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At least 523 records · Page 29Linked to original sources
PubMed1995

When CHIVA treatment could be video guided.

BACKGROUND: Hemodynamic correction (CHIVA) is a conservative, ambulatory, and controversial varicose vein treatment. It consists of selected ligatures of the superficial venous system decided by means of preoperative duplex mapping. OBJECTIVE: Prospective evaluation of 80 patients, operated on according to the CHIVA technique described by Claude Franceschi. Mean follow-up length was 30 months. METHODS: Fifty-five consecutive patients were operated on after clinical, ultrasonographic, ambulatory venous pressure and light reflection rheography evaluations. After a 3-year follow-up, another 25 consecutive patients were selected applying some exclusion criteria that emerged in the first part of the study. This second series was operated on by means of intraoperative angioscopy. The same preoperative evaluations have been used to study the outcome in all patients. RESULTS: CHIVA failed in the short saphenous vein territory varices and when the long saphenous vein and the insufficient perforating veins had a preoperative diameter greater than 10 and 4 mm, respectively. The procedure showed a long saphenous vein patency of 90.4% and registered a total recurrence rate of 18.7%. CONCLUSIONS: CHIVA seems to be a more effective varicose vein treatment than high ligation and distal stab avulsion. It also preserves a higher rate of long saphenous veins, suitable for bypass surgery.

Adolescent↗
PubMed1993

Reduction of vasoreactivity and thrombogenicity with laser-thermal angioplasty: comparison with balloon angioplasty.

UNLABELLED: The vasoreactivity and thrombogenicity of laser-thermal angioplasty were examined and compared with those of balloon angioplasty in an atherosclerotic rabbit iliac artery. Eight rabbits underwent laser-thermal angioplasty with a 1.7-mm hot-tip probe activated at 7 W with a probe temperature of 126 +/- 19 degrees C in one iliac artery. The other iliac artery was treated with balloon angioplasty using a 2.0-mm balloon. Angiographic luminal diameter increased from 0.19 +/- 0.15 to 1.54 +/- 0.35 mm by laser and from 0.29 +/- 0.22 to 1.84 +/- 0.20 mm by balloon (P less than 0.0001, respectively). However, it decreased to 1.34 +/- 0.42 for laser and 0.45 +/- 0.39 for balloon 60 minutes later (P less than 0.0001 vs immediately post). Both iliac arteries were visualized using angioscopy, which revealed thrombotic obstruction of 91% stenosis in the ballooned artery and 8% stenosis in the lased artery. Vasoreactivity of treated vessels was also investigated. Segments 3-mm long were obtained from either treated artery or control artery and examined for noradrenaline (10 -7 M) contraction. The segments were then mounted isometrically with 1 g tension in Krebs-bicarbonate buffer. Developed tension was 0.13 +/- 0.21 g for laser thermal and 2.33 +/- 0.4 g for its control (P less than 0.0001), and 0.15 +/- 0.16 g for balloon dilatation and 2.12 +/- 0.43 g for its control (P less than 0.0001). Neither acetylcholine at 10 -6 M or papaverine at 10 -4 M induced relaxation of treated segments. Histology showed slight thermal injury at thermally-treated sites without thrombus, and intimal and medial dissection with thrombus formation at balloon dilated site. IN CONCLUSION: (1) neither a laser-thermal recanalized or a balloon dilated obstructed artery is vasoreactive to constrictive or relaxant agents; and (2) laser-thermal angioplasty results in less thrombogenicity than balloon angioplasty under moderate probe temperature.

Angioplasty, Balloon, Coronary↗
PubMed1993

Effects of ultrasound energy on total peripheral artery occlusions: initial angiographic and angioscopic results.

Ultrasonic energy has been shown to ablate atherosclerotic plaques and arterial and venous thrombi. We used an ultrasonic angioplasty device developed by our group in ten patients with totally occluded femoral artery during surgical bypass. Ultrasonic angioplasty was performed with a 130-cm long and 0.8-cm diameter titanium probe with a 2- or 2.5-mm titanium ball-tip. In one patient, angioplasty could not be performed. Angiographic and angioscopic examination were performed before and after angioplasty in nine patients. Before ultrasound recanalization, angioscopic examination showed that the proximal end of the occlusion was formed by atheromatous material in 3 cases, red thrombus in 3 cases, amd white thrombus in 3 cases. After ultrasound recanalization, angioscopy showed residual stenosis at the site of entry in only one case. In three other cases, the artery was free of residual stenosis without persistent clot. In the five other patients, a residual stenosis was present beyond the proximal occlusion point with some fibrin mesh and small clots. At angiography, flow was restored in 4 cases; in 4 patients flow rate of entry was slow in the distal segment; and in 1 patient, the distal arterial bed could not be opacified. Altogether, ultrasonic angioplasty was able to recanalize a complete occlusion in nine out of ten patients, with partial or complete dissolution of clots and with no complication. At its present stage of development, adjunctive balloon angioplasty would be needed in most cases to obtain unrestricted flow and unsignificant residual stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Peripheral retinal vasculature in normal Jamaican children.

A prospective study of the peripheral retinal vasculature in a Jamaican cohort of subjects with sickle cell disease has been in progress over a period of 12 years using fluorescein angiography. Various vascular patterns were identified but their significance was unclear since no comparable records were available in subjects of a similar age with normal (AA) haemoglobin genotype. Fluorescein retinal angioscopy and angiography have been performed in 76 haemoglobin AA controls participating in the cohort study. The peripheral retinal capillary bed could be seen and photographed in a limited portion of the temporal peripheral fundus in a majority of this group, and there was considerable variation in the vascular pattern which could be characterised. These observations allow deviations from normal to be identified in the retinal vasculature in subjects with sickle cell disease.

Adolescent↗
PubMed1995

Unstable angina. A comparison of angioscopic findings between diabetic and nondiabetic patients.

BACKGROUND: Patients with diabetes mellitus have a higher prevalence of atherosclerotic heart disease and a higher incidence of myocardial infarction than the general population. Diabetic patients also have several hematologic, rheologic, and metabolic abnormalities not present in their nondiabetic counterparts that may predispose them to atherosclerotic plaque rupture and intraluminal thrombosis and consequently may lead to the formation of morphologically complex plaques and the development of acute coronary syndromes. METHODS AND RESULTS: Percutaneous coronary angioscopy was performed in 55 consecutive patients with unstable angina. We observed plaque color, texture, and the incidence of intracoronary thrombus associated with the culprit lesions of these patients. The population consisted of 17 (31%) diabetic and 38 (69%) nondiabetic patients. The presence of coronary risk factors was not significantly different between the two populations. Ulcerated plaque was found in 16 of 17 (94%) diabetic patients versus 23 of 38 (60%) nondiabetic patients (P = .01). Intracoronary thrombi were seen in 16 of 17 (94%) diabetic patients versus 21 of 38 (55%) nondiabetic patients (P = .004). CONCLUSIONS: The results of the angioscopic examination show that diabetic patients with unstable angina have a higher incidence of plaque ulceration and intracoronary thrombus formation than nondiabetic patients. This increased frequency of complex lesion morphology is consistent with the disproportionately higher risk for development of acute coronary syndromes in these patients.

Aged↗
PubMedDate not supplied

Coronary angioscopic findings in the infarct-related vessel within 1 month of acute myocardial infarction: natural history and the effect of thrombolysis.

BACKGROUND: Limited angioscopic information is available on the natural history of infarct-related plaque after myocardial infarction (MI), in particular the effect of thrombolysis. METHODS AND RESULTS: We studied with angioscopy the morphological characteristics of the infarct-related lesion in 56 patients between 24 hours and 4 weeks after MI. Forty of these patients were initially treated with a thrombolytic agent. Most lesions were complex (complex + ulcerated shape = 54%). The predominant color of the plaque was yellow in 79% of cases; only 6% were uniformly white. Angioscopically visible thrombus was found in 77% of cases. Despite angioscopic evidence of instability, only 7% of the patients had post-MI angina. During the 1-month time window since the occurrence of MI, there was no significant difference in the angioscopic appearance of the plaque except for a slight increase in uniformly white plaques (P=.07). The use of a thrombolytic agent at the onset of MI was associated with a reduction in thrombus size and less protruding thrombi (P=.02) but not with a decreased frequency of plaque containing thrombi. Furthermore, a trend for more frequently ulcerated plaques (45% versus 16%, P=.06) was associated with the use of a thrombolytic agent. CONCLUSIONS: These results suggest that healing of the infarct-related lesion requires more than 1 month and that an "unstable" yellow plaque with adherent thrombus is common during that period. This finding may partly explain the unique behavior of recent infarct-related lesions, which are more prone to occlude than other lesions.

Angioscopy↗
PubMed1998

Mechanism of rethrombosis after thrombolytic therapy: angioscopic findings and investigation of the coagulation system in dogs.

The purpose of this study was to angioscopically observe the process of thrombolysis after intracoronary administration of thrombolytic agents and to investigate the effects of these agents on coagulation/fibrinolysis systems in dogs. The coronary endothelium was removed and thrombus formation was confirmed by angioscopy. In the tissue plasminogen activator (tPA) group (n=8), complete thrombolysis occurred in all animals, but thrombolysis was incomplete in the urokinase (UK) group (n=6). The plasma level of plasmin alpha2-plasmin inhibitor complex peaked at 15 minutes after treatment in both the tPA and UK groups. Plasma thrombin-antithrombin III (TAT) complex decreased transiently at 15 minutes after tPA administration but increased at 30 and 60 minutes (P<0.05). In the UK group, plasma TAT also showed a transient decrease followed by an increase, which was minimal compared with that in the tPA group. Plasma TAT decreased transiently after infusion of tPA and subsequently increased to above the pretreatment level, suggesting a risk of rethrombosis after successful recanalization.

Angioscopy↗
PubMed2003

Angioscopic appearance and histopathology of coronary artery thrombi.

A 70-year-old woman presented with acute coronary syndrome. Coronary angiography documented occlusion of the left circumflex coronary artery, and coronary angioscopy showed large red thrombi at the site of occlusion. These thrombi were aspirated using a RESCUE thrombectomy catheter, after which coronary flow was reestablished. Histological examination of the aspirated thrombi revealed platelets, irregularly intermingled erythrocytes, and a large number of leukocytes (mainly neutrophils); tissue resembling vascular endothelium also was present.

Aged↗
PubMedDate not supplied

Lower extremity arterial disease in sports.

The recent description of exercise-induced intimal fibrosis affecting mainly the iliac artery (and therefore usually described as external iliac artery endofibrosis) has dramatically changed the diagnostic approach of unexplained recurrent lower limb exercise pain, especially in cyclists. Because arterial disease is often associated with the aftereffect of various concomitant musculotendinous lesions, several months may pass before an arterial origin is suspected. The arterial origin of the pain must not be eliminated on normal ankle-to-arm index or normal Doppler velocity profiles at rest. Ultrasound examinations taken at rest may show the lesions in 80% of endofibrotic patients and allow for the diagnosis of popliteal entrapment syndrome during dorsiflexion of the foot. However, the hemodynamic consequences of a stenosis on the aortoiliofemoral axis can only be proved by measurement of the ankle-to-arm index after exercise. A cutoff of this index <0.5 provides an 85% sensitivity in the detection of endofibrosis. Invasive investigations (arteriography or angioscopy) will confirm the diagnosis before surgery is discussed. Although long-term results in endofibrosis are unknown, most of the surgically treated patients return to competition.

Angiography↗
PubMed1992

The pathogenesis of an impending infarction and its treatment--an angioscopic analysis.

To clarify the pathogenesis of an impending infarction and to investigate the difference between the pathogenesis of an acute myocardial infarction and an impending infarction, we have performed percutaneous transluminal coronary angioscopy in 13 patients with an impending infarction and in 13 patients with an acute myocardial infarction. As a result, coronary thrombi were observed in 12 of the 13 patients with an impending infarction, and a similar frequency of thrombi was observed in the patients with an acute myocardial infarction. Further, grayish white thrombi were observed in 9 of 12 patients with an impending infarction, but no such thrombi were noted in those with an acute myocardial infarction. Reddish thrombi, however, were observed in all patients with acute myocardial infarction, whereas such thrombi were observed in only 3 of 12 patients with an impending infarction. Informatively, occlusive thrombi occurred more frequently in patients with an acute myocardial infarction than in those with an impending infarction. As a thrombus plays an important role in an impending infarction, we also evaluated the effect of anticoagulant and thrombolytic therapy for an impending infarction in 79 patients. The incidence of recurrent angina and a subsequent acute myocardial infarction were significantly higher in non-heparin-treated patients and in thrombolytic-treated patients than in heparin-treated patients. In conclusion, a thrombus plays an important role in the pathogenesis of an impending infarction and in an acute myocardial infarction, though the characteristics of the thrombus differ in each instance. This difference may account for the differing results of thrombolytic therapy. Heparin was found an effective treatment for myocardial ischemia in an impending infarction.

Angioscopy↗
PubMed1993

Reduction of thrombogenicity with argon laser angioplasty. Comparison with balloon angioplasty.

Direct argon or thermal laser angioplasty (LA) was evaluated for thrombogenicity using angioscopy, and compared with balloon angioplasty (BA). In each of 8 dogs, 4 segments (both proximal and distal iliac arteries) were treated by laser-thermal and/or balloon angioplasty. One segment was treated by balloon angioplasty and 3 other segments were treated with either thermal LA with 7 W using a "Hot-Tip" laser probe (2.0 mm), or BA and thermal LA, or a special optical probe which emits a 3 W argon laser beam. Mean percent area stenosis by thrombus was 44 +/- 23 in balloon-dilated, 23 +/- 21 in thermally-treated and balloon-dilated, 3 +/- 3 in thermally-treated, and 1 +/- 4 in directly-lased segments at 30 min. It was 62 +/- 28 in balloon dilated, 31 +/- 29 in thermally-treated and balloon-dilated, 5 +/- 6 in thermally-treated, and 1 +/- 2 in directly-lased segments at 60 min. Balloon-inflated segments had the highest percent area stenosis which was significantly higher than that of either the direct laser or thermally-treated segments (p < 0.0005). Histology showed thermal necrosis in laser-treated sites, and wall tears in BA sites. Thus, LA can provide a less thrombogenic arterial surface than BA.

Angioplasty, Balloon↗
PubMed1995

Local delivery of heparin inhibits neointimal hyperplasia in injured rabbit artery.

The efficacy of local delivery of an antithrombotic drug on neointimal hyperplasia was investigated in 17 rabbits. One rabbit iliac artery was injured by a balloon catheter as a control injured artery. The other iliac artery was also injured and treated by local delivery of 25 U/kg of heparin. One hour after the balloon injury, angioscopy demonstrated an occlusive or mural thrombus in all the controls, but few in the locally-treated arteries. Four weeks after balloon injury, the percent stenosis was 34 +/- 31% in the heparin treated group (n = 7, p < 0.005) vs control side 73 +/- 17%). Accumulation of FITC-labeled heparin at the injured site was confirmed by microscopy. The activated partial thromboplastin time and fibrinogen level did not change significantly. PDGF-B chain was prominent at the neointimal layer in all the controls, whereas it was less in the locally treated arteries. Thus local delivery of heparin can inhibit neointimal hyperplasia after balloon injury by reducing thrombus-related growth stimulation.

Angioscopy↗
PubMed2002

Angioscopic evaluation of stabilizing effects of an antilipemic agent, bezafibrate, on coronary plaques in patients with coronary artery disease: a multicenter prospective study.

To evaluate the stabilizing effects of an antilipemic agent, bezafibrate, on coronary plaques, we carried out a prospective angioscopic and angiographic open trial. From April 1997 to December 1998, 24 patients underwent coronary angioscopy of plaques in non-targeted vessels during coronary interventions and then again 6 months later. The patients were divided into control (10 patients, 14 plaques) and bezafibrate (14 patients, 21 plaques) groups. Oral administration of bezafibrate (400 mg/day) was started immediately after the intervention and was continued for 6 months. The vulnerability score was determined based on the angioscopic characteristics of plaques and compared before and 6 months later. Six months later, the vulnerability score was reduced (from 1.6 to 0.8; P<0.05) in the bezafibrate group and unchanged (from 1.4 to 1.3; NS) in the control group. In the bezafibrate group, the changes in the vulnerability score were not correlated with those in % stenosis or minimal lumen diameter. The plasma total cholesterol level (T-C) was unchanged, triglyceride level (TG) was decreased, and high density lipoprotein cholesterol level (HDL-C) was increased in the bezafibrate group, but were unchanged in the control group. In the bezafibrate group, T-C and TG were decreased and HDL-C was increased in patients with a reduced vulnerability score but were unchanged in those with an unchanged score. These results indicate that 6 month administration of bezafibrate stabilizes coronary plaques and that the stabilization is not correlated with angiographic changes.

Angioscopy↗
PubMed1996

Recurrent carotid disease: optimum technique for redo surgery.

Carotid restenosis has been a well-recognized, though not well-understood, long-term complication of carotid endarterectomy. Various factors contribute to recurrent stenosis, but the chief cause is technical faults during the primary procedure. Redo endarterectomy or graft reconstruction are the traditional and most effective procedures for treating symptomatic or high-grade (> 80%) asymptomatic restenotic lesions. To reduce the potential for carotid restenosis, eversion endarterectomy is recommended as the technique of choice for de novo carotid disease treatment. Angioscopy is useful in detecting correctable technical errors that could predispose to restenosis.

Angioscopy↗
PubMed1996

Influence of angioscopic vein graft preparation on development of neointimal hyperplasia in an organ culture model of human saphenous vein.

PURPOSE: Angioscopy for in situ vein graft preparation has been criticized on the basis that the trauma of instrumentation may predispose to accelerated intimal hyperplasia, jeopardizing patency rates following infrainguinal revascularization. The aim of this study was to assess the effects of angioscopic preparation on endothelial integrity and smooth muscle cell (SMC) behavior in an established organ culture model of human saphenous vein (HSV). METHODS: HSV was harvested from 12 patients during bypass surgery before and after angioscopic preparation. Endothelial integrity was evaluated by immunohistochemical staining with JC-70 and scanning electron microscopy (SEM); remaining segments of pre- and postangioscopy vein were maintained in culture for 14 days in medium supplemented with 30% fetal calf serum. Viability was confirmed by measurement of tissue adenosine triphosphate on day 14 and thickness of the neointima was measured by computerized image analysis of histologic sections. Monoclonal antibodies to proliferating cell nuclear antigen (PCNA) were used as an immunohistochemical marker for proliferating SMCs. RESULTS: There was a significant reduction in the percentage staining by JC-70 (71.3% versus 20.4%) in pre- versus postangioscopy vein (p = 0.002 by Wilcoxon's rank test; n = 12). This was supported by SEM images. Despite this, there were no significant differences between the pre- and postangioscopy HSVs after 14 days of culture with respect to neointimal thickness (61 versus 56 microns) and staining with PCNA (4.80 versus 4.08 nuclei per 10 microns), all according to Wilcoxon's rank test. CONCLUSIONS: Angioscopic vein graft preparation is associated with endothelial cell loss but does not induce additional neointimal hyperplasia in HSV in vitro. These results suggest that angioscopic manipulation does not alter SMC behavior.

Adenosine Triphosphate↗
PubMed2000

[Intraoperative quality control in carotid surgery].

The intraoperative quality control in carotid surgery is performed by different methods: angiography, duplex-ultrasonography, transcranial Doppler ultrasonography, cw-Doppler, B-mode ultrasonography, pulsed Doppler with spectral analysis, angioscopy and flow-measurements. In Germany these measures are used only in one third of the carotid reconstructions. Especially with angiography and duplex-ultrasonography technical defects can be detected and differentiated if they were without clinical relevance like low-grade stenoses, small intima-flaps and residual plaques or needed to be reexplored. These are high-grade stenoses, acute thrombus-formations of the endarterectomised area and large intima-flaps. Abnormalities were detected in a mean of 17% of all carotid reconstructions by intraoperative control methods. In 5% severe irregularities lead to an immediate revision. Despite that there does not exist clear evidence whether the use of quality control methods reduces the perioperative neurological complication rate. It is not necessary to perform intraoperative quality control if meticulous operative technique with shunting and patch angioplasty is applied and a low perioperative complication rate is reached. For the documentation of the surgical result angiography can be recommended.

Angiography, Digital Subtraction↗
PubMed1999

A method of endoscopic investigation of vascular structures directly through flowing blood.

BACKGROUND: Noninvasive cardiovascular diagnosis has improved immensely due to key technological refinements such as digital subtraction angiography, ultrasonography, Doppler flow analysis, and magnetic resonance imaging. Each of these methodologies provides a unique image of the cardiovascular system but will not permit surgical maneuvers or repairs during real time imaging. Our group has developed a new method of endoscopic visualization of the luminal surface of blood vessels directly through flowing blood without interference of the blood or vessel wall. This opens new possibilities in both diagnosis and surgical interventions. METHODS: Transluminal imaging through flowing blood was performed in normal animals using laser frequency light delivered and retrieved via conventional fiberoptic angioscopic instruments. The reflected light energy was reconstructed into a viewable image using a specialized method of optical data processing and filtering systems. Unlike conventional angioscopy, displacement of flowing blood was not needed as the images were obtained with higher frequency laser light. RESULTS: A total of 20 canine experiments were performed between 1996 and 1997 using our endoluminal imaging system. The images obtained revealed details of luminal surfaces, although primitive and low resolution with this first generation of technology. Images of the topography of the femoral, axillary, and subclavian arteries and veins, as well as several intracardiac structures (aorta and aortic valve) were successfully obtained without trauma or physiologic consequence to the animal. CONCLUSIONS: Using conventional fiberoptic angioscopes coupled with laser light of differing wavelengths, it was possible to image the interior of vascular structures through flowing blood. This method visualizes the intraluminal surface in real time and is dependent only on the delivery and capacity of the endoscope. The implications for future cardiovascular diagnosis and corrective surgical procedures are widespread.

Angioscopy↗
PubMed1990

Indirect evaluation of blood oximetry by digitized conjunctival capillarography: effects of naftidrofuryl.

Microcirculatory disturbances are essential elements in peripheral and visceral oxygenation. Microcirculation can be studied by conjunctival angioscopy with morphological studies (arterioles, veinules, and capillaries appearances) and blood flow dynamics by digitized photographies (indirect oxymetric measurements in vivo). We studied the effects of naftidrofuryl on 20 atherosclerotic patients (mean 70 years old). After 3 months' treatment some parameters were significantly improved: interstitial edema, arteriolar sludge, and mainly vascular oxymetry. This means better microcirculatory hemodynamics and thus a better tissular oxygenation.

Aged↗