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At least 217 records · Page 12Linked to original sources
PubMed2002

Virtual coronary angioscopy using multislice computed tomography.

BACKGROUND: With faster image acquisition times and thinner slice widths, multislice detector computed tomography (MSCT) allows visualisation of human coronary arteries with diagnostic image quality. In addition to conventional axial slices, virtual coronary angioscopies (VCA) can be reconstructed using MSCT datasets. OBJECTIVE: To evaluate the feasibility of reconstructing VCA and to determine the clinical value of this new application in detecting atherosclerotic coronary artery lesions. METHODS: Datasets obtained by contrast enhanced non-invasive coronary angiography using MSCT (Somatom VZ) were analysed from 14 consecutive patients. VCA were simulated in 14 coronary arteries (left anterior descending, n = 7; right coronary, n = 7). Lesion detection was undertaken on conventional contrast enhanced axial slices, as well as by VCA. Intracoronary ultrasound (ICUS) was used as the gold standard for in vivo plaque detection. RESULTS: 38 lesions were detected both on ICUS and on axial slices: 14 severe target lesions of > 75% area stenosis (11 calcified, three non-calcified), and 24 intermediate lesions of < or = 75% area stenosis (seven calcified, 17 non-calcified). Using VCA, all severe lesions (n = 14) and all calcified intermediate plaques (n = 7) could clearly be identified. However, non-calcified intermediate lesions (n = 17) could not be accurately distinguished from the vessel wall; they were recognised as vessel wall alterations without significant luminal narrowing. CONCLUSIONS: Current MSCT technology allows reconstruction of VCA with good image quality. Despite a more anatomical view of heart and coronary vessels on three dimensional reconstruction, conventional axial slices were found to be superior for detecting coronary lesions. Thus further technical innovations are required before VCA can become a useful technique in clinical cardiology.

Adult↗
PubMed2006

Carotid artery stent implantation: evaluation with multi-detector row CT angiography and virtual angioscopy--initial experience.

Approval for this HIPAA-compliant study was obtained from the institutional review board; informed consent was not required for retrospective review of patient studies that had been performed for clinical evaluation. The purpose of this study was to retrospectively compare the accuracy of intrastent luminal diameter, as measured on transverse computed tomographic (CT) angiograms and virtual angioscopic views, with the manufacturer's specifications for phantom diameter and with digital subtraction angiographic (DSA) measurements of stent diameter obtained in patients. Intrastent diameter was measured by using standard and stent-optimized reconstruction kernels with three window settings. Endoluminal virtual angioscopic views of the stent-containing vessels were also generated. Measurements at CT angiography were compared with known specifications for the phantom and with DSA measurements in patients. Erroneous measurements of intrastent diameter occurred when a standard kernel and nonoptimized window settings were used. A set of parameters that minimized error relative to measurements obtained at DSA was also identified. Virtual angioscopy helped demonstrate morphologic aspects of stenosis that were otherwise difficult to appreciate.

Aged↗
PubMed1975

Color angiography and angioscopy.

The authors present the results of their color fluorescein angiographies carried out with a pocket retinograph equipped with new interferential filters. After the graphic examination, they propose to use these same filters mounted on different instruments for binocular and monocular angioscopy. Their results show that retinal vessels are translucid and that their color changes according to their background. The authors termed this change 'versicolored effect'. Moreover, color angiography with these new filters eliminates pseudofluorescence and adds to the fluoroscopic examination an element of analytic perfection, thus giving a new opening to differential diagnosis in endo-ocular diseases.

Color↗
PubMed1996

Dynamic anatomical study of cardiac shunting in crocodiles using high-resolution angioscopy

Prolonged submergence imposes special demands on the cardiovascular system. Unlike the situation in diving birds and mammals, crocodilians have the ability to shunt blood away from the lungs, despite having an anatomically divided ventricle. This remarkable cardiovascular flexibility is due in part to three anatomical peculiarities: (1) an 'extra' aorta (the left aorta) that leaves the right ventricle and allows the blood from the right ventricle to take an alternative route into the systemic circulation instead of going to the lungs; (2) the foramen of Panizza, an aperture that connects the right and left aortas at their base immediately outside the ventricle; and (3) a set of connective tissue outpushings in the pulmonary outflow tract in the right ventricle. Using high-resolution angioscopy, we have studied these structures in the beating crocodile heart and correlated their movements with in vivo pressure and flow recordings. The connective tissue outpushings in the pulmonary outflow tract represent an active mechanism used to restrict blood flow into the lungs, thus creating one of the conditions required for a right-to-left shunt. We observed that the foramen of Panizza was obstructed by the medial cusp of the right aortic valve during most of systole, effectively differentiating the left and right aortic blood pressure. During diastole, however, the foramen remained open, allowing pressure equilibration between the two aortas. Contrary to current theories, we found that the left aortic valves were unable to cover the foramen of Panizza during any part of the cardiac cycle, supporting the reversed foramen flow hypothesis. This would ensure a supply of blood to the coronary and cephalic circulation during a complete shut-down of the left side of the heart, such as might occur during prolonged submergence.

Journal Article↗
PubMedDate not supplied

Oral fluorescein angioscopy in aphakic children.

Seven children who had undergone removal of congenital cataracts were evaluated postoperatively for cystoid macular edema during outpatient visits. Fluorescein was administered orally in a fruit juice cocktail, and the eyes examined by angioscopy 10-20 minutes and 45-60 minutes after dye ingestion. No evidence of macular leakage was observed in any of the 11 eyes examined. It appears that this diagnostic procedure is feasible in young patients, and that the incidence of cystoid macular edema after congenital cataract extraction may be less than has been previously reported.

Aphakia, Postcataract↗
PubMed1986

From angiography to angioscopy: informal discussion.

Devices for visualizing blood vessels have evolved from a rigid, illuminated tube (1913), to a tube with an added convex lens (1922), to one with a transparent inflatable balloon for displacing blood from the line of vision (1943), to a flexible angioscope (1960s). Recent fiberoptic developments make it possible to visualize the orifices of the coronary arteries and simultaneous laser angioplasty. The characteristic fluorescence of hematoporphyrin derivative under ultraviolet light has been visualized angioscopically in experimental atherosclerotic plaque, where it accumulates and acts as a marker. However, several requirements need to be met in order for angioscopy to fulfill its therapeutic possibilities in angioplasty, thrombolytic therapy, intraoperative inspection of vascular anastomoses, and its diagnostic potential in distinguishing plaques from clots and pulmonary embolisms from other obstructions. These requirements are: (1) variously-sized angioscopes to accommodate iliac, femoral, renal, and coronary arteries; (2) percutaneous introducers in the various sizes to prevent back-bleeding; (3) a more flexible, easily manipulated fiberoptic; (4) a sufficiently inflatable balloon tip; (5) cross hairs and reference points in the optical system; and (6) optimal focal lengths for the areas to be visualized.

Journal Article↗
PubMed1992

[Angioscopy of the pulmonary arteries].

The endoscopic investigation of the pulmonary arteries was developed during the 1980's. Current angioscopic techniques, which are still very limited in availability, enable an accurate endoluminal view and allow for a direct approach to endovascular obstruction. The authors describe the technique of angioscopy of the pulmonary arteries and also its indications.

Arteries↗
PubMed1991

Angioscopy.

Improved technology has made the technique of video angioscopy available. This technique, when routinely applied, can provide a wealth of important information to the vascular surgeon. The long term benefits will include improvement of surgical techniques and the potential to simplify and lower the cost of vascular surgery. The angioscope has emerged as a potentially powerful tool for today's vascular surgical team. Nurses need to be aware of this procedure so that they can provide quality care for these patients.

Blood Vessels↗
PubMedDate not supplied

Angioscopy.

Over the past three to four decades vascular surgery has experienced increasing interest and rapid growth. This surgical specialty continues to show an annual increase in the number of procedures performed, and demonstrates increasing use of innovative technology. The author explains how the angioscope has emerged as a potentially powerful diagnostic tool for today's vascular surgeon. Its implications, complications and the post operative nursing care for the patient undergoing angioscopy will be discussed.

Angiography↗
PubMed1990

Intraoperative coronary angioscopy: development of practical techniques.

Techniques and equipment for intraoperative coronary angioscopy were studied in the coronary arteries and cardiac veins of excised and in vivo animal hearts. These studies then allowed development of safe, practical techniques for human clinical use. In coronary artery bypass operations, multichannel angioscopes of 2.3 to 2.8 mm diameter gave the best results for examinations of the bypass vein and anastomosis, whereas smaller optical fibers of 1 mm diameter were required for inspection of the native coronary artery. Abnormalities were detected in 11 of 48 (23%) coronary bypass anastomoses, and significant discrepancy in the degree of coronary artery stenosis as compared with the preoperative angiogram was revealed in 2 patients. The authors concluded that a new design of ultrafine, multichannel angioscope would be more suitable to the different requirements for inspection of both the anastomosis and the recipient artery.

Animals↗
PubMed1990

Microvascular angioscopy.

The desire for immediate assessment of endovascular pathology in hand and microvascular surgery has led to an investigation of the microvascular angioscope. This study evaluated three angioscopes of differing sizes and specifications to determine their ability to detect intimal lesions such as tears, crush injury, and surface clots. Studies were done in 80 Sprague-Dawley rats and in cadaveric hands. Angioscopic findings were correlated with gross and histologic inspection and found to be 100 percent accurate. We conclude that microvascular angioscopy can provide important information concerning the integrity of vessels less than 1 mm in diameter with excellent optical resolution and with minimal time expenditure.

Anastomosis, Surgical↗
PubMed1988

[Intraoperative fiber optic angioscopy during cardiovascular surgery].

The usefulness and limitation of intraoperative angioscopy in the field of cardiovascular surgery were investigated based on our clinical experience. Considerable leakage of cardioplegic solution through the aortic valve due to valve regurgitation was angioscopically demonstrated when the infusion pressure in the aortic root was less than 10 mmHg. This indicates that the cardioplegia must be infused with an aortic pressure of above 20 mmHg for appropriate myocardial protection. After thromboendarterectomy on the arteriosclerosis obliterans, fixation with the edge of the residual intimal flap to the arterial wall was performed correctly under direct visualization. The status of thrombus organization in deep vein thrombosis was evaluated. Even after complete thrombectomy, iliac compression was still demonstrated. Blood in the cardiovascular lumen can be easily cleaned by saline flushing. However, careful attention to fluid overloading must be employed when the observation period is prolonged.

Aortic Valve↗
PubMed1988

[Diagnostic significance of angioscopy in patients with coronary heart disease].

Coronary angioscopy (CA) using ultrathin fiberscopes was performed in 30 patients with coronary heart disease during cardiac catheterization and in 11 patients during bypass surgery. For percutaneous CA the angioscope was introduced from the femoral artery through a 9F guiding catheter. During short-time occlusion of the coronary ostium by the tip of the guiding catheter the viewing field was flushed with Ringer's solution. Intraoperative CA was performed both by the retrograde and antegrade way during flushing with cardioplegic solution. Percutaneous CA was successful in 57% of patients. 13 patients showed eccentrically and irregularly shaped stenoses and 3 of these patients had an additional plaque rupture. In 2/5 patients CA after PTCA revealed intimal dissections not visualized by angiography. Intraoperative CA was successful in 9/11 patients. In 3 patients nonocclusive thrombi were found at the site of the coronary lesion. Additionally we studied the efficacy of angioscopic guidance during intravascular radiofrequency application. In 11/11 thrombotically occluded peripheral vessels this new method allowed a nearly complete recanalization. There was only one perforation of the vessel. We conclude, that CA is a powerful diagnostic tool providing prognostically relevant information in the diagnosis of coronary heart disease.

Animals↗
PubMed1988

[Conjunctival and peri-ungual angioscopy in noninsulin-dependent diabetes mellitus. Informational value of observed anomalies].

Microangiopathy is one of the most frequent and serious complications of diabetes. Its diagnosis is based on fundus of eye and fluorescein angiography findings, but several teams have emphasized the value of conjunctival angioscopy (CA) and peri-ungual capillaroscopy (PUC), describing suggestive anomalies: microectatic venous dilatation (V/A greater than 4.5), sludge on CA, "fish shoal" capillaries on PUC. Up to the present, however, the diagnostic value of these anomalies has not been evaluated based on data that are sensitive, specific and indicate predictive positive and negative values of a sign (Se, Sp, PPV, NPV). Anomalies of CA and PUC as a function of presence or absence of "diabetes" were studied in 114 patients with moderate hypertension, including 46 "diabetics" (33 with glucose regulation disorders and 13 non-insulin dependent diabetics). "Diabetes" was observed more predominantly in males of more advanced age and with a significantly higher global CA score (4.25 +/- 1.44 as against 2.65 +/- 1.35), and this in an increased manner as the "diabetes" was severe. Some anomalies had themselves a major orientation value with an Sp greater than 80% and an Se close to 40% (global score greater than 4; V/A greater than 4.5, microectasia, rheologic changes). For the fish shoal appearance the Sp was 73.5% and the Se 43.5%. The Sp was greater than 95% when at least 4 of the following 6 signs were present: global score greater than 4, V/A greater than 4.5, microectasia, rheologic disorders, fish shoal, gerontoxons. The more signs associated the more the Sp increased; the Se decreased from 40% for one sign to less than 10% for 4 associated signs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Angioscopy as intraoperative outcome control after reconstructive surgery of the renal arteries: presentation of a new method].

Main reasons for obstruction of renal arteries are atherosclerosis and fibromuscular dysplasia. In our clinic transaortic renal endarterectomy and interposition of a vein segment are preferred for arterial reconstruction. The surveillance of the distal intimal ridge after blind transaortic endarterectomy is still an unsolved problem, and the distal anastomosis of a vein graft must be checked, as it is performed under difficult conditions, if the suture is done in situ. We introduce angioscopy as a means of intraoperative surveillance.

Anastomosis, Surgical↗