Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urokinase, the plasminogen activator from human urine, produces a dose-dependent increase in blood flow in the canine superior mesenteric artery when injected intraarterially at doses from 10(-1) to 10(3) units kg-1. This vasodilation persists despite blockade of beta-adrenergic and histamine H1 and H2 receptors as well as inhibition of plasminogen activation, suggesting that these mechanisms are not involved. Infusion of urokinase at 10(2) CTA (Committee on Thrombolytic Agents) units kg-1 min-1 does not produce a sustained vasodilation, but is effective in achieving complete lysis of thrombi within 100 min in the superior mesenteric arterial circulation. Increasing the dose slightly to 125 CTA units kg-1 min-1 results in unwanted clotting abnormalities without attaining a vasodilator level. Decreasing the dose to 75 CTA units kg-1 min-1 still results in complete thrombolysis. In contrast to the results in the femoral circulation, the dose required for fibrinolysis-thrombolysis does not overlap with that for vasodilation in the superior mesenteric artery. Nevertheless, these experiments provide some basis for the use of intraarterial urokinase infusion in the treatment of nonocclusive mesenteric ischemia and, perhaps, thrombotic occlusion of the superior mesenteric artery.
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PMID:Vasodilation, fibrinolysis, and thrombolysis with intraarterial infusion of urokinase in the canine superior mesenteric artery. 9 90

Sixty nine patients were treated with local intra-arterial urokinase (37,500 U/CTA. hr-1) for recent severe ischemia of lower limbs: 27 (40%) ultimately required amputation. The difference of amputation rate between the groups with and without thrombolysis was not significant (33% v. 42%). A biological study in 6 patients showed that local arterial plasminemia occurred in only 1 patient. Local urokinase does not strongly stimulate "endogenous" thrombolysis and enhances "exogenous" thrombolysis only very inconstantly. A better adaptation of urokinase dosage or the use of an agent with higher affinity for fibrin might improve the efficiency of local thrombolytic therapy.
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PMID:Effect of local urokinase on arterial occlusion of lower limbs. 702 40

The accuracy of three-dimensional CT angiography (3D-CTA) for delineating atherosclerotic carotid stenosis was examined in comparison with digital subtraction angiography (DSA) in symptomatic patients. In cases undergoing carotid endarterectomy (CEA), the clinical usefulness of 3D-CTA for surgical planning was also evaluated in the light of intraoperative findings. From July 1992 to June 1995, 52 patients suffering from internal carotid ischemia and/or presenting carotid bruit were evaluated to detect carotid bifurcation stenosis by 3D-CTA. Shaded surface reconstruction (SSR) for three-dimensional display and maximum intensity projection (MIP) were employed in multiple projection to evaluate sites of stenosis. DSA was performed in 18 out of 31 patients having atherosclerotic carotid stenosis shown by 3D-CTA. MIP reconstructions accurately delineated sites of stenosis close to DSA and allowed precise depiction of ulcerated plaque and intramural calcification. The percentage of carotid stenosis was determined by comparing the narrowest point to the internal carotid artery (ICA) beyond the bulb on both 3D-CTA and DSA. Assessment of carotid stenosis was highly correlated between 3D-CTA and DSA (r = 0.987, p < 0.0001). In this series, 9 carotid arteries in 8 patients underwent CEA for severe stenosis. 3 patients with ICA occlusion and 1 patient with elongated severe stenosis underwent STA-MCA anastomosis. Using MIP reconstructions and two-dimensional original images it was found that ICA occlusion was apparently distinguished from high grade ICA stenosis. SSR provided valuable informations during CEA for atherosclerotic plaque regarding anatomical relationship with the internal jugular vein and bony structures. This advanced means of 3D-CTA can be adequate as a screening method to detect carotid stenosis in symptomatic patients and useful for surgical planning of CEA and post-operative follow-up examination.
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PMID:[Evaluation of carotid artery stenosis with three-dimensional CT angiography and surgical revascularization]. 893 67

The roles of noncontrast computed tomography (NCCT) and CT angiographic/CT perfusion (CTA/CTP) imaging in the rapid triage of clinically suspected hyperacute stroke patients to appropriate therapy is reviewed. Contraindications to thrombolysis include NCCT hemorrhage (absolute) and significant parenchymal hypodensity (relative). The sensitivity of NCCT for early (<6 h) stroke detection, higher than that of conventional magnetic resonance imaging, is improved further by using nonstandard window and level review settings. CTA/CTP is fast and convenient, adding approximately 10 min to the NCCT examination. CTA/CTP's accuracy in diagnosing ischemia and localizing thrombus to proximal or distal intracranial vessels far exceeds that of clinical examination (including National Institutes of Health stroke scale use), facilitating triage of appropriate candidates to intra-arterial thrombolysis. The size of the ischemic CTP hypodensity (proportional to reduced cerebral blood volume) predicts final infarct volume and clinical outcome; its location can guide the decision to perform intra-arterial thrombolysis, intravenous thrombolysis, or other treatment.
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PMID:Computed tomographic angiography and computed tomographic perfusion imaging of hyperacute stroke. 1114 26

The authors report a case of persistent sciatic artery presenting with limb ischemia and pulsatile mass in the buttock treated only by femoro tibio peroneal by pass graft since follow up helical CTA at six months showed spontaneous aneurysmal exclusion by thrombosis of the persistent sciatic artery above the aneurysm. Review of the literature confirms the rarity of this anomaly, which is frequently associated with aneurysmal transformation and its specific inherent complications. It is treated by femoro popliteal shunt with endovascular embolization.
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PMID:[Aneurysm of the persistent sciatic artery]. 1471 48

The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) has not been previously applied to perfusion CT (CTP). Five raters assigned ASPECTS to baseline noncontrast CT (NCCT), CT angiography source images (CTA-SI), CTP source images (CTP-SI), and CTP maps of cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) from 37 consecutive patients with less than 6-hour anterior circulation ischemic stroke. Major reperfusion was identified on follow-up imaging. Mean baseline ASPECTS was compared with follow-up imaging ASPECTS. Rates of favorable outcome were compared for dichotomized baseline ASPECTS. In patients with major reperfusion, mean CBV and CTP-SI ASPECTS closely predicted final infarct ASPECTS. In patients without major reperfusion, mean CBF and MTT ASPECTS best predicted final infarct ASPECTS. There were significant increases in rates of favorable outcome for CTP-SI and CBV ASPECTS of greater than 6, versus less than or equal to 6, but not for other baseline CT modalities. ASPECTS applied to CTP is more accurate at identifying the extent of reversible and irreversible ischemia and at predicting final clinical outcome than NCCTor CTA-SI.
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PMID:Perfusion computed tomography: prediction of final infarct extent and stroke outcome. 1643 64

The influence of different table feeds (TF) on vascular enhancement and image quality in patients undergoing lower extremity runoff-CTA for peripheral artery occlusive disease (PAOD), acute ischemia (AI) or abdominal aortic aneurysm (AAA) with PAOD was investigated retrospectively. One hundred eighty-five patients (PAOD: n = 132; AI: n = 40; AAA: n = 13) underwent 16-detector runoff-CTA (120 kV; 140 mAs; rotation time 0.5 s, collimation 16 x 1.5 mm) using different TF (30 mm/s: n = 25; 40 mm/s: n = 91; 48 mm/s: n = 36; 56 mm/s: n = 33). Vascular enhancement of the large arteries was measured every 10 cm along the z-axis from the upper abdomen to the toe. Arterial enhancement in the distal lower leg was compared (ANOVA, Bonferroni post-test). Qualitative assessment of bolus timing was performed independently by two radiologists. The study was IRB approved. In patients with PAOD or AI, enhancement of calf arteries using a TF of 48 mm/s (278 +/- 79 HU) was significantly higher in comparison to two slower TF (30 mm/s: 201 +/- 70 HU, P < 0.001; 40 mm/s: 251 +/- 79 HU, P < 0.05; 56 mm/s: 261 +/- 57 HU, NS) and the fewest noninterpretable arterial segments below the knee were observed with a TF of 48 mm/s (reader 1: 5/121 = 4.1%; reader 2: 4/121 = 3.3%). In patients with AAA, the fewest nondiagnostic segments occurred with a TF of 30 mm/s (2/12 = 17%, both readers) and 40 mm/s (4/24 = 17%, both readers). A TF of 48 mm/s provided the best synchronization of CT data acquisition and contrast bolus propagation and thus the best image quality in patients with PAOD and AI. In patients with AAA, a slower TF of 30 mm/s provided better image quality than faster CT protocols.
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PMID:Quantitative and qualitative evaluation of the influence of different table feeds on visualization of peripheral arteries in CT angiography of aortoiliac and lower extremity arteries. 1837 44

Penetrating injuries may infrequently cause pseudoaneurysms, lacerations and arteriovenous fistulas involving the subclavian artery. These injuries present with life-threatening bleedings, associated regional injuries and critical limb ischemia and although surgery has been considered the treatment of choice, subclavian injuries pose a real surgical challenge. We prospectively examined data of six patients presenting with penetrating subclavian artery injuries that were treated by urgent endovascular stent-graft placements. All stent-grafts were deployed successfully achieving complete exclusion of the pseudoaneurysm, control of bleeding and reconstruction of the injured artery. No procedural complications, stent thrombosis or stent infections occurred during hospitalization. One patient developed stenosis at 7 months, which required angioplasty. The series mean clinical and ultrasound-CTA follow-up is 38+/-19.7 months (range 11-60 months) and 28+/-19.1 months (range 6-58 months), respectively. This series shows the feasibility of endovascular repair by means of stent-grafts for selected patients with acute penetrating injuries of the subclavian arteries. This approach proved to be safe and effective in restoring the arterial lumen and patency, excluding the pseudoaneurysms and controlling the bleeding caused by subclavian lacerations. Mid-term follow-up on stent-graft patency rates are encouraging.
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PMID:Urgent endovascular stent-graft placement for traumatic penetrating subclavian artery injuries. 1864 95

The aim of this study was to determine the accuracy of multidetector row CT angiography in the diagnosis of acute mesenteric ischemia. Ninety-three consecutive studies on 91 patients with clinically suspected acute mesenteric ischemia underwent abdominal CT angiography as the first, and usually the sole, diagnostic procedure. CT was performed with a multidetector 16-row CT system from the level of the diaphragm to the pelvis in two phases: early arterial and late portal phase. CT examinations were reviewed by the duty radiologist. Final diagnosis was established by a senior radiologist. CTA was diagnostic in 92 studies. Mesenteric ischemia was diagnosed in 18 patients, 14 of them were of the thromboembolic type and four from the nonocclusive type. Positive CTA findings were confirmed by surgery in 13 patients and by clinical follow-up in three cases. Other reasons for abdominal pain were diagnosed by CT in 38 patients out of the remaining 74. There were two false positive and two false negative CT results, resulting in an overall accuracy of 95.6%. Multidetector CT angiography is a fast and accurate investigation for the diagnosis of acute mesenteric ischemia and in most cases can be used as the sole diagnostic procedure.
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PMID:Multidetector CT angiography in the evaluation of acute mesenteric ischemia. 1869 Apr 54

Aneurysmal dilation of saphenous vein grafts is a relatively rare complication of the now common surgical procedure of coronary artery bypass graft (CABG) surgery. The true prevalence of this condition is not clear, however, literature review by Jorgensen et. al. between 1975 and 2002 revealed only 76 published cases. 1 Recent review of literature, utilizing OVID (search terms: saphenous vein, aneurysm, graft, pseudoaneurysm, coronary bypass) suggests a significantly higher prevalence with 14 such cases published in a variety of multinational journals during the period of 2006 to April 2007. The causes of this dramatic increase is likely multifactorial, however, in the author's opinion, likely reflects the increased sophistication and utilization of cross sectional imaging modalities. Regardless of the true prevalence of the condition, there is little debate that the potential for serious morbidity and mortality in this patient population is significant, and that increased detection and discussion of viable therapeutic options is critical. 1 Therefore, we present a case report and discussion of a patient with symptomatic cardiac ischemia, found to have a large saphenous vein graft aneurysm (SVGA) on coronary CTA.
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PMID:Aneurysm of an autologous aorta to right coronary artery reverse saphenous vein graft presenting as a mediastinal mass: a case report. 1902 10


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