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At least 55 records · Page 3Linked to original sources
PubMed1994

Impact of angioscopy on infrainguinal graft patency.

To investigate the impact of angioscopy on infrainguinal graft patency, 50 consecutive cases with angioscopy as an adjuvant to infrainguinal arterial bypass performed during a 12-month period were reviewed (group I). For comparison, 42 similar cases of infrainguinal arterial reconstruction performed during the 12 months prior to introduction of routine intraoperative angioscopy were also reviewed (group II). Patients were followed up for 12 months and graft patency was determined at 1, 3, 6, and 12 months. An abnormality was identified in 13 (26%) group I patients (10, angioscopy alone; 1, arteriography alone; 2, both). Defects were anastomotic abnormalities (n = 7), vein sclerosis (n = 3), retained valve cusp (n = 2), and proximal artery stenosis (n = 1). A similar percentage, but different types of defects, were seen in group II; 11 patients (26%) had an abnormality (anastomotic abnormality [n = 3], vein sclerosis [n = 4], retained valve cusp [n = 1], and arterial outflow stenoses [n = 3]). All significant defects were surgically explored and corrected. Graft patency rates in group I and II at 1, 3, 6, and 12 months were 100% and 85% (P < 0.005), 94% and 80% (P < 0.05), 87% and 74% (P = non-significant [NS]), and 86.1% and 73.7% (P = NS), respectively. Intraoperative angioscopy detects anastomotic and vein graft defects not always seen on arteriography; the repair of these defects significantly improves early infrainguinal bypass graft patency rates.

Adult↗
PubMed1994

[Comparison of the value of angioscopy, angiography and ultrasonography in detection of pathologic vascular processes].

AIMS: The ability of angioscopy, angiography and sonography to evaluate arteriosclerotic vascular lesions were compared to determine if angioscopy is a valuable addition in the diagnostic armamentarium. METHODS: An in-vitro study was selected to enable microscopic assessment of the arteries. Angiography was followed by sonography and endoscopy and finally the vessels were evaluated macro- and microscopically. RESULTS: The configuration of the vascular stenosis (plaque-shape, semicircular-eccentric, circular-concentric) was more reliably defined with angioscopy as compared to angiography and sonography. Intense calcification of plaque was detected sonographically with a high sensitivity (90%) using the acoustic shadowing and high amplitude criteria. Angioscopy was superior in differentiating between simple and complicated plaques and the assessment of ulcerations, while the visualization of the entire vascular tree with potential collaterals remained the domain of angiography. CONCLUSIONS: Angioscopy seems to be valuable addition in the evaluation of arterial vascular disease. It can be used in the quality control after interventional radiology and surgery.

Angiography↗
PubMed1994

The clinical utility of angioscopy during intracoronary stent implantation.

Angiographic evidence of thrombus may have important implications during coronary stent deployment procedures. The periprocedural presence of thrombus has been shown to increase the risk of subsequent stent thrombosis. Coronary angioscopy is a new technology that may prove more accurate for the detection of coronary thrombus. Angiographic filling defects suspicious for thrombus were observed in 15 (22%) of 64 patients undergoing coronary angioscopy during stent implantation procedures. Angioscopy confirmed the presence of thrombus in 9 (60%) of these 15 patients. Protruding thrombus was found in four cases and only mural thrombus in five. In six cases (40%) thrombus was not visualized and angioscopy provided an alternative explanation for the angiographic filling defect. Bulky atherosclerotic plaque was seen protruding into the lumen in two cases, disection with protruding fronds of tissue was found in three cases and a ruptured venus valve was found in one final case. Thrombolytic therapy was administered in all four cases containing protruding thrombus, in only two of the five cases containing mural thrombus, and in none of the cases where thrombus was not visualized. Angioscopy was more accurate than angiography for the diagnosis of thrombus and allowed more precise tailoring of the intervention to the underlying anatomical substraight. This resulted in an excellent clinical outcome, with no episodes of stent thrombosis and limitation of the risks associated with thrombolytic therapy to only those patients at increased risk of a thrombotic complication.

Adult↗
PubMed1999

[The role of angioscopy and intravascular ultrasound imaging in acute coronary syndrome].

Evaluation of the severity of coronary atherosclerosis by intracoronary imaging may be closely relevant with the prevention and treatment of acute coronary syndromes. Coronary angioscopy as one of the innovative methods of imaging and intravascular ultrasound makes the insight visualization of coronary vessel wall and histological recognition possible recently. Yellow plaques rich in lipid materials and covered by thin membrane are more often ruptured than white ones to cause acute coronary syndromes. In patients with unstable angina and acute myocardial infarction, the yellow plaques with intimal flaps and irregularities are frequently observed by angioscopy. Angioscopy is also the most powerful tool to detect intracoronary thrombus. In patients with acute myocardial infarction, thrombosis occludes vessel lumen totally, but it does not in the unstable angina cases. After thrombolytic therapy, the white thrombus is more often observed than the red one. Although angioscopy is superior to any other examination in diagnosing thrombosis, some complicated plaques are difficult to distinguish from thrombus. In addition to measurements of vascular dimension and plaque volume, histological diagnosis of plaque is being made by intravascular ultrasound. More precise evaluation of plaque histology may be a clue to predict the occurrence of acute coronary syndrome. Intravascular ultrasound is not so useful enough to diagnose thrombosis. In conclusion, the applications of intravascular imaging technologies, such as angioscopy and intravascular ultrasound, may play a critical role in the diagnosis and treatment of acute coronary syndromes.

Angioscopy↗
PubMed1993

[Percutaneous coronary angioscopy].

In the last few years, major advances in catheter technology and miniaturization of fiber optics have allowed percutaneous coronary angioscopy to become a reality. Current angioscopy systems provide an outstanding image quality yielding precise evaluation of coronary atherosclerosis morphology in its various clinical manifestations. However, coronary angioscopy is a new diagnostic tool whose indications and specific role are yet to be delineated. Investigation on the potential roles of this technology are mainly centered in the field of acute coronary syndromes and interventional coronary therapies. In the near future, coronary angioscopy may play an important role in the investigation of the natural history of coronary artery disease, in the field of thrombolysis, and in the selection of specific therapy. In this article, coronary angioscopy system and technique are described and its potential clinical applications discussed.

Angina, Unstable↗
PubMed1993

[Angioscopy of lower limb arteries. History and technique, cost and practical information].

The historical background to angioscopy shows that the principal successes recorded by its use result from the miniaturization of fibroscopes and the progress in video imaging. The first tentative use of angioscopy was by surgeons during operations carried out at about 1970, that of percutaneous angioscopy dating from 1984. The material used for diagnostic (fibroscope, cinecamera, video system, flushing pump) and interventional (fibroscope, clamps, Dormia cage, endoprostheses ... ) angioscopy is such that the basic equipment requires an outlay of about 150 to 200,000 francs. Percutaneous angioscopy implies the insertion of a catheter allowing flushing of the arterial lumen by means of a pressurized perfusion pump which, when reversed, is transformed into an aspirating pump for removal of the clot and/or atheromatous debris. The procedure is simple and does not expose to more complications than conventional arteriography.

Angioscopy↗
PubMed1989

Routine intraoperative angioscopy in lower extremity revascularization.

The inability to see through blood remains the main obstacle to the widespread and routine use of angioscopy. Local irrigation with a balanced salt solution is presently the most widely used method to clear the blood. By applying basic principles of irrigation and using a unique, dedicated, irrigation pump, we found that routine angioscopy during lower extremity revascularization that yields consistent high-quality studies is feasible, clinically useful, and safe. Between May 1, 1987, and July 31, 1988, 136 intraoperative angioscopies were performed during 112 peripheral bypass procedures, 15 thrombectomies, 2 embolectomies, and 7 miscellaneous revascularization procedures. Mean total irrigation fluid used in the peripheral bypasses was 398 mL (range, 0 to 1400 mL). Good visual quality was obtained in more than 80% of angioscopies and the failure rate was only 1.8%. On the basis of the findings in 71 of the 136 angioscopies, 78 clinical or surgical decisions were made. No complications were directly attributable to the insertion of the angioscope or use of the pump.

Angiography↗
PubMed1989

Intraoperative angioscopy: principles of irrigation and description of a new dedicated irrigation pump.

The value of intraoperative angioscopy in the detection and immediate correction of technical errors and deficiencies during vascular surgery has been previously documented. The inability to see through blood remains the most significant limitation to the general application of angioscopy. Local irrigation with a balanced salt solution is the most commonly used method to clear the blood from a restricted field in a particular vessel. We have developed a new catheter irrigation pump system (maximum flow rate 340 ml/min) to establish and maintain visibility of the field during intraoperative angioscopy. Furthermore, we have demonstrated the safety of irrigating with high volume flows in the peripheral arteries and defined the basic principles of irrigation for angioscopy. The prototype pump tested in this study provides a wide range of flow rates and permits precise measurements of the fluid delivered. The instrument's display and its control with a single foot pedal makes its use relatively simple, obviating the need for additional support personnel while increasing the efficacy and safety of the angioscopic examination and increasing the number of situations where angioscopy may be very useful.

Animals↗
PubMed1997

Angioscopy in vascular surgery.

The role of intraoperative angioscopy continues to evolve. To better define the role of angioscopy in vascular surgery, a review of the recent literature was performed. The most well-established indication for angioscopy is preparation of the saphenous vein for in situ bypass; however, angioscopy has also been demonstrated to be useful in the assessment of carotid endarterectomy, femoral vein valve repair, thromboembolectomy, and may be beneficial during endovascular stent grafting. Angioscopy is now a valuable adjunct in the management of the patient with peripheral vascular disease.

Angioscopes↗
PubMed1981

Identification of pulmonary emboli in the dog: comparison of angioscopy and perfusion scanning.

Fifteen dogs were studied by perfusion scan, angioscopy and autopsy. In 10, emboli were formed in leg veins and released before study; five dogs were not embolized and served as controls. In controls, angioscopy disclosed no emboli, perfusion scans were normal after angioscopy and autopsy disclosed no emboli. Among the embolized dogs, 23 emboli were identified at autopsy. Perfusion scans disclosed 23 defects, but in three dogs there was a disparity between scan and autopsy localization. Angioscopy identified 21 of the 23 autopsy-defined emboli and localized them correctly; two emboli in vessels less than 1 mm in diameter were not visualized. Angioscopy may provide a useful new approach in animal investigations of pulmonary embolism and perhaps, after additional study, in selected patients.

Animals↗
PubMed1990

Experimental and clinical percutaneous angioscopy experience with dynamic angioplasty.

The authors have used ultrathin angioscopes with high optical resolution to assess the effects of dynamic angioplasty in vitro and in vivo. Experimentally, angioscopy was used to study the effects of the 5F "Kensey" catheter in "normal" porcine coronary arteries (NPCA) and postmortem human coronary arteries (PMHCA). In NPCA, the catheter keeps a coaxial position. Intimal flaps (IFs) were seen in 21/23 NPCAs. They occurred with all cam rotation speeds and were usually single and small (less than 25% of lumen). Perforations in patent arteries were rare (1/23). However, when the catheter was forced against the wall by passing through a narrowing of 5F diameter (made by a band ligature), perforations were more common at higher cam speeds. The epicardium remained intact in two thirds of perforations. Angioscopy visualized perforations in only 10% of cases (1/10), the common sign being that of large and multiple intimal flaps, which were often obstructive (5/10). In PMHCAs, angioscopy was more sensitive than angiography in detecting atheromatous lesions. The authors were able to give a better assessment of the effect of dynamic angioplasty on treated lesions, including the demonstration of intimal flaps that were not visible on angiography. In vivo, they have performed percutaneous angioscopy before and after dynamic angioplasty using 8 French Kensey catheters. Angioscopy revealed features that were not shown angiographically.

Angioplasty, Balloon↗
PubMed1992

The effectiveness of coronary angioscopy in detecting intraluminal pathologic changes.

We have evaluated the feasibility of percutaneous transluminal coronary angioscopy for detecting intraluminal pathological changes as a diagnostic tool, and investigated the pathogenesis of two acute coronary disorders, acute myocardial infarction and unstable angina. Twelve patients with an acute coronary disorder and 20 patients who underwent percutaneous transluminal coronary angioplasty were selected for this comparison between the diagnostic accuracy of angioscopy and arteriography. One hundred and thirty patients were investigated by angioscopy as follows in order to investigate the pathogenesis of their acute coronary disorders: 22 within 8 h of onset acute myocardial infarction; 28 from one day to 2 months since onset recent myocardial infarction; 37 with an old myocardial infarction; 26 with unstable angina; and 23 with stable angina. Our results have indicated thrombi were detected more frequently by angioscopy than by arteriography (p less than 0.01). Also, 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 coronary angioscopy is a much more sensitive method for detecting intraluminal changes, and 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 precede its rupture.

Coronary Angiography↗
PubMed1993

[Carbon dioxide as an irrigation medium for percutaneous angioscopy].

Since technical progress has allowed the development of small and flexible endoscopes, percutaneous, transluminal angioscopy promises to be a diagnostic and therapeutic tool. Nevertheless, the main problem is to obtain a satisfactory bloodless visual field. The saline solutions used for this purpose present problems with hypervolaemia, insufficient clearance, and decreased refraction. We investigated a CO2 application system for angioscopy that allows the reproducible injection of variable quantities of gas, pressure, and injection time. In 10 pigs undergoing angioscopy, CO2 was injected through a Swan-Ganz catheter under blockade of the distal aorta. Using a bifemoral approach, the application of gas and the blocking balloon were controlled by an automatic gas injector. The CO2 was injected through the tip of the catheter with a constant flow and a variable pressure and time. The angioscopy procedures were videotaped. With small volumes of carbon dioxide (approximately 50 cm3; 1000 mbar application pressure) a column of gas can be created which, unlike liquids, completely displaces blood from the vessels and allows for several minutes a bloodless inspection of the aorta and the side branches without blood mixture. Carbon dioxide application allows safe and successful percutaneous angioscopy under optimal conditions if the quantities of gas, pressure, and injection time are adjustable. The tested gas injection device fulfills these conditions.

Angioscopes↗
PubMed1996

Angioscopy-assisted valvuloplasty for primary deep venous valvular insufficiency.

Primary deep venous valvular insufficiency causes reflux syndrome. Angioscopy permits the surgeon not only to ascertain that venous valves have not been destroyed but to perform external valvuloplasty under visual control with the valves under pressure. We have performed angioscopy-assisted venous valvuloplasty in three men (mean age 36 years; range 30 to 38 years) and one woman (age 58 years). All four patients had class 3 disease (SVS/ISCVS classification). Descending phlebograms showed grade 3 reflux in one patient and grade 4 reflux in three patients. In all patients angioscopy-assisted valvuloplasty of the superficial femoral vein was combined with wrapping with a segment of polytetrafluoroethylene prosthesis, stripping of incompetent superficial veins, and subfascial ligation of perforating veins. Mean follow-up was 12 months (range 6 to 17 months). In three patients ulcers healed and did not recur; in the remaining patient nearly complete healing was obtained after skin grafting. In all patients ambulatory venous blood pressure improved significantly and venous filling time returned to normal (> 15 seconds). At duplex ultrasonography and descending phlebography, no residual reflux was demonstrated. At final follow-up, all repaired valves were patent and competent. Our experience demonstrates that angioscopy-assisted venous valvuloplasty combines the accuracy of valvuloplasty by means of phlebotomy and the simplicity of external valvuloplasty and thus is preferred to either of these methods.

Adult↗
PubMed1997

Coronary angioscopy. Clinical applications.

Percutaneous coronary angioscopy is an invaluable alternative imaging modality that can not be used routinely in the interventional cardiac catheterization laboratory. The major value of angioscopy lies in its ability to determine safely, quickly, and accurately intraluminal morphologies before and after coronary interventions. The results from angioscopy can then be used to target more specific treatment strategies, given the vast array of interventional treatment strategies available. Percutaneous coronary angioscopy, however, requires meticulous attention for the proper preparation and use of the angioscope to minimize the potential risks associated with the imaging procedure.

Angioscopy↗
PubMed1995

Quantitative endoluminal measurements during angioscopy: an innovative technique.

AIM: To evaluate angioscopy in this Unit with respect to its application in lower limb vascular reconstructions. By providing magnified, colour images of the luminal surfaces of vein grafts, anastomoses and native arteries, angioscopy allows direct visualisation of imperfections and is sensitive in diagnosing technical problems. However, assessment is qualitative and magnification of the image can distort the operator's impression of true size. Angioscopy would be more versatile if it were possible to quantify the observed images. METHOD: A new technique has been developed to measure intra-luminal diameter from the angioscopic images. A linear displacement transducer is attached to the angioscope and accurately monitors its axial shift. Signals from the transducer are received by a personal computer equipped with a video frame grabber and analogue digital converter, together with appropriate software. The computer generates calculated dimensions based on geometrical principles, once each angioscope has been appropriately calibrated at the outset. RESULTS: Laboratory studies examining tubes of known dimensions have confirmed the reproducibility and accuracy of the technique. Simultaneous angioscopic and Duplex ultrasound measurements of the internal diameters of segments of vein suspended in a water bath were then carried out. Using the Duplex results as the 'gold standard', there was a strong correlation between the measurements obtained with the two techniques (Rs = 0.92). CONCLUSIONS: In the clinical context, this system has the capability to generate accurate endoluminal measurements during angioscopy. This has application for quality control in the selection of veins and inspection of run-off vessels during bypass grafting and in completion studies, following both operative and percutaneous procedures.

Analog-Digital Conversion↗
PubMed1996

Angioscopy for quality control of saphenous vein during bypass grafting.

OBJECTIVES: Although autogenous vein is the conduit of choice for infrainguinal bypass grafting, some 20-30% of vein grafts fail during the first year postoperatively. Many of these failed veins are now known to have pre-existing pathological changes. Angioscopy enables intraoperative endoluminal visualisation of veins and can reveal anomalies, some previously unsuspected, despite preoperative Duplex ultrasound mapping and normal external appearances. The aim of this study was to compare angioscopic findings with contemporary histological appearances and with subsequent graft outcome and ultimately, to identify those endoluminal features which might be predictive for failure. METHODS: Angioscopic vein inspection was carried out using Olympus 1.4 and 2.2mm angioscopes in patients undergoing femoropopliteal/distal bypass. Severe disease in the veins of five patients led to preferential use of polytetrafluoroethylene (PTFE) for above-knee bypasses. The remaining 38 videotaped sequences were reviewed by two surgeons and scored using a scale of 0 to 3, based on frequency and distribution of angioscopically detected lesions. These included haemorrhagic mural plaques, flimsy intraluminal strands, webs/bands and mobile/adherent thrombus. Vein harvested at operation was assessed by a pathologist according to the level of pre-existing abnormality. RESULTS: There were significant associations between angioscopy/histology scores and graft survival (chi 2 = 22.00; df:3; p < 0.001; chi 2 = 22.43; df:3; p < 0.001 respectively). There was a significant correlation between angioscopy and histology scores (R8 = 0.725; p < 0.001). CONCLUSIONS: Angioscopy allows immediate identification of the at risk, poor quality vein graft at the time of surgery, without the delays inherent with histological preparation and assessment. Recognition of abnormalities at angioscopy may ultimately improve graft outcome by prospectively eliminating use of poor vein.

Adult↗
PubMed2006

Update on coronary angioscopy: review of a 20-year experience and potential application for detection of vulnerable plaque.

Predicting the occurrence of future acute coronary syndromes remains an important challenge of contemporary cardiology. It is thought that detecting the individual vulnerable plaques in patients can be an important step to preventing myocardial infarction and sudden cardiac death. Coronary angioscopy can provide detailed information of the luminal surface of plaque, such as color, thrombus, or disruption, and is one of a few possibly useful imaging modalities for identifying vulnerable plaques. During its 20-year history, coronary angioscopy has been used as a diagnostic tool or to guide coronary angioplasty, and has contributed to our understanding of the pathophysiology of coronary artery disease. Yellow plaques seen during angioscopy seem to have many characteristics of high risk or vulnerable plaques, most consistent with the thin-cap fibroatheroma. Moreover, differences in yellow color have been reported to reflect differences in the structure or composition of plaques. Development of quantitative methods to assess plaque color and histopathologic correlations in conjunction with prospective natural history studies may lead to advances in vulnerable plaque detection by coronary angioscopy. Although current angioscopic devices are limited by the need to displace the column of blood in order to see the vessel wall, and by the lack of quantitative colorimetric methods, advances in technology may lead to new device versions that could be practical for expanded clinical use.

Angioscopy↗