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At least 127 records · Page 7Linked to original sources
PubMed1997

Carbon dioxide angioscopy.

Endovascular intervention has become an increasingly more popular method of diagnosing and treating vascular disease. Its expanding scope includes applications ranging from visualization of the peripheral vascular system to coronary artery interventions. This trend is primarily a result of the limitations of angiography, the current imaging standard, when compared to angioscopy. Multiple disease entities, including atherosclerotic plaque, embolic debris, and thrombus, can not be differentiated between based on angiographic appearance. Angioscopy is a more sensitive method of distinguishing between the above disease states by allowing direct visualization of the luminal surface. The significance of this distinction lies in the fact that the treatment options are notably different based upon the diagnosis. Yet another advantage of angioscopy is its therapeutic value in addition to its diagnostic abilities. Directed embolectomy, guide-wire or catheter placement, or pseudointimal resection are all possible through the angioscope at the time of diagnosis.

Journal Article↗
PubMed1991

Results of angioscopy-assisted intraoperative transluminal angioplasty of the iliac and femoral artery.

Angioscopy as a guide for intraoperative transluminal angioplasty was used in the treatment of 36 arterial occlusive lesions in 32 patients, thirty males and two females with mean age of 67.72 +/- 5.95 years (range from 57 to 75 years). Of these, 19 involved the iliac artery and 17 the femoropopliteal artery. All the intraluminal lesions of the artery were successfully visualized. Patency rate for iliac transluminal angioplasty was 95% at the first year and 85% at the second and third years. For femoropopliteal transluminal angioplasty it was 80% at the sixth month and 72% one to three years after. The results in our series were satisfactory when angioscopy was used as an adjunct to assist intraoperative transluminal angioplasty so that the operation could be done more safely and more time-saving with no significant clinical complications. In view of these encouraging results, we will recommend angioscopy as a specific ancillary technique in certain cases of peripheral vascular disease during concomitant vascular surgery, but long term investigation is necessary.

Aged↗
PubMed1991

[Angioscopy in peripheral vascular diseases].

Angioscopy is a useful investigation in patients referred for vascular surgery. The material has been improved over the last few years to make available angioscopes with external diameters ranging from 0.55 to 3.2 mm. The angioscopes are either rigid, composed of two groups of fibre optics (image and light transmission) or orientable and more complex. Both systems may carry operating channels. The angioscopy may be performed peroperatively or percutaneously. Other essential equipment includes catheter guides, balloon catheters, counterpulsation balloons or perfusion pumps. This investigation is used for diagnostic evaluation but when used peroperatively it may also help guide therapeutic intervention. Angioscopy is complementary to ultrasonic and radiological methods of vessel imaging.

Catheterization↗
PubMed1990

[Angioscopy and angioplasty of the iliac and femoral arteries].

Angioscopy is a technique of endoscopic investigation of the vascular lumen and its contents, which we have coupled with iliac and femoral angioplasty. The material comprises 3 main elements: the angioscope, the TV-monitoring assembly and the infusion system. No complication was recorded in a series of 94 angioscopies (47 iliac, 44 distal femoral and 3 grafts) performed over a period of 18 months. The technical quality of the images obtained was good in 90% of cases (85/94). Angioscopy revealed lesions that had either been nonvisualized or underrated by angiography, and played a determinant role in 16% of cases (15/94), whereby the therapeutical procedure could be modified accordingly.

Angioplasty, Balloon↗
PubMed1986

Percutaneous transluminal angioscopy. A new imaging technique for diagnosis of extracranial arterial disease.

Angiography and ultrasound techniques are well established methods for the detection of extracranial vascular disease, but they only allow indirect demonstration of changes in the vessel wall. The development of an ultra-thin fiberscope allows direct demonstration of the pathogenic process in the vessel lumina by angioscopy. The percutaneous transfemoral approach for carotid angiography enables the combination of both methods. After development of an appropriate catheter system we investigated the value of this method producing definite lesions by vascular surgery in adult dogs followed by repeated examinations using angioscopy. Vessel wall alterations such as stalagmite-shaped lesions, subintimal bleeding and thrombotic layers, plaques, ulcerations and postoperative intimal bridging or ablation, which could not be identified by angiography have been analysed with high resolution of details using angioscopy with a video monitoring technique.

Animals↗
PubMed1986

Angioscopy as an adjunct to arterial reconstructive surgery: a preliminary report.

To date our use of angioscopy as an adjunct to in situ vein grafting, arterial embolectomy, femoropopliteal bypass surgery, and laser recanalization has been studied in 11 patients. Three angioscopes have been used: a 1.7 mm optiscope, a 2.8 mm laser optiscope, and a 3.2 mm bronchoscope. Scopes were introduced through an arteriotomy and a clear field maintained by continuous saline infusion. Twenty-four angioscopic evaluations were performed in the 14 patients studied. Adequate visualization was achieved with all three scopes. Angioscopy showed total atherosclerotic occlusion of six superficial femoral and popliteal arteries, intimal flaps in two arteries, thrombus in two arteries and one graft, adequate valvulotomy in three saphenous veins used for in situ bypass grafting, and removal of thrombus after embolectomy in one artery. With the 2.8 mm laser optiscope, the optical fiber used for laser recanalization could be positioned at the site of arterial occlusion before lasing and recanalization were done under direct vision. The 1.7 mm scope could be passed through the recanalized artery to inspect the channel and confirm communication with the artery distal to the occlusion. Thus, angioscopy appears to be potentially useful as a diagnostic device in arterial occlusive disease and as an adjunct in in situ saphenous vein grafting or laser recanalization of occluded arterial segments.

Arterial Occlusive Diseases↗
PubMed1998

Chromatic distortion during angioscopy: assessment and correction by quantitative colorimetric angioscopic analysis.

Angioscopy represents a diagnostic tool with the unique ability of assessing the true color of intravascular structures. Current angioscopic interpretation is entirely subjective, however, and the visual interpretation of color has been shown to be marginal at best. The quantitative colorimetric angioscopic analysis system permits the full characterization of angioscopic color using two parameters (C1 and C2), derived from a custom color coordinate system, that are independent of illuminating light intensity. Measurement variability was found to be low (coefficient of variation = 0.06-0.64%), and relatively stable colorimetric values were obtained even at the extremes of illumination power. Variability between different angioscopic catheters was good (maximum difference for C1, 0.022; for C2, 0.015). Catheter flexion did not significantly distort color transmission. Although the fiber optic illumination bundle was found to impart a slight yellow tint to objects in view (deltaC1 = 0.020, deltaC2 = 0.024, P < 0.0001) and the imaging bundle in isolation imparted a slight red tint (deltaC1 = 0.043, deltaC2 = -0.027, P < 0.0001), both of these artifacts could be corrected by proper white balancing. Finally, evaluation of regional chromatic characteristics revealed a radially symmetric and progressive blue shift in measured color when moving from the periphery to the center of an angioscopic image. An algorithm was developed that could automatically correct 93.0-94.3% of this error and provide accurate colorimetric measurements independent of spatial location within the angioscopic field. In summary, quantitative colorimetric angioscopic analysis provides objective and highly reproducible measurements of angioscopic color. This technique can correct for important chromatic distortions present in modern angioscopic systems. It can also help overcome current limitations in angioscopy research and clinical use imposed by the reliance on visual perception of color.

Algorithms↗
PubMed1993

Angioscopy in variant angina: coronary artery spasm and intimal injury.

Studies in pigs and dogs show that intimal injury is related to coronary artery spasm; it is not known whether intimal injury is related to coronary artery spasm in human beings. We examined intima at the site of coronary artery spasm by percutaneous transluminal coronary angioscopy in 10 of 13 consecutive patients with variant angina. Coronary artery spasms occurred spontaneously or were induced by intracoronary acetylcholine (10-100 micrograms). Angioscopy showed intimal injuries (haemorrhage, flap, thrombus, or ulcer) in 4 of the 10. We suggest that intimal injury is related to coronary artery spasm in human beings.

Acetylcholine↗
PubMed2005

The difficult hemodialysis access extremity: proximal radial arteriovenous fistulas and the role of angioscopy and valvulotomes.

BACKGROUND: Native arteriovenous (AV) fistulas (NAVF) offer significantly lower risks than grafts or catheters. Individuals with a difficult access extremity (DAE) are often viewed as unsuitable for NAVFs. The proximal radial artery (PRA) NAVF offers a safe and reliable opportunity for a direct fistula in most patients, and we find it an important surgical option in the DAE. METHODS: Consecutive vascular access operations were reviewed to find individuals with DAE. We defined the DAE patient group as those individuals where a wrist (Cimino) or upper arm brachiocephalic NAVF was not possible or was predicted to fail. RESULTS: Preoperative physical and ultrasound examinations identified 58 individuals with DAE. Mean age was 56 years (range 11 to 87), 34 were female, 29 were diabetic, and 27 had previous access surgery. NAVFs were constructed in all patients. No grafts were utilized. Forty-six patients had a PRA NAVF constructed. NAVF patency was 91%. Twenty-three patients required retrograde angioscopy or passage of a valvulotome to gain forearm access. Twenty-one of these 23 individuals maintained an open NAVF segment in the forearm. CONCLUSION: NAVFs were constructed in all patients. PRA NAVFs play an important role in extending hemodialysis by NAVF for this difficult patient group. Forearm access is often possible in these patients and may be successfully augmented by angioscopy or valvulotomes.

Adolescent↗
PubMed2004

Cross-sectional area reduction of the aortic ostium by suprarenal stent wires: in vitro phantom study by CT virtual angioscopy.

The study aims to investigate the reduction of cross-sectional area of the aortic ostium by the presence of aortic stent wires observed using CT virtual angioscopy in an aorta phantom. A human aorta phantom was built with a commercial stent graft placed in situ to simulate a repaired aortic aneurysm. Virtual angioscopic images of the aortic ostium and stent wires were generated in the locations of renal arteries, superior mesenteric artery and corresponding cross-sectional area reduction caused by stent wires was measured by virtual angioscopy in various scanning parameters. Our study showed that cross-sectional area reduction of the aortic ostium was determined by the diameter of renal ostium and stent wires, as well as the number of stent wires crossing the aortic ostium.

Angioscopy↗
PubMed2003

Morphologic changes in infarct-related plaque after coronary stent placement: a serial angioscopy study.

OBJECTIVES: The aim of this study was to investigate the morphologic changes in infarct-related lesions after stenting in acute or recent myocardial infarction (MI) with coronary angioscopy. BACKGROUND: There is no information on the serial morphologic changes, which occur after stenting, and the time course of neointimal coverage of stents for disrupted unstable plaques. METHODS: Forty-three patients with MI within seven days of onset were examined. Angioscopy was serially performed for the infarct-related lesions at baseline (n = 43), after balloon angioplasty (n = 35), and after stenting following balloon angioplasty (n = 39) and at one (n = 36) and six months (n = 30) after stenting. RESULTS: At baseline, most of the lesions had complex morphology, yellow plaque color, and protruding thrombus (96%, 96%, and 74%, respectively). Although balloon angioplasty reduced the protruding thrombus, it remained in 37%, and an intimal flap was observed in 89% of the lesions. After stenting, the protruding thrombus and intimal flap disappeared, with an increased luminal size obtained in all lesions. At one-month follow-up, an irregular and yellow surface, along with a lining thrombus, was still observed, with partial neointimal stent coverage in most of the lesions. At six-month follow-up, the neointima was found to have sufficiently formed over the stent. The plaque shape and color were almost all classified as smooth (97%) and white (93%). CONCLUSIONS: These results suggest that a stent not only compressed and covered a disrupted plaque with a protruding thrombus and intimal flap, leading to a wide vessel lumen, but also helped to seal the unstable plaque through neointimal proliferation.

Aged↗
PubMed2006

Number of yellow plaques detected in a coronary artery is associated with future risk of acute coronary syndrome: detection of vulnerable patients by angioscopy.

OBJECTIVES: We sought to test whether the risk of acute coronary syndrome (ACS) can be estimated by angioscopy. BACKGROUND: Disruption of vulnerable plaque and subsequent thrombosis is regarded as a major mechanism of ACS. Although yellow plaques are supposedly vulnerable, the association between angioscopically determined extent of coronary atherosclerosis and risk of ACS events has not been reported. METHODS: Patients (n = 552) who received catheterization and angioscopic examination for the diagnosis of coronary artery diseases were prospectively included and followed up for new onset of ACS events. Yellow color intensities of all detected yellow plaques were graded as 1, 2, or 3 according to the standard colors. Number of yellow plaques (NYP) in a coronary artery and maximum color grade of detected yellow plaques (maxYP) were determined. Association between the incidence of ACS events and angioscopic findings were analyzed. RESULTS: Follow-up interval was 57.3 +/- 22.1 months. Acute coronary syndrome events were detected in 39 patients (7.1%). Although maxYP was not statistically different (2.0 +/- 0.7 vs. 1.8 +/- 0.9; p = 0.18), NYP was higher in the patients with an ACS event than those without the event (3.1 +/- 1.8 vs. 2.2 +/- 1.5; p = 0.008). Patients with NYP > or =2 and those with NYP > or =5 had 2.2- and 3.8-fold higher event rates, respectively, than those with NYP 0 or 1 (9.0% and 15.6%, respectively, vs. 4.1%; p = 0.02). Multivariate logistic regression analysis revealed NYP and multivessel disease as the independent risk factors of ACS events. CONCLUSIONS: Patients with multiple yellow plaques per vessel have a higher risk of suffering ACS events than those with NYP 0 or 1. Angioscopy would be useful to detect vulnerable patients.

Acute Disease↗
PubMed1998

Morphologic comparison of atherosclerotic lesions in native coronary arteries and saphenous vein graphs with intracoronary angioscopy in patients with unstable angina.

BACKGROUND: Coronary vein grafts develop accelerated atherosclerosis after aortocoronary bypass surgery. Previous pathologic studies have suggested that the morphologic appearance of atherosclerotic lesions in saphenous vein grafts may have subtle differences compared with those of native coronary arteries and may be more prone to disruption and thrombus formation. However, a comparative in vivo assessment of the angioscopic morphology differences between these two types of vessels has not been reported previously. We compared the angioscopic lesion morphology of native coronary arteries and saphenous vein grafts in patients with unstable angina. METHODS AND RESULTS: Percutaneous coronary angioscopy was performed in 60 consecutive patients with unstable angina. Plaque color, texture, friability, and the presence of atherosclerotic plaque ulceration or intracoronary thrombus were noted in the culprit lesion. The culprit lesion was located in native coronary arteries in 42 (70%) patients and in a saphenous vein graft in 18 (30%) patients. There were no significant differences in age, sex, and coronary risk factors including tobacco use, hypertension, hypercholesterolemia, or diabetes mellitus between the two populations. There were also no significant differences between the two groups in terms of plaque color, surface texture, or the incidence of complex plaque morphology (plaque ulceration and intracoronary thrombosis). Loosely adherent, friable plaque, detected by angioscopy, was absent in native coronary arteries and was present in 44% of the saphenous vein grafts (p < 0.0001). CONCLUSIONS: The results of our angioscopic study indicate that other than a high incidence of plaque friability in vein grafts, the surface morphology of culprit lesions in unstable angina patients is quite similar for saphenous vein grafts and native coronary arteries.

Angina, Unstable↗
PubMed1999

Intracoronary surface changes after Palmaz-Schatz stent implantation: serial observations with coronary angioscopy.

BACKGROUND: The objective of this study was to evaluate the appearance of the intraluminal surface after Palmaz-Schatz stent implantation by using coronary angioscopy. METHODS AND RESULTS: Coronary angioscopy was performed immediately after stenting and at 1, 3, and 6 months later in 43 patients with 45 lesions. The presence or absence of red thrombus and/or dissection and the extent of neointimal coverage of the stent struts were analyzed. Immediately after stenting, red thrombus and dissection were observed in 9 (41%) and 12 (56%) of 22 lesions, respectively, and these rates decreased with time. Complete coverage of the stent struts by smooth white neointima was observed in 55% of 11 lesions at 1 month and in 80% of 21 lesions at 3 months. However, incomplete neointimal coverage was seen in 3 lesions at both 3 and 6 months. CONCLUSIONS: In human coronary arteries, neointimal coverage of an implanted Palmaz-Schatz stent may take as long as 6 months or more.

Angina Pectoris↗
PubMed1998

Diagnostic and interventional angioscopy.

As an imaging modality, angioscopy provides a simple method for the careful evaluation and treatment of the lumen of native vessels and bypass grafts. When used as a diagnostic study, angioscopy can provide more accurate information regarding the flow surface than conventional tests, such as angiography or duplex imaging. It can significantly enhance the ability of the surgeon to detect flow surface problems. With the recent advance in endovascular tools, angioscopically guided luminal intervention has become an increasingly useful approach to many vascular problems. More precise treatment of endoluminal abnormalities and a reduction in incision length and soft-tissue dissection can result in decreased patient morbidity and extended patient benefit.

Angioscopes↗
PubMed2001

Mechanical and structural characteristics of vulnerable plaques: analysis by coronary angioscopy and intravascular ultrasound.

OBJECTIVES: Mechanical and structural characteristics of vulnerable plaques were evaluated using coronary angioscopy and intravascular ultrasound. BACKGROUND: Mechanical stress and composition of plaques play an important role in plaque disruption. METHODS: Thirty-eight lesions in 38 patients were examined pre-interventionally. The plaques were classified as either yellow or white using coronary angioscopy. Intravascular ultrasound imaging was performed simultaneously with electrocardiographic and intracoronary pressure recordings to calculate distensibility index and stiffness beta. Moreover, the type of remodeling was classified. RESULTS: We identified 27 patients with yellow plaques and 11 patients with white plaques. Patients with yellow plaques presented acute coronary syndromes more frequently than stable angina (85% vs. 36%, p < 0.01). The distensibility index in yellow plaques was significantly greater than it was in white plaques (2.7 +/- 0.8 mm Hg(-1) vs. 0.7 +/- 0.8 mm Hg(-1), p < 0.0001), while stiffness beta for white plaques was significantly greater than it was for yellow plaques (34.9 +/- 16.3 vs. 8.7 +/- 2.7, p < 0.0001). Compensatory enlargement occurred more frequently with yellow plaques than with white plaques (56% vs. 9%, p < 0.01), while paradoxical shrinkage occurred more frequently with white plaques than it did with yellow plaques (64% vs. 4%, p < 0.001). CONCLUSIONS: Yellow plaques with an increased distensibility and a compensatory enlargement may be mechanically and structurally weak. As a result, mechanical "fatigue," caused by repetitive stretching, may lead to plaque disruption. Plaques with a high distensibility and a compensatory enlargement may be vulnerable.

Aged↗
PubMed1999

Valvulotomy of non-reversed saphenous vein bypass grafts: a randomised, blinded, angioscopy-controlled study.

OBJECTIVES: to compare the result of vein valve disruption with two different valvulotomes during non-reversed saphenous vein bypass. DESIGN: a randomised, blinded clinical study. MATERIALS AND METHODS: twenty patients undergoing femorodistal non-reversed saphenous vein arterial bypass were randomised into two equal groups. Valve leaflet disruption was performed either with a standard size plastic valvulotome or with a metal valvulotome with an exchangeable cutting head. Valvulotomy was done after full exposure of the vein and completion of the proximal anastomosis. The result was evaluated by a surgeon blinded to the valvulotome used, using angioscopy. RESULTS: a total of 219 valve cusps were inspected with angioscopy. There were 83 completely lysed cusps (69%) by plastic and 76 (78%) by metallic valvulotomes (p=0.14). Of all the incompletely lysed cusps 12 (29%) occurred in the most proximal valve pocket treated with valvulotomy. CONCLUSIONS: no significant difference in performance between the investigated valvulotomes was found. Incomplete valvulotomy occurred mainly in the proximal part of the vein and was obviously caused by a size mismatch between the diameter of vein and the valvulotome. Construction of a valvulotome with a variable diameter cutting head is therefore recommended.

Aged↗
PubMed2001

Angioscopy.

Angioscopy provides a magnified, real-time, 360-degree view of the endoluminal surface of blood vessels, yielding unique information that is often complementary to conventional angiography. This unique perspective can significantly enhance one's perception and appreciation of endovascular disease. Although angioscopy is primarily used as a research tool, its ability to characterize accurately the morphology and color of atherosclerotic lesions may lead to improved treatment and better clinical outcomes.

Angioscopy↗