physiology ; Cerebrovascular Circulation ; Humans ; Rats ; Vertebral Artery ; physiology

Aneurysm of the carotid artery in the neck is rare lesion and may elicited in patient with Behcet's disease. To achieve maintenance of critical perfusion pressure of brain during the cross clamping of the carotid body, the anesthesiologist is familiar with the use, reliability and limitation of various monitoring modalities and posses a working knowledge of basic brain physiology and protective measures available to protect against cerebral ischemia and hypoxia. We report here our anesthetic experiences and considerations of 2 surgical patients with both common carotid artery aneurysm and false carotid artery aneurysm associated with Behcet's disease.
Aneurysm* ; Anoxia ; Brain ; Brain Ischemia ; Carotid Arteries* ; Carotid Artery, Common ; Carotid Body ; Constriction ; Humans ; Neck ; Perfusion ; Physiology

As is well known, the zero stress state of an artery is brought by cutting a ring of the artery radically and then the ring segment springs open into a sector. The zero stress state is a foundation of strain analysis of an artery. There are two methods to measure the dimensions of a blood vessel in the zero stress state. First, it is a way to measure immediately an opening angle. Second, it is a method of assuming that a cut-open, stress-free specimen forms a circular sector and there are two edge angles. In this paper, we proposed a new method to measure the dimensions of an arterial wall in the zero stress state. The new method is to measure immediately the curve length of an arterial wall in zero stress state by computer image process (CIP). We used the curve lengths to define a standard circle for the strain analysis. We compared these three methods on descending thoracic aortas, common carotid arteries, and femoral arteries of white rabbits. Conclusions are: (1) the new method, that is the strain analysis method from the curve length, is the best method among the three methods of strain analysis; (2) the lengths of a ring segment (the length between D/2 and 2D) do not affect the dimensions of the zero stress state.
Animals ; Aorta, Thoracic ; physiology ; Arteries ; physiology ; Carotid Artery, Common ; physiology ; Elasticity ; Femoral Artery ; physiology ; Rabbits ; Stress, Mechanical ; Tensile Strength

The aim of the present study was to investigate the effect of removal of the adventitia on vascular remodeling and vasoconstriction of the carotid artery in New Zealand rabbit. Adventitia of carotid artery was removed mechanically. The histology, morphology and reactivity of the carotid artery was observed by immunohistochemistry and measurement of carotid ring tension immediately, 1 week and 2 weeks after removal of the adventitia. No damage of intima and media was observed after removing the adventitia. Removal of the adventitia caused a remarkable proliferation of the vascular media and formed the neointima. Compared with the control ring, norepinephrine (NE)-induced vasocontraction in adventitia-denuded carotid artery was significantly reduced immediately and 1 week after the operation (P<0.05). Adventitia removal promoted the neointima formation and decreased vasoconstriction of the carotid artery, indicating that the adventitia is involved in the regulation of vascular remodeling and vasoconstriction.
Animals ; Carotid Arteries ; pathology ; physiology ; surgery ; Connective Tissue ; physiology ; surgery ; Muscle, Smooth, Vascular ; pathology ; Rabbits ; Tunica Intima ; pathology ; Vasoconstriction ; physiology

The maximum frequency waveforms of Doppler ultrasound blood flow signals were analyzed using a multi-scale wavelet transform. The variation of maxima of wavelet transform modulus under various scales was extracted from the time-scale representation. This novel approach was applied to the analysis of Doppler signals from carotid blood flow. It was found that the shape of this variation from cases with normal cerebral vessels differed from those associated with abnormal cases. The curve was fitted by a polynomial, and its coefficients were put into a back-propagation (BP) neural network to make a classification. The clinical experiments showed that this approach got good performance and could be a new means in the clinical diagnosis of cerebral vascular disease.
Algorithms ; Angiography ; Carotid Arteries ; physiology ; Echocardiography, Doppler ; Humans ; Neural Networks (Computer) ; Regional Blood Flow ; Wavelet Analysis

Pulsatile blood flow plays an important role in maintaining normal vascular endothelial function. Quantitative measurement of pulsatility of artery blood pressure and blood flow in dogs and effects of enhanced external counterpulsation (EECP) on the pulsatility were taken in this study. Common carotid artery blood pressure and blood flow were measured in 6 beagle dogs that had suffered from an acute myocardial infarction 6 weeks before. A 6F tip transducer catheter was inserted into the right common carotid artery to measure blood pressure, and blood flow was measured in the left common carotid artery by an electromagnetic blood flow probe under anesthesia before and during EECP. Blood pulse pressure, pulsatility index (ratio of peak pressure to end diastolic pressure) and standard deviation of blood pressure were calculated to evaluate the pulsatility of arterial blood pressure. Blood pulse flow, pulsatility index (ratio of peak flow to trough flow) and standard deviation of blood flow were calculated to evaluate the pulsatility of blood flow. Mean vascular resistance (MVR) was calculated as MVR = mean blood pressure/mean blood flow. Blood pulse pressure, pulsatility index and standard deviation of blood pressure were elevated from 30 +/- 9 mmHg, 1.26 +/- 0.05 and 8.7 +/- 2.5 mmHg to 43 +/- 8 mmHg (P < 0.05), 1.54 +/- 0.13 and 12.4 +/- 2.0 mmHg (P < 0.05) before and during EECP, respectively. Blood pulse flow, pulsatility index and standard deviation of blood flow were elevated from 317 +/- 48 ml/min, 2.85 +/- 0.21 and 96 +/- 21 ml/min to 447 +/- 88 ml/min, 4.56 +/- 0.90 and 131 +/- 39 ml/min before and during EECP (P < 0.05). MVR was decreased from 578 +/- 72 before EECP to 476 +/- 85 Wood units during EECP(P < 0.05). These data demonstrate that EECP gives an elevation of pulsatility to blood pressure and blood flow, thus it may lead to the decrease of vascular resistance.
Animals ; Blood Pressure ; Carotid Arteries ; physiology ; Counterpulsation ; Dogs ; Hemodynamics ; Pulsatile Flow ; Regional Blood Flow ; Vascular Resistance

The severity of carotid intima-media thickness (IMT) is an independent predictor of atherosclerosis which causes transient cerebral ischemia, stroke, and coronary events such as myocardial infarction. The IMT consists of intima thickness (IT) and media thickness (MT). However, the Individual clinical significance of IT and MT has not been well studied. We devised a method of measuring IT, MT, and IMT using B-mode ultrasound image processing technique for the diagnosis of atherosclerosis. To inspect the clinical significance of IT, MT, and IMT, one hundred forty-four consecutive patients (mean age; 57 years old, 72 males) were underwent common carotid artery scanning using high-resolution ultrasound. Results showed that, the IT (p<0.05), MT (p<0.05) as well as IMT (p<0.01) of patients with atherosclerotic disease were significantly thicker than that of the patients without atherosclerotic disease. Patients with hypertension showed significantly thicker IT (p<0.01), MT (p<0.001), and IMT (p<0.001). However, only IT was thicker in patients with smoking (p<0.01). The IT (r=0.374, p=0.001), MT (r=0.433, p=0.000), and IMT (r=0.479, p=0.000) showed positive correlation with age. The coefficients of determination (r(2)) were estimated to be 92.4% for IMT and MT, 49.1% for IMT and IT, and 27.4% for IT and MT. This result suggests that the intima layer of the carotid artery has a different physiology with the media layer.
Atherosclerosis ; Carotid Arteries ; Carotid Artery, Common ; Carotid Intima-Media Thickness ; Diagnosis ; Humans ; Hypertension ; Ischemic Attack, Transient ; Middle Aged ; Myocardial Infarction ; Physiology ; Smoke ; Smoking ; Stroke ; Ultrasonography

To understand the local hemodynamics of modified TF-AHCB carotid bifurcation model, using particle image velocimetry technique to measure the instantaneous velocity distribution of the model attatched to a circuit. The velocity was controlled by regulating the height of the reservoir. The working fluid consists of glycerine and water mixture with viscosity of 3.75 mPa.s similar to human blood. Instantaneous velocity fields were obtained by PIV and the shear stresses were calculated according to the velocity. The results showed that inside the model, there were a large flow separation and an anticlockwise rotating vortex on the lateral wall of ICA, The location and distance of the vortex changed with the flow velocity. The higher the flow velocity, the smaller the vortex distance, and the farther the location. The shear stresses on the lateral wall were significantly lower in all work condition. And there a low shear stress kernel when the velocity was lower than 0.839 m/s. The location of the low shear stress was just the position of atherosclerosis. The flow pattern inside the model consists of large flow separation and vortex zones. And there are low shear stress zones at the lateral wall of ICA, Where are thought to be associated with the genesis of atherosclerosis.
Blood Flow Velocity ; Carotid Arteries ; physiology ; Models, Cardiovascular ; Pulsatile Flow ; Regional Blood Flow ; physiology ; Rheology ; methods ; Stress, Mechanical

BACKGROUNDEndothelial cell damage is an important pathophysiological step of restenosis after angioplasty and stenting. Cell transplantation has great therapeutic potential for endothelial recovery. We investigated the effect of transplanting endothelial progenitor cells (EPCs) derived from human early fetal aortas in rat injured arteries.

METHODSThe carotid arterial endothelium of Sprague-Dawley rats was damaged by dilatation with a 1.5 F balloon catheter, and then EPCs derived from human early fetal aortas (<14 weeks) were injected into the lumen of the injured artery in transplanted rats, with an equal volume of normal saline injected into control rats. Rats were sacrificed at 2 and 4 weeks after treatment and transplanted cells were identified by immunohistochemical staining with anti-human CD31 and anti-human mitochondria antibodies. Arterial cross-sections were analyzed by pathology, immunohistochemistry, and morphometry.

RESULTSGreen fluorescence-labeled EPCs could be seen in the endovascular surface of balloon-injured vessels after transplantation. The intimal area and intimal/medial area ratio were significantly smaller in the transplanted group than in the control (P < 0.05) and the residual lumen area was larger (P < 0.05). After EPC transplantation, a complete vascular endothelial layer was formed, which was positive for human von Willebrand factor after immunohistochemical staining, and immunohistochemical staining revealed many CD31- and mitochondria-positive cells in the re-endothelialized endothelium with EPC transplantation but not control treatment.

CONCLUSIONEPCs derived from human early fetal aorta were successfully transplanted into injured vessels and might inhibit neointimal hyperplasia after vascular injury.

Animals ; Carotid Arteries ; pathology ; Cell Adhesion ; physiology ; Cell Survival ; physiology ; Cell Transplantation ; Endothelial Progenitor Cells ; cytology ; physiology ; Humans ; Immunohistochemistry ; Microscopy, Fluorescence ; Neointima ; therapy ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To establish an arterial remodeling model of rats and to investigate the expression and role of Hippo signaling pathway in this model. METHODS: In the model group (n=40), the left common carotid artery was removed through the median incision of the neck. The 6-0 non-absorbable line was used to ligate the carotid artery near the proximal end as far as possible, completely blocking the blood flow. The common carotid artery of rats in control group (n=20) was not ligated using the operative line. After 14 days, the animals were sacrificed and the common carotid arteries were separated through the original surgical pathway and the arteries from the ligature to the distal end were collected. Arterial morphology and fibrosis were observed by HE and MASSON staining. Immunohistochemical staining was used to detect the expressions of anti-α smooth muscle actin (α-MSA) and proliferating cell nuclear antigen (PCNA) in the carotid artery. Western blot was used to detect the expressions of yes associated protein (YAP), transcriptional coactivator with PDZ-binding motif (TAZ), TEAD1, Bcl-2-like protein 4 (Bax), and B-cell lymphoma-2 (Bcl-2). RESULTS: Compared with the control group, the HE staining showed that the vascular remodeling was obvious, the ratio of the neointima/middle membrane was increased significantly, and the MASSON staining indicated that the fibrosis was significantly increased in model group. The immunohistochemical staining suggested that the expressions of α-SMA and PCNA were increased significantly; Western blot suggested that the expressions of YAP, TAZ, TEAD1, and Bcl-2 were increased in carotid artery of the model group. While the expression of Bax and the ratio of Bax/Bcl-2 were decreased. CONCLUSION A rat model of arterial remodeling mediated by carotid artery ligation was established successfully in this study. Hippo signaling pathway was proved to be activated in the arterial remodeling model induced by carotid artery ligation in rats, and might regulate the change of Bax/Bcl-2 ratio related to proliferation and apoptosis, and subsequently involved in the proliferation of smooth muscle cells to promote vascular remodeling.
Animals ; Carotid Arteries ; metabolism ; Carotid Artery, Common ; Cell Proliferation ; Myocytes, Smooth Muscle ; Protein-Serine-Threonine Kinases ; metabolism ; Rats ; Signal Transduction ; Vascular Remodeling ; physiology