Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Angioscopes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed1991

Histopathologic validation of angioscopy and intravascular ultrasound.

BACKGROUND: To establish a histopathologic basis for angioscopic and ultrasound image interpretation we studied 70 postmortem human arterial segments in vitro. METHODS AND RESULTS: We used 7- to 9-French fiber-optic angioscopes and 20- to 30-MHz intravascular ultrasound imaging catheters. Three observers assigned an angioscopic and ultrasound image classification to each vessel segment. The image and histological classification categories were then compared. The sensitivity, specificity, and accuracy of both methods separately or in combination for normal vessels were each greater than or equal to 95%. The predictive value was better for angioscopy than for ultrasound due to incorrect ultrasound interpretations of normal anatomy in the presence of thrombus. For stable atheroma the sensitivity, specificity, and accuracy of the individual methods were each greater than 90%. However, both angioscopy and ultrasound had classification errors in that disrupted atheroma was identified and classified as stable atheroma. Consequently, the predictive value was 74% for angioscopy and 78% for ultrasound. For disrupted atheroma the sensitivities for angioscopy and ultrasound were only moderate (73% and 81%, respectively), whereas the specificity, accuracy, and predictive value were each high (greater than 90%). For thrombus detection, the specificity, accuracy, and predictive value were high (greater than 93%) for each method. The sensitivity of angioscopy was 100%. However, sensitivity was lower for ultrasound (57%) due to false-negative interpretation of laminar clots in normal vessels and an inability to distinguish disrupted or stable atheroma from intraluminal thrombus. CONCLUSIONS: Contingency analyses showed that each imaging method alone or combined had significant agreement with the results obtained from histology (p less than 0.001). When assessing all cases in which angioscopy and ultrasound were concordant, there was a 92% agreement with the histological classification.

Coronary Artery Disease↗
PubMed1995

Ischemia-related lesion characteristics in patients with stable or unstable angina. A study with intracoronary angioscopy and ultrasound.

BACKGROUND: Postmortem-derived findings support the common beliefs that lipid-rich coronary plaques with a thin, fibrous cap are prone to rupture and that rupture and superimposed thrombosis are the primary mechanisms causing acute coronary syndromes. In vivo imaging with intracoronary techniques may disclose differences in the characterization of atherosclerotic plaques in patients with stable or unstable angina and thus may provide clues to which plaques may rupture and whether rupture and thrombosis are active. METHODS AND RESULTS: We assessed the characteristics of the ischemia-related lesions with coronary angiography and intracoronary angioscopy and determined their compositions with intracoronary ultrasound in 44 patients with unstable and 23 patients with stable angina. The angiographic images were classified as noncomplex (smooth borders) or complex (irregular borders, multiple lesions, thrombus). Angioscopic images were classified as either stable (smooth surface) or thrombotic (red thrombus). The ultrasound characteristics of the lesion were classified as poorly echo-reflective, highly echo-reflective with shadowing, or highly echo-reflective without shadowing. There was a poor correlation between clinical status and angiographic findings. An angiographic complex lesion (n = 33) was concordant with unstable angina in 55% (24 of 44); a noncomplex lesion (n = 34) was concordant with stable angina in 61% (14 of 23). There was a good correlation between clinical status and angioscopic findings. An angioscopic thrombotic lesion (n = 34) was concordant with unstable angina in 68% (30 of 44); a stable lesion (n = 33) was concordant with stable angina in 83% (19 of 23). The ultrasound-obtained composition of the plaque was similar in patients with unstable and stable angina. CONCLUSIONS: Angiography discriminates poorly between lesions in stable and unstable angina. Angioscopy demonstrated that plaque rupture and thrombosis were present in 17% of stable angina and 68% of unstable angina patients. Currently available ultrasound technology does not discriminate stable from unstable plaques.

Adult↗
PubMed1992

Angioscopy in endovascular surgery: recent technical advances to enhance intervention selection and failure analysis.

Recent technical and procedural modifications have greatly enhanced the usefulness of angioscopy during angioplasty. A pulsed irrigation system, proximal and distal blood flow control by pressure, and attention to sheath/vessel diameter ratio were incorporated into a study in which angioscopy was used for pretreatment assessment in 23 patients with symptomatic peripheral vascular disease presenting for initial (8 patients) evaluation or repeat treatment (15 patients) following a previous vascular procedure. Twenty-five lesions were examined with a 2.3 mm flexible angioscope equipped with an irrigating lumen; there were no complications attributable to angioscopy. The angioscope was useful in the characterization of lesions for selection of the recanalization technique. Lesions more amenable to initial atherectomy were visualized in 12 patients; 7 occlusions were successfully treated with laser/balloon angioplasty, with angioscopy assisting in probe and/or wire passage in 4 cases. Three late reocclusions were identified angioscopically as due solely to thrombosis, indicating the need for thrombolytic therapy. Angioscopy also identified 4 cases of incomplete recanalization despite a satisfactory arteriographic image. Angioscopy was also used to evaluate stenotic lesions unaccompanied by thrombus formation in patients previously treated with laser-assisted angioplasty. Histologic evaluation of the biopsied plaques identified intimal hyperplasia as the etiology, matching identically similar specimens harvested from a lesion treated with balloon dilation only.

Aged↗
PubMed2001

Preliminary report of a new approach to sparing the greater saphenous vein for grafting: valvuloplasty combined with axial transposition of a competent tributary vein.

PURPOSE: To compare a new vessel-sparing technique combining valvuloplasty with axial transposition of a competent tributary vein versus single valvuloplasty for the treatment of greater saphenous vein (GSV) incompetence. METHODS: In 55 patients with GSV incompetence, 29 of 57 limbs were treated by angioscopic valvuloplasty of the subterminal valve alone, whereas the remaining 28 limbs underwent angioscopic valvuloplasty combined with axial transposition of a competent tributary vein identified preoperatively by duplex scanning. After angioscopic valvuloplasty in the latter group, the competent tributary vein was exposed and cut 1.5 cm distal to its insertion point on the GSV. The transected vein was anastomosed end to side to the GSV, which was ligated between the tributary insertion site and the anastomosis. Changes in venous hemodynamics, including venous filling index (VFI), ejection fraction (EF), and residual volume fraction (RVF), were analyzed by use of air plethysmography. RESULTS: In the 1-year follow-up, no venous thrombosis was detected in either group. In the valvuloplasty-only group, 22 (75.9%) limbs exhibited reflux in the proximal GSV; recurrent varicose veins were detected in 5 (17.2%) limbs. In contrast, only 2 (7.1%) limbs showed reflux in the valvuloplasty + transposition group. There were no significant differences in EF and RVF between the groups before or after the operation, although a significant difference was seen in VFI at 1 year (p = 0.005, Wilcoxon rank sum test). CONCLUSIONS: Valvuloplasty combined with tributary vein transposition gives a better result than valvuloplasty alone at 1 year. This new treatment option may be useful for both reducing the rate of varicose veins and sparing the GSV for grafting.

Adult↗
PubMed1993

Clinical application of angioscopy during carotid endarterectomy for patients with internal carotid artery stenosis.

The accuracy of angioscopy in detecting atherosclerotic changes, such as plaque, ulcer, and mural thrombus, in the extracranial cerebral arteries was evaluated during carotid endarterectomy by comparison with angiographic and operative findings. Ten patients with internal carotid artery stenosis underwent intraoperative angioscopy during surgery. After clamping the carotid bifurcation, intra-arterial atherosclerotic lesions were observed with an angioscope (0.8 or 1.4 mm outer diameter) inserted through a small incision in the common carotid artery. Angioscopic findings correlated well with both angiographic and operative findings in six patients, and provided additional information in two patients, such as organized thrombi within the ulcer and mural thrombi. Angioscopic findings were quite different to those from angiograms in two patients. In one, an ulcer on angiograms was false positive, and in the other, false negative. These findings were confirmed intraoperatively. Our results suggest that preoperative carotid angioscopy is of great value in detecting ulcers more accurately than angiography, and in selecting candidates for carotid endarterectomy, although further development of equipment is needed.

Adult↗
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↗
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↗
PubMed1993

Preliminary experience of angioscopy in femorodistal bypass.

During femorodistal bypass angioscopy can be used in vein graft preparation allowing valve lysis and the identification of tributaries under direct vision. A total of 30 patients have undergone angioscopic assisted femorodistal bypass using either an Olympus or Stortz system. Nineteen patients have undergone full vein mobilisation and valve lysis under direct vision. Eleven patients had in situ bypass with ligation of tributaries, identified by the angioscope, through small stab incisions. No evidence of fistula or retained valve cusps was found by subsequent duplex scanning and arteriography. One of these grafts failed at 6 days due to an unrecognised outflow stenosis. The mean hospital stay after operation for this latter group of patients was 5.2 days (range 4.4-6.0 days) compared with 9.5 days (8.6-10.3 days) in a historical group of 30 patients (P < 0.001). Angioscopy is a useful aid in the performance of femorodistal bypass. Early experience suggests that hospital stay may be reduced by angioscope assisted in situ femorodistal bypass because of the minimal dissection involved.

Adult↗
PubMedDate not supplied

[Video-assisted venous surgery].

The use of intraoperative angioscopy, till now utilized exclusively in arterial surgery, is now used also in venous surgery. From January 1992 54 patients underwent to video-guided venous surgery: 23 cases of external valvuloplasty of the sapheno-femoral junction (EV-SFJ), 25 cases of hemodynamic correction of varicose veins (French acronyms CHIVA), 5 cases of high ligation plus long saphenous vein intraoperative sclerotherapy (HL-IS) 1 case of sub-fascial perforators interruption (SPI), the only extraluminal videoguided procedure. We have used 3 different video-angioscopes: a 1 mm monofibroscopy let in a 6 Fr Fogarty catheter, a disposable 2,8 mm colangioscope and a 2,2 mm operative angioscope. For the perforators interruption we have utilised the thoracoscope. EV-SFJ: the angioscopy has confirmed the presence of normal valvular cusps in a dilated vein wall in 21 cases, so excluding 2 patients from the planned treatment. At the end of the operation the angioscope has verified the reapproach of valvular cusps. CHIVA: the angioscopy has allowed to identify the exact points of the superficial venous system which should be interrupted, according to the Franceschi's theory. This procedure can avoid the technical errors due to intraoperatory misleadings of the duplex mapping. HL-IS: consists of a classic high ligation followed by long saphenous vein intraoperative sclerotherapy. The angioscopy has allowed a complete deconnection of the long saphenous vein from tributaries and perforators. Furthermore has facilitate the proportional distribution of the sclerosing agent along the long saphenous vein. SPI: the videoassistance have permitted the identification of the insufficient perforating veins reducing their surgical exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioscopy↗
PubMed1996

Sapheno-femoral valves. Histopathological observations and diagnostic approach before surgery.

BACKGROUND: Since the literature indicated that in the early stages of primary venous disease valves are simply dilated, some authors performed external valvuloplasty of deep and superficial venous valves with encouraging results, although some failures were observed without being sufficiently explained. OBJECTIVE: To obtain further interpretations of the natural history of venous valve pathology, clarify methods for a correct diagnostic approach, and provide indications for the external valvuloplasty procedure. METHODS: Forty-two proximal valves of the long saphenous vein removed for varicose veins of the lower limbs were studied with optical microscopy. The relationship between histologic alterations and age of varicose disease was investigated. Five valvuloplasties were explanted for recurrent reflux and submitted to histopathological observation. Preoperative echographic findings and histologic observations were compared. Nineteen limbs were subjected to external valvuloplasty under angioscopic control; preoperative echographic findings and angioscopic observations were compared. RESULTS: The histologic alterations observed in venous valves were mainly hypotrophy of cusps, which seemed to be the main cause of failure after external valvuloplasty. The frequency of such hypotrophic alterations increases with the age of varicose disease but no statistically significant relationship was found. Preoperative echographic imaging of venous valves does not appear sufficiently predictive when compared with histologic and angioscopic examinations. CONCLUSION: Hypotrophic valve damage seems to be prevalent in patients with varicose veins of the lower limbs. Valve cusp hypotrophy may be present in early disease though some normal cusps can be found in advanced disease. When preoperative echographic visualization of cusps is doubtful, intraoperative angioscopy plays the main role in the diagnosis of venous valve disease before and during external valvuloplasty.

Angioscopy↗
PubMed1994

[The present state of arts and the future prospects of coronary angioscopy].

The angioscope catheter is 1.55 mm in outer diameter and 1.2 m in length. This distal end is tapered, therefore its outer diameter decreased to 1.1 mm. It has an inflatable balloon at the distal tip and four circular channels. Through one of the lumina, 0.014 inch PTCA guide wire can be used. The steerable guide wire enable the angioscope to be inserted to the target lesion safely and accurately. Recently we investigated the appearance of coronary artery in acute coronary syndromes. The results have indicated that thrombi, intimal irregularities, and xanthomatous atheromas were observed more frequently in patients with acute myocardial infarction, recent myocardial infarction and unstable angina. It is concluded that a thrombus overlying a rupture in the lining of plaque plays a major role in an acute coronary disorders, and that the fragile, lipid-rich gruel atheroma may procede its rupture. Coaxial alignments of the coronary artery were obtained in more than 80% of attempted patients. However, a finer controllable distal tip to allow good coaxial alignment and a larger balloon to reduce the coronary good flow and make the angioscopic catheter easier to track, are necessary for more complete visualization.

Angioscopy↗
PubMed1998

[Complications after treatment of acute coronary syndrome].

The rupture of the unstable plaque and the thrombus formation caused the occlusion of the coronary artery and followed myocardial ischemia and/or myocardial necrosis, then resulted in clinical worse outcome. The reopen of the occluded artery is the most important things for the treatment of acute coronary syndrome, and there are usually two established ways to open the occluded artery. Thrombolysis and angioplasty are already established ways to reopen, however has some complications, that is, failure to reopen, reocclusion, and bleeding. Angioscopic observations reveal the mechanism underlying these complications and suggest that platelet rich white thrombus formation continues until a month after the onset and unstable yellow plaques exist until 18 months after the onset. The most problems for the treatment in today are the unaware of the mechanism of the occlusion. If the thrombus is the major mechanism for the occlusion, thrombolytic therapy must be chosen. If the plaque is the major occlusive mechanism, the angioplasty must be chosen. To reveal the mechanisms underlying the coronary artery occlusion, we will have to use the angioscope instead of coronary angiography. After we will be able to clarify the occlusive mechanism by angioscope, we will reduce the dosage of thrombolytic agents and resulted in the decrement of bleeding complications and reopen the coronary artery effectively without complications.

Acute Disease↗
PubMedDate not supplied

Quantitative angioscopy: a novel method of measurement of luminal dimensions during angioscopy with the use of a "lightwire".

PURPOSE: To determine the accuracy and reproducibility of luminal dimension measurements of a newly developed method of quantitative angioscopy. METHODS: A method was developed for quantitation of luminal dimensions during angioscopy, as variation in magnification with lens-object distance and ambiguity associated with identification of corresponding points about the circumference of a given discrete cross-section render subjective estimates unreliable. A transverse ring of fiberoptically transmitted light was emitted from a guidewire or its housing at a known distance from the distal end of an angioscope and discrete cross-sections of interest were observed as the ring of light was reflected from the luminal surface. Caliper measurement of the diameter of the light ring image (< 50 mW at 488/515 nm), obtained on angioscopic video recordings of cylindrical phantom vessels of known dimensions, was performed by three observers on five occasions. RESULTS: The mean absolute difference between measured and known luminal diameter (n = 405 observations) was 65 microns +/- 35 microns and the mean coefficient of variation was 4.2%, and the mean difference between measured and known areas (n = 195 observations) was 0.4 mm2, with a mean coefficient of variation of 6.5%. CONCLUSION: By use of this new lightwire method, luminal dimensions can now be measured in vitro with a high degree of accuracy and reproducibility during angioscopy.

Angioscopes↗
PubMed1993

Intraoperative coronary angioscopy--technique and results: a study of 38 patients.

Over a period of 11 months, 38 patients submitted to coronary artery revascularization underwent intraoperative angioscopy of the coronary arteries and internal thoracic arteries. Fifty-nine lesions were observed, but only 31 stenoses responsible for coronary insufficiency were observed (33%). Forty-four distal anastomoses were explored (47%) but ten of these explorations were incomplete. None revealed technical failure of the anastomosis. Thirteen harvested left internal mammary arteries were explored. One of the explorations led to rejection of the graft due to an intimal fracture. Some tiny intimal flaps were observed in our experience, as in others. Although the iatrogenic origin of these lesions in relation to the introduction of the angioscope is obvious, it does not seem to influence the outcome of the operation. In our opinion, two main fields appear to be developing in coronary angioscopy: preoperative assessment of the quality of internal thoracic artery grafts, and control of distal graft anastomoses. The flexibility of the angioscopes and of the leading catheters must be improved to minimize the risk of arterial wall traumatic lesions.

Angioscopes↗
PubMed1993

[Technique for endoscopic vein preparation in infra-inguinal in situ bypass].

In situ saphenous vein bypass for infrainguinal reconstructions achieves excellent results, especially for distal anastomoses. The achilles heel of the method is the complete and atraumatic disruption of the valves and the location of significant tributaries of the saphenous vein. An intraoperative quality control is necessary to mend early patency rates. Several control instruments are described: intraoperative arteriography, duplex- or Doppler sonography and angioscopy. We describe the technique of a semiclosed angioscopy guided technique with a novel flushing valvulotome. We use an angiofiberscope with 2.2 or 1.4 mm outer diameter, being introduced through the proximal exposed end of the saphenous vein. Through the distal end or a side branch a modified Mill's valvulotome with a flushing channel (flexible or non flexible) is moved upwards to the angioscope. Every valve cusp is incised under direct vision in a retrograd direction. Simultaneously relevant tributaries are angioscopically located and ligated through small skin incisions. To use the potential of angioscopy we have developed the occluder valvulotome, making endoluminal embolization of tributaries of the saphenous vein possible. Details of these techniques are described.

Angioscopes↗
PubMed1984

Angioscopy in vivo.

Recent developments in optical instrumentation have made possible the direct, three-dimensional viewing of intravascular structures. Using an angioscope (the Trimedyne Optiscope, Trimedyne Inc., Santa Ana CA) and a xenon cold lamp (the Xenon Cold Light Fountain, Karl Storz Endoscopy America, Inc., Culver City, CA), the authors have visualized, without complications, the normal orifices of various arteries and their bifurcations in 12 dogs, the atherosclerotic aortas of eight post mortem humans, and the coronary arteries of six post mortem humans. Potential applications of the instruments include more accurate diagnosis of occlusive diseases of the blood vessels, evaluation of such interventional procedures as angioplasty, intraoperative assessment of anastomoses, and safer laser surgery. The angioscope also enables the physician to combine pressure recording and dye injection simultaneously with the visualization of the inner walls of the vessels.

Animals↗
PubMed1992

The natural history of intimal flaps caused by angioscopy.

UNLABELLED: This study tried to determine the natural history of angioscopy-induced arterial intimal flaps as assessed by video angioscopy, light and transmission electron microscopy. Eight mongrel dogs were anesthetized and bilateral femoral and carotid arteries surgically exposed. A 3.0 mm American Edwards angioscope was inserted into each artery and passed vigorously until an intimal flap was visualized by angioscopy. The location of intimal flaps was externally marked with 6-0 polypropylene adventitial sutures. Animals were then recovered and follow-up angioscopy performed at one, two, three, and four week intervals. Following repeat angioscopy, all animals were sacrificed and vessels perfusion-fixed in situ with 2.5% glutaraldehyde in 0.1 M sodium cacodylate. A total of 37 intimal injuries were created (immediate, n = 10; one week, n = 8; two weeks, n = 4; three weeks, n = 8; four weeks, n = 7). No arterial thrombosis occurred following intimal flap formation. Only one of 37 (2.7%) lesions progressed to a hemodynamically significant stenosis. Histology of immediate lesions demonstrated deep intimal fractures extending into the tunica media. Complete healing of intimal flaps was observed by follow-up angioscopy in zero of eight lesions by one week, zero of four lesions by two weeks, one of eight lesions by three weeks, and four of seven lesions by four weeks (p = 0.02). Light and electron microscopy confirmed the angioscopic intimal fractures and regrowth of denuded endothelium. CONCLUSION: follow-up angioscopy and microscopy one month after angioscopy-induced arterial intimal trauma demonstrated a significant trend towards complete endothelial healing.

Animals↗
PubMed1992

Safety of saline irrigation for angioscopy: results of a prospective randomized trial.

This study evaluates the hemodynamic effects and safety of saline irrigation necessary to obtain high-quality completion angioscopic studies, as compared with standard completion arteriography during infrainguinal bypass grafting. One-hundred ten patients undergoing primary infrainguinal bypass grafting, were prospectively randomized to either arteriography (N = 50) or angioscopy (N = 60) for a completion study to monitor the bypass procedure. All patients were hemodynamically monitored with pulmonary artery catheters and arterial lines. The arteriography group received an average of 27 ml (range 8-60 ml) of contrast per completion study, with a total administered intraoperative fluid volume of 2095 ml (range 650-4000 ml). The angioscopy group received an average bolus of 321 ml (range 90-650 ml) of irrigation fluid per completion angioscopy study, with a total administered intraoperative fluid volume of 2140 ml (range 850-5000 ml). Transient increases in pulmonary artery systolic and diastolic pressures and central venous pressures were measured during angioscopy. Although these changes reached statistical significance, the changes were of minimal clinical relevance, 1.9 (= 4.5), 1.6 (= 3.0) and 1.4 (= 2.3) mmHg respectively, and returned to baseline levels within 30 minutes. Intraoperative intervention with vasodilators and diuretics, the perioperative cardiac morbidity, and less than 30 day mortality, was not different between the two groups. Pressures generated within 24 bypass grafts were within physiologic arterial range for most of the study. With careful angioscopic technique applied and high quality care extended to the patient, irrigation with saline solution is simple, effective and safe.

Angiography↗