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At least 343 records · Page 19Linked to original sources
PubMed2006

Intramuscular administration of vascular endothelial growth factor augmenting collateral circulation in a rat hindlimb replantation model.

This study evaluated the effect of exogenous vascular endothelial growth factor (VEGF) on augmentation of collateral circulation in a rat hindlimb replantation model. Twenty-eight rats, divided into four groups, underwent right hindlimb replantation. In experimental Group 1, the rats received daily intramuscular VEGF injections (1 microg/kg). In Group 2, the rats received 25 microg/kg VEGF injections. In Group 3, the rats received 50 microg/kg VEGF injections. In Group 4, the control group, rats received saline injections. Seven days after replantation, the repaired femoral vessels were excised. Seven days after excision of the femoral vessels, toe necrosis ratios of the replanted hindlimbs were grossly examined, and calf blood pressures were measured. Angiography was performed and muscle tissue was biopsied for histology. The results showed that administration of VEGF significantly decreased toe necrosis and improved calf blood pressure ratio, angiographic score, and capillary density in the replanted hindlimbs that underwent late vessel excision. The effect of VEGF was significantly dose-dependent. The authors conclude that VEGF can augment angiogenesis and collateral vessel formation in replanted limbs, and improve survival in replanted limbs with potential late arterial insufficiency.

Analysis of Variance↗
PubMed1976

Collateral circulation to an ischemic kidney.

A review of 301 consecutive abdominal arteriograms given to patients suspected of having occlusive arterial diseases was conducted. In 99 patients, 35% or more stenosis of the renal artery was demonstrated; of these, 40 showed demonstrable collaterals to the ischemic kidney. The adrenal and lumbar arteries contributed four times more frequently than the periureteric arteries to the collateral circulation. Characteristic ureteral notching from the periureteric artery collateral was noted in only 50% of the cases. Intrarenal collaterals were observed and appeared to contribute to the preservation of the size and function of the affected kidney.

Angiography↗
PubMed1995

Leukocyte adherence in an ischemic muscle perfused by a collateral circulation.

Leukocyte adherence was studied in an original experiment that allowed study of the microcirculation in an ischemic muscle perfused by a collateral circulation. In this model, the artery feeding the cremaster muscle was ligated. Then the muscle homolateral to the ligation and its contralateral muscle were both studied by intra-vital-microscopy at 4 h, 1, 3, 7, and 21 days after the ligation. Rats were treated or not with 20 mg/kg/day pentoxifylline (PTX) i.m. In untreated rats, we found that both short-lasting and long-lasting leukocyte adherence was largely increased in the postcapillary venules of the ischemic muscle but not in its contralateral control. This dramatic increase was not limited to the hours immediately after the arterial ligation but was also found up to 3 weeks after the ligation when blood flow was almost restored to normal. This suggested that when muscle blood flow was chronically reduced, some changes promoting leukocyte adherence may occur in the endothelium. In rats treated with PTX, we found very effective inhibition of leukocyte adherence.

Animals↗
PubMed2001

Ultrasonic characteristics of periportal collateral circulation in hepatocellular carcinoma with portal vein invasion.

Real-time ultrasound (US) was used to analyze the morphological characteristics of periportal collateral circulation (PPCC) and the hepatic artery in hepatocellular carcinoma (HCC) patients with portal vein invasion (PVI). During a 5-year interval, a total of 17 HCC patients with main portal vein thrombosis and detectable periportal vessels were collected: 14 men and 3 women, aged 27 to 76 years old. We examined these patients' periportal vessels by real-time US, then differentiated PPCC from hepatic artery by duplex Doppler US. We analyzed the morphological appearances of real-time US imaging of PPCC and the hepatic artery. Our results showed that the PPCC was always torturously worm-like in appearance on real-time US, and the hepatic artery usually had a linear channel appearance on real-time US. When these two kinds of vessels were seen simultaneously along the pathway of a thrombosed portal vein, the inner vessel was always the hepatic artery with linear channel structure, and the outer vessel was always PPCC with a torturously worm-like structure. In conclusion, real-time US is a useful and reliable modality in detecting periportal vessels and differentiating PPCC from the hepatic artery.

Adult↗
PubMedDate not supplied

[Internal maxillary artery and collateral circulation in thrombosis of internal carotid artery (author's transl)].

From 53 cases of thrombosis of the internal carotid artery in the neck, collateral circulation through external carotid branches was angiographically demonstrated in 34 subjects. Anastomosis between external and intracranial circulations was seen to take place through three ways formed by internal maxillary, superficial temporal and facial arteries. The role of internal maxillary artery is emphasised as the most important pathway in the connections between the two circles.

Adult↗
PubMed2006

Impact of coronary collateral circulation on QT dispersion in patients with coronary artery disease.

OBJECTIVE: The aim of this study was to assess the effect of coronary collateral circulation (CCC) on QT dispersion (QTD) in coronary artery disease. BACKGROUND: A prolonged QTD has been linked to increased heterogeneity of ventricular repolarization implicated in the genesis of ventricular arrhythmias and has been associated with an adverse prognosis in patients with coronary artery disease. METHOD: CCC and corrected QTD (QTcD) were established in patients who had at least 85% stenosis in the left anterior descending coronary artery or in proximal part or in the body of the right coronary artery. Furthermore, left ventricular function score was determined for all the patients. RESULTS: While CCC was not present (CCC grade 0) in 32 patients, 68 patients were observed with CCC (CCC grade > or =1). Mean QTcD was higher in patients who had CCC grade > or =1 than in patients with grade 0 (64.3+/-3.5 and 46.8+/-2.7, respectively, P=0.002). We detected a significant correlation between the collateral score and QTcD (r=0.354, P=0.001). CCC grade > or =1 patients had higher mean left ventricular function scores than grade 0 patients (P=0.048). Left ventricular function score and QTcD were observed to be correlated (r=0.200, P=0.046). CONCLUSION: CCC in chronic coronary artery disease was not established to have a positive decreasing effect on QTcD. On the contrary, QTcD values were observed to be even higher in patients with well developed CCC. Further research including larger series and long-term follow-up is required to investigate this issue.

Arrhythmias, Cardiac↗
PubMed1991

Effects of nitroglycerin and diltiazem on well-developed coronary collateral circulation in conscious dogs.

The purpose of the present study was to compare the effects of nitroglycerin and diltiazem on coronary collateral circulation. Studies were conducted in 8 conscious dogs instrumented for the measurement of left circumflex coronary artery (LCCA) flow, subendocardial segment lengths in areas perfused by the LCCA, and left anterior descending coronary artery (LAD). Brief, repeated LCCA occlusions sufficiently developed collateral vessels for the resting metabolic requirement in the LCCA region. One week following the cessation of repeated LCCA occlusions, two-minute coronary occlusions with and without drug pretreatment were performed on separate days. The ischemic responses to coronary occlusions were not altered by diltiazem (50 micrograms/kg, IV), but nitroglycerin (5 micrograms/kg, IV) attenuated myocardial ischemia definitely. The authors conclude that nitroglycerin produces greater effects than diltiazem in attenuating myocardial ischemia in the collateral dependent zone when effects of each drug on systemic and coronary circulation were minimized by pretreatment with small doses.

Animals↗
PubMed1978

Significance of collateral circulation in patients with left main coronary artery disease.

Fifty patients with left main coronary artery disease were studied to evaluate the functional role of collateral circulation. The left main was narrowed 50-70% in 22 patients (group I), and more than 70% in 28 patients (group II). Significant disease in the other vessels was equally common in each group. There was no significant difference in the incidence of inter- and intracoronary collaterals in the two groups. Fifteen patients with no collaterals were compared with 35 patients with collaterals, and to a subset of 11 patients with very rich right-to-left collaterals, and there was no significant difference in historic or ECG evidence of old infarction, duration of angina, incidence of unstable angina, left ventricular end-diastolic pressure, cardiac index, ejection fraction, or segmental contraction abnormalities. We conclude that there is no evidence of protective effect of collateral vessels in patients with left main disease.

Adult↗
PubMed1998

Long-term physical exercise and quantitatively assessed human coronary collateral circulation.

OBJECTIVES: This prospective, cross-sectional study sought to determine an association between the level of long-term physical activity as well as other clinical and angiographic variables and an index of collateral flow to the vascular region undergoing percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: There is limited and conflicting information about the effect of physical exercise on the coronary collateral circulation in humans, partly because previous studies lacked a quantitative means of assessing collateral channels. METHODS: In 79 patients (mean [+/-SD] age 58 +/- 10 years) with coronary artery disease undergoing PTCA (no transmural myocardial infarction), a coronary collateral flow index was determined as the ratio between the intracoronary (IC) distal flow velocity time integral during (Vi(occl)[cm]) and after (Vi(occl) [cm]) PTCA of the stenosis. Vi(occl)/Vi(occl) was measured by a 0.014-in. Doppler guide wire, from which an IC electrocardiogram (ECG) was also recorded. Patients without ECG ST-T wave changes during PTCA were considered to have sufficient collateral channels (n = 29); those with ST-T wave changes were considered to have insufficient collateral channels (n = 50). The level of long-term physical activity was determined by a structured interview (score from 1 to 4). Univariate and multivariate analyses were used to find associations between physical activity as well as 30 other clinical and angiographic variables and the collateral flow index. RESULTS: Long-term physical activity during leisure time, but not during work hours, and the severity of the stenosis undergoing PTCA were found to be independently and directly associated with sufficient versus insufficient collateral channels and with Vi(occl) Vi(occl) (leisure time physical activity [LTPA] score 3.3 +/- 0.9 vs. 2.4 +/- 1.0, p = 0.0002; percent diameter stenosis 88 +/- 12% vs. 80 +/- 14%, p = 0.001; Vi(occl)/Vi(occl) = 0.1 +/- 0.1 LTPA score, p = 0.0002 for trend). CONCLUSIONS: In patients with coronary artery disease, the level of long-term physical activity during leisure time and the severity of the stenosis undergoing PTCA are directly associated with the quantitative degree of collateral flow.

Adult↗
PubMed1989

[Indices of left ventricular diastole in patients with unstable angina and angiographically documented collateral circulation].

23 patients (20 males, 3 females) aged 26-62 (mean 45.9 +/- 9.9) with unstable angina underwent the study to evaluate the effect of collateral circulation vessels (CCV) on left ventricular diastole. There was no evidence of myocardial infarction in the past and ejection fraction was normal (EF greater than 60%). At least one branch of left coronary artery was significantly stenosed (more than 75% of a vessel lumen). Patients were divided into two groups: group I -- with CCV, group II -- without CCV. Obtained data were compared between these groups and with the control group (K) consisted of 10 persons. CCV were only observed if a coronary artery was occluded or subtotally stenosed. When a coronary artery was occluded, CCV could prevent myocardial infarction. Time constant (T) prolongation (43.6 +/- 10.8 vs 32 58 +/- 7.9 ms, p less than 0.05 for groups I and K and 49.31 +/- 18.8 vs 32.58 +/- 7.9 ms, p less than 0.02 for groups II and K) testifies to relaxation slowing down in patients with unstable angina, which indicates left ventricular myocardial ischemia. Lack of CCV influence on time constant T (43.6 +/- 10.8 vs 49.31 +/- 18.8 ms, p less than 0.5) as well as remaining left ventricular diastolic parameters (EDVI, EDP) seems that CCV were an insufficient source of a blood flow to myocardium supplied by a stenosed artery.

Adult↗
PubMedDate not supplied

CT angiography in the evaluation of intracranial occlusive disease with collateral circulation: comparison with MR angiography.

The purpose of this study is to determine whether three-dimensional computed tomography angiography (CTA) is superior to magnetic resonance angiography (MRA) in the evaluation of collateral circulation in patients with intracranial arterial occlusive disease. Conventional angiography was used as the standard reference. Collateral vessels were well visualized by CTA, but not by MRA, while conventional angiography revealed leptomeningeal collateral vessels that were filled in a retrograde fashion. CTA is superior to MRA for evaluating collateral vessels.

Adolescent↗
PubMed1983

[Relation between various pathways of collateral circulation and cerebral circulatory disorders resulting from extracranial occlusion of one of the vertebral arteries].

The data obtained during angiographic and clinical examination of 35 patients with extracranial occlusion of one vertebral artery (VA) have been compared. The clinical picture of extracranial occlusion of one VA may vary. Also, the disease may run an asymptomatic course. The clinical symptoms of injuries to the vertebro-basilar vessels are less pronounced during noticeable occlusive alterations within the system of the carotid arteries. The main pathways of collateral circulation in extracranial occlusion of one VA involve intrasystemic anastomoses (within the system of the subclavian arteries). Of the greatest functional importance is the unoccluded VA.

Basilar Artery↗
PubMed2005

Cardiac ischemic score determines the presence of coronary collateral circulation.

PURPOSE: The presence of coronary collaterals is of vital importance during acute ischemia, however, marked interindividual variability exists. We examined the extent to which the burden of cardiac ischemia, expressed as a cardiac ischemic score, affects coronary collateral presence. METHODS: Cross-sectional study in 244 patients, admitted for elective coronary angioplasty. Collaterals were graded with Rentrop's classification. Coronary collateral presence was defined as Rentrop-grade > or =1. The cardiac ischemic score (range 0-4) was calculated by adding 1 point for each of the following four clinical factors present: angina pectoris on exertion, angina pectoris during emotions, previous myocardial infarction, and previous coronary intervention. These four clinical factors were chosen because they can be easily assessed in every patient. We used logistic regression with adjustment for gender, age, hypertension, diabetes mellitus, and hyperlipidemia. RESULTS: The extent of the cardiac ischemic score (odds ratio 1.8 per score-point; 95% confidence interval 1.3-2.5) was strongly associated with coronary collateral presence. Additional adjustment for multivessel coronary disease left the relation essentially unchanged. Also, if the definition of collateral presence was limited to Rentrop-grade 2 and 3, results were effectively the same. CONCLUSION: The extent of the cardiac ischemic score determines the presence of coronary collaterals, and may provide a new index for simple assessment of collateral vascular development.

Angioplasty, Balloon, Coronary↗
PubMed1992

Recent insights into coronary collateral circulation.

The functional significance of coronary collaterals in humans has been debated for many years. Correlations have now been made between the anatomic appearance of coronary collateral vessels visualized at the time of intracoronary thrombolytic therapy during the acute phase of myocardial infarction and the creatine kinase time--activity curve, infarct size, and aneurysm formation. These studies demonstrate a protective role of collaterals in hearts with coronary obstructive disease, showing smaller infarcts, less aneurysm formation, and improved ventricular function compared with patients in whom collaterals were not visualized. There is ample evidence that collaterals respond to myocardial ischemia by opening preexistent channels. When the cardiac myocyte is rendered ischemic, collaterals develop actively by growth with DNA replication and mitosis of endothelial and smooth muscle cells. Heparin-binding growth factors are present in the heart, but their biological activity is quiescent under normal physiological conditions. Once ischemia develops, these factors are activated and become available for receptor occupation, which may initiate angiogenesis after exposure to exogenous heparin. This characteristic of heparin to potentiate the mitogenic activity of acidic fibroblast growth factor has recently been used in the clinical setting as a possible therapeutic modality in patients with coronary artery disease. Patients performing 20 rounds of exercise serially after receiving intravenous injection of heparin showed significantly greater increases in exercise capacity and improvement of clinical symptoms compared with the control group who performed the same exercise without heparin. Further study of neovascularization may lead to a new therapeutic strategy for ischemic heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed2001

Surgical implications of variations in hand collateral circulation: anatomy revisited.

OBJECTIVES: One of the risks associated with harvesting the radial artery is hand ischemia. Accordingly, this study investigated the variations of the hand collateral circulation. METHODS: Fifty hands of cadavers were examined. Variations of the palmar arches were recorded. A classic superficial palmar arch was defined as direct continuity between the ulnar artery and the superficial palmar branch of the radial artery. A classic complete deep palmar arch was defined as direct continuity between the radial artery and the deep branch of the ulnar artery. RESULTS: A classic superficial palmar arch was found in 10% (5/50) of hands, and a classic complete deep palmar arch was found in 90% (45/50) of hands. The superficial palmar branch of the ulnar artery supplied blood to all fingers in 66% (33/50) of hands. Although the superficial palmar branch of the ulnar artery was continuous with the radial artery in only 34% (17/50) of hands (including the classic type of superficial palmar arch), every hand had at least one major branch connecting the radial and ulnar arteries. CONCLUSIONS: Variations in the terminations of the radial and ulnar arteries are common. Although the classic type of superficial palmar arch occurs relatively infrequently, there is always a significant anastomosis between the radial and the ulnar artery in the hand. This anatomic study confirms the presence of a collateral supply in the hand. In the absence of vascular disease, harvesting the radial artery should be regarded as a safe procedure.

Arteries↗