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 235 records · Page 13Linked to original sources
PubMed2003

Plaque characterization and atherosclerosis evaluation by coronary angioscopy.

When observed by angioscopy, the culprit lesions of acute coronary syndrome (ACS) have a common appearance of a yellow plaque with irregular surface covered by a thrombus. Angioscopy is a powerful device to detect not only the ruptured plaques at ACS lesions but also the yellow plaques in their early stages. The culprit lesions of ACS are sometimes detected by angioscopy even in the angiographically normal segments of coronary arteries. Angioscopy can further classify the culprit lesions of ACS as (1) vasospasm, (2) plaque rupture, or (3) plaque erosion according to the angioscopic definitions. These classifications may be beneficial to determine the treatment strategy. Anti-vasospastic medications rather than stenting may be more suitable for the treatment of vasospasm-induced ACS. Percutaneous coronary intervention (PCI) of ruptured plaque rather than of erosive plaque tends to cause more distal embolization with thrombus and plaque contents. Therefore, distal protection device may be more beneficial for those cases. Although angioscopy may be able to identify vulnerable plaques as the plaques of intensive yellow color, it may be more practical to identify the patients at high risk of suffering ACS by evaluating the extent of coronary atherosclerosis. The process and the time course of plaque formation, maturation, and disruption are left to be clarified, however, the number of yellow plaques or the yellow color intensity of those plaques may be a marker of coronary atherosclerosis. Angioscopy should be useful not only as a diagnostic tool but also as an investigational tool. The effect of medications that regress coronary atherosclerosis may be evaluated by the angioscopically determined markers of coronary atherosclerosis.

Acute Disease↗
PubMed1997

Endoscopic venous valve transplantation with a valve-stent device.

In this report we describe the outcome of a 6-week study of the valve-stent device in a goat model. Six female goats underwent endoscopic subcutaneous harvest of a valve-containing segment of external jugular vein. This segment was sutured inside a 10-mm Wallstent (Schneider Inc., USA), and the device was compressed and loaded into a 12 Fr. introducer sheath and deployed through a venotomy into the contralateral external jugular vein. The animals were anticoagulated for 1 week and euthanized at 6 weeks. Flow studies, manual strip test, and angioscopic evaluation were performed prior to sacrifice. All six valve-stents were patent at harvest by Doppler flow studies, and five of six were competent as demonstrated by the manual strip test. At angioscopic evaluation, the valves were open. Gross and histologic examination revealed intact valve leaflets in five specimens. This technique is a minimally invasive approach to valve harvest and transplantation with a valve-stent device. We have demonstrated that valve-stent can remain patent and competent for up to 6 weeks. This technique may have potential application in venous valvular incompetence.

Animals↗
PubMed2004

Color of culprit lesion at 6 months after plain old balloon angioplasty versus stenting in patients with acute myocardial infarction.

BACKGROUND: Although the healing process of disrupted yellow plaques at myocardial infarction (MI) culprit lesions has been reported, the effect of stenting on this process has not been clarified. Stenting has been reported to deteriorate the endothelial function after percutaneous coronary intervention (PCI). Therefore, we compared the angioscopic morphology of culprit lesions at 6 months after plain old balloon angioplasty (POBA) and stenting to clarify the effect of stenting on the healing of disrupted culprit plaques of acute MI. METHODS: Patients with acute MI who had yellow culprit plaque, successful reperfusion therapy with POBA (n = 21) or stenting (n = 22), and a successful 6-month follow-up angioscopic examination were included in this study. Oral ticlopidine (200 mg/day) was administered for 3 to 6 months after stenting. RESULTS: At 6 months after reperfusion therapy, the color of the culprit lesion became white in significantly more patients treated with stenting than treated with POBA (50% vs 14%; P = .01). However, the prevalence of thrombus appeared to be higher in patients treated with stenting than in patients treated with POBA (27% vs 5%; P = .04). Although there was some difference in the patients' characteristics in the groups, logistic regression analysis revealed no significant influence of those factors on the color of or on the prevalence of thrombus at the culprit lesion. CONCLUSIONS: Coronary stenting in patients with acute MI leads to the disappearance of yellow color at a significantly higher rate than POBA; however, whether it stabilizes the plaque requires further investigation.

Angioplasty, Balloon, Coronary↗
PubMed1999

Minimally invasive in situ bypass.

Since the report of a successful femoropopliteal in situ saphenous vein bypass in 1962, surgeons have attempted to make this bypass a less invasive operation and simplify the two principal technical components of the operation: (1) rendering the saphenous vein valves incompetent and (2) occluding the venous side branches. To accomplish this bypass, however, a long incision that is the length of the leg over the course of the saphenous vein is often necessary, which can be fraught with hazard, especially in patients with diabetes in whom wound complications can be devastating. An angioscopically assisted technique that allows the surgeon to perform valvulotomy and occlude venous side branches from within the saphenous vein--a minimally invasive in situ vein bypass--has been developed. This article discusses preclinical, fluoroscopic clinical, and angioscopic clinical studies of minimally invasive in situ bypass.

Animals↗
PubMed1992

Angioscopy.

Endoscopy of the vascular system has evolved over recent years from an experimental procedure to a sophisticated diagnostic and therapeutic technique for surgical or percutaneous interventions of the peripheral vascular system. Particularly in procedures involving remote instrumentation of arteries, the angioscope provides a method of controlled guidance and a monitor of the effects of the various instruments on the vessel wall and allows immediate assessment of results. Angioscopic examination reveals the extent of intimal injury after angioplasty, in situ vein preparation, trauma, and thrombectomy and gives insights into the mechanisms and effects of endovascular devices.

Aged↗
PubMed2000

Endovascular-assisted versus conventional in situ saphenous vein bypass grafting: cumulative patency, limb salvage, and cost results in a 39-month multicenter study.

OBJECTIVE: In this retrospective multicenter study, the results of a minimally invasive method of endovascular-assisted in situ bypass grafting (EISB) versus "open" conventional in situ bypass grafting (CISB) were evaluated with a comparison of primary and secondary patency, limb salvage, and cost. METHODS: Enrolled in this study were 273 patients: 117 underwent CISB (42 femoropopliteal, 75 femorocrural) and 156 underwent EISB (41 femoropopliteal, 115 femorocrural). EISB was performed with an angioscopic Side Branch Occlusion system and an angioscopically guided valvulotome. All the patients underwent follow-up examination with serial color-flow ultrasound scanning. RESULTS: Both groups had similar comorbid risk factors for diabetes mellitus, coronary artery heart disease, hypertension, and cigarette smoking. The primary patency rates (CISB, 78.2% +/- 5% [SE]; EISB, 70.5% +/- 5%; P =.156), the secondary patency rates (CISB, 84.1% +/- 4%; EISB, 82.9% +/- 5%; P =.26), and the limb salvage rates (CISB, 85.8%; EISB, 88.4%; P =.127) were statistically similar, with a follow-up period that extended to 39 months (mean, 16.6 months; range, 1 to 40 months). In veins that were less than 2.5 to 3.0 mm in diameter, the EISB grafts fared poorly, with an increased incidence of early (12-month) graft thromboses (CISB, 10 grafts, 8.5%; EISB, 24 grafts, 15.3%). However, wound complications (CISB, 23%; EISB, 4%; P =.003), mean hospital length of stay (CISB, 6.5 days +/- 4.83; EISB, 3.2 days +/- 3.19; P =.001), and mean hospital charges (CISB, $25,349 +/- $19,476; EISB, $18,096 +/- $14,573; P =.001) were all significantly reduced in the EISB group. CONCLUSION: The CISB and EISB midterm primary and secondary patency and limb salvage rates were statistically similar. In smaller veins (< 2.5 to 3.0 mm in diameter), however, EISB is not appropriate because overly aggressive instrumentation may cause intimal trauma, with resultant early graft failure. With the avoidance of a long leg incision in the EISB group, wound complications and hospital length of stay were significantly reduced, which lowered hospital charges and justified the additional cost of the endovascular instruments. When in situ bypass grafting is contemplated, EISB in appropriate patients is a safe, minimally invasive, and cost-effective alternative to CISB.

Aged↗
PubMed1991

Angioscopy of the inferior vena cava: preliminary observations in cases with involvement by neoplasm. Work in progress.

Angioscopy of the inferior vena cava (IVC) was performed in 10 patients. Tumor thrombus extending into the IVC was suspected in six patients, and direct invasion of the IVC wall was suspected in four, based on computed tomographic and venographic findings. In each case, a fiberscope was directed to the area of interest in the IVC via a transfemoral 5-F catheter. Blood displacement by means of a saline infusion enabled angioscopic observation of the IVC wall. The neoplasms were seen clearly in all patients but one. The color and texture of the tumor thrombi surface made it easy to distinguish from the healthy IVC wall. In the four patients believed to have direct invasion of the wall, there were no angioscopic differences between the suggestive areas and adjacent areas of normal IVC wall. In these four cases, the absence of direct invasion was confirmed at surgery. Thus, angioscopy helps make an accurate nonoperative or preoperative diagnosis of tumor thrombi possible and may aid in the exclusion of direct invasion.

Adult↗
PubMed1993

[Doppler ultrasound of the saphenous vein as a bypass. Detection of arteriovenous fistulae].

In 13 patients who underwent a femorodistal revascularisation with an in situ saphena vein graft and who had been operated on by angioscopic technique, intraoperative angiography and postoperative colour-coded Doppler sonography and i.v./i.a. digital subtraction angiography (DSA) were performed to detect arteriovenous fistulas (AV fistulas). In intraoperative completion angiography no AV fistulas were seen. Colour-coded Doppler sonography and DSA studies performed three to five days postoperatively revealed AV fistulas in 8 patients. The fistulas could be exactly located by sonography, and, if confirmed haemodynamically significantly by i.v./i.a. DSA, they were marked on the skin and ligated. In the detection of AV fistulas in in situ saphenous vein grafts operated by angioscopic technique colour-coded doppler sonography and i.v./i.a. DSA showed equivalent results. In the detection of connections of AV fistulas to the deep draining veins the i.v./i.a. DSA was superior.

Aged↗
PubMed1990

Endoscopic intravascular surgery removes intraluminal flaps, dissections, and thrombus.

Over the last 3 years angioscopic techniques have been used to guide intraluminal instrumentation in 73 patients undergoing thrombectomy, nine patients with vascular trauma, and 32 patients during laser angioplasty and balloon dilation. After balloon-catheter thromboembolectomy residual, occlusive thrombi tightly adherent to the arterial wall were removed with flexible biopsy forceps in 13 of 73 (18%) patients; underlying intimal flaps were removed in another four. In nine patients traumatic intimal defects caused by iatrogenic cannulation injuries (n = 5) or external trauma (n = 4) were managed by thrombectomy followed by complete or partial intravascular removal of the intimal flap (n = 6) or dissection plane (n = 3) with long flexible forceps and rotating brushes. Traumatic intimal defects observed in two additional patients were judged to be too severe for endoscopic manipulation and required immediate bypass grafting. Inspection after angioplasty in 32 patients revealed wall charring and obvious thermal damage after laser procedures in 28 (87%) and plaque cracking, intimal flaps, and fragmentation in 26 (81%). These defects were underestimated on intraoperative angiography. Large flaps and thrombus were removed endoscopically in three. We conclude that angioscopic study reveals the extent of intimal injury and gives insights into mechanisms of instrumentation. Adherent thrombus after embolectomy by balloon catheter and intimal flaps caused by trauma or angioplasty are common and, if severe, can be successfully treated by endoscopic intravascular manipulation in selected patients.

Blood Vessels↗
PubMed1992

A prospective study on percutaneous coronary angioscopy with different guiding techniques in patients with coronary heart disease.

The technical success of percutaneous coronary angioscopy using different guiding techniques was evaluated in 17 patients before (n = 17) and after (n = 8) coronary angioplasty. Steering the angioscope along or over a guidewire was successful in both groups; failures were predominantly due to insufficient alignment of the angioscope using along-the-wire guiding. Although over-the-wire angioscopy promises superior guiding and alignment capabilities, several technical problems remain unsolved.

Adult↗
PubMed1995

Mechanisms of luminal enlargement and quantification of vessel wall trauma following balloon coronary angioplasty and directional atherectomy.

OBJECTIVES: The purpose of this study was to assess the dual action of lumen enlargement and vessel wall damage following either balloon angioplasty or directional atherectomy, using intracoronary ultrasound, and angioscopy. BACKGROUND: Differences in the mechanisms of action of balloon angioplasty and directional atherectomy may have a significant bearing on the immediate outcome and the restenosis rate at 6 months. METHODS: A total of 36 patients were studied before and after either balloon angioplasty (n = 18) or directional atherectomy (n = 18). Ultrasound measurements included changes in lumen area, external elastic membrane area and plaque burden. In addition, the presence and extent of dissections were assessed to derive a damage score. Angioscopic assessment of the dilated or atherectomized stenotic lesions was translated into semi-quantitative dissection, thrombus and haemorrhage scores. RESULTS: Atherectomy patients had a larger angiographic vessel size compared with the angioplasty group (3.55 +/- 0.46 mm vs 3.00 +/- 0.64 mm, P < 0.05); however, minimal lumen diameter (1.18 +/- 0.96 mm vs 0.85 +/- 0.49 mm) and plaque burden (17.04 +/- 3.69 vs 15.23 +/- 4.92 mm2) measurements did not differ significantly. As a result of plaque reduction, atherectomy produced a larger increase in luminal area than the angioplasty group (5.80 +/- 1.78 mm2 vs 2.44 +/- 1.36 mm2, P < 0.0001). Lumen increase after angioplasty was the result of 'plaque compression' (50%) and wall stretching (50%). Additionally, in both groups there was indirect angioscopic evidence of thrombus 'microembolization' as an adjunctive mechanism of lumen enlargement. Angioscopy identified big flaps in six and small intimal flaps in 11 of the atherectomized patients as compared with five and 12 patients in the angioplasty group. Changes in thrombus score following both coronary interventions were identical (0.72 +/- 3.42 points atherectomy vs -0.38 +/- 3.27 points balloon angioplasty, ns). CONCLUSIONS: Lumen enlargement after directional atherectomy is mainly achieved by plaque removal (87%), whereas balloon dilation is the result of vessel wall stretching (50%) and plaque reduction (50%). Despite the fact that the luminal gain achieved by directional atherectomy is twice that achieved with balloon angioplasty, the extent of trauma induced by both techniques seems to be similar.

Aged↗
PubMedDate not supplied

Angioscopy in transluminal balloon and laser angioplasty in the management of chronic hemodialysis fistulae.

In chronic hemodialysis patients, there is the major problem of occlusion in the arteriovenous fistulae. To investigate this problem, the authors have developed angioscopy for examination and detection of occlusion developing to allow early use of transluminal balloon angioplasty (PTA) or laser angioplasty and prevent occlusions. The authors have examined 27 patients using a 2.7 mm diameter Olympus flexible angioscope and 9F sheath, following-up with a 4 mm balloon catheter (BARD) or SLT Nd-YAG laser. PTA was performed for 25 cases, with 19 demonstrating after one session patency lasting 9 months to date. Three cases revealed restenosis and have each received three PTA sessions. Laser angioplasty was performed in one case of 15 cm chronic occlusion, with subsequent PTA successfully enabling hemodialysis. Angioscopically, the authors were able to observe the various rest-forms within the shunt and detected the mural thrombus attached to the punctured pore. Both circumferential and valvular stenoses were observed. Initially after laser angioplasty, rough irregularity and a mural thrombus in the vessel was observed, but 2 months later, the vessel lumen had become smooth, probably due to intimal growth. Thrombus is acute stenosed cases were clearly observed. Angioplasty enabled new observations in the A-V fistulae, which allows investigation of the mechanism of stenosis or occlusion and enables an extended use of the hemodialysis blood access.

Angioplasty, Balloon↗
PubMed2006

Carotid artery stent implantation: evaluation with multi-detector row CT angiography and virtual angioscopy--initial experience.

Approval for this HIPAA-compliant study was obtained from the institutional review board; informed consent was not required for retrospective review of patient studies that had been performed for clinical evaluation. The purpose of this study was to retrospectively compare the accuracy of intrastent luminal diameter, as measured on transverse computed tomographic (CT) angiograms and virtual angioscopic views, with the manufacturer's specifications for phantom diameter and with digital subtraction angiographic (DSA) measurements of stent diameter obtained in patients. Intrastent diameter was measured by using standard and stent-optimized reconstruction kernels with three window settings. Endoluminal virtual angioscopic views of the stent-containing vessels were also generated. Measurements at CT angiography were compared with known specifications for the phantom and with DSA measurements in patients. Erroneous measurements of intrastent diameter occurred when a standard kernel and nonoptimized window settings were used. A set of parameters that minimized error relative to measurements obtained at DSA was also identified. Virtual angioscopy helped demonstrate morphologic aspects of stenosis that were otherwise difficult to appreciate.

Aged↗
PubMedDate not supplied

Haziness on coronary angiogram after percutaneous transluminal coronary angioplasty evaluated with angioscopy.

Coronary angiograms obtained after percutaneous transluminal coronary angioplasty are often hazy due to uneven distribution of contrast medium at the angioplasty site, In this study, structural changes resulting in haziness after percutaneous transluminal coronary angioplasty were identified angioscopically. The affected coronary arteries of 35 patients who underwent successful percutaneous transluminal coronary angioplasty were examined with angioscopy. Coronary angioscopic examination of the sites subjected to percutaneous transluminal coronary angioplasty revealed large surface disruptions in 17 cases, small surface disruptions in four cases, and thrombi in 24 cases. Angiographic haziness was recognized in 24 of 35 patients after percutaneous transluminal coronary angioplasty. Haziness on angiography was more significant in patients who exhibited large surface disruption (88% vs 50%, p < 0.05), and was significantly greater in patients who exhibited white thrombus (100% vs 56%, p<0.05). Moreover, it appears that percutaneous transluminal coronary angioplasty-induced large surface disruption and white thrombus likely play an important role in increasing haziness.

Adult↗
PubMed1989

Clinical experience of percutaneous coronary angioscopy in cases with coronary artery disease.

Direct visualization of the coronary arteries was performed by using a new ultrathin angioscopic catheter system in experimental animals and 4 patients with coronary artery disease during percutaneous transluminal coronary angioplasty (PTCA). In this catheter system, inspection of the coronary arteries was achieved during washout of blood by bolus infusion of 8-10 ml of saline into the coronary artery through the guide catheter. In the preliminary experience with this coronary angioscopic system, there were some limitations. In 2 patients, removal of coronary blood by manual injection of saline was not adequate, and diagnostic TV images could not be obtained. In 2 patients with tortuous coronary arteries, the catheter could not pass to the atheromatous plaques owing to lack of flexibility of the fiberoptic catheter. Furthermore, angina pectoris occurred in 2 patients during angioscopy, owing probably to interference with coronary blood flow by the guide catheter and/or fiberoptic catheter itself. For future clinical application of coronary angioscopy, further improvements in the instrument are necessary.

Angioplasty, Balloon↗
PubMed2001

Surgical repair of coronary artery aneurysm after percutaneous coronary intervention.

Two cases of coronary artery aneurysm after percutaneous coronary intervention are presented. In both cases, follow-up coronary angiography revealed an expanding saccular aneurysmal formation and restenosis or a new lesion. Consequently, surgical repair and revascularization were indicated. The intraoperative angioscope was used to identify the aneurysm, which had not been visible on the heart surface in one case. Its optic fiber light was a useful guide, but little information was obtained from direct vision because of the small caliber of the angioscope. Plication of the aneurysm and bypass grafting distal to the aneurysm were performed. A whitish and thick-walled aneurysm was easily found in one case, in which ligation of the aneurysm was attempted with added distal bypass. The postoperative course was uneventful in both cases, and follow-up angiography showed disappearance of the aneurysm with patent grafts. There was a fragile thrombus inside both the aneurysmal sacs, which might have caused myocardial infarction and, therefore, justified the surgical repair of the aneurysm with concomitant revascularization.

Aged↗
PubMed2002

Method for evaluating optical characteristics of endoscopes for recording fluorescence-related cardiac electrical activity.

Nondestructive methods were used to evaluate marketed fiber-optic endoscopes (intended for simple viewing) for fluorescence recording. Our application is for optical recording from the heart. For one angioscope, we measured a focal length of 0.33 mm, a field of view of 45 degrees, an aperture of 0.26 mm, and an efficiency of 43%. We calculated that the angioscope would give a signal-to-noise ratio of 1.0 for a cardiac action potential, if its field of view were divided into a nine-pixel array (for safe continuous illumination). Our methods are useful in designing and evaluating fluorescence fiber-optic systems with superior signal quality and spatial resolution.

Electrophysiology↗
PubMed1993

The state of the art of CO laser angioplasty system.

A unique percutaneous transluminal coronary angioplasty system using new infrared therapy laser with infrared glass fiber delivery under novel angioscope guidance was described. Carbon monoxide (CO) laser emission of 5 mm in wavelength was employed as therapy laser to achieve precise ablation of atheromatous plaque with a flexible As-S infrared glass fiber for laser delivery. We developed the first medical CO laser as well as As-S infrared glass fiber cable. We also developed 5.5 Fr. thin angioscope catheter with complete directional manipulability at its tip. The system control unit could manage to prevent failure irradiations and fiber damages. This novel angioplasty system was evaluated by a stenosis model of mongrel dogs. We demonstrated the usefulness of our system to overcome current issues on laser angioplasty using multi-fiber-catheter with over-the-guidewire system.

Angioplasty, Balloon, Laser-Assisted↗