[Clinical significance of collateral blood circulation].
Explore the source record for details and available documents.
Cerebral Angiography↗
SEARCH · PubMed Health
Results for “Collateral Circulation”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Overall management of vascular lesions considered treatable with extracranial-intracranial bypass: part 1. Internal carotid occlusion.
From 1973 to 1979, 49 patients with internal carotid occlusion were evaluated and treated. Eighteen of 49 (37%) presented with transient ischemic attack/prolonged reversible ischemic neurological deficit, 14 of 49 (29%) presented with mild completed stroke, 13 of 49 (27%) presented with severe completed stroke, and 4 of 49 (8%) were asymptomatic. Surgical treatment consisting of extracranial-intracranial (EC-IC) bypass, internal carotid stump reconstruction and endarterectomy to open the occlusion, contralateral endarterectomy for carotid stenosis opposite the occlusion, and iatrogenic carotid occlusion with EC-IC bypass was carried out on 22 (45%) patients considered at risk for ischemia based on angiographic evidence of poor collateral circulation and potential sources of emboli. Medical treatment consisting of anticoagulants or anti-platelet aggregation agents was used in 27 (55%) patients with good collateral circulation. By 6 weeks after the initiation of treatment, 10 of 49 (20%) reached end points of new strokes and death. By an average of 3 years after treatment began, 30 of 49 (61%) reached the same end points. The results suggest that new ischemic events in the distribution of the occluded carotid artery occur infrequently if the angiographic study shows adequate collateral circulation to the ischemic territory at risk. Surgical revascularization should be reserved for patients with (a) recurrent ischemic events after the diagnosis of carotid occlusion or (b) poor collateral circulation.
Brain Ischemia↗
Coronary collateral quantitation in patients with coronary artery disease using intravascular flow velocity or pressure measurements.
OBJECTIVES: This study evaluated two methods for the quantitative measurement of collaterals using intracoronary (IC) blood flow velocity or pressure measurements. BACKGROUND: The extent of myocardial necrosis after coronary artery occlusion is substantially influenced by the collateral circulation. So far, qualitative methods have been available to assess the human coronary collateral circulation, thus restraining the conclusive investigation of, for example, therapies to promote collateral development. METHODS: Fifty-one patients with a coronary artery stenosis to be treated by percutaneous transluminal coronary angioplasty (PTCA) were investigated using IC PTCA guidewire-based Doppler and pressure sensors positioned distal to the stenosis. Simultaneous measurements of aortic pressure, IC velocity and pressure distal to the stenosis during and after PTCA provided the variables for calculating collateral flow indices (CFIv and CFIp) that express collateral flow as a fraction of flow via the patent vessel. Both CFIv and CFIp were compared with conventional methods for collateral assessment, among them ST-segment changes >1 mm on IC and surface electrocardiogram (ECG) at PTCA. Also, CFIv and CFIp were compared with each other. RESULTS: In 11 patients without ECG signs of ischemia during PTCA (sufficient collaterals), relative collateral flow amounted to 46% as determined by Doppler and pressure wire. Patients with insufficient collaterals (n=40) had relative collateral flow values of 18%. Using a threshold of CFI=30%, sufficient and insufficient collaterals could be diagnosed with 100% sensitivity and 93% specificity by IC Doppler, and 75% sensitivity and 92% specificity by IC pressure measurements. The agreement between Doppler and pressure measurements was good: CFIv=0.08 + 0.8 CFIp, r=0.80, p=0.0001. CONCLUSIONS: Intracoronary flow velocity or pressure measurements during routine PTCA represent an accurate and, at last, quantitative method for assessing the coronary collateral circulation in humans.
Angioplasty, Balloon, Coronary↗
The septal artery and its collaterals in dogs with and without circumflex occlusion.
The purpose of this investigation was to study myocardial perfusion and the collateral circulation of the septal artery in dogs without occlusion and to determine the magnitude and time course of septal collateral development with gradual circumflex occlusion. After the dogs with circumflex occlusion for 1 and 3 mo were allowed to develop a prolific collateral circulation under normal physiological conditions, coronary and collateral resistances were determined on an isolated heart preparation with maximal vasodilation. It was found that the septal artery contributes about 25% to the collateral circulation of the major coronary arteries (right, circumflex, and anterior descending). Septal collateral growth increased up to 15 times with circumflex occlusion. Due to the anatomic location of the septal artery, this collateral growth was intramyocardial in contrast to epicardial collaterals. Although there was collateral proliferation to all major coronary vessels, the most significant growth was toward the circumflex, the ischemic vascular bed. Although primary collateralization in the dog is via epicardial collaterals, the septal artery participates in collateral development.
Animals↗
Role of nitric oxide in the control of cerebral microcirculation under physiological and pathological conditions.
Effect of nitric oxide (NO) on vasomotor tone of cerebral parenchymal arterioles was studied in rats. Then, the role of NO was clinically investigated in the pathogenesis of progressive cerebral vascular occlusive disease, moyamoya disease. In rat, the cerebral arterioles, about 30-60 microm in diameter, were dilated by L-arginine, a precursor of NO, at concentrations as low as 0.1 micromol with maximal dilation of 14% at 100 micromol. The arterioles were constricted by N(G)-monomethyl-L-arginine (L-NMMA), a NO synthesis inhibitor. Superoxide dismutase, which seems to protect NO from inactivation, increased sensitivity of L-arginine. Compared with control specimens of cerebral spinal fluid (CSF) obtained from 16 patients, concentrations NO metabolites in the CSF of 23 patients with moyamoya disease were significantly higher. NO metabolites concentrations obtained during initial surgery decreased during a second, contralateral procedure. NO plays an important role in the regulation of basal tone of cerebral parenchymal arterioles and contributes to the increase in collateral circulation in cerebral occlusive disease like moyamoya disease. Vascular bypass surgery can reduce NO metabolites together with abnormal collateral circulation.
Animals↗
Intracarotid pressure measurements in the evaluation of a computer model of the cerebral circulation.
BACKGROUND: It is difficult to predict which patients will tolerate occlusion of the internal carotid artery. This difficulty arises primarily because of uncertainties in the prediction of the adequacy of collateral circulation. Because of these uncertainties, balloon test occlusion and other methods have been developed to determine a priori the safety of carotid occlusion. However, all the methods are associated with significant false-positive and false-negative rates, as well as other neurologic complications. Because of these problems, more accurate and less invasive methods for predicting tolerance of carotid occlusion are needed. METHODS: In this report, we present the initial clinical evaluation of a new method for assessing the collateral circulation aided by a mathematical model of the cerebral vasculature. Data from the angiograms of 14 patients who underwent carotid endarterectomy were used to create individualized simulations of their cerebral circulations. As a test of the accuracy of the simulations, we compared values of the intracarotid stump pressures predicted by the model to those measured at surgery during the period of carotid occlusion. RESULTS: The pressure predictions of the model correlated well with those measured at surgery. Linear regression analysis of measured versus predicted values yielded a line with slope 1.05. The line with slope 1.00, which denotes perfect agreement between predictions and measurements, is within the 95% confidence interval of the slope determined from the regression analysis. CONCLUSIONS: Mathematical models of the cerebrovascular circulation can provide good predictions of intravascular pressure in the collateral circulation, and may provide accurate predictions of the flow as well. The present study reveals several areas that need further development, such as the models of the microvasculature, measurement of the arterial dimensions from angiograms, and consideration of other collateral sources such as the leptomeningeal and retrograde ophthalmic sources of flow. Incorporation of these improvements may lead to a clinically useful, noninvasive assessment of the state of the cerebrovascular collateral circulation in the individual patient.
Angiography↗
Collateral bronchopulmonary circulation after spontaneous recanalisation of pulmonary thromboemboli in the dog.
STUDY OBJECTIVE: The aim was to study the fate of enlarged bronchial arteries after resolution of experimental pulmonary embolism. DESIGN: Embolisation of the pulmonary arteries of both lungs was performed with intravenous gelfoam. Pulmonary pressure and pulmonary arteriolar resistance were measured 1 h, 40 d and 80 d after embolisation. Pulmonary angiography and aortography were performed at the same time to evaluate the pulmonary emboli and the collateral bronchopulmonary circulation. Aortography and gross pathological and histological examination of the lungs was performed after 80 d. EXPERIMENTAL MATERIAL: 15 adult mongrel dogs of either sex were studied, weight 22-25 kg. Nine dogs were embolised and there were six controls. MEASUREMENTS AND MAIN RESULTS: All animals survived until 80 d. There was a rise (p less than 0.001) in mean pulmonary artery pressure and arteriolar resistance 1 h after embolisation. Pulmonary artery pressures and resistances were still raised 40 d after embolisation but had returned to normal after 80 d. Pulmonary arteriography at 1 h confirmed massive thromboembolism. After 40 d antegrade pulmonary blood flow was almost completely restored, and the thromboemboli had largely disappeared. Pulmonary angiograms were completely normal after 80 d. Aortography after 40 d showed a well developed collateral bronchopulmonary circulation, most pronounced in the lower lobes, which persisted unchanged until 80 d. Aortography and gross pathological and histological examination at necropsy confirmed the presence of hypertrophic well developed bronchial arteries to both lower lobes and to a lesser extent to the middle and upper lobes, with only a few organised and recanalised thrombi in segmental arteries of both lower lobes. CONCLUSIONS: Our data show a temporal dissociation between the resolution of pulmonary thromboemboli in the present model and the eventual regression of developed bronchopulmonary collateral vessels. The mechanism of this dissociation could not be elucidated.
Animals↗
[Detection of severity of coronary stenosis by quantitative myocardial tomography with Tc-99m-MIBI at rest].
To evaluate the role of myocardial tomography with Tc-99m-MIBI (MB) in detecting abnormal coronary arteries, 34 patients with myocardial infarction underwent resting quantitative SPEC with MB and coronary arteriography within one month. When segmental MB uptake was < 560% of the left ventricular peak activity, there was 88% probability that a totally occluded or severely stenosed coronary artery (stenosis > 90%) was involved. There was 82% probability of finding no significant stenosis of coronary arteries in the normal myocardial segments. In the myocardial segments supplied by occluded coronary arteries, there was significantly higher MB uptake in the segments with good collateral circulation as compared with those subtended by a vessel totally occluded with poor collateral circulation (P < 0.05). The sensitivity and specificity of detecting abnormal coronary artery by quantitative analysis of myocardial tomography was 87% and 90% respectively. It is suggested that quantitative analysis of myocardial tomography with MB can differentiate between myocardial segments supplied by severely stenosed and normal coronary artery and evaluate the existence of collateral circulation.
Aged↗
Thrombotic occlusion of the middle cerebral artery.
BACKGROUND AND PURPOSE: Epidemiological study of middle cerebral artery occlusion is important because the indication for extracranial-intracranial arterial bypass remains in dispute. To help clarify this issue, we investigated the prognosis of thrombotic middle cerebral artery occlusion in Japanese patients. METHODS: We studied 40 patients with thrombotic middle cerebral artery occlusion who were selected on the basis of clinical features, computed tomographic findings, and angiographic findings. Patients with causes of embolism (i.e., cardiomyopathy, valvular heart disease, cardiac arrhythmia, and carotid ulceration) were excluded. The 40 patients were classified into three groups according to the site of middle cerebral artery occlusion: there were 13 patients with occlusion of the proximal portion of the M1 segment, 13 with distal M1 segment occlusion, and 14 with occlusion of the M2 segment. RESULTS: Good collateral circulation was associated with improved outcomes both clinically and by computed tomography in patients with occlusion of the proximal and distal portions of the M1 segment but not in those with M2 occlusion. CONCLUSIONS: It is reasonable to assume that not only collateral circulation but also the site of occlusion plays an important role in the outcome of middle cerebral artery occlusion. Our finding that good collateral circulation improves the outcome for thrombotic occlusion of the proximal and distal M1 segments supports the possible benefits of such surgery.
Adult↗
[EXPERIMENTAL DATA ON COLLATERAL BLOOD CIRCULATION IN THE SURFACE VESSELS OF THE BRAIN].
Explore the source record for details and available documents.
Anatomy, Comparative↗
[Analysis of a myotropic component in the action of antihistaminic preparations and cardiac glycosides on the collateral coronary circulation].
Explore the source record for details and available documents.
Animals↗
[Experimental study of reduced collateral blood circulation in organs].
Explore the source record for details and available documents.
Animals↗
[Characteristics of the effect of strophanthin on collateral coronary circulation].
Explore the source record for details and available documents.
Animals↗
Comparison of collateral vascular responses in the donor and recipient coronary artery during transient coronary occlusion assessed by intracoronary blood flow velocity analysis in patients.
OBJECTIVES: This study was designed to evaluate the hemodynamic variables of the collateral circulation during acute coronary occlusion. BACKGROUND: There is limited information on the physiology of the collateral circulation in coronary artery disease. METHODS: Angiography of the contralateral donor artery was performed before and during balloon coronary occlusion in 57 patients with one-vessel disease. Recruitable collateral flow was assessed during coronary occlusion by blood flow analysis of the contralateral donor artery (n = 19) or the ipsilateral recipient artery (n = 15), or both (n = 23), using a Doppler catheter or guide wire. Ischemia was evaluated by the ST segment shift (> or = 0.1 mV) on a 12-lead electrocardiogram at 1 min of coronary occlusion. RESULTS: The presence (n = 39), compared with the absence (n = 18), of recruitable collateral vessels was associated with an increase of blood flow velocity in the donor artery (20 +/- 19% vs. 4.8 +/- 5.9% [mean +/- SD], p = 0.003) and the recipient artery (velocity integral 7.2 +/- 5.5 vs. 2.8 +/- 2.2 cm, p = 0.02) related to a reduced relative collateral vascular resistance (9.2 +/- 10 vs. 20 +/- 11, p = 0.003). Collateral flow in the donor artery yielded a similar predictive value for recruitability of collateral vessels as collateral flow determined in the recipient artery or the coronary wedge/aortic pressure ratio (areas under the receiver operating characteristics curves 0.76 +/- 0.07, 0.78 +/- 0.08, 0.77 +/- 0.07, respectively, p = NS). Collateral flow in the recipient artery was a better predictor for ischemia than collateral flow in the donor artery or angiographic grading of collateral vessels (areas 0.90 +/- 0.05, 0.64 +/- 0.10, 0.73 +/- 0.07, respectively, p < 0.05). CONCLUSIONS: Coronary blood flow velocity analysis of the donor and recipient coronary arteries can characterize the dynamics of the collateral circulation during acute coronary occlusion. The protective effect of recruitable collateral vessels relates to an increase of flow in the donor and recipient coronary arteries due to a reduced collateral vascular resistance. This study underscores the importance of physiologic variables for the evaluation of the function of recruitable collateral vessels.
Adult↗
Improvement of exercise-induced ischaemia and myocardial perfusion after aminophylline.
BACKGROUND: Previous studies have suggested that aminophylline improves exercise-induced ischaemia by preventing the redistribution of the coronary flow from ischaemic to non-ischaemic myocardium. The purpose of the study was to assess whether aminophylline improves myocardial perfusion in zones supplied by collateral circulation. METHODS: Twenty-three patients with an occluded coronary artery and collateral circulation from a non-diseased vessel underwent two symptom-limited exercise 99mTc-MIBI, single-photon emission computed tomography (SPECT) myocardial scintigraphy experiments, which were preceded by an intravenous infusion of either aminophylline (5 mg/kg over 20 min) or saline solution in a randomized double-blind control procedure. The MIBI SPECT images were analysed by two experienced observers who were blinded to each other's data. RESULTS: All patients underwent cardiac catheterization. For 16 patients this was because of stable angina and the remaining eight were post-myocardial infarction patients with a positive exercise test. Aminophylline significantly increased the time to the onset of ischaemia in the 15 patients with a positive exercise test (mean +/- SD, 6.5 +/- 1.9 compared with 5.3 +/- 1.8 min, P < 0.005); and ischaemia occurred at higher rate-pressure product (230 +/- 68 compared with 195 +/- 68 HB x mmHg, P < 0.03). After aminophylline, exercise ST-segment depression was 1.1 +/- 0.5 mV, compared with 1.5 +/- 0.8 mV after placebo (P < 0.01). All patients had perfusion defects that resolved partially or completely in the rest images. The imaging score was significantly lower after aminophylline infusion than after placebo (9.7 +/- 9 compared with 12.1 +/- 10, P < 0.01). CONCLUSIONS: Aminophylline significantly delayed the time to onset of exercise-induced ischaemia and improved perfusion in zones supplied by collateral circulation. Aminophylline-like drugs may be useful in the treatment of selected patients with ischaemic heart disease.
Aminophylline↗
Risk factors of incomplete distribution of cardioplegic solution during coronary artery grafting.
Myocardial distribution of cardioplegic solution infused by combined antegrade/retrograde routes was assessed with myocardial contrast echocardiography in 18 patients with chronic stable angina and three-vessel disease undergoing elective coronary artery bypass grafting. Overall myocardial opacification was significantly greater in retrograde than in antegrade cardioplegia (77.7% +/- 13.4% versus 59.1% +/- 15.7%; p = 0.0009). The difference was affected by collateral circulation, as pointed out by the significant interaction between coronary collateral circulation and percent of myocardial opacification after antegrade and retrograde cardioplegia (p = 0.002). When we performed multiple comparisons, in patients with good collaterals the opacification difference between antegrade and retrograde cardioplegia was not statistically significant (66.4% +/- 10.2% versus 76.0% +/- 15.2%; p = not significant), whereas in patients with poor collaterals myocardial opacification during retrograde cardioplegia was significantly greater (44.3% +/- 15.0% versus 81.2% +/- 9.0%; p < 0.02). During antegrade cardioplegia, patients with poor collaterals showed a lower degree of myocardial opacification than patients with good collaterals (44.3% +/- 15.0% versus 66.4% +/- 10.2%; p < 0.01). Our results show that retrograde cardioplegia in patients undergoing elective coronary artery bypass grafting offers no advantage over antegrade cardioplegia when collateral circulation is well developed. On the other hand, conventional aortic root infusion may not provide adequate myocardial protection in the subset of patients with significantly narrowed or occluded coronary arteries and poor collaterals.
Angina Pectoris↗
Esophageal varices before and after endoscopic variceal ligation: evaluation using helical CT.
The purpose of this study was to demonstrate the utility of helical CT in assessing the therapeutic effects of endoscopic variceal ligation (EVL). Twenty-four patients with esophageal varices were examined. Helical scanning was initiated 60 s after intravenous injection (Iopamidol 300 mgI/ml, total 120 ml, 3 ml/s) was started. Esophageal varices were clearly depicted as high-density areas. Multiplanar reformation and 3D images demonstrated collateral circulation three-dimensionally. After EVL, mucosal high-density areas had diminished markedly, but collateral veins around the esophagus, and gastro- and/or spleno-renal shunts, were unchanged in all patients. Of 21 patients with collateral circulation, esophageal varices recurred endoscopically in 6 patients within 12 months. In 3 patients without collateral circulation, esophageal varices did not recur within 12 months. From these findings, we conclude that helical CT is a useful method for assessing the therapeutic effects of EVL.
Collateral Circulation↗
Relation of coronary arterial occlusion pressure during percutaneous transluminal coronary angioplasty to presence of collaterals.
To investigate the relation of the gradient across a coronary artery stenosis and the pressure distal to the stenosis after proximal occlusion during percutaneous transluminal coronary angioplasty to the amount of angiographically estimated collateral circulation, 63 patients (55 men, 8 women) were studied. All patients had 1-vessel disease (54 left anterior descending, 8 right coronary artery and 1 circumflex coronary artery). All patients had documented ischemia, and angioplasty was carried out within 4 weeks after the initial angiogram. The patients were separated into 4 groups: 0 = no collaterals (35 patients), +1 = just visible collaterals (8 patients), +2 = collaterals without reaching the contralateral vessel (10 patients), and +3 = filling of the contralateral vessel (10 patients). There was no difference in age among the 4 groups. There was a significant negative relation of the gradient vs the extent of collateral circulation, although the degree of stenosis increased significantly from group 0 to group +3. There was a significant positive relation of the occlusion pressure (in absolute terms and in percent of the proximal systolic pressure) vs the extent of collateral circulation. There was a significantly smaller change of the occlusion pressure vs the distal pressure before occlusion if good collaterals were present. The occlusion pressure remained constant during 1 occlusion up to 40 seconds and was reproducible in 3 successive occlusions. In conclusion, the pressure distal to a coronary artery stenosis is mainly dependent on the severity of the stenosis and on the collateral flow. If anterograde flow is eliminated by proximal occlusion the distal pressure is only dependent on the extent of collateral circulation.
Adult↗