[The problem of creating artificial collateral blood circulation].
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
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The development of a collateral coronary circulation has been well studied by angiography in two main clinical situations: myocardial infarction (by durable coronary occlusion) and angina (due to significant coronary artery stenosis), but only rarely in spastic angina. The authors report the case of severe spasm at the site of non-significant stenosis after a methylergometrine test, with immediate contro-lateral collateral circulation in a patient with a short history of spastic angina without myocardial infarction. This observation demonstrates that collateral circulation may develop very rapidly in spastic angina (without basal ischaemia in the absence of significant coronary stenosis), because this patient only had seven ten-minute episodes of clinical ischaemia. As collateral circulation may mask clinical and electrical signs in spastic angina, this case suggests that angiographic control should be systematic during the methylergometrine test.
On the basis of an analysis of about 1000 coronary angiogrammes it is established that collaterals develop in stenosis of the coronary arteries in 52.3% of the patients surviving myocardial infarction, and in 20% of those free of myocardial infarction. Coronary angiogrammes of 100 patients with coronary collaterals were examined. Twenty different ways of collateral circulation were revealed. Certain regularities were noted in the development of collaterals depending on the lesions of different coronaries or combined lesions of several arteries. Intersystemic collaterals are most typical for the occlusions of the anterior interventricular branch. In cases of occlusions of the right coronary artery either intersystemic, or intrasystemic collaterals develop, depending on the localization of the occlusion. A study of the collaterals in cases of multiple coronary lesions has demonstrated that under such conditions a complicated system of anastomoses develops, and the flow in them is multidirectional.
Collateral circulation was studied in the heart of 20 normal human fetuses aged 19 to 39 weeks, using a radiographic technique. The radiograms showed the presence of coronary anastomoses ranging in size from 3 to 50 mu. The anastomoses were more abundant and of larger diameter in the interventricular septum and in the subendocardial layers. Anastomoses between the superficial vessels were also present but were less frequent and of smaller diameter.
The study presents the concepts of collateral circulation in the heart. These vessels can reduce the fatal consequences of occlusion of large coronary artery. There are described two mechanisms of its growth: vasculogenesis (mitosis of endothelial cells, and smooth muscle cells), and angiogenesis (migration and mitosis of endothelial cells). These processes are triggered by ischemia and by expression of peptide growth factors. Growth factors are produced by macrophages and often are found in inflammation tissue. Therapeutic angiogenesis remains controversial, however in the near future stimulation of angiogenesis by peptides, drugs and gene therapy will have a place in therapy of ischemic heart disease.
OBJECTIVE: to describe collateral circulation in the gallbladder wall in relation with portal hypertension syndrome, and to determine whether this syndrome is frequently associated portal vein thrombosis. METHODS: images were retrospectively reviewed for 9 patients with previously diagnosed portal hypertension syndrome, in whom ultrasound results suggested the presence of varices of the cystic vein. RESULTS: four patients showed signs suggesting portal vein thrombosis. The gallbladder wall showed diffuse hypoechoic thickening in all patients, 7 of whom had intramural dilation of tubular, tortuous appearance. Ultrasound findings, however, were not very specific, and differential diagnosis with a large number of other entities is required to rule out other possible causes of focal and diffuse thickening of the gallbladder wall. The use of Doppler sonographic techniques made it possible to determine the cause of the varices, and to confirm suspicions of portal thrombosis. This method was found to be just as sensitive as ultrasound imaging, and much more specific. Angiograms obtained in 3 patients for different reasons confirmed the ultrasonographic findings in all cases. CONCLUSIONS: this study confirms the association between thromboses and varices, and analyzes the physiopathological hypotheses invoked to explain this association. We emphasize the need for correct diagnosis, given the frequency of surgical iatrogenic bleeding or misdiagnosis resulting from confusion with other possible causes of gallbladder wall thickening. Doppler ultrasound is considered the ideal diagnostic method as it is harmless, sensitive and specific.
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BACKGROUND: The development of coronary collateral vessels is the physiological response of myocardial tissue to hypoxia or ischemia, which results in an increase in blood supply to the tissue. However, a lack of collateral vessels or the presence of poor collateralization in some patients despite the presence of significant coronary stenosis or obstruction and evidence of myocardial ischemia suggest that some other factors may affect the development of collateral circulation. In the present study we aimed to evaluate coronary collateral circulation in patients with metabolic syndrome with advanced coronary artery disease and compare the results with those of patients without metabolic syndrome. METHOD: The study population comprised 102 patients with metabolic syndrome and advanced coronary artery disease (>or=90% diameter stenosis in at least one major epicardial coronary artery) and 102 control participants without metabolic syndrome who also had >or=90% diameter stenosis in at least one major epicardial coronary artery. The diagnosis of metabolic syndrome was based on the National Cholesterol Education Program Adult Treatment Panel III clinical definition. Coronary collateral vessels were analysed according to the Cohen and Rentrop grading system. Both groups were also divided into two additional groups according to the Rentrop collateral score as patients with poor collateral circulation (Rentrop score 0-1) and good collateral circulation (Rentrop score 2-3). RESULTS: The mean Rentrop collateral score for patients with metabolic syndrome was significantly lower than for those without metabolic syndrome (1.38+/-0.79 compared with 1.99+/-1.08, respectively, P<0.001). When two groups were compared with respect to poor and good collateral circulation, poor collateral circulation was found to be significantly higher in the metabolic syndrome group (70% compared with 32%, respectively, P<0.001). Moreover, multivariate logistic regression analysis revealed a significant relationship between poor collateral circulation and metabolic syndrome (odds ratio=4.29, 95% confidence interval=1.73-10.69, P=0.002). CONCLUSION: We have shown for the first time that the development of coronary collateral vessels is poorer in patients with metabolic syndrome with advanced ischemic heart disease than in control participants without metabolic syndrome. Thus, it can be suggested that metabolic syndrome is one of the significant factors affecting the development of coronary collateral vessels adversely.
An angiographic study of 231 patients with tetralogy of Fallot (TOF) in both neonatal and adult age groups (0 to 49 years) was in this condition. Cases of pulmonary atresia with ventricular septal defect were excluded. Two types of collateral pulmonary circulation were observed: the most common form is the result of distal intrapulmonary anastomosis between systemic parietal, mammary and bronchial vessels with the pulmonary arteries. This type of collateral circulation represents an evolutive stage of TOF and is directly related to age and to the degree of hypoxia; the other, oa rare and probably congenital form (1.7 p. 100 of cases) observed even in young children, consisting of proximal anastomoses between systemic vessels arising from the aorta (1 to 3 vessels) and the pulmonary arterial tree. The rare forms of TOF with single pulmonary arteries acquired after palliative or congenital anastomoses (1.4 p. 100) have both types of collateral circulation. Preoperative diagnosis of the collateral pulmonary circulation requires opacification of the aorta especially of the descending thoracic segment and its branches, completed in cases of an absent pulmonary artery by wedged pulmonary venous opacification. The haemodynamic effects of this collateral circulation on the pulmonary bed to a variable degree of histological change. This may partially explain some of the poor surgical results of repair of TOF and, in view of recent progress in cardiopulmonary bypass techniques in children, incite to earlier surgical correction of this condition.