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Results for “Collateral Circulation”

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PubMed2004

Irreversible lower limb ischaemia following ligation of the inferior mesenteric artery in the surgical treatment of rectal cancer.

Rectal cancer and cardiovascular disease are both commoner in the elderly and may coexist. In some severe arteriopaths the blood supply to the lower limbs may be a collateral circulation from the inferior mesenteric artery. Patients with aorto-iliac occlusion or severe stenosis may have collaterals from the inferior mesenteric artery to the lower limb blood vessels. Ligation of the inferior mesenteric artery in treating rectal cancer can result in irreversible ischaemia as outlined in this report. Routine palpation of the femoral pulses and awareness of collateral circulation may avoid the disastrous consequences seen in the two cases described.

Aged↗

PubMed1997

Vasculogenesis and angiogenesis: extracellular matrix remodeling in coronary collateral arteries and the ischemic heart.

Heart failure secondary to ischemic cardiomyopathy is the primary cause of cardiovascular mortality. The promise of the collateral circulation lies in its potential to alter the course of the natural history of coronary heart disease. The collateral circulation of the heart is responsible for supplying blood and oxygen to the myocardium at ischemic risk following severe stenosis and reduced vasoelasticity function of a major coronary artery. In response to flow, stress, and pressure, collateral vessels are restructured and remodeled. Vascular remodeling by its very nature implies synthesis and degradation of extracellular matrix components in the vessel wall. Under normal physiological conditions proteinases that break down the specialized matrix are tightly regulated by antiproteinases. The balance between proteinase and antiproteinase influences is discoordinated during collateral development which leads to adaptive changes in the structure, function, and regulation of extracellular matrix components in the vessel wall. The role of extracellular matrix components in coronary collateral vessel formation in a canine model of chronic coronary artery occlusion has been demonstrated. The role of matrix proteinases and antiproteinases in the collateral vessel play a significant role in the underlying mechanisms of collateral development. This review presents new and significant information regarding the role of extracellular matrix proteinases and antiproteinases in vascular remodeling, function, and collateral development. Such information will have a significant impact on the understanding of the basic biology of the vascular extracellular matrix turnover, remodeling, and function as well as on elucidating potential avenues for pharmacological approaches designed to increase collateral formation and optimize myocardial blood flow in the treatment of ischemic heart disease.

Animals↗

PubMed1993

[Diagnosis of intracranial occlusive vascular disease and evaluation of extracranial-intracranial (EC/IC) arterial bypass using three-dimensional magnetic resonance angiography].

The three-dimensional time-of-flight (TOF) magnetic resonance angiograms (MRA) were studied to evaluate its accuracy in the assessment of the intracranial carotid occlusive lesions, collateral circulation and also the patency of extracranial-intracranial (EC/IC) arterial bypass surgery. All occlusive lesions of the intracranial major arteries seen in conventional angiograms were revealed clearly with MRA. However MRA had its practical limitation in the evaluation of the leptomeningeal anastomosis (collateral circulation) probably due to the deterioration of contrast in its slow flow and saturation effect of the magnetization. In addition to that, MRA often exaggerated the severity of the stenotic lesions, mostly in severe cases. The post-operative state of collateral flow and the patency of EC/IC bypass could be evaluated as properly with MRA as with conventional angiography, although MRA was limited in spatial resolution and evaluation of flow direction. In conclusion, MRA was considered t be a reliable non-invasive modality as a screening examination for the evaluation of the carotid occlusive disease and as the follow-up study of the post-operative patients with EC/IC bypass surgery.

Carotid Artery Diseases↗

PubMed1978

[The natural course of temporal branch vein occlusion (author's transl)].

The knowledge of the individual collateral circulation is mandatory to judge the natural course and the prognosis of temporal branch vein occlusion. When collateral circulations are present a favourable final result can be anticipated even in cases with pronounced decreased visual acuity. To determine the time for coagulation treatment the differentiation between reversible and irreversible retinal lesions following branch vein occlusion is helpful. Particularly attention has to be paid to save those vessels, serving as a drainage function of the macula. On the other hand those neovascularisations have to be eliminated, leading ultimately to vitreous hemorrhage.

Aged↗

PubMed1987

[Noninvasive identification of collateralized myocardium by 201 thallium tomography in vasodilation and redistribution].

Coronary arteriolar vasodilatation may provoke the redistribution of flow to collateral-dependent jeopardized myocardium. To assess the physiologic significance of collateral channels, 80 consecutive postinfarction patients (aged: 58 +/- 8 years) underwent vasodilatation/redistribution thallium-201 tomographic (SPECT) imaging using 0.56 mg dipyridamole/kg body weight. Circumferential profile analysis of redistribution and slow washout in representative left ventricular tomograms provided quantitative evaluation of transient and persistent defects and a separation between a periinfarctional and distant inducible hypoperfusion. Tomographic perfusion data were correlated to subsequent cineangiographic analysis of wall motion and to the extent of collateral circulation between two distinct anatomic perfusion areas, one of which involved the infarct zone. Patients were grouped according to the presence (59%) or absence (41%) of angiographically visible collateral channels to the jeopardized myocardium. In the presence of collaterals, distant reversible defects were larger than in the absence of collaterals (p less than 0.05); the extent of combined periinfarctional and distant redistribution was also larger in collateralized patients (p less than 0.025), whereas the size of the persistent perfusion defect was similar in both groups. In a prospective analysis, the tomographic perfusion pattern of combined periinfarctional and distant ischemia revealed a sensitivity of 85% and a specificity of 78% for the detection of significant collateral circulation in this group of patients. Thus, using the limited collateral flow reserve as a diagnostic tool, vasodilatation/redistribution thallium-201 tomography has some potential for identifying and quantifying collateral-dependent myocardium and may guide diagnostic and therapeutic decision-making.

Aged↗

PubMed1989

Acute total occlusion of the left main coronary artery associated with long-term survival--a case report.

The occurrence of total occlusion of the left main coronary artery (LMCA) is rare. Prognosis with complete LMCA occlusion is generally considered poor and essentially depends on the rate of obstruction and the extent of collateral circulation. The authors report a case of long-term survival after complete occlusion of the left main coronary artery without prior development of collateral circulation.

Acute Disease↗

PubMed1982

Rectal ammonia tolerance test in the evaluation of portal circulation in dogs with liver disease.

An ammonia tolerance test (ATT) is described in control dogs and in patients affected by liver disease with or without portosystemic collateral circulation. The administration of a 5 per cent ammonium chloride solution rectally proved to be preferable to oral administration. A statistically significant difference was shown between the results of the ATT in patients with and those without portal shunts, but not between control dogs and patients without portal collateral circulation. A simplified ATT is proposed in which venous ammonia determinations are made before and 20 and 40 minutes after rectal administration of 5 per cent ammonium chloride solution at a dose of 2 ml/kg bodyweight.

Ammonia↗

PubMed1976

Definition of myocardial perfusion by continuous infusion of krypton-81m.

Krypton-81m, a radionuclide emitting a 190 kev gamma ray, has a half-life of 13 seconds. It is a radioisotope of an inert water-soluble noble gas and is produced at a constant rate by spontaneous decay of rubidium-81 in an 81Rb-81mKr generator-delivery system. Delivery is through a minibore Teflon catheter that can be threaded through a standard no. 7 or 8F angiographic catheter. The generator is eluted by 5 percent dextrose-in-water, delivered by infusion pump at 1.5 ml/min, and the eluate is infused intraarterially directly into any organ. Delivery and decay reach equilibrium within 2 minutes, producing a heterogeneous distribution that is proportional to the perfusibility of the tissue concerned and the time required to reach it. The ultrashort halflife of the radionuclide rapidly eliminates activity when delivery ceases; thus, experiments can be sequentially repeated at brief intervals. The radiation hazard for easily imaged doses is negligible. Preliminary studies in open chest dogs were visualized by scintillation camera, stored on digital data disk, processed, and displayed in dual channel, dual color mode on a video system. Images of myocardial perfusion defined relative levels of perfusion, collateral circulation between coronary arterial branches, equilibrium time of diffusible perfusion of the myocardium, focal defects in induced occlusion, collateral circulation to occlusion, and reactive hyperemia after release of induced coronary occlusion. The system and technique appear applicable to human subjects.

Animals↗

PubMed1978

[The indications for operative revascularization of acute and chronic renal artery embolism (author's transl)].

Renal artery embolism, which in our patients accounts for 0.4% of all arterial emboli and 6.5% of all operations on the renal arteries, demands rapid diagnosis and immediate operative revascularization. Three of our own cases of complete renal artery embolism which were successfully operated on and 5 with total chronic embolism of the renal arteries, also successfully operated, verify this indication. The importance of the collateral circulation in complete embolism of the renal artery for the maintenance of the organ is pointed out. This collateral circulation can prolong the revival time of the organ so that surgical restoration of the flow can be successful even after a long time. Intraoperative renal biopsy permits the prognosis to be assessed.

Acute Disease↗

PubMed1997

Determining variations in colonic circulation during aortic surgery.

The aim of this study was to compare transanal Doppler examination, intraoperative angiography via the inferior mesenteric artery, and the inferior mesenteric artery stump pressure measurement during abdominal aortic surgery to assess the collateral circulation to the inferior mesenteric artery bed. Transanal Doppler examination revealed that the collateral circulation depended on the superior mesenteric artery in 25 patients (superior mesenteric artery-dominant group), the inferior mesenteric artery in two patients (inferior mesenteric artery-dominant group), and the internal iliac artery in one patient (internal iliac artery-dominant group). The mean (+/-S.D.) inferior mesenteric artery stump pressure index was 0.65 (+/-0.12) in the superior mesenteric artery-dominant group, which was significantly different from 0.43 (+/-0.00) in the inferior mesenteric artery- and internal iliac artery-dominant groups. The Intraoperative angiography showed the meandering mesenteric artery clearly in the superior mesenteric artery-dominant group. The Transanal Doppler examination as well as inferior mesenteric artery stump pressure measurement were useful methods to assess a dominant artery to the inferior mesenteric artery bed and colonic viability.

Aged↗

PubMed1986

[Occlusion of the common trunk of the left coronary artery. Physiopathological features and clinical findings].

The total occlusion of the left main coronary artery is rarely observed (approximately 0.05% of coronary angiographic studies). We have tried to draw the clinical and pathophysiological outline of this condition, starting from our experience and reviewing the published reports. A hard selection, principally by the high mortality in patients with left main coronary stenosis, limits the number of those who present total occlusion. These subjects show a remarkable variability in their clinical presentation. It is not possible to find out a significant correlation with a single risk factor, clinical manifestation or electrocardiographic picture. Therefore, these patients cannot be distinguished from other subjects affected by severe atherosclerotic ischemic heart disease. The angiographic finding of a dominant right coronary artery is most frequent. A rich collateral circulation to the left coronary is usually observed. From a pathophysiological point of view, the efficiency of coronary collateral circulation is confirmed by the significant correlation of its extent with the left ventricular function. An important role is also played by the rate of progression of left main stenosis in total occlusion and by the presence of right coronary lesions. Even if statistical evidence is still lacking, surgical treatment is unanimously indicated and achieves satisfying results. The use of nonsurgical recanalization techniques, such as intracoronary thrombolysis and transluminal angioplasty, may be lifesaving in those patients in whom left main coronary occlusion suddenly occurs.

Angiography↗

PubMed1983

Arteriographic features of angina pectoris associated with ST segment depression during coronary arterial spasm.

To examine the angiographic features of vasospastic angina associated with ST segment depression, we attempted to analyze the coronary arteriograms of 12 patients who exhibited ST segment depression during the ergonovine provocative test. Right and left coronary arteriograms were obtained successively within a short period when the ergonovine administration revealed ST segment depression. Eight out of 12 patients showed non-total spastic obstructions in one of the major coronary arteries. Among them, a collateral augmentation was found only in one patient. Two cases exhibited the well-developed collateral channels during non-anginal periods and in one case a collateral blood supply was reduced by the spasm occurred in the donating artery. In another one, the collateral circulation did not change during anginal period. Three out of 4 patients who showed total spastic obstructions demonstrated transiently augmented collateral circulation which was supplied by the non-spastic artery. These findings may indicate that ST segment depression during coronary artery spasm could attribute to a subendocardial ischemia caused by an incomplete occlusion of large coronary artery and transient reduction or augmentation of collateral blood flow.

Adult↗

PubMed1981

Vascular changes underlying cerebral lesions in stroke-prone spontaneously hypertensive rats. A serial section study.

The relationship of the vascular changes to the cerebral lesions has been studied using serial sections of the brains from five cases of the stroke-prone spontaneously hypertensive rats. Infarction was observed in a form of microinfarct related to single or plural occluded arterioles in the brain and subarachnoid space. Though most arterioles with fibrinoid necrosis of the wall were occluded with thrombus, infarct, which was obviously related to the occluded arterioles, was verified only in a few occasions. It was proved that infarction did not develop in all the areas irrigated by the occluded arterioles, and the regional circulation was assumed to have been maintained by the collateral circulation. There was rarefaction of the neutrophil with preservation of the neurons in the cortex around the vascular changes, such as fibrinoid necrosis of the wall. Widespread rarefaction and cyst formation were observed in the subjacent white matter, which were more marked in the vicinity of the vascular changes in the cortex. These histological changes were interpreted to be the tissue degeneration secondary to edema.

Animals↗

PubMed1996

Cerebral revascularization using omentum and serratus anterior muscle free flap transfer for adult moyamoya disease: case report.

BACKGROUND: Use of the omentum in the treatment of moyamoya disease is now widely accepted, and, especially in patients with ischemic symptoms of anterior or posterior cerebral artery distribution, omental transplantation or other indirect revascularizations are indicated. CASE REPORT: A 39-year-old man, who developed left homonymous hemianopia, was discovered to have occlusion of the distal portion of bilateral internal carotid arteries. We performed indirect revascularization with an omental flap on the left cerebral hemisphere and a serratus anterior muscle flap on the right cerebral hemisphere. RESULTS: Subsequent clinical course was uneventful. Cerebral blood flow study and angiography revealed good collateral circulation in both the omentum and muscle flap. The collateral circulation was more developed than that arising from the omental transfer on the contralateral side at the same postoperative period. CONCLUSIONS: This type of encephalomyosynangiosis (EMS)-EMS with free muscle flap-is as effective as that with the omental flap in adult moyamoya disease. Especially in a patient who is in need of vascular reconstruction of an extensive ischemic area, serratus anterior muscle flap transfer is one of the alternative methods.

Adult↗

PubMed1987

[Unusual aneurysm of the pancreas arcade in occlusion of the celiac trunk].

This is a report about a rare aneurysm of the pancreas arcade--the angiography showing an occlusion of the celiac axis. Using a diagram of the arterial phase of the angiography, the morphology of the collateral circulation between the celiac axis and the superior mesenteric artery is described. The reason the occlusion of the celiac axis formed collateral circulation and the origin of the aneurysm and the therapeutic steps to be taken are discussed.

Aged↗

PubMed1995

Prospective, randomized, placebo-controlled, double-blind, multicenter study of exercise with enoxaparin pretreatment for stable-effort angina.

In this double-blind, placebo-controlled, multicenter trial, we examined the combined effects of repeated exercise and intravenous enoxaparin (low-molecular-weight heparin) on treadmill exercise capacity and angiographic collateral growth and compared them with the effect of repeated exercise with placebo. Fifty-two patients with stable-effort angina were randomly assigned to receive one of two doses of enoxaparin (40 or 60 mg) or placebo. In each patient, 20 treadmill exercise sessions were performed with the pretreatment of enoxaparin or placebo for 2 to 3 weeks. Before and after treatment, coronary cineangiography was repeated to evaluate the changes in coronary and collateral circulation. Improvement of rate-pressure product (RPP) at the onset of angina was taken as an index of enhanced collateral flow reserve. Although the mean differences in the magnitude of increase in RPP were not significantly different between the 3 groups, a heterogeneous response was observed: 1620 beats/min.mm Hg in 40 mg (p = 0.12), 3060 beats/min.mm Hg in 60 mg (p = 0.02), and 1090 beats/min.mm Hg in placebo (p = 0.44). The end-points of the exercise test were changed from chest discomfort to leg fatigue or dyspnea in 10 (28%) of 36 enoxaparin-treated patients but in only 1 (6%) of 16 placebo patients (p = value not significant (NS)). Similarly, the extent of coronary and collateral circulation to the completely obstructed coronary artery was increased in 17 (47%) of 36 enoxaparin-treated patients but only in 4 (25%) of 16 placebo patients (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1984

Bronchial arteriography in patients with pulmonary embolism.

At various times after clinical embolism, bronchial arteriography was performed in 23 patients with documented pulmonary embolism. In 17 patients with no radiologic infiltrates, chronic stage bronchial arteriograms demonstrated bronchial-to-pulmonary arterial collaterals with antegrade filling of distal pulmonary arteries. No collateral circulation was detected at the acute stage. In one case of massive pulmonary embolism with well-developed bronchial-to-pulmonary arterial collaterals and antegrade filling of distal pulmonary arteries, brisk back-bleeding occurred at surgery, and an excellent therapeutic result following thromboembolectomy was gained. By contrast, in six patients with radiologic infiltrates, only one patient (subacute stage) showed bronchial-to-pulmonary arterial collaterals; these were peripheral and associated with retrograde, not antegrade, filling of distal pulmonary arteries. Bronchial arteriography has provided information about the development of collateral circulation in pulmonary embolism, and might be useful when thromboembolectomy is planned.

Adult↗

PubMed1993

Transient myocardial ischemia during nifedipine therapy in stable angina pectoris, and its relation to coronary collateral flow and comparison with metoprolol.

There are conflicting results concerning the anti-ischemic effect of nifedipine in patients with chronic stable angina. Therefore, the purpose of this study was to assess whether the anti-ischemic effect of nifedipine may be related to coronary collateral circulation. Forty-one patients with stable angina and coronary artery disease were randomized to a parallel double-blind study with nifedipine and metoprolol, and compared for effects on transient ischemic episodes during ambulatory electrocardiographic monitoring and exercise-induced ischemia. The effects were correlated to the presence of collateral circulation. In 17 patients, angiographically poor or no collateral flow was observed (group 1), and 24 had good collateral flow (group 2). Nifedipine was administered to 20 patients (8 in group 1, and 12 in group 2). In group 1, nifedipine reduced the frequency of total and asymptomatic ischemic episodes (p < 0.05), whereas significant increases in both total (p < 0.05) and silent (p < 0.01) ischemia were observed in group 2. Exercise variables were slightly improved (p = NS) during nifedipine therapy in group 1, and slightly worsened (p = NS) in group 2. Reflex tachycardia was not observed at either the onset of transient ischemia out of the hospital or exercise-induced ischemia. This was in contrast with the effect in 21 patients treated with metoprolol (9 in group 1, and 12 in group 2) where significant reductions were observed in the frequency of both total (p < 0.01) and silent (p < 0.01) ischemia in both groups. Furthermore, a beneficial effect was observed on all exercise variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗