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PubMed1995

Coronary angioscopy.

Coronary angioscopy will not replace angiography as the gold standard for imaging atherosclerotic coronary arteries. However, there may well be a clinical niche for a technology that gives accurate information regarding a specific lesion, if that information can be used to improve the acute or chronic outcome of an interventional procedure. Our experience demonstrates that angioscopy indeed provides this information. Using angioscopy, we now have access to information regarding arterial wall disease that heretofore has been available only at necropsy. In addition, whereas angiography has provided only a 2-dimensional, gray-scale image of the coronary vessels, angioscopy offers a full-color, 3-dimensional perspective of the intracoronary surface morphology. These important lesion-specific details, not reliably available from angiography alone, may ultimately be used to improve patient outcome and to assess risk.

Angioplasty, Balloon, Coronary↗
PubMed1994

Role of completion angioscopy in detecting technical error after carotid endarterectomy.

Completion fibreoptic angioscopy was performed in 30 consecutive patients after carotid endarterectomy. The aim was to evaluate the potential role of angioscopy as a quality-control technique. Major abnormalities (two initial flaps, two large thrombi) were identified in four patients and minor adherent thrombus was encountered in five. All abnormalities were corrected before restoration of flow. This preliminary experience suggests that completion angioscopy merits further study as a method for the intraoperative detection of potentially harmful lesions after carotid endarterectomy.

Angioscopy↗
PubMed2004

Atheromatous plaque cap thickness can be determined by quantitative color analysis during angioscopy: implications for identifying the vulnerable plaque.

BACKGROUND: Coronary angioscopy in acute myocardial infarction has frequently revealed disrupted yellow lesions. Furthermore, postmortem studies have demonstrated that these lesions have thin collagenous caps with underlying lipid-rich cores. HYPOTHESIS: We hypothesized that the yellow color is due to visualization of reflected light from the lipid-rich yellow core through a thin fibrous cap. Thus, quantification of yellow color saturation may estimate plaque cap thickness and identify vulnerable plaques. METHODS: To test this hypothesis, the feasibility of detecting cap thickness was tested using both a model of lipid-rich plaque and human atherosclerotic plaque. The model was constructed by injecting a yellow beta-carotene-lipid emulsion subendothelially into normal bovine aorta. Human plaque was obtained from cadaver aorta. Digitized images were obtained by angioscopy, and percent yellow saturation was analyzed using a custom computer program. Plaque cap thickness was measured by planimetry of digitized images on stained tissue sections. Percent yellow saturation was then correlated with plaque cap thickness. RESULTS: In the bovine model, plaque cap thickness and percent yellow saturation correlated inversely (r2 = 0.91; p = 0.0001). In human plaques, yellow saturation was significantly greater in atheromatous than in white plaques (p < 0.0004). Also, there was a high correlation between plaque cap thickness and yellow saturation at various angles of view between 40 degrees and 90 degrees, the greatest between 50 degrees and 80 degrees (r2 = 0.75 to 0.88). CONCLUSION: Plaque cap thickness is a determinant of plaque color, and this can be assessed by quantitative colorimetry. Thus, plaque color by angioscopy may be useful for detecting vulnerable plaques.

Angioscopy↗
PubMedDate not supplied

Percutaneous angioscopy: improved technique.

Ten angioscopies with a pressure infusion set resulted in similar visualization times and irrigation volumes as 42 angioscopies with a specially constructed roller pump. Diagnostic image quality, however, was obtained almost exclusively with the roller pump. Three examinations were nondiagnostic. Total viewing time per patient was approximately 1 min with the roller pump and 2 min with the pressure infusion system. In the 30 patients examined, angioscopy changed the initially chosen form of therapy in 5 patients.

Aged↗
PubMed1995

Prediction of acute coronary syndromes by percutaneous coronary angioscopy in patients with stable angina.

To pinpoint the link between plaque characteristics and acute coronary syndromes, we performed a 12-month prospective follow-up study in 157 patients with stable angina pectoris in whom regular coronary plaques were observed by percutaneous coronary angioscopy. Acute coronary syndromes occurred more frequently in patients with yellow plaque than in those with white plaques (11 of 39 vs 4 of 118; p = 0.00021). Moreover, the syndromes occurred more frequently in patients with glistening yellow plaques than in those with nonglistening yellow plaques (9 of 13 vs 2 of 26; p = 0.00026). Thrombus arising from the ruptured identical plaques was confirmed by angioscopy as the culprit lesion of the syndromes. The results indicate that acute coronary syndromes occur frequently and in a short time in patients with glistening yellow plaques and that angioscopy but not angiography is feasible for prediction of the syndromes.

Acute Disease↗
PubMed1994

Angioscopy after laser and balloon coronary angioplasty.

OBJECTIVES: Percutaneous intracoronary angioscopy was used to study the morphologic changes occurring in coronary arteries after balloon or laser angioplasty. BACKGROUND: Angioscopy is thought to provide details of the coronary vessel lumen and the inner wall. METHODS: Coronary lesions were studied in 44 patients with a 4.5F Imagecath angioscope before and after each interventional procedure. Balloon and laser angioplasty were performed in 21 (group I) and 23 patients (group II), respectively. There was no difference in age, gender or angiographic lesion appearance before the procedure between the two groups. RESULTS: Circumferential visualization of the target lesion was successfully completed in 17 group I and 19 group II patients. A larger lumen than that observed at baseline was seen in all 17 group I and in 13 of the 19 group II patients. Tissue remnants were observed in all group I and II patients. Laser irradiation resulted in characteristic sharp-edged craters. Dissection was identified in 2 of 19 patients before versus 9 of 19 patients after balloon angioplasty (p < 0.05) and in 0 of 23 patients before versus 4 of 23 patients after laser angioplasty (p = NS). Subintimal hemorrhage was observed in 3 of 19 patients before versus 11 of 19 patients after balloon angioplasty (p < 0.05) and in 2 of 23 patients before versus 4 of 23 patients after laser angioplasty (p = NS). The frequency of hemorrhage was higher in group I than in group II (11 of 19 vs. 4 of 23, respectively, p < 0.02). CONCLUSIONS: Angioscopy provides valuable information on lesion morphology after coronary interventions. Balloon dilation results in a high rate of dissection and subintimal hemorrhage. Laser angioplasty is able to ablate obstructing tissue and results in a lower rate of subintimal hemorrhage than balloon dilation.

Aged↗
PubMed1997

Heterogeneity of cardiac allograft vasculopathy: clinical insights from coronary angioscopy.

OBJECTIVES: With this study, we sought to examine the heterogeneity of cardiac allograft vasculopathy in vivo using coronary angioscopy as an adjunct to intravascular ultrasound, and we evaluated the clinical relations of immunologic and nonimmunologic risk factors with the different forms of cardiac allograft vasculopathy detected angioscopically. BACKGROUND: Intravascular ultrasound detects vascular intimal proliferation accurately but is limited in its ability to delineate morphologic characteristics. Coronary angioscopy can evaluate intimal surface morphology by direct visualization and can differentiate pathologically distinct forms of plaque topography on the basis of color and contour. METHODS: We studied 107 consecutive heart transplant recipients with intravascular ultrasound and angioscopy at the time of their annual angiogram, and we assessed the relation of nonimmunologic and immunologic risk factors to the development of cardiac allograft vasculopathy distinguished angioscopically into a pigmented (yellow) or nonpigmented (white) intimal thickening. We further evaluated the clinical differences in cardiac events among these two forms of angioscopically heterogeneous forms of cardiac allograft vasculopathy. RESULTS: Significant clinical predictors of nonpigmented intimal thickening were advanced donor age and lower mean cyclosporine levels, whereas hyperlipidemia, cumulative prednisone dose and time since transplantation correlated with pigmented intimal hyperplasia. In addition, comparisons between the two angioscopic groups revealed increased intimal thickening, serum cholesterol, low density lipoprotein cholesterol, acute allograft rejection and time since transplantation in the group with pigmented intimal thickening (p < 0.05). With regard to cardiac events, nonpigmented plaque was more frequently found in the sudden death group (53% vs. 20%, p = 0.05), whereas the nonsudden cardiac event group had a significantly higher prevalence of pigmented plaque (80% vs. 47%, p = 0.07). CONCLUSIONS: These findings indicate that cardiac allograft vasculopathy is a heterogeneous disease with varied morphologic expressions with different clinical implications. Furthermore, this investigation provides insight into the cohesive, yet diverse influences of various factors, particularly immunosuppression, in these forms of cardiac allograft vasculopathy.

Adult↗
PubMed1994

Intraoperative control following femorodistal revascularization: angioscopy is superior to angiography.

Intraoperative angioscopic control was performed in an early series of 27 patients undergoing peripheral vascular surgery. The majority were complex or re-do operations; reversed saphenous vein and PTFE-grafts were used as bypass material exclusively. Angioscopic findings were compared to conventional angiography with respect to the detection of technical problems leading to further surgical procedures. Angioscopy was feasable in 92.5%, it failed twice due to irrigation problems, which was before we used a dedicated angioscopy roller-pump. In 6 patients relevant findings requiring further surgical manipulations were only detected angioscopically, in 2 patients such findings were detected by angioscopy as well as by angiography. Such findings included technical problems (graft rotation [n = 1], anastomotic narrowing [n = 2]), balloon catheter injuries after thromboembolectomy (n = 2) and residual thrombi after local thrombectomy (n = 3); 5 of these patients had undergone previous vascular procedures in the same operation field. After local correction (n = 5) or placement of a new bypass (n = 3) there was no early graft failure. This early angioscopic experience confirmed previous reports that satisfactory visualization and specific recognition of angiographically unsuspected problems after peripheral reconstructions can be obtained by intraoperative angioscopic control. This was seen very distinctively in more complex and re-do operations, which we see as the cases most needing routine angioscopic control.

Aged↗
PubMed1993

An alternative method of salvaging occluded suprainguinal bypass grafts with operative angioscopy and endovascular intervention.

PURPOSE: A study of technical feasibility was undertaken to determine whether angioscopy and parallel endovascular instrumentation could effectively evaluate and restore inflow into occluded suprainguinal grafts. METHODS: Several endobronchial instruments were selected for adaptation for use in clearing occluded grafts under angioscopic guidance. These instruments were used in the treatment of 12 thrombosed grafts limbs in 10 patients who were admitted 1 to 40 days after occlusion. The occluded suprainguinal graft limbs were exposed just proximal to the femoral anastomosis. Blind retrograde balloon thrombectomy and clot extraction were performed. Graft limbs underwent angioscopy, and the presence of luminal defects were recorded. Endoluminal instruments were then inserted parallel to the angioscope, and luminal defects were corrected. After inflow was reestablished, the distal portion of the graft was thrombectomized, and any necessary distal revisions were performed. RESULTS: Blind retrograde thrombectomy was successful in restoring inflow deemed normal in (67%) eight of 12 graft limbs and present but diminished in two (17%) graft limbs. Balloon thrombectomy was ineffective in restoring graft flow in two (17%) graft limbs. Angioscopy revealed luminal defects in 10 (83%) graft limbs after blind retrograde thrombectomy. Only 2 (17%) graft limbs had no luminal defects after thrombectomy. Findings included pseudointimal flap in eight of 12 (67%), adherent residual thrombus in 4 (33%), and kinked graft limbs in 2 (17%) graft limbs. Endovascular instrumentation was successful in resecting all luminal disease under angioscopic guidance. There were no deaths, no episodes of graft injury or distal embolization, and only one groin hematoma. During a mean follow-up period of 6 months (2 to 13 months), there was one late reocclusion at 7 months. CONCLUSION: We conclude that angioscopically guided thrombectomy and endovascular graft revision is a useful approach to the treatment of the occluded suprainguinal graft. Enhanced luminal visualization permits refined diagnostic assessment and definitive therapy. This may prolong the benefit of suprainguinal reconstructions.

Aged↗
PubMed1999

Angioscopy-assisted aneurysm clipping.

OBJECTIVE: To test the concept that endovascular angioscopy can assist surgical intracranial aneurysm clipping by providing an endoluminal view of the aneurysm-parent vessel complex. METHODS: A carotid bifurcation aneurysm was surgically created in a dog at the lingual artery origin. A balloon catheter was inflated proximal to the aneurysm to block proximal blood flow and allow endoluminal visualization. A flexible angioscope connected to a video monitoring system and to a high-intensity light source was then advanced within the catheter lumen and positioned immediately distal to the catheter tip. The aneurysm neck was clipped, and the clip was repositioned several times along the neck, with or without distal parent vessel compromise. Each time, the endovascular image on the monitor was interpreted by an observer blinded to the position of the clip. Clip position and image interpretation were communicated independently to a third person, who analyzed the correlation between them. RESULTS: Angioscopy allowed clear visualization of the extent of aneurysm neck occlusion (complete, incomplete, residual "dog ear") after clip application, as well as the presence or absence of distal parent vessel compromise. Aneurysm neck configuration, size, presence of thrombus, and suture line definition were depicted. Critical structures external to the aneurysm-parent vessel complex were transilluminated by the high-intensity lamp. CONCLUSION: Although acknowledged as the treatment of choice for intracranial aneurysms, surgical exclusion can be accompanied by significant morbidity related to perforator occlusion, parent artery compromise, and/or persistent residual aneurysm. The availability of a device allowing visualization of an aneurysm from an endoluminal perspective theoretically could reduce the incidence of these complications. Angioscopy has the potential to become a useful adjunct during intracranial aneurysm clipping because it provides real-time endoluminal viewing of the aneurysm-distal parent vessel complex, which is sometimes obscured to the surgeon.

Angioscopy↗
PubMed1995

Intraoperative angioscopy for coronary bypass surgery.

Despite advances in coronary artery surgery, technical abnormalities remain a significant cause of early graft closure. The development of small fiberoptic angioscopes now allows direct intravascular magnified examination. Seventy-five distal anastomoses and vein grafts, and five selected coronary arteries were examined with 0.8- to 2.5-mm diameter angioscopes introduced through the proximal vein graft while irrigating with clear cardioplegia. Angioscopic findings were correlated with angiographic data, vessel morphology, graft flow, and postoperative course. Satisfactory images were obtained in 72 of 75 anastomotic inspections. Each examination took less than 2 minutes and required less than 100 cc of flush. Angioscopic abnormalities that did not require revision were noted in 17 of 72 anastomoses; intimal flaps in 9, thrombus on posterior wall plaque in 4, intimal irregularities in 4, bucking of posterior wall in 3, and valve near anastomoses in 1. No outflow obstruction nor misplaced sutures were noted. Average flow rate through the grafts with anastomotic angioscopic abnormalities was 33 cc/min versus 40 cc/min in the remaining grafts. However, regression analysis revealed that low-graft flow was correlated with vessel size and runoff but was not with angioscopic findings. Intracoronary angioscopy revealed discrepancy with angiographic findings in 4 of the 5 examinations. No complications occurred as a result of angioscopy. No graft closure has occurred during early follow-up. Intraoperative angioscopy can be done with minimal alteration of the usual routine. The 24% occurrence of minor angioscopic abnormalities did not appear to compromise graft flow or early patency.

Angioscopy↗
PubMed2002

Virtual angioscopy using 3-dimensional rotational digital subtraction angiography for endovascular assessment.

PURPOSE: To investigate the feasibility of 3-dimensional rotational digital subtraction angiography (3D DSA) and the creation of virtual angioscopic images from its data before and after endovascular treatment. TECHNIQUE: Data sets from 3D DSA studies were used to create intraluminal images simulating angioscopy for 36 patients with arterial stenosis, aneurysm, or endoleak after stent-graft deployment. A biplanar DSA unit was used to acquire rotational angiography data, which was then processed with a surface-rendering technique to create maximum intensity projections, shaded surface displays, multiplanar reconstructions, and virtual angioscopy. 3D reconstructions were created in 2 minutes after angiography and provided realistic views adequate for vessel measurement, morphology assessment, and endoleak evaluation. CONCLUSIONS: 3D DSA and virtual angioscopy are novel techniques that have been successful in recreating images of blood vessels immediately after angiography. These techniques could be useful as additional imaging modalities to complement computed tomography or magnetic resonance imaging in the evaluation of vascular diseases after endovascular therapy.

Angiography, Digital Subtraction↗
PubMed1998

Virtualized angioscopy of the thoracic aorta in a rabbit model of atherosclerosis.

The purpose of this study was to apply virtual reality technology to spiral computed tomographic (CT) angiogram images in a rabbit model of atherosclerosis and to correlate the images with histopathologic evaluation of the aorta. Image data were transferred to the virtual endoscope system in a graphics workstation. "Virtualized angioscopy" includes an interactive graphic user interface, which controls the viewpoint, the direction of the observation, and rendering and navigation functions. The virtual angioscopy system demonstrated irregularities of the luminal surface of the ascending aorta and a smooth luminal surface in the descending aorta. These observations were correlated with histopathologic findings. The results of this study indicate that the potential and real benefits of virtualized angioscopy far outweigh several technical limitations.

Angioscopy↗
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↗
PubMed2001

Femoral vein valve repair with angioscopy-assisted anterior valve sinus plication. Early results.

BACKGROUND: The efficiency of angioscopy-assisted anterior valve sinus plication for primary deep venous insufficiency was evaluated. METHODS EXPERIMENTAL DESIGN: retrospective, clinical study with short follow-up. SETTING: institutional practice. PATIENTS: 15 limbs in 12 patients had class 4 or higher disease (SVS/ISCVS classification). Descending venography showed class 3 or 4 reflux in all patients. Venous refilling time (VRT) was abnormal (<15 sec) in all of the nine limbs in which photoplethysmography was conducted. The limbs were treated with angioscopy-assisted anterior valve sinus plication of the superficial femoral vein. Postoperative descending venography was performed between the first and third day after operation. Clinical evaluation and VRT measurement were repeated when the patients were discharged and checked at the outpatient office. RESULTS: Mean follow-up was 22 weeks with a range of 1 to 70 weeks. At postoperative descending venography, the reflux of the superficial femoral vein was significantly improved. At final follow-up, all patients reported greater or lesser relief of subjective symptoms. In four limbs with class 6 disease, ulcers healed and did not recur. In one limb with class 5 disease, ulcers did not recur. In the other 10 limbs with class 4 disease, a distinct clinical improvement occurred with resolution of skin changes. VRT was normal in 11 of the 12 limbs examined. CONCLUSIONS: Our preliminary experience demonstrates that angioscopy-assisted anterior valve sinus plication gives early good clinical and hemodynamic improvement in patients with primary deep venous insufficiency.

Adult↗
PubMed2002

[Usefulness of coronary angioscopy for the evaluation of hyperlipidemia].

Hyperlipidemia is one of the major coronary risk factors, which leading to the clinical worse outcome in patients with coronary artery disease, that is, acute coronary syndrome. Coronary plaque rupture followed by the formation of thrombus has been revealed to be a major cause of acute coronary syndrome. It would be important to detect the vulnerable plaque before its rupture, but there were no ways to detect by the conventional methods except coronary angioscopy. Yellow plaque and thrombus are mostly observed at the culprit lesion by the coronary angioscopy, which suggests that vulnerable plaque is dark yellow. Coronary angioscopy may diagnose the high-risk group among patients with hyperlipidemia.

Angioscopy↗
PubMed1994

[Peroperative monitoring of femoral-popliteal vein bypasses by angioscopy].

For the past few years, arteriography has been the gold-standard examination for the intra-operative control of femorodistal bypass grafts. Angioscopy is an alternative method permitting to assist the preparation of the venous graft, and to control the quality of the lumen as well as the anastomoses at the end of the procedure. The techniques employed and the results published in the medical literature are analysed in this study. After completion of this survey, it seems that angioscopy and arteriography used as means of control of infra-inguinal arterial reconstructions can be compared regarding the facility of the examination, the time necessary for its realisation, and its cost. However angioscopy is more sensitive than arteriography for the diagnosis of technical imperfections that may result in immediate failure of infrainguinal bypasses.

Anastomosis, Surgical↗
PubMedDate not supplied

[Percutaneous coronary angioscopy: 200 observations in 100 candidates for angioplasty].

Due to the recent technological advances, it is possible to perform percutaneous coronary angioscopy in a straightforward fashion in most patients. To know the safety and usefulness of this technique we present 200 observations in 100 patients candidates for coronary intervention. We used a coronary angioscope (Baxter, Edwards LIS Division), that can be placed using the conventional technique for percutaneous coronary angioplasty. The system incorporates a proximal occluding balloon, and distally a movable optical fiber. Case selection considered non-ostial coronary segments relatively straight. It was possible to obtain adequate images in 86 percent of cases. The technique is safe in experienced hands: there were two cases of ventricular fibrillation, and two cases of local dissection occurred, none of these associated with clinical consequences. No myocardial infarction, surgery or death, related to this procedure occurred. Valuable diagnostic information is derived from angioscopy as the method provides some histopathological correlation. Stable plaques are usually uniformly white or yellow. Unstable plaques are yellow and ulcerated. Thrombus can be easily recognized in acute coronary syndromes. Also in percutaneously treated segments, the final result and the presence of dissection or hemorrhage can be visualized. Coronary percutaneous angioscopy is safe and brings useful clinical information. Its applications in the clinical practice are still to be determined.

Angioplasty, Balloon, Coronary↗