Search

Carotid plaque vulnerability features beyond the degree of stenosis may play a key role in the pathogenesis and recurrence of ischemic cerebrovascular events. This study sought to compare intraplaque hemorrhage (IPH) as a marker of plaque vulnerability in symptomatic patients with mild ( We included patients who experienced ischemic cerebrovascular events with no other identifiable sources and underwent carotid endarterectomy for mild (n=32), moderate (n=47), and severe (n=58) carotid artery stenosis. The degree of stenosis and imaging hallmarks were assessed by computed tomography angiography or magnetic resonance angiography. Plaque specimens were stained with hematoxylin and eosin and Movat pentachrome staining. Carotid plaques of patients with mild stenosis had a higher extent of IPH (%) on tissue analysis compared with patients with moderate (mild, 15.7% [interquartile range, 7.8%–26.7%]; moderate, 3.9% [0.0%–9.2%]; P P P Our major finding is the association of IPH with mild carotid artery stenosis based on histological analysis. The current study may suggest that IPH potentially plays a role in the mechanism of stroke in patients with nonobstructive carotid stenosis.

A 52-year-old man, with a history of allergic rhinitis and without coronary risk factors, transferred to our hospital because of cardiac arrest. Coronary angiography revealed no significant stenosis in left coronary arteries ([Figure 1A][1]), and mild stenosis in right coronary artery ([Figure 1B

As the degree of luminal narrowing increases, shear stress increases, and high shear stress is known to activate platelets. However, the relationship between the degree of luminal narrowing and the composition of thrombus in patients with plaque erosion has not been studied. A total of 148 patients with plaque erosion and thrombus detected by optical coherence tomography were divided into tertiles based on the minimum lumen area (MLA) at the culprit lesion. Thrombus was categorized as platelet-rich or fibrin-rich. Among 148 patients, 50 (34%) were in the mild stenosis group, 49 (33%) were in the moderate stenosis group, and 49 (33%) were in the severe stenosis group. The composition of thrombus was significantly different among the 3 groups (prevalence of platelet-rich thrombus was 60% in the mild stenosis group; 78% in the moderate stenosis group; and 84% in the severe stenosis group; P = 0.021). The pattern of fibrin-rich thrombus showed the opposite: 40%, 22%, and 16%, respectively. In the multivariate analysis, current smoking was independently associated with fibrin-rich thrombus (odds ratio [OR] 2.364 [95% CI 1.004–5.567], P = 0.049). This study demonstrated that platelet-rich thrombus was the predominant type of thrombus in plaque erosion. The prevalence of fibrin-rich thrombus was highest in the mild stenosis group.

Objective Measurement of the degree of stenosis is not enough to decide on the treatment strategy for patients with carotid stenosis. Plaque morphology examination is needed for such a decision-making. Thus, we evaluated the usefulness of plaque magnetic resonance imaging (MRI) to decide on the modality of treatment for patients with carotid atherosclerotic plaques. Materials and Methods Fifteen patients presenting with carotid stenosis between 2014 and 2016 were included. They underwent angiography for measurement of the degree of stenosis. Carotid plaques were visualized using MRI. Results There were six (40%) stable and nine (60%) unstable plaques. Seven symptomatic patients (77.7%) had unstable lesions and two symptomatic patients (33.3%) had stable lesions (p = 0.096). There were six (40%) intraplaque hemorrhage (IPH) cases. There were six symptomatic patients (100%) in the IPH group and three symptomatic patients (33.3%) in the non-IPH group (p = 0.013). The mean stenosis degree was 58.9% in the IPH group and 70.4% in the non-IPH group (p = 0.094). Symptoms occurred irrespective of the degree of the stenosis in the IPH groups. In the IPH group, the recurrent ischemic cerebrovascular event rate was 33.3%. Particularly, the recurrent ischemic cerebrovascular event rate was 66.7% in the IPH group with mild stenosis treated with medications. Conclusion IPH in plaque MRI is significantly associated with ischemic symptoms and has a high risk for subsequent ischemic cerebrovascular events irrespective of the degree of stenosis. Plaque MRI is a useful tool in predicting symptomatic risks for carotid stenosis irrespective of the degree of such stenosis.

We report the case of a young boy with a history of total occlusion of the superior caval vein, diagnosed early after complex neonatal cardiac surgery, who developed severe protein-losing enteropathy. Protein-losing enteropathy was precipitated by a relatively mild stenosis at the junction of the inferior caval vein with the right atrium. Percutaneous stent dilation of the veno-atrial junction definitively relieved the stenosis, and the protein-losing enteropathy subsequently resolved.

Heat and mass transfer effects on Newtonian biomagnetic fluid of blood flow through a tapered porous artery with a stenosis is investigated. Governing equations have been modeled by treating blood as Newtonian biomagnetic fluid. The governing equations are simplified under the assumption of mild stenosis. Exact solutions have been evaluated for velocity, temperature, and concentration profiles. The effects of Newtonian nature of blood on velocity, temperature, concentration profile, wall shear stress, shearing stress at the stenosis throat and impedance of the artery are discussed graphically. Stream lines have been presented in last section of the article.

Background The ratio of peak to mean pressure decrease is a new measure of transaortic continuous waveform shape that could be useful for grading aortic stenosis. Methods We retrospectively analyzed echocardiograms in 163 patients with all grades of aortic stenosis as assessed by the continuity equation. Results The peak to mean pressure decrease ratio was 1.75 (0.14) in mild stenosis, 1.66 (0.13) in moderate stenosis, 1.56 (0.10) in severe stenosis, and 1.57 (0.07) in severe aortic stenosis with left ventricular ejection fraction less than 40%. Receiver operating characteristic curve analysis showed that a threshold of less than 1.50 gave a specificity of 94% against continuity area whereas a ratio less than 1.75 gave a sensitivity of 96%. Conclusion The peak to mean pressure decrease ratio is a simple and quick cue to the likelihood of severe aortic stenosis in patients with low left ventricular ejection fraction when transaortic pressure decreases appear only moderate.

PURPOSE To determine 3-D time of flight MR angiography for evaluation of fibromuscular dysplasia in cervical vessels. MATERIAL AND METHODS In 386 selective angiograms of cervical vessels fibromuscular dysplasia was revealed in 4 female patients in the age of 30-54 years. FMD was located in the carotid artery (n = 5) and in the vertebral artery (n = 2) with a total of 8 lesions. RESULTS 6/8 of the lesions of the seven cervical vessels were located typically in the mid cervical portion of the vessels and 2/6 lesions were located in the atlas loop of the vertebral artery. 4 lesions showed moderate stenosis and 4 vessels showed only mild stenosis. These patterns which demonstrated the typical morphology of fibromuscular dysplasia with alternating irregular zones of widening and narrowing were evaluated well with MR angiography, the others were missed. CONCLUSION MR angiography is suitable for detection of fibromuscular dysplasia when the characteristic pattern is combined with moderate stenosis of the vessel. Conventional angiography remains the standard of reference.

An attempt has been made to investigate the non-Newtonian behaviour on blood flow through artery with mild stenosis using Hershel-Bulkley fluid model. It has been shown that the resistance to flow and wall shear stress increases with the size of stenosis, but these increases is comparatively small due to non-Newtonian behaviour of the blood.

The foreskins of phimosis in children have been retracted as much as possible at the out-patient clinic, to avoid unnecessary operations. Five-hundred and twenty-seven cases of phimosis were experienced since 1986, and 427 of them were classified into 6 types according to the appearance of the penis and preputial orifice; type I (burried penis, 22 cases), type II (bottle neck, 86), type III (pinhole, 60), type IV (moderate stenosis, 154), type V (mild stenosis, 101), and type VI (scarred stenosis, 4). The foreskins were unable to retract in 13 cases (59.1%) of type I, 17 cases (19.8%) of type II, and 2 cases (50%) of type VI. In all cases of pinhole type, which looked highly stenotic, the foreskins were retractable. As a result, operation was performed only in 32 cases (6.1%) of all cases. Our best effort to retract the foreskin has reduced the operative indications of phimosis markedly.

Flow in the trachea is essential to be properly understood since it is the inlet to the lungs. Disturbance to this flow will disrupt the inlet conditions to both bronchi. In this study, disturbance of flow due to mild stenosis is investigated via numerical models. The effect of various stenosis sizes, at the middle of the trachea, to the flow pattern is studied and analyzed. 3D simplified trachea models were used and different flow conditions were applied. The results show two stages of pressure drop behavior appear as the size of the stenosis reaches fifty percent of the airway size. The inlet condition to the bronchi is also significantly disturbed as the stenosis reaches fifty percent.

In this paper, the blood flow through a tapered artery with a stenosis by considering axially non-symmetric but radially symmetric mild stenosis on blood flow characteristics is analyzed, assuming the flow is steady and blood is treated as Williamson fluid. Perturbation solutions have been evaluated for velocity, resistance impedance, wall shear stress and shearing stress at the stenosis throat. The graphical results of different type of tapered arteries (i.e. converging tapering, diverging tapering, non-tapered artery) have been examined for different parameters of interest.

Purpose: We evaluated the CT characteristics of atherosclerotic coronary plaques in relation to the degree of stenosis. Materials and Methods: We analyzed coronary CT angiography of 239 patients showing plaques obtained from December 2005 to May 2008, in terms of degree of stenosis (mild 75%), location of plaque, plaque types, and calcium score. Results: Total 694 segments were found to have plaque in 239 patients. Multiple lesions were found in 151 patients (57.1% of patients with mild stenosis; 87.5% with severe stenosis). The type of plaque was classified into noncalcified, mixed, and calcified in 26.7%, 22.5%, 50.8% of patients with mild stenosis and 22.9%, 56.3%, 20.8% with severe stenosis, respectively. The most common plaque location was the proximal left anterior descending artery. In patients with calcified or mixed plaques, there was a significant correlation between degree of stenosis and calcium score. Conclusion: Mixed plaque was the most common type in severe stenosis, while calcified plaque was the most common in mild stenosis. Multiple lesions were found in most patients with severe stenosis. The calcium score was significantly higher in patients with severe stenosis.

Coronary occlusion and myocardial infarction often evolve from mild to moderate stenoses, as documented in previous reports. However, the evolution time from mild stenoses to an infarct-related arteries is still not known. According to a previous study, the features of infarct-related coronary segments 3 days before acute myocardial infarction (AMI) were the presence of a significant stenosis of >50% and multiple irregularities, an indicator of plaque rupture and thrombi; and the features at …

The prognosis for the patient with pulmonic stenosis was analyzed from a study of 100 current patients, with long-term observations on 58 of them. Congestive heart failure occurred in seven, all of whom had severe stenosis. Subacute bacterial endocarditis developed in another seven, even when the stenosis was less marked. With appropriate medical supervision of those with mild stenosis who have no cardiac disability, and open-heart surgery for those with more severe obstruction, the outlook for the patient with pulmonary stenosis should be a full and active life.

A mechanical model of a branched coronary artery with a graft bypassing an 80% stenosis of one branch was used to study the reduction in coronary flow due to stenosis of the bypass graft. Flow Reynolds number and ratio of aortic pressure to dynamic pressure were matched to the living system. Changes in coronary flow were measured for a range of stenoses (0-100%) of bypass grafts with graft-to-coronary-diameter ratios of 4:1, 3:1, 2:1 and 1:1 for conditions that simulated rest and exercise. The results of these studies indicate that: 1) marked stenosis of bypass grafts is needed to decrease coronary flow in the resting state, and even moderate stenosis will decrease flow during exercise when the diameter of the bypass is large relative to the coronary artery; 2) coronary flow is decreased with mild stenosis for bypass grafts of the same diameter as the coronary artery; and 3) a marked decrease in flow due to stenosis of a bypass graft occurs only when the diameter of a stenosis in a graft is less than the diameter of the coronary artery.

An analysis of the effects of couple stresses on the blood flow through thin artery in the presence of very mild stenosis has been carried out with the help of two nondimensional parameters, alpha (the length ratio parameter) and eta (the parameter characterizing the antisymmetric property of the couple stress tensor). It is shown that an increase in the couple stress (small value of alpha and eta), increases the resistance to the flow and the wall shear stress. These characteristics are further enhanced by the presence of the stenosis.

Eighteen of 20 patients with moderate and severe mitral stenosis had positive exercise phonocardiographic tests. None of the 10 patients with mild stenosis had a positive test. Pour of 7 patients who had positive tests preoperatively and were retested after mitral valvotomy had negative tests. The exercise phonocardiogram is a simple procedure for evaluating the severity of mitral stenosis.

Accurate noninvasive evaluation of patients with valvar aortic stenosis (AS) would improve selection for catheterization. 29 children with AS, ages 2 to 16 years, were evaluated by cardiac catheterization and echocardiography. No patient had congestive heart failure or more than trace aortic insufficiency. Left ventricular to aortic pressure difference (LV-Ao) was estimated by: LV-Ao=13×(murmur score)+RV6(mm.)−6×QV6(mm.)−9. Resting LV and Ao pressures were measured and aortic valve area (AVA/m2) was calculated. The systolic left ventricular posterior wall thickness (LVPW) and internal diameter (LVID) were measured on the echocardiograms without knowledge of catheterization findings. A predicted LV-Ao