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At least 1,351 records · Page 75Linked to original sources
PubMed1981

[Effect of isoptin and its combination with strophanthin on collateral coronary circulation and systemic hemodynamics in acute myocardial ischemia].

It was established in acute experiments on dogs with the anterior interventricular branch of the left coronary artery ligated in the middle third that isoptin increases essentially the blood flow and oxygen tension in the focus of acute myocardial ischemia, increases the cardiac stroke and minute volumes, and reduces the total peripheral vascular resistance. Strophanthin removes the favourable effect of isoptin on collateral coronary circulation and contractile myocardial activity and increases the total peripheral vascular resistance.

Acute Disease↗
PubMed1979

[Coronary collaterals and function of the left ventricle. Practical applications of a collateral score].

The most important collateral pathways in the coronary artery system goes through the apex, the ventricular septum, left and right atrial branches and the ventricular wall of the left ventricle. In a collective of 52 patients who underwent aortocoronary-bypass surgery we controlled the collateral circulation and left ventricle function. Patients with multiple-vessel-disease had in 71% good collateral circulation and the collateral score was more than twice as high as in patients with one-vessel-disease. In addition we compared the LVEDP in these 52 operated patients and in 52, whose condition did not permit coronary surgery. The enddiastolic pressure is lower in patients with good collaterals and was also better in patients who underwent surgery.

Blood Pressure↗
PubMedDate not supplied

[Free radical centers in the dog myocardial tissue in regional ischemia].

The effect of regional ischemia on canine myocardial in situ free radical species was studied by the EPR method. Rapid fixation of heart muscle samples by freezeclamping was performed at the following physiological states: native myocardial blood circulation, regional ischemia with the presence of collateral circulation, total ischemia, and postischemic reperfusion. EPR spectra of the samples at -40 degrees C exhibited two free radical signals from the semireduced forms of ubiquinone and flavine coenzymes. Upon transition from normal blood supply to regional ischemia, an increase in the contribution of the flavine signal was registered, but reperfusion resulted in the recovery of the characteristics of EPR signals. It was found that the increase in the intensity of collateral circulation in the ischemic area led to an increase in the portion of ubisemiquinone in the integral EPR signal, whereas in total ischemia this signal was not registered. It was shown that the changes in spectral characteristics of integral free radical signals are accompanied by changes in their relaxation parameters.

Animals↗
PubMed1989

[Effect of perfluorochemicals on experimental cerebral ischemia].

It has been noted that perfluorochemicals (PFC) which were developed as artificial blood substitutes, protect against ischemic brain injury by their ability to serve as oxygen carriers. It is also known that normovolemic hemodilution (HD) improves cerebral blood flow (CBF) and neurological symptoms in cerebral infarction. However, there are few reports concerning the effect of PFC on the collateral circulation via pial anastomoses in cases of middle cerebral artery (MCA) occlusion. The ability to record the pial arterial blood pressure (PAP) without interfering blood flow now makes it possible to measure the segmental resistance of cerebral vessels. By using this method, one can measure collateral vessel resistance through pial anastomoses following MCA occlusion. In this paper, we studied the protective effects of PFC combined with HD on ischemic brain injury with the focus on the collateral circulation via pial anastomoses following occlusion of the MCA. Twenty adult cats were studied: control, 8; HD, 5; Fluosol (Fluosol-DA), 7. The systemic arterial pressure (SAP) and PeCO2 were continuously monitored. Subsequently the MCA was occluded via the transorbital approach. CBF in the ectosylvian gyrus (central area of the ischemic lesion) was measured by the hydrogen clearance method. A small pial artery about 100 microns in diameter on the exposed ectosylvian gyrus was punctured nonocclusively with a micropipette filled with 2 M sodium chloride which was connected to a servo-null micropressure system (Model 900, W-P Instruments, Inc. U.S.A.). The electroencephalogram (EEG) was recorded from the ectosylvian gyrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

[Physical factors in the combined treatment of patients with postthrombophlebitic disease of the legs].

95 patients with postthrombophlebitis affection of the lower limbs were treated according to three schemes: conventional therapy alone (anticoagulants, anti-inflammatory therapy, etc.), training of collateral circulation plus minimal standard chemotherapy, training of collateral circulation plus local and endovasal laser radiation plus minimal standard chemotherapy. A total of 75 patients were treated (27, 32 and 36 patients of group 1, 2 and 3, respectively). The best results were achieved in group 3.

Adult↗
PubMed2006

Clinical interest of digestive arterial trunk anastomoses.

Arterial vascularization of the gastrointestinal tract is a three-level system composed of the coeliac trunk, and both superior and inferior mesenteric arteries. The three levels are joined together via arterial trunk anastomoses such as the so-called and well-known Riolan arcade or supramarginal arcade. The aim of this study was to review the embryology of the digestive arteries in order to understand the anatomic variations, the development of the arterial trunk anastomoses and the potential collateral circulation in the case of obstruction of one or several arterial trunks. The arch theory by Mac Kay and Tandler longitudinal arterial anastomosis account for the genesis of the arterial trunk anastomoses and the main anatomic variations. The coeliac trunk and the superior mesenteric artery are joined together via the pancreaticoduodenal arcades and the Bühler arcade. These anastomoses are divided during pancreatic resections but developed in the case of coeliac trunk stenosis. The mesenteric arteries are joined together by the Riolan, Villemin arcades and by the marginal artery of Drummond. This collateral circulation and the Riolan arcade in particular, is utilized during left colonic resection. In the case of this collateral circulation insufficiency, inferior mesenteric artery reimplantation is necessary during abdominal aortic aneurysmectomy. Arteriopathy, more and more frequent due to population ageing is responsible for frequent obliteration of one or several digestive arterial trunks with subsequent development of collateral circulation. For such reasons, a sound knowledge of digestive arterial anatomy is an absolute prerequisite for surgical practice.

Arteriovenous Anastomosis↗
PubMed1999

Revascularization of occluded internal carotid arteries by hypertrophied vasa vasorum: report of four cases.

OBJECTIVE AND IMPORTANCE: The vasa vasorum are involved in the pathophysiological development of carotid artery atherosclerosis, providing vascular support to the thickened intima and plaque. When advanced atherosclerosis causes carotid artery occlusion, the vasa vasorum may serve as a means of revascularization. CLINICAL PRESENTATION: We studied four patients with internal carotid artery occlusion who exhibited revascularization, distal to the occlusion, by small vascular channels that were inconsistent with recanalization through the thrombus. The channels had an angiographic appearance consistent with their being hypertrophied vasa vasorum. Significant collateral circulation was provided by the revascularization. INTERVENTION: All four patients exhibited adequate collateral circulation and were treated with antiplatelet or anticoagulation medication. CONCLUSION: The vasa vasorum have not been previously reported to contribute to the revascularization of occluded arteries. The four cases presented in this report suggest that the vasa vasorum can be a source of collateral circulation after carotid artery occlusion secondary to atherosclerotic disease.

Aged↗
PubMed1997

Manipulation of coagulation factors in acute stroke.

In patients with an acute cerebral infarction, anticoagulation may spare tissue in the ischaemic penumbra from irreversible necrosis by preventing thrombus extension from a vascular bed with good collateral circulation to one with poor collateral circulation. In addition to the possibility of limiting infarct volume, anticoagulation may be given acutely to prevent early recurrent cerebral infarction or to prevent or treat thrombus outside the nervous system (i.e. deep venous thrombosis or pulmonary embolus). In one controlled trial of a low molecular weight heparin, administration of nadroparin calcium within 48 hours of onset of cerebral infarction decreased the combined incidence of dependency and all-cause mortality at 6 months. Another controlled trial in patients with cerebral venous thrombosis demonstrated the benefit of continuous intravenous adjusted-dose unfractionated (UF) heparin compared with placebo. Although results of anticoagulation appear promising in patients with acute cerebral infarction and cerebral venous thrombosis, the benefits of these agents remain unconfirmed. The results of large multicentre trials using a heparinoid (ORG 10172) and subcutaneous UF heparin in patients with acute cerebral infarction are expected within the year.

Acute Disease↗
PubMed2005

Hypoxia-inducible factor-1alpha DNA induced angiogenesis in a rat cerebral ischemia model.

BACKGROUND: Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that regulates the adaptive response to hypoxia in mammalian cells. It consists of a regulatory subunit HIF-1alpha, which accumulates under hypoxic conditions, and a constitutively expressed subunit, HIF-1beta. In this study, we investigated HIF-1alpha naked DNA-induced angiogenesis in a cerebral ischemic model in vivo. METHODS: We utilized a rat encephalo-myo-synangiosis (EMS) model and inoculated HIF-1alpha DNA into the brain surface or the temporal muscle. We analysed whether HIF-1alpha induced angiogenic factors and collateral circulation. RESULTS: A histological section treated with HIF-1alpha DNA showed an increased expression of HIF1 a and VEGF with collateral circulation, in comparison with control DNA (p < 0.01). The HIF-1alpha transcription factor is able to promote significant angiogenesis development. CONCLUSION: These results suggest the feasibility of a novel approach for therapeutic collateral circulation of cerebral ischemia in which neovascularization may be achieved indirectly using a transcriptional regulatory strategy.

Animals↗
PubMed1991

Interval gangrene of the lower extremity: a complication of vascular surgery.

Interval gangrene, segmental ischemic necrosis proximal to a functioning distal anastomosis, is a rare complication after successful peripheral vascular reconstruction. Previous reports have demonstrated the gravity of this event in that major limb amputation was required in all cases. Two cases are presented to emphasize the need for maintaining segmental collateral circulation after successful distal extremity bypass. Despite a satisfactory result after distal (inframalleolar) bypass of a popliteal aneurysm, one patient had progressive ischemic gangrene of the upper leg and eventually required amputation. The contralateral limb was successfully managed by distal ligation of the superficial femoral artery, which maintained collateral flow from the proximal superficial femoral artery to the knee and leg. The second patient required a microvascular free flap to replace tissue loss and provide vascular graft coverage after initial multiple bypass failures and a final successful remote reconstruction to the dorsal artery of the foot that excluded the popliteal-crural collateral network. Patients with inadequate collateral circulation or disruption of the profundus or geniculate collateral pathways may require revascularization of sequential vascular beds. Recognition of the potential for interval gangrene is essential since the likelihood of its occurrence will increase in proportion to the number of distal bypasses being performed for limb salvage. Although adjunctive procedures will not completely eliminate the possibility of interval gangrene, awareness of this phenomenon with attention to the segmental collateral circulation can decrease the incidence of its occurrence.

Adult↗