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At least 685 records · Page 38Linked to original sources
PubMed1995

[Unstable angina pectoris: coagulation disorder and its therapy].

The initiating event in unstable angina is plaque rupture. It triggers platelet activation and aggregation, leading to the formation of an intracoronary thrombus, which can be detected on autopsy, angiography, and by fiber-optic coronary angioscopy. Biochemical markers of platelet and thrombin activity are usually increased and support the pathophysiologic role of coronary thrombosis in unstable angina. Aspirin and heparin have been shown to be effective, whereas thrombolytic therapy has no beneficial clinical effect. Newer specific antithrombotic drugs (hirudin, hirulog) and GPIIb/IIIa platelet receptor inhibitors are being tested in clinical trials and seem to provide a new dimension for the treatment of acute coronary syndromes.

Angina, Unstable↗
PubMed1993

[Intravascular echographic imaging: experimental validations and limits. An in vitro study].

Intravascular ultrasound is a new method of visualizing details of vascular pathology, providing (real time) high resolution images of vascular walls. Most of the research on the technique has explored its qualitative and quantitative capabilities to improve the assessment of atherosclerotic vascular disease in vivo. Intravascular ultrasound differs from angiography and angioscopy in its ability to penetrate below the surface of the vessel lumen, demonstrating specific appearances of the distribution and composition of plaque. Image analysis is operator dependent. Although this technology is very promising limitations such as artefacts and loss of image quality in heavily calcified vessels hinder its use. There is hope that this imaging technique may ultimately improve the results of endovascular interventions.

Arteries↗
PubMed1993

Intravascular ultrasound imaging: development and clinical applications.

Intravascular ultrasound is an exciting, new catheter based technique for imaging blood vessels. It provides accurate, real-time information about the types and distribution of vascular disease and displays both the macro- and micro-structure of blood vessels utilizating transducer frequencies of 10 MHz to 50 MHz. This paper discusses the development and current clinical applications of intravascular ultrasound technology, based on early intracardiac devices in the 1950s and resulting in very small diameter (1.3 mm), flexible probes in the 1990s for use in coronary and small peripheral vessels. Preliminary studies have established the dimensional accuracy of intravascular ultrasound, and more recent techniques such as three-dimensional image reconstruction have produced a very powerful research and clinical tool. The value of intravascular ultrasound in the diagnosis and therapy of vascular disease is based on its ability to define the transmural distribution of disease within the vessel, characterize plaque and intimal lesions, and provide accurate cross-sectional information regarding luminal and vessel wall morphology before and after intervention. Major priorities in the ongoing development of intravascular ultrasound are the need for further miniaturization and cost-effective manufacturing. Future angioplasty guidance devices may combine the benefits of angioscopy and intravascular ultrasound in a single delivery system suitable for incorporation into any ablative (mechanical or laser) catheter.

Arterial Occlusive Diseases↗
PubMed1994

[Drug treatments of chronic venous insufficiency: pharmaco-clinical evaluation].

There are many methods for the assessment of venotropic drugs. Clinical trials based on randomized comparison with placebo are essential. The different methodes used for the evaluation of the functional effects are chosen on the basis of their performance and pertinence for the study objectives. These include three aims which we feel are essential: increased venous tone, decreased capillary permeability and reversal of microcirculatory impairment. Calf plethysmography is highly adapted for the evaluation of venous tone. The mercury gauge works well, but the future will tell if air plethysmography is more adapted here. For capillary permeability, fluoresceine angioscopy is without a doubt the most sensitive and specific method. Unfortunately many laboratories do not have this equipment. If it is not available, the suction cup test or the Landis isotope test may be used although these tests have their limits. For impaired microcirculation, the most interesting test is the laser-Doppler; the results are well correlated with the severity of the chronic venous insufficiency and return to normal after treatment. TcPO2 and capillaroscopic measurements are less sensitive, but are useful in severe cases. Other investigations may be important in individual cases depending on the impact of the medication under study. Drug-induced serum fibrinolytic activity can be measured by the euglobulin lysis time. A haemorheologic effect can be assessed with routine assays (Haematocrit, serum fibrinogen) and measured with tests of red cell deformability and erythrocyte agreggation capacity.

Blood Viscosity↗
PubMed1993

Cardiac allograft vasculopathy: current concepts.

The major cause of late death in cardiac transplant recipients is cardiac allograft vasculopathy also referred to as cardiac transplant atherosclerosis which occurs in 15% to 20% of transplant recipients. It differs from traditional atherosclerosis in that it is a concentric and diffuse intimal hyperplastic process, the internal elastic lamina remains intact, and calcification is rare. The distal portion of the coronary vessel is the earliest to occlude, with occlusion occurring rapidly. Sometimes a low grade vasculitis is also present. There is no definitive reason for cardiac allograft vasculopathy occurring though it has been suggested that it may actually be caused by immunologic and nonimmunologic damage to endothelial cells resulting in myointimal proliferation. Intravascular ultrasound and coronary angioscopy seem to be a more sensitive diagnostic measure of cardiac allograft vasculopathy than coronary angiography. To date, retransplantation seems to be the only definitive therapy for cardiac allograft vasculopathy. But only fair results are being seen with this procedure.

Coronary Artery Disease↗
PubMed1996

[Radiofrequency ablation: physical bases and principles].

Radiofrequency currents are the reference physical agent for endocavitary ablation, especially of supraventricular tachycardias. They are delivered in a continuous mode or sinusoidal waves. Because of the high frequency between 200 and 3,000 kHz there is no stimulation of the neuromuscular cells. The mechanism of the resulting lesion is essentially related to heating of the biological surroundings of the active electrode. The temperature increase remains localised around the active electrode and its kinetics are progressive, which implies close and stable contact between the active electrode and the tissues. The lesional effect is obtained 60 to 90 degrees C in order to avoid the deleterious effects induced by temperatures of over 100 degrees C: boiling, coagulation, vaporization and carbonization of the tissues leading to an increase in impedence. The volume of lesions depends on many factors which are sometimes difficult to control in vivo. It is more closely correlated to the temperature of the active electrode than to the parameters of delivery (power, duration ...). The histological lesions correspond to scar tissue which respects the surrounding architecture. The major technological innovations of this method have resulted in an increase in the volume of the lesions produced, a reduction in the frequency of undesirable effects such as the formation of coagulum and in an immediate evaluation of the anatomic lesional effect. They have consisted in the introduction of specific electrodes and of systems of monitoring the electrical and thermal effects with the use of imaging techniques such as endovascular and transoesophageal echocardiography and angioscopy. New indications will require development of specific catheter-generator equipment to create lesions of size and shape adapted to the arrhythmogenic substrate.

Animals↗
PubMed1996

[Early detection of atherosclerosis].

Within certain limits, it is not possible to screen for asymptomatic early atherosclerotic lesions with the aim of prevention. The effectiveness of different screening tests varies. A vascular murmur has little predictive value. Coronary or aorto-iliofemoral calcifications sometimes occur early. ECG or exertion thallium scan and low distal pressure at rest or during exercise can provide indirect clues as can continuous Doppler or the carotids or peripheral vessels. Pulsed Doppler and color-Doppler are the best screening tools for detecting wall thickening or a silent plaque. Arteriography is essential for patients with coronary artery disease and is often required for carotid or abdominal vessels, but is unfortunately an invasive method and underestimates lesions which do not give a defect image. Angioscopy and endoechography are difficult to manipulate and interpret and cannot be used in routine screening. No biological or genetic markers have been identified as formal indicators of atherosclerosis. Screening is justified in young patients at risk (high blood pressure, intensive smoking, major hyperlipidemia, diabetes, severe family history) because early lesions would lead to a more adapted treatment which can be expected to stabilize or even improve early lesions, or even reduce the risk of plaque rupture. In addition, carotid or iliofemoral lesions increase the risk of coronary artery disease.

Arteriosclerosis↗
PubMed1995

[Chronic pulmonary heart disease: therapeutic indications].

Chronic thromboembolic cor pulmonale is a serious condition and its frequency seems to be on the increase. The authors report their personal experience of 100 cases and review the literature to describe the natural history, diagnostic strategy and therapeutic indications of this condition. The mechanisms of this aberrant evolution of acute pulmonary embolism are unknown. They key symptom is effort dyspnea without a ventilatory deficit. The most useful diagnostic investigations are Doppler echocardiography and perfusion pulmonary scintigraphy. The diagnosis is confirmed by pulmonary angiography which, with the aid of a thoracic CT scan or endovascular techniques (ultrasonography or angioscopy), allow assessment of the feasibility of thromboendarteriectomy. Medical treatment is based on long-term anticoagulation, in some cases of lower limb thrombosis associated with interruption of the inferior vena cava. Two possible curative surgical techniques are available in selected patients; thromboendarteriectomy and pulmonary transplantation, the relative indications of which are listed. Of all the causes of pulmonary hypertension, chronic thromboembolic cor pulmonary should be systematically looked for because curative surgical treatment is possible in some cases.

Anticoagulants↗
PubMed1996

[Thrombo-aspiration in the surgical treatment of acute ischemia of the legs. Preliminary experience].

Eleven thrombo aspirations were performed in ten patients with lower limb acute ischemia. Three were performed under local and 8 under general anesthesia. They were associated with 4 thrombectomies, 6 transluminal angioplasty procedures, 1 limb infusion, 1 treatment of a false aneurysm, 1 aponeurotomy, 1 angioscopy. Clinical and radiological success was achieved in 9 patients whereas there was one immediate failure requiring a popliteal distal bypass. Late partial rethrombosis requiring medical treatment occurred in one patient. Thrombo aspiration is a safe effective technique which can be combined with other endoluminal procedures in patients with acute lower limb ischemia.

Acute Disease↗
PubMed1997

[Usefulness of directional coronary atherectomy as a bail-out device for acute closure after coronary angioplasty].

The usefulness of directional coronary atherectomy (DCA) as a bail-out device for acute closure (reclosure) after percutaneous transluminal coronary angioplasty (PTCA) was evaluated. PTCA was performed in 1,023 patients (182 with acute myocardial infarction) between January 1993 and January 1994 in our hospital. Thirty-one patients (11 with acute myocardial infarction) suffered acute closure (reclosure) after PTCA. In six patients (five with acute myocardial infarction), DCA was performed as a rescue treatment for acute closure (reclosure). In three of these patients, angioscopy was performed before DCA, which demonstrated intimal tear and some thrombi although coronary angiography showed no evidence of thrombus. Bail-out DCA was successful in all six patients without complications. DCA is useful as a bail-out device for acute closure (reclosure) after PTCA when the thrombus is not massive.

Angioplasty, Balloon, Coronary↗
PubMed1997

Reparative surgery of valves in the treatment of superficial venous insufficiency. External banding valvuloplasty versus high ligation or disconnection. A prospective multicentric trial.

OBJECTIVE: A prospective study was performed in order to compare results obtained in the treatment of early and/or limited primary varicose veins of the lower limbs using two different procedures: external valvuloplasty and high ligation or disconnection of the sapheno-femoral junction. MATERIALS AND METHODS: 116 limbs (113 patients) were selected. 57 with normal cusps in dilated valves were subjected to external valvuloplasty with Silicone prosthesis under Doppler control (intraoperative angioscopy in 16 cases); 59 limbs were subjected to high ligation or disconnection of the junction; 57 limbs out of 116 were subjected to complementary procedures. Duplex and photoplethysmographic examinations were performed before and after the surgical procedures in all patients. Doppler venous pressures were measured in 36 limbs and invasive pressures in 40 limbs. Patients were postoperatively followed up every 4 months until the 12th month. RESULTS: Indications for valvuloplasty were found in 8.2% of cases and in 66.3% of the early varices. Clinical results were slightly superior in the reparative surgery group. Thrombotic occlusion of the proximal long saphenous vein was significantly higher in the ligation-disconnection group. Results from photoplethysmography and venous pressure measurements indicated that both operations are equally effective in the elimination of reflux in the junction.

Adult↗
PubMed1997

Atherosclerosis: imaging techniques and the evolving role of nuclear medicine.

UNLABELLED: Quantitative assessment of atherosclerotic or atherothrombotic disease during its natural history and following therapeutic interventions is important for understanding the progression and stabilization of the disease and for selecting appropriate medical or surgical interventions. A number of invasive and noninvasive imaging techniques are available to detect and display different characteristics of vascular lesions of clinical and/or research interest. METHODS: Angiography, the traditional "gold standard," detects advanced lesions and measures the degree of stenosis. Angioscopy clearly identifies thrombus. In carotid arteries and arteries in lower extremities, duplex ultrasonography is useful for providing the degree of stenosis, as well as plaque morphology, and assessing changes in wall thickness. RESULTS: Magnetic resonance angiography, being noninvasive, may replace conventional angiography for anatomical imaging of the vasculature. Ultrafast electron beam CT measures the calcium content in the atherosclerotic lesions. Intravascular ultrasound is the only technique that appears to be clinically useful in imaging the unstable, vulnerable plaques in coronary arteries. Magnetic resonance imaging techniques may be able to image vulnerable plaques and characterize plaques in terms of lipid and fibrous content and identify the presence of thrombus associated with the plaques. In regard to the nuclear scientigraphic imaging techniques, radiolabeled lipoproteins, platelets and immunoglobulins have shown some clinical potential as imaging agents, but due to poor target-to-background and target-to-blood ratios these agents are not ideal for imaging coronary or even carotid lesions. Technetium-99m-labeled peptides and monoclonal antibody fragments that clear from circulation rapidly and bind specifically to different components of the atherosclerotic lesion showed significant potential in animal models and in limited clinical studies. FRE Peptides capable of binding to GPIIb/IIIA receptors on activated platelets appear to offer significant diagnostic potential for imaging intra-arterial thrombus. Positron emission tomography with metabolic tracers like [18F]-fluorodeoxyglucose (FDG) also appears to offer new opportunities for noninvasive imaging of atherosclerosis and atherothrombosis.

Arteriosclerosis↗
PubMedDate not supplied

The non-healing leg ulcer: peripheral vascular disease, chronic venous insufficiency, and ischemic vasculitis.

The non-healing leg ulcer is examined by discussing three disease processes: peripheral vascular occlusive disease (PVOD), chronic venous insufficiency (CVI), and vasculitis. For PVOD, management decisions are based on risk factors and disease history. Comprehensive management includes the discontinuation of smoking, exercise conditioning and regulation of diabetes, hyperlipidemia, hypertension, and the appropriate application of anticoagulant/antiplatelet drugs. Methods of surgical management include bypass with autogenous or synthetic material in addition to reconstructive surgery with patch angioplasty or extra-anatomic bypass, amputation, percutaneous transluminal angioplasty/stents, thrombolytic infusion, atherectomy, intraluminal ultrasound, and angioscopy. The optimal healing environment for all ulcers prevents contamination, pain, and fluid loss. In CVI, higher venous pressure in the veins of the lower limb during exercise results in ambulatory venous hypertension and ulceration. Various theories are associated with the disease and ulceration process; the classic treatment of elevation, ambulation, and compression for venous disease remains unchallenged. Diagnosis is based on history, physical examination, invasive venography, and/or non-invasive studies. Two groups of vasculitic disorders that share varying degrees of vascular inflammation and necrosis are arteritis (lupus, erythematosus, periarteritis nodosa, dermatomyositis) and blood dyscrasias (sickle cell disease, thalassemia). Leg ulcers associated with vasculitis are due to inadequate tissue oxygenation at the local level, are typically chronic, slow to heal, and commonly recur.

Education, Nursing, Continuing↗
PubMedDate not supplied

[Intra and postoperative control in carotid surgery].

After fourty years of practice in carotid surgery the rate of neurologic complications related to technical defects seems not to be reduced and still is responsible of 30-40% of all perioperative strokes. Intraoperative quality control seem at present, of outmost importance to further reduce the impact of technical defects on perioperative neurological complications. Angiography, Duplex Scanning and more recently angioscopy have been utilized as intraoperative assessments. All of them demonstrated imperfections of arterial reconstruction potentially at risk for early and late patency failure and indicated immediate intraoperative correction. In some report this behaviour determined a relevant reduction both on perioperative results and lesser incidence of early restenosis. Concerning postoperative control of carotid endarterectomy early restenosis represent the most important and more common failure after carotid endarterectomy. In spite of the efforts to clear the causes of this phenomenon, none of the numerous papers published in literature has defined a specific cause determining restenosis. Nevertheless, at present, this hyperplastic response of the arterial wall to trauma after operation is generally considered benign because rarely is responsible for new neurological symptoms or early internal carotid artery occlusion. This unanimous conviction has been achieved after years of instrumental and clinical postoperative follow-up performed all over the world. At the same time and probably for the above mentioned reasons, recently, has begun a new discussion about the usefulness and cost-effectiveness of prolonged Duplex scanning postoperative surveillance of the endarterectomized carotid arteries. After a meticolous review of our experience as the review of many reports of literature we, in agreement with others, are convinced that the patients operated of carotid endarterectomy, need, in most cases, a short even aggressive period of careful follow up (generally the first six months). If during this period no irregularities or new stenosis is detected at the site of the endarterectomy, we believe that it is justified the patients to be withdrawn from a prolonged instrumental follow-up, permitting laboratory working time to be redirected towards the diagnosis of new vascular diseases.

Carotid Artery Diseases↗
PubMed1998

[Simultaneous or stepwise procedure in combined minimal invasive and conventional operation methods in vascular surgery].

Long-term results of femoral angioplasty and stenting are not as successful as open surgical procedures. Transfemoral retrograde recanalisation of the iliac vessel by semiclosed endarterectomy is a low-invasive procedure. Certainly the outcome is characterised by a number of early occlusions caused by dissections or remaining intimal flaps. Recent advances in endovascular management of occlusive disease have changed the situation. Intraoperative control of lumen by angioscopy and removal of occlusive material via TV-monitored endoscopic manipulation has induced better results of endarterectomy. In addition to this more effective recanalisation, the proximal intimal step, mostly at the level of the iliac bifurcation, is managed by intraoperative balloon dilatation and stenting. This combined approach has reduced the necessity of reoperation by about 15%. The cumulative 5-year patency rate for this combined procedure is 88%.

Angioplasty, Balloon↗
PubMed2000

Value of capillary microscopy in the diagnosis of hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a hereditary disorder, leading to easily bleeding telangiectases on the skin and mucosal surfaces. The disease is associated with arteriovenous malformations in multiple organs. Potentially serious complications warrant an early diagnosis. Telangiectases are the hallmark of the disease, but may be difficult to distinguish. OBJECTIVES: To evaluate the value of capillary microscopy in the diagnosis of HHT and to compare the capillary pattern of the fingernail folds in patients with HHT and healthy persons. SETTING: Outpatient department of a general hospital. PARTICIPANTS: A random sample of 54 patients with HHT and a volunteer sample of 40 healthy persons. MAIN OUTCOME MEASURE: The difference in the capillary pattern between patients with HHT and healthy volunteers. RESULTS: Forty-five (83%) of 54 patients with HHT had giant loops between the normal capillaries in the nail fold. Two patients had only enlargement of the draining limb of the capillary. Seven patients (13%) had no vascular abnormalities in the nail fold. Seven of 9 patients with HHT but without cutaneous telangiectases had microvascular abnormalities. None of the volunteers had vascular abnormalities. The difference between both groups was significant (chi2, P<.001). CONCLUSION: Capillary microscopy can be a valuable tool in diagnosing HHT.

Adolescent↗
PubMed2003

The handheld dermatoscope as a nail-fold capillaroscopic instrument.

BACKGROUND: The presence of nail-fold capillary abnormalities may be useful in diagnosing several connective tissue disorders, including scleroderma, dermatomyositis, and mixed connective tissue disease, and in differentiating primary Raynaud phenomenon from Raynaud phenomenon due to scleroderma and mixed connective tissue disease. Capillaroscopy, however, usually requires special equipment and may be time consuming. Purpose To investigate the potential use of the unmodified common handheld dermatoscope as a capillaroscopic instrument. Subjects The study included 106 patients who were consecutively referred and a control group of 170 healthy subjects or patients with unrelated skin disorders. METHODS: A nail-fold capillaroscopic examination using a standard handheld dermatoscope was performed on all fingers of each subject. A scleroderma-dermatomyositis pattern was defined as the presence of 2 or more of the following findings in at least 2 nail folds: enlargement of capillary loops, loss of capillaries, disorganization of the normal distribution of capillaries, "budding" ("bushy") capillaries, twisted enlarged capillaries, and capillary hemorrhages (extravasates). RESULTS: A scleroderma-dermatomyositis pattern was found in 19 (70.4%) of 27, 7 (63.6%) of 11, and 4 (50%) of 8 patients with scleroderma, dermatomyositis, and mixed connective tissue disease, respectively. These frequencies were statistically significantly higher than a null percentage of scleroderma-dermatomyositis pattern in the control group (P<.001) and a scleroderma-dermatomyositis pattern in only 1 (4.5%) of 22 patients with systemic lupus erythematosus as well as in 2 (5.3%) of 38 patients with Raynaud phenomenon but without evidence of a connective tissue disorder (P<.01). CONCLUSIONS: The capillaroscopic results obtained with the dermatoscope are comparable to those described with other instruments. Therefore, the unmodified hand-held dermatoscope may be used as a capillaroscopic instrument to detect a scleroderma-dermatomyositis pattern and to help the dermatologist in the clinical diagnosis of connective tissue disorders.

Adolescent↗