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At least 649 records · Page 36Linked to original sources
PubMed2004

[Intravascular ultrasound imaging and histological evaluation of the aorta].

UNLABELLED: It has been shown in several in-vitro studies that IVUS images correlate well with histology and angioscopy. The existing data on intravascular imaging of large-diameter elastic arteries are scant. The aim of this study was to compare the IVUS images of aorta with the reference method--histological section by evaluating the accuracy of measurements performed at corresponding aortic segments. MATERIALS AND METHODS: 15 human aortic specimens were derived from post-mortem examination and in-vitro IVUS imaging was performed, including measurements of vessel diameters and cross-sectional areas in three specified areas. Corresponding regions of interest obtained with histology were subsequently evaluated and parameters matched to those by IVUS were calculated. RESULTS: Total of 45 pairs of measurement were compared. Mean vessel internal diameter on IVUS was 14.4 mm (SD 2.7 mm) and intima thickness was 0.6 mm (SD 0.8 mm). The corresponding aortic internal diameter observed with histology was 13.2 (SD 2.6 mm) and intima thickness--0.3 mm (SD 0.03). An overall agreement between IVUS and histology specimens was high, yelling correlation ratio of 0.99. The highest level of agreement was observed for external vessel area validation--correlation ratio 0.98. The largest discrepancy was observed for intima and media thickness, with correlation ratios of 0.61 and 0.72, respectively. CONCLUSIONS: Our data suggest that examination of aorta with intravascular ultrasound is feasible and may provide additional information in assessment of cardiovascular pathology. More complete risk stratification, which includes IVUS examination of aorta, is an important factor to determine the necessity for early preventive treatment, especially in patients with normal coronary arteries.

Aorta↗
PubMed2004

New trends in non-invasive coronary angiography with multislice CT.

Recent trends in computed tomography (CT) scanner technology has opened new frontiers in the field of non-invasive coronary angiography. Given the relatively important number of negative invasive angiographies performed each year, eliminating the risks inherent to this procedure by non-invasive methods greatly contribute to diminishing the risk. After injection of contrast, the procedure is performed under short apnea and triggered by electrocardiographic (ECG) recording that provides a multitude of possible image reconstructions; ie, volume rendering, virtual angioscopy, and three-dimensional (3D) reconstruction of the heart and coronary vessels. In 100 patients, adequate visualisation of the coronary arteries was achieved in 98%, with the advantage of visualizing the coronary wall as well as the lumen. The main reasons for failure were arrhythmia and excessive motion. Besides evaluating coronary artery atherosclerosis, computed tomography angiography (CTA) allowed the diagnosis of coronary aneurysm and exact localization of postoperative false aneurysm. The main disadvantages of the technique are the absence of dynamic films and exposure to radiation. The increased accuracy and sensitivity of noninvasive coronary angiography make it an excellent diagnostic tool and a probable replacement to invasive procedures. It should reduce the morbidity and mortality as well as the cost of conventional coronary arteriography. Furthermore, it has the added benefit of offering spacial resolution of the examined vessels.

Coronary Angiography↗
PubMed1992

Coronary angiography and interventional cardiology.

Percutaneous transluminal coronary angioplasty has become the most commonly applied coronary revascularization procedure. Its growth is due to expanding indications and new patient populations including patients with multivessel coronary artery disease, acute myocardial infarction or cardiogenic shock, and elderly patients. Success rates and complications for percutaneous transluminal coronary angioplasty have remained the same or improved despite the expanding indications and the persistent problem of restenosis. Several recent studies have examined new biologic approaches to restenosis. However, the most exciting area of interventional cardiology continues to be the use and development of new mechanical devices including stents, lasers, and atherectomy for unfavorable anatomic lesions, acute occlusion after angioplasty, and to prevent restenosis. The gold standard in the assessment of coronary disease is still angiography, but newer imaging techniques including intravascular ultrasound and angioscopy have added to our understanding of angioplasty, unstable angina, and the use of new devices.

Angioplasty, Balloon, Coronary↗
PubMed1992

[A method of modeling strangulation ileus].

A method for modeling of strangulation ileus consisting in passing the intestinal loop through a strip of cycle rubber nipple with a diameter of 2 mm, width of 4 mm is suggested. Advantages of the method were confirmed by the findings of angioscopy and morphologic study in ileus modeling in 175 rats. The method suggested permits easy and prompt creation of a standard model of strangulation ileus in rats in all the cases, and study after the nipple transection of the changes characteristic of the postischemic period.

Animals↗
PubMed1991

[Unstable angina: from physiopathology to therapeutics].

Unstable angina is a term which encompasses several clinical syndromes (crescendo angina, angina de novo, resting angina, postinfarction angina), intermediary between stable angina and myocardial infarction. The results of coronary angioscopy have allowed differentiation of accelerated effort angina which seems related to ulceration of an atheromatous plaque from resting angina, more commonly associated with intraluminal thrombosis. The diagnosis of unstable angina is clinical and justifies immediate hospital admission to a coronary care unit because of the risk of myocardial infarction and/or sudden death. Medical management comprises triple anti-ischemic therapy (nitrate derivatives, betablockers, calcium antagonists), anticoagulants and platelet antiagregants. Randomised therapeutic trials versus placebo have shown that this treatment decreases the incidence of refractory angina and myocardial infarction. Several studies are under way to assess the role of thrombolytic therapy in unstable angina. When unstable angina is refractory to maximal medical therapy, emergency coronary angiography should be performed. However the outcome is usually favourable and coronary angiography can be performed several days after the acute event. The coronary lesion responsible for unstable angina is often "complex", an eccentric, irregular, severe stenosis or appearances of thrombosis. Whenever possible, depending on the coronary lesion, myocardial revascularisation by coronary angioplasty or aorto-coronary bypass should be proposed. Surgical treatment has been shown to be more effective (symptomatic relief, improved survival) than medical therapy in patients with triple vessel disease. However, the results of studies comparing medical or surgical treatment with coronary angioplasty are not yet available.

Adrenergic beta-Antagonists↗
PubMed1991

[Intraluminal ultrasound echotomography: a new method in the study of arterial angioplasty. Evaluation of a case].

Intravascular ultrasound angioscopy allows to better define the structure of arterial wall and the effect of angioplasty. We report the case of a patient previously treated by coronary angioplasty, who underwent peripheral angioplasty for a stenosis of the left iliac artery. Intravascular ultrasound imaging performed before and after balloon dilatation clearly identified the plain of dissection and the partial resolution of the stenosis in a better way compared to digital angiography.

Angiography↗
PubMed1991

[Primary results of laser recanalization in the endovascular treatment of arterial stenosis and occlusion of the lower limbs. Apropos of 45 treated cases].

Forty-five lower limb arterial lesions were treated by Nd Yag laser angioplasty using 1.4 and 2 mm hybrid catheters in 31 patients. This population comprised 28 men and 3 women (average age 63.8 +/- 3 years) 20 were in Stage II, 5 in Stage III and 6 in Stage IV of Fontaine's classification. The arteriographic lesions were 22 occlusions with an average length of 12.3 cm and 23 stenoses averaging 87% luminal reduction a few millimeters long to a maximum of a string of stenoses. Seventeen of these lesions were very calcified. The stenoses were situated on the iliac artery (7 cases), superficial femoral artery (28 cases), popliteal artery (9 cases) and the tibio-peroneal artery (1 case). There were no fatalities or recourse to emergency surgery. All patients underwent complementary balloon dilatation. The immediate patency rate was 91% in stenotic and 72% in occlusive lesions. At one week, the patency rate for stenotic lesions was unchanged but it had fallen to 59% for occlusive lesions (arteriographic evaluation). Angioscopy was used 22 times: it was indissociable to laser angioplasty as it enabled diagnosis and controlled the result. The use of thermal laser with hybrid catheters (metallic window tip) in endovascular procedures is a safe and effective method of treating stenosis and occlusion of lower limb arteries.

Adult↗
PubMed1991

[Surgical results in stage 2 arterial diseases].

The results of surgical treatment of peripheral artery disease at the stage of intermittent claudication may now be assessed with a 40 year follow-up. In selected cases the 10 year patency rate of aortoiliac revascularisation is 90% and the 5 year patency rate of femoropopliteal revascularisation is 85%. When the indications are widened to include less favourable lesions giving rise to severe claudication, the patency rate falls to 60% at 5 years. These results should improve with better preoperative assessment by Doppler ultrasonography the use of new material and methods (endovascular) and stricter control of the revascularisation procedure by angioscopy in patients with severe effort ischaemia which is the principal surgical indication; the association of endovascular revascularisation procedures has increased the therapeutic indications and improved the functional result.

Blood Vessel Prosthesis↗
PubMed1991

Trends in endovascular surgery.

Endovascular surgery is currently in its infancy. Much work is necessary before its full potential can be realized. Initial enthusiasm has appropriately turned into more sober, realistic cautiousness. This review summarizes experiences with angioscopy, IU, PTA, laser angioplasty, atherectomy, and stent placement. Solving the restenosis problem following endovascular interventions could significantly broaden the applications of endovascular surgery. The nursing challenges brought by this new field are not different from those of traditional vascular surgery and catheterization. Keeping up with the new technology as it quickly evolves and documenting clinical effectiveness probably require an endovascular nurse specialist in a center planning to do a great deal of procedures.

Hemodynamics↗
PubMedDate not supplied

[Prostaglandins in the pathogenesis of vascular lesions in patients with rheumatic diseases].

Using the radioimmunological method the authors studied the level of prostaglandins (PG) E and F2 alpha in 76 patients with rheumatic diseases (RD) including 34 with various forms of systemic vasculitis (SV), 30 with systemic lupus erythematosus (SLE) and 12 with systemic sclerodermia (SSD). The condition of the microcirculatory bed was assessed by the method of bulbar angioscopy. A relationship between PG and first of all the pressor series, and the nature of vascular lesions in patients with RD was established. Hyperproduction of PGE was revealed in patients with lupus nephritis and SV in whom diseases ran their course with involvement of the kidneys and the nervous system. The level of PGF2 alpha correlated with the markedness of vascular disorders in patients with ischemic and vasospastic syndromes as well as with skin forms of vasculitis in SLE.

Adolescent↗
PubMed1991

Interventional cardiology.

Percutaneous transluminal coronary angioplasty remains the standard interventional catheterization approach for the treatment of coronary artery disease. Three broad groups of new therapeutic devices, including atherectomy or devices for mechanical debridement, lasers, and endoprostheses, and diagnostic devices such as ultrasonography and angioscopy are discussed in this article.

Angioplasty, Laser↗
PubMed1990

[Intraoperative diagnosis of the heart and great vessels--measuring blood flow and angiocardiography].

Among the methods for intraoperative diagnosis during cardiac surgery, flow measurements and angiography are of significant value. According to our experience, the electromagnetic method is the leading technique for judging bypass flow after coronary artery surgery; new trends using ultrasound techniques are promising. An exact demonstration and documentation of the operative situation, (e.g., bypass surgery) is only possible using intraoperative cinecoronary angiography. A wall-mounted unit provides excellent pictures; the method, however, is elaborate, expensive, and confined to one operating table only. Thus, a transportable angiography unit is desired that uses digital spot imaging for better evaluation. Recent developments such as intraoperative angioscopy, thermoangiography, and two-dimensional echocardiography present a promising outlook.

Angiocardiography↗
PubMed1990

[Femoral angioplasty. Long-term results].

A study on the long-term efficacy of femoral-popliteal angioplasty was carried out on 185 angioplasty cases over a 5 year follow-up period. A classification of data according to the type of lesion treated, revealed that results were favorable in case of stenosis (87%), short obstruction (70%) and long obstruction (35%). A special study of the outcome of treatments for stage IV arteritis was carried out. After comparing results with those obtained by other teams, the authors list the complications encountered, hematomas, and thromboses, and show their current tendency for regression. Lastly, the authors stress the advantages of angioscopy, which permits to identify the nature of the treated lesions and to predict possible complications, which are usually underrated by angiography.

Angioplasty, Balloon↗
PubMed1990

Intravascular ultrasound: a new potential modality for angioplasty guidance.

Current angioplasty devices are limited by significant rates of arterial perforation and dissection, due to inadequate techniques of guidance, and by restenosis, which may be partly attributed to inadequate debulking of lesions. This paper describes the authors' initial experience in-vitro and in-vivo with intravascular ultrasound as a possible method of enhancing the three-dimensional guidance of devices through atherosclerotic obstructions. Using an in-vitro model they correlated the dimensions and histologic morphology of animal and human arteries with ultrasound images of the specimens. Additional in-vivo evaluations of this technology in canine arteriosclerotic and human atherosclerotic arteries preliminarily support the hypothesis that intravascular ultrasound defines the transmural arterial morphology and may enhance the accuracy of angioplasty procedures. Simultaneous imaging with angioscopy and intravascular ultrasound is demonstrated as a potential method of accurately defining both intraluminal and transmural arterial wall characteristics.

Angioplasty, Balloon↗
PubMedDate not supplied

New trends in laser application: atherolysis.

Attempts to define optimal laser sources for vascular recanalization--new phenomenon--decreasing of the atherosclerotic volume under the influence of low-intensity laser beam were made. He-Ne and dye lasers (wave length: 632 nm) were used as a laser source with a mean exposure of 15 +/- 7 min. This phenomenon was established without any administration of exogenous porphyrin and was confirmed by morphological, ultrastructural and immunochemical studies. Ultrastructural investigation revealed that the action of low-intensity bares radiation on atherosclerotic plaque tissue is mediated by destruction of cells in the surface layers of the atherosclerotic arterial segments. It is noteworthy that the necrotic alterations in cells caused by laser radiation were due to primary damage of cytoplasmic structures. These observations were used in view of a new method of treating atherosclerotic lesions by transluminal laser atherolysis (TLA). Both TLA (37 patients) or laser illumination of vessels added to the conventional ball on angioplasty (25 patients) showed good patency after mechanical recanalization (9 patients). The procedure was verified by digital angiography, direct angioscopy, Doppler etc. The successful rate (82%) has proved that laser atherolysis is an effective tool in the prevention and treatment of atherosclerosis.

Adult↗
PubMedDate not supplied

Endovascular surgery: an overview.

Endovascular surgery, a new discipline for the treatment of vascular disease, is still in its infancy. Techniques consist of procedures that open total obstructions or partial stenosis of the vascular system and are for the most part in clinical trials. Balloon angioplasty, angioscopy, mechanical atherectomy and laser angioplasty are the major techniques in endovascular surgery. This article describes procedures, the techniques and complications.

Catheterization↗
PubMed1990

[Laser angioplasty. Problems and perspectives].

Percutaneous endoluminal balloon angioplasty opened a new area in the field vascular therapeutic. Percutaneous laser angioplasty and mechanical abrasion are logical extension of this new therapeutic approach. A number of patients have been treated by these advanced technics, but their use is not yet of current practice in medical centers. Furthermore, from one center to another there are notable differences between the means used for angioplasty, what reflects the numerous problems which are to be solved: choice of the wavelength : infrared emitted by Nd-YAG lasers, visible by argon lasers or ultraviolet by excime lasers, pulsed or C.W. lasers, control of the desobstruction process, either by radiology, angioscopy, intraluminal vascular ultrasound or fluoroscopy, indications. The problem is still real. A lot of desobstruction have been performed on proximal lesions, but the future of this technics concerns perhaps more distal lesions.

Angioplasty, Laser↗
PubMed1989

[Laser angioplasty].

Laser energy is capable of breaking up plaques of atheroma to clear obstructed arteries. Laser rays are transmitted by optic fibers, fine and flexible, or bundles of fibers. In order to avoid perforation of the arterial wall, major difficulty and pitfall of this technique, a centering balloon is used or an absorption gradient between plaque and normal tissue, or improved guiding devices such as angioscopy, ultrasounds or detection of the atheroma by spectroscopy. The laser energy may also be transformed into heat, procedure carried out by thermoplasty. In order to avoid the drawbacks of the cutting end of the bare optic fibers, it may be covered with sapphire optics which conducts well laser energy. Arterial and coronary disobstructions were performed by so called continuous lasers, such as Argon, YAG of pulsed laser such as Excimer or color lasers. These are selectively absorbed by the atheroma and operate according to a computerized system after detection of atheromatous plaques by spectroscopy. Excellent results have recently been obtained with such a system on short and long term complete peripheral arterial obstructions.

Arterial Occlusive Diseases↗