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At least 145 records · Page 8Linked to original sources
PubMed1986

Laser angioplasty with angioscopic guidance in humans.

An experimental study was conducted in 11 patients to evaluate the immediate effects of laser recanalization during peripheral arterial bypass surgery. Angioscopy allowed precise localization and identification of the occlusion. A 1 or 2 mm optical fiber probe was used. Laser energy was regulated using the least amount of energy necessary for recanalization. New vascular channels were made in 10 of the 11 patients. After recanalization the arterial segment was excised for histologic evaluation. Smaller channel diameters were made with the 1 mm probe (1.5 +/- 0.6 mm) than with the 2 mm probe (3 +/- 0.3 mm) (p less than 0.05). Flow through channels (mean pressure 80 mm Hg) made with the 2 mm probe was greater than that through channels made with the 1 mm probe (150 +/- 102 versus 19.7 +/- 10 cc/min) (p less than 0.05). The amount of debris formed was small with both probes. Vascular perforations were less frequent with the 2 mm probe (two of nine arteries) compared with the 1 mm probe (four of four arteries). Successful recanalization with flow rates expected to maintain vascular patency was achieved only with the 2 mm probe. Histologic studies at nonperforated sites demonstrated that the elastica of the artery appeared to be preserved whereas the overlying plaque and underlying media were thermally disrupted. This suggests that the elastic tissue acts as an optical window allowing the argon beam to go through it without causing morphologic damage. Except for fresh thrombus, atheromas including calcific plaque and old organized thrombus were readily vaporized. These results are encouraging for the use of the laser for vascular recanalization in humans.

Aged↗
PubMed2004

Significance of angioscopic morphology for the estimation of macrophage infiltration and vascular physiology.

OBJECTIVE: The aim of the present study was to determine whether direct visual morphology can predict vascular physiology, macrophage infiltration and plaque architecture of atherosclerotic lesions. METHODS: Twenty male New Zealand white rabbits weighing 2.5-2.8 kg (mean, 2.7 +/- 0.2 kg) were used. We fed rabbits a 1% cholesterol diet after creating an injury in the middle abdominal aorta using a 2 Fr Fogarty balloon catheter. After 8 weeks, the morphology of plaque lesions was evaluated by angioscopy, and was classified as protruding or lining. Vascular endothelial function (VEF) was evaluated using a Doppler guidewire, and was expressed as ratio of basal to peak velocity (cm/s) in 30 s occlusion using a balloon catheter. Macrophages obtained from abdominal sections were stained with monoclonal antibody against rabbit macrophages (RAM-11). Density of total macrophage cell infiltration was quantified as absolute area of RAM-11 staining. RESULTS: Macrophage density and intima/media (I/M) ratio were significantly higher in the protruding group than in the lining group: macrophage density, 40 +/- 10 vs. 5 +/- 10%, p < 0.01; I/M ratio, 1.2 +/- 1.4 vs. 0.2 +/- 4, p < 0.05. Vascular flow reserve (VFR) was lower in the protruding group than in the lining group (1.8 +/- 0.7 vs. 2.2 +/- 0.5, p < 0.05). There was significant negative correlation between VEF and macrophage cell density (r = -0.593, p < 0.01), whereas there was no significant correlation between VEF and I/M ratio (r = -0.332, p = 0.330). CONCLUSION: The present findings suggest that protruding lesions revealed by angioscopy are rich in macrophages and have a higher I/M ratio and lower VFR.

Angioplasty, Balloon↗
PubMed1992

Angioscopic evaluation of coronary-artery thrombi in acute coronary syndromes.

BACKGROUND: Disruption of an atherosclerotic plaque in a coronary artery followed by the formation of a thrombus is believed to be the cause of both unstable angina and acute myocardial infarction. Although thrombolytic therapy is efficacious in patients with acute myocardial infarction, for unknown reasons it is far less effective in patients with unstable angina. We postulated that there might be differences in the composition of the coronary-artery thrombi in unstable angina and acute myocardial infarction. METHODS: To investigate the appearance of coronary-artery thrombi, we performed percutaneous transluminal coronary angioscopy in 15 patients with unstable angina and 16 with acute myocardial infarction. Angioscopy was performed within 48 hours after an episode of pain at rest in the patients with unstable angina and within 8 hours of onset in those with acute myocardial infarction. RESULTS: Angioscopy revealed coronary thrombi in all but two patients (one in each group). Of the 29 patients with thrombi, those with unstable angina were frequently observed to have grayish-white thrombi (10 of 14, 71 percent), but none were seen in the 15 patients with acute myocardial infarction (P less than 0.01). By contrast, reddish thrombi were observed in all 15 patients with acute myocardial infarction who had thrombi, but in only 4 of the 14 patients with unstable angina and thrombi (P less than 0.01). As assessed by coronary angiography, occlusive thrombi occurred frequently in patients with acute myocardial infarction (13 of 16 patients) but were not seen in any of the 15 patients with unstable angina (P less than 0.01). CONCLUSIONS: Coronary-artery thrombi play an important part in the pathogenesis of unstable angina and acute myocardial infarction. However, the appearance of the thrombi is different in the two conditions, possibly reflecting differences in the composition of age of the thrombi or the presence or absence of blood flow in the artery. This difference may account for the contrasting results of thrombolytic therapy.

Angina Pectoris↗
PubMed1991

Initial results of laser angioplasty under angioscopic guidance for salvage of an ischemic lower limb: preliminary report.

From March to July 1989, nine patients at risk for peripheral artery disease underwent intraoperative Nd:YAG laser angioplasty using angioscopy at the Veterans General Hospital (Taipei, Taiwan, Republic of China). Following the laser angioplasty, balloon dilatation was performed in all cases. Eight men and one woman at an average age of 68 were included in the study (range: 58 to 78 years old). Ischemic symptoms included five patients with disabling claudication, four with pain at rest and one with gangrene on the toes. Eight of the nine patients had complete occlusions ranging from 2 to 19 cm in length. Two patients had high degree multiple segmental stenosis of the superficial femoral artery from 1 to 2 cm in length. Initial clinical success (indicated by relief of symptoms and increase in Doppler ankle pressure and index) and improvement in the angiographic luminal diameter was noted in 9 of 10 occluded vessels (90%) that underwent Nd:YAG laser treatment which was delivered at 10 to 12 watts through laser probes. Prelaser intraluminal diameter increased from 0.05 +/- 0.07 to 0.53 +/- 0.07 mm, Doppler ankle pressure index rose from 0.51 +/- 0.12 to 0.81 +/- 0.12, Doppler ankle pressure increased from 62.44 +/- 16.10 to 104 +/- 21.21 mmHg and the amplitude of pulse volume recorder at ankle level rose from 5.77 +/- 2.80 to 12.11 +/- 2.77 mm as compared with prelaser therapy (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2006

Angioscopic differences in neointimal coverage and in persistence of thrombus between sirolimus-eluting stents and bare metal stents after a 6-month implantation.

AIMS: The neointimal coverage and intracoronary thrombi within stented segments at 6 months after implantation between sirolimus-eluting stents (SESs) and bare metal stents (BMSs) were compared by direct visualization using angioscopy. METHODS AND RESULTS: Forty-six patients (36 stable angina and 10 acute coronary syndrome) were treated with 33 SESs and 33 BMSs. Immediately after and 6 months after stenting, each of the stented segments, edge body, and overlapping segment were observed by angioscopy and the grade of neointimal coverage over the stents was classified as 0: absent neointima, 1: visible struts through thin neointima, or 2: invisible struts. The existence of thrombi was also evaluated. The average grade of the neointimal coverage at 6 months follow-up was lower in the SES than that in the BMS (edge: 1.4+/-0.7 vs. 1.9+/-0.2, body: 1.0+/-0.5 vs. 1.8+/-0.5, overlapping segment: 0.6+/-0.7 vs. 1.8+/-0.5; P<0.0001, P<0.0001, P=0.0069, respectively). The frequency of persistence of thrombus was significantly higher in the SESs than that in the BMSs (86 vs. 29%, respectively; P=0.031). CONCLUSION: The present study suggested a delayed neointimal stent coverage and slower thrombus disappearance process in the SESs in comparison to the BMSs.

Aged↗
PubMed1994

Intracoronary ultrasound and angioscopic imaging facilitating the understanding and treatment of post-infarction angina.

We report on the use of intravascular ultrasound, coronary angioscopy and on-line quantitative angiography in an unstable patient soon after myocardial infarction. Combined intracoronary imaging made it possible to solve the therapeutic problem posed by an unusual angiographic appearance secondary to intracoronary thrombolysis during coronary recanalization. The pathological validation of the observations performed with angioscopy and intravascular ultrasound was made possible with the concomitant use of directional atherectomy.

Angina Pectoris↗
PubMed1995

Intraoperative coronary artery dilatation with angioscopic guidance.

The use of intraoperative balloon dilatation during coronary artery bypass surgery has been limited due to relatively unpredictable and potentially damaging results. The development of fiberoptic angioscopy permits safe visualization of the interior of coronary arteries and may be a valuable adjunct to intraoperative balloon dilatation. A 56-year-old male underwent four vessel coronary grafting with progressive intraoperative balloon dilatation of a second more distal stenosis of the left anterior descending coronary artery. Angioscopy was used to determine optimal balloon sizing and allowed visualization of associated intimal changes that occurred during the procedure, resulting in a successful outcome for this patient.

Angioplasty, Balloon, Coronary↗
PubMed2001

Angioscopic evaluation of the effect of estrogen on ovariectomized Japanese monkeys.

Using angioscopy to study the atheroprotective effect of estrogen, atherosclerotic changes in surgically postmenopausal Japanese monkeys were observed for a long period. Changes in serum lipids and estradiol were also followed. About 3-6 months after the 2% cholesterol diet, serum cholesterol increased up to three times normal value, and atheroma was first found at the orifice of major branches of the abdominal aorta. However, in the other group of 2% cholesterol including an oral estrogen diet, the appearance of atheroma was inhibited until 12 months, although serum cholesterol increased gradually. The chronologic investigation was continued over 3 years. From these results we concluded that the most important atheroprotective effect of estrogen is the direct inhibition of atherosclerosis in the arterial wall, and improvement in lipid metabolism is of secondary importance.

Animals↗
PubMed2002

In vivo quantitative tissue characterization of human coronary arterial plaques by use of integrated backscatter intravascular ultrasound and comparison with angioscopic findings.

BACKGROUND: The purpose of the present study was to define whether integrated backscatter (IB) combined with conventional intravascular ultrasound (IVUS) makes tissue characterization of coronary arterial plaques possible. METHODS AND RESULTS: IB-IVUS was performed in coronary arteries (total 18 segments) of 9 patients at autopsy, and the findings were compared with the histology. RF signals, which were digitized at 2 GHz in 8-bit resolution, were obtained with an IVUS system with a 40-MHz catheter. IB values of the RF signal from the region of interest (ROI) (100-microm depth, 1.4 degrees per line) were calculated by use of a personal computer. IB values on the ROIs were divided into 5 categories, compared with each of the plaque histologies: category 1 (thrombus), -88 < IB < or = -80; category 2 (intimal hyperplasia or lipid core), -73 < IB < or = -63; category 3 (fibrous tissue), -63 < IB < or = -55; category 4 (mixed lesions), -55 < IB < or = -30; and category 5 (calcification), -30 < IB < or = -23. On the basis of these categories, we analyzed 5120 ROIs per segment in each ring-like arterial specimen. Color-coded maps of plaques were constructed by use of these IB data and conventional IVUS data, which reflected the plaque histology of autopsied coronary arteries well. Then, the same method was undertaken in 24 segments with plaque from 12 patients in vivo with angina pectoris. Comparisons between coronary angioscopy and IB-IVUS revealed that the surface color of plaques in angioscopy reflected the thickness of the fibrous cap rather than the size of the lipid core. CONCLUSIONS: IB-IVUS represents a new and useful tool for evaluating the tissue structure of human coronary arterial plaques.

Aged↗
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↗
PubMed2006

Sustained attenuation of neointimal coverage over the stent following brachytherapy for in-stent restenosis: angioscopic findings.

BACKGROUND: The nature of the vessel lumen following vascular brachytherapy (VBT) has not been extensively explored in the clinical setting. METHODS AND RESULTS: By using angioscopy, 33 stents treated with percutaneous balloon angioplasty with or without VBT for in-stent restenosis after 8.9 +/- 2.1 months of the treatment were followed (VBT =14 lesions; control =19 lesions). Neointimal coverage, stent attachment, and the presence of red or white thrombi were factors that were assessed. The majority of the stents (74%) were fully covered with non-transparent neointima in the control group. In contrast, stent struts were clearly seen in 57% lesions with VBT. The absence of neointima with glittering stent struts were only seen in 29% of lesions in VBT (p = 0.03). Incomplete stent attachment was not detected in the controls, whereas 14% were in VBT (p = 0.17). Red thrombi were observed in 14% with VBT and in 16% in controls, which showed that there was a similar incidence regardless of the treatment. Neither exposure of stent struts (p = 0.5) nor incomplete stent attachment (p = 1.0) was related to thrombi. CONCLUSIONS: The exposure of stent struts and incomplete stent attachment were occasionally observed by angioscopy even 9 months after VBT for the treatment of in-stent restenosis.

Aged↗
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↗