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At least 19 recordsLinked to original sources
PubMed1994

Serial angioscopic and angiographic observations during the first hour after successful coronary angioplasty: a preamble to a multicenter trial addressing angioscopic markers for restenosis.

Percutaneous coronary angioscopy was used in 13 patients in a pilot study to assess the intracoronary changes that occur during the first hour after balloon angioplasty (PTCA). The dilated segment was studied with 4.5F angioscopes and with quantitative coronary angiography (QCA) immediately after PTCA and at 15-minute intervals for up to 1 hour after PTCA. Significant progression of intimal dissection and thrombus formation could be demonstrated with angioscopy. These dissections and thrombi remained undetected with angiography, which only showed haziness. Thus through its superior sensitivity to intimal damage and thrombus, coronary angioscopy can reveal important intravascular events that apparently occur even after successful PTCA. The relation of such angioscopic observations to restenosis will be addressed in a subsequent multicenter study.

Angioplasty, Balloon, Coronary↗
PubMed1998

Chromatic distortion during angioscopy: assessment and correction by quantitative colorimetric angioscopic analysis.

Angioscopy represents a diagnostic tool with the unique ability of assessing the true color of intravascular structures. Current angioscopic interpretation is entirely subjective, however, and the visual interpretation of color has been shown to be marginal at best. The quantitative colorimetric angioscopic analysis system permits the full characterization of angioscopic color using two parameters (C1 and C2), derived from a custom color coordinate system, that are independent of illuminating light intensity. Measurement variability was found to be low (coefficient of variation = 0.06-0.64%), and relatively stable colorimetric values were obtained even at the extremes of illumination power. Variability between different angioscopic catheters was good (maximum difference for C1, 0.022; for C2, 0.015). Catheter flexion did not significantly distort color transmission. Although the fiber optic illumination bundle was found to impart a slight yellow tint to objects in view (deltaC1 = 0.020, deltaC2 = 0.024, P < 0.0001) and the imaging bundle in isolation imparted a slight red tint (deltaC1 = 0.043, deltaC2 = -0.027, P < 0.0001), both of these artifacts could be corrected by proper white balancing. Finally, evaluation of regional chromatic characteristics revealed a radially symmetric and progressive blue shift in measured color when moving from the periphery to the center of an angioscopic image. An algorithm was developed that could automatically correct 93.0-94.3% of this error and provide accurate colorimetric measurements independent of spatial location within the angioscopic field. In summary, quantitative colorimetric angioscopic analysis provides objective and highly reproducible measurements of angioscopic color. This technique can correct for important chromatic distortions present in modern angioscopic systems. It can also help overcome current limitations in angioscopy research and clinical use imposed by the reliance on visual perception of color.

Algorithms↗
PubMedDate not supplied

Angioscopic valvulotomy: evaluation of a new miniaturized prototype.

This study compares valvulotomy performed by a new experimental instrument delivered through the angioscope with the standard technique used in the in situ arterial bypass procedure. Eighteen mongrel dogs (approximately 20 kg) were anesthetized and both femoral veins were exposed from the groin to the knee. A 2.5-mm-external-diameter angioscope was passed through the medial saphenous vein to just below the proximal superficial femoral vein valve. Under direct vision, an experimental valvulotome passed through one of the angioscope ports cut the valve leaflets. In the contralateral limb, a Mills valvulotome was inserted in the same fashion and blindly cut the valve. Operative time was recorded and difficulties were noted. Bilateral ascending lower limb venography, animal sacrifice, and removal of the vein segment containing the area of previous valvulotomy for gross and histologic study were performed immediately (n = 3), and at 2 (n = 3), 7 (n = 3), 21 (n = 4), and 42 (n = 5) days after valvulotomy. In each case, both techniques had cut the valve leaflets by visual and histologic evaluation. It took significantly longer to perform the operative procedure with the angioscope (8.0 +/- 3.7 min) than with the Mills valvulotome (0.8 +/- 0.4 min) (P less than or equal to .001, Student's ttest). There was no difference in the patency of the venous system by venographic study but evaluation for a histologically normal venous system was more common with the Mills technique. The angioscopic technique demonstrated 8 of 18 samples to be histologically normal versus 14 of 18 by the Mills technique (P less than or equal to .05, chi-square test). Both techniques are effective in valve leaflet incision. The new angioscope device is more technically demanding (e.g., operative time) and may be more traumatic (e.g., histologic study). However, a gross estimation of luminal damage (venography) does not find the angioscopic method more thrombogenic. The new angioscopically directed device for venous valvulotomy does function effectively. However, adaptation to the in situ bypass technique to replace present angioscopic methods or blind valvulotomy methods requires an appraisal of just what degree of intraluminal trauma is permissible before the risks outweigh the possible benefits.

Analysis of Variance↗
PubMed1999

Evaluation of disinfection and sterilization of reusable angioscopes with the duck hepatitis B model.

PURPOSE: Nosocomial transmission of viral hepatitis and retrovirus infection has been reported. The expected risk is greatest for the hepatitis B virus (HBV). The duck HBV (DHBV) has similar biologic and structural characteristics to HBV and has been adopted as a suitable model for disinfectant testing. METHODS: Angioscopic examination of the external jugular vein was performed on DHBV-infected ducks. After use, the instrument was air dried for 3 minutes. Samples were obtained by flushing the channel with 5 mL of phosphate buffered saline solution. The samples were collected immediately after drying (control), after flushing with 5 mL of water, after glutaraldehyde disinfection for 5, 10, and 20 minutes, and after ethylene oxide gas sterilization. Angioscopes were either precleaned or uncleaned before disinfection/sterilization. Residual infectivity was assessed with inoculation of samples into the peritoneal cavity of day-old ducks (n = 231). RESULTS: DNA analysis results of liver samples showed that all 38 control ducks became infected. The frequency of DHBV infection was reduced to 93% (14 of 15) by flushing the angioscope with 5 mL of sterile water. No transmission occurred after the use of any of the properly precleaned and disinfected/sterilized angioscopes. However, after the use of the uncleaned angioscopes, the transmission rate was 90% (9 of 10) and 70% (7 of 10) after 5 and 10 minutes of contact time, respectively, in 2% glutaraldehyde. Even after the recommended 20 minutes of contact time, there was still 6% (2 of 35) transmission. After ethylene oxide sterilization, two of the recipient ducklings (2 of 35) were infected with DHBV. CONCLUSION: There was no disease transmission after reuse of disposable angioscopes adequately cleaned before disinfection or sterilization. However, if the angioscopes are inadequately cleaned, DHBV can survive despite glutaraldehyde disinfection or ethylene oxide sterilization. This contrasts with previous in vitro and in vivo data with solid surgical instruments. It is postulated that the presence of a narrow lumen or residual protein shielding within the lumen may compromise effective inactivation of hepadnaviruses on angioscopes, with the potential risk for patient-to-patient transmission.

Angioscopes↗
PubMed1996

Angioscopic evaluation of atherosclerotic plaques: validation by histomorphologic analysis and association with stable and unstable coronary syndromes.

OBJECTIVES: We validated coronary angioscopic observations with histologic assessment of material removed by atherectomy. BACKGROUND: Up to now, angioscopic findings have been primarily descriptive, and the clinical significance still needs to be substantiated. The proposed Ermenoville classification is relevant but has not yet been validated by histomorphologic analysis. METHODS: We compared angioscopic findings in patients with different coronary syndromes and used atherosclerotic material retrieved by directional coronary atherectomy to validate the angioscopic observations. Coronary angioscopy was performed in 63 patients (56 men, 7 women) with stable (26 patients) and unstable angina (37 patients) before and after directional coronary atherectomy. The identity of atherectomized material was confirmed by ex vivo visualization with the angioscope and by postatherectomy angioscopy. Angioscopic and histologic findings could be compared in 44 of 63 patients. RESULTS: Angioscopic findings were grouped into gray-white and yellow lesions (gray-yellow, deep yellow, yellow-red or yellow-pink). We found that patients with unstable angina had predominantly yellow lesions (89%). In patients with stable angina, gray-white (43%) or yellow (57%) lesions were similarly distributed. Ruptured yellow plaques and red or pink thrombi were identified in 11% of patients with stable angina and 39% of patients with unstable or early postmyocardial infarction angina. Histologically, gray-white lesions represented fibrous plaque without degeneration in 64% and with degeneration in 36% of patients. Gray-yellow lesions were associated predominantly with degenerated plaque (64%) and, to a lesser extent, with fibrous plaque (14%) or atheroma (14%). Deep yellow and yellow-red lesions represented either atheroma (53%) or degenerated plaque (42%). CONCLUSIONS: Our study establishes a histomorphologic basis for classification and interpretation of angioscopic findings. Yellow plaque color is closely related to degenerated plaque or atheroma and is associated with unstable coronary syndromes.

Angina Pectoris↗
PubMed1989

New percutaneous transluminal coronary angioscope.

A new percutaneous transluminal coronary angioscopic catheter has been developed for visualization of the coronary artery. A specially made balloon, fixed at the catheter tip, and an angulation mechanism made a precise coaxial alignment possible in the coronary lumen. This angioscopic catheter, 1.22 mm in outer diameter, has four channels, one for irrigation in which a 0.36 mm (0.014 in.) angioplasty guide wire can be used. With the use of this angioscope, coronary lumens in 8 dogs, thrombi that were produced with copper coils in the left anterior descending coronary artery in 11 dogs, atherosclerotic coronary arteries in 20 patients during cardiac catheterization and the sequence of transluminal coronary angioplasty in 1 patient were observed. The angioscopic catheter was introduced into the coronary artery by an 8F guide catheter. The steerable guide wire enabled the angioscopic catheter to be accurately and safely inserted into the target lesion in all cases. The inflated balloon and angulation mechanism allowed a curved coronary lumen and atheroma to be seen with a limited volume of irrigation fluid. Visualization was good (complete visualization of the inner lumen) in 46% (10 of 22 lesions), moderate (visualization of greater than 50% of the inner lumen) in 36% (8 of 22 lesions) and poor (visualization of less than 50% of the inner lumen) in 18% (4 of 22 lesions) in humans. There were no major complications. These preliminary experiences in closed chest cardiac catheterization in dogs and in humans indicate the feasibility of this angioscope. The information yielded by angioscopy may be clinically useful in the study of the pathophysiologic changes in coronary disease that are not detected by coronary arteriography.

Aged↗
PubMedDate not supplied

Evaluation of a prototype steerable angioscopic laser catheter in a canine model: a feasibility study.

To overcome some of the persisting technical problems related to laser angioplasty, a new catheter was designed and investigated in a canine model. This 5F catheter contained a deflectable tip for steerability, an angioscope, and a laser fiber. Catheter steerability, angioscopic function, and the effects of a 480 nm flash lamp pumped pulsed dye laser on normal canine vessel walls were evaluated. Steering, angioscopic guidance, and application of laser energy were easy and fast to perform in a bloodless vessel segment. Maintaining a condition of bloodlessness at the target site, critical to angioscopic guidance, proved to be the most difficult part in this prototype evaluation. It was noted that the 480 nm pulsed dye laser did not cause macroscopic alterations or perforations to the normal vessel wall. We conclude that a relatively simple deflection mechanism of a small-caliber angioscope provides the kind of aiming ability requisite for precise endovascular therapy. Complete bloodlessness of the area is necessary for both viewing and laser ablation at 480 nm.

Angioplasty, Balloon, Laser-Assisted↗
PubMed2001

Angioscopic predictors of restenosis following coronary angioplasty--the impact of yellow smooth plaques.

Despite angioscopy being used for more than 10 years, data regarding the prognostic significance are still limited. This study evaluated the prognostic relevance of the angioscopic lesion morphology and plaque colour on restenosis rate following coronary angioplasty. Out of 66 patients with coronary angioscopy prior to an angioplasty procedure, 46 patients with successful balloon dilation and 16 patients with stenting were included into the study. Angioscopic plaque morphology and plaque colour were correlated with the anginal status, the angiographic lesion morphology, the procedural result, and the restenosis rate during six months follow-up. Clinical follow-up was obtained from all patients, re-angiography was performed in 61%. Angioscopically complicated lesions were more frequent in patients with unstable versus stable angina (63% versus 28%, p < 0.005) and ACC/AHA type B2/C versus A/B1 stenoses (86% versus 7%, p < 0.03). In addition yellow plaques were more often seen in unstable versus stable angina (80% versus 50%, p < 0.02) and in type B2/C versus A/B1 lesions (81% versus 47%, p < 0.005). There were no deaths or myocardial infarctions during follow-up. Restenosis (n = 11) occurred significantly more frequent in patients with smooth, yellow lesions (37%) compared to all other lesion morphologies (9%, p < 0.02). Logistic regression analysis revealed angioscopically smooth, yellow plaques (p < 0.05) and angiographically type B2/C lesions (p < 0.03) as independent predictors for restenosis. We conclude that angioscopically smooth, yellow plaques covered by an intact inner vessel surface are associated with a higher incidence of restenosis following coronary angioplasty, potentially indicating a higher proliferative response after a mechanical trauma of such lesions.

Aged↗
PubMed1993

Angioscopically directed interventions improve arm vein bypass grafts.

PURPOSE: Our purpose was to determine the incidence and segmental distribution of intraluminal disease in the arm veins of patients in whom saphenous vein was unavailable or inadequate for bypass, determine whether angioscopic evaluation and directed interventions can upgrade the quality of arm vein conduit and improve early graft patency, and describe the angioscopic technique of in situ retrograde arm vein inspection. METHODS: Retrospective review of 109 infrainguinal arm vein bypass grafts in 104 patients performed with intraoperative angioscopic vein preparation and monitoring between August 1989 and March 1992 was undertaken. Four additional arm veins harvested were discarded because of diffuse disease. RESULTS: Intraluminal disease was noted in 71 (62.8%) of 113 arm veins, "webs" in 61 (54%), vein sclerosis in 25 (22.1%), localized stenosis in 11 (9.7%), and thrombus in 7 (6.2%). Intraluminal disease was most common in the cephalic (forearm 49.2%; arm 35.1%) and median cubital (33.3%) veins and least common in the basilic vein (11.7%). Eighty-three angioscopically directed interventions in 68 of 71 abnormal arm veins resulted in upgraded vein conduit quality in 47 (66.1%) of 71. Primary patency (< 30 days) was 99 (90.8%) of the 109 grafts, 85 (95.5%) of 89 grafts with normal or upgraded quality conduits, and 14 (70%) of 20 inferior-quality grafts (p = 0.0024). These differences persisted through 1 year by life-table analysis, (p < 0.001). CONCLUSIONS: Not only is the routine use of the angioscope in arm vein bypass grafting a sensitive technique to detect the intraluminal diseases so prevalent in arm veins but it can also direct endoluminal and surgical interventions that upgrade the quality of the vein conduit and improve early graft patency.

Adult↗
PubMed1996

Morphological changes after percutaneous transluminal coronary angioplasty of unstable plaques. Insights from serial angioscopic follow-up.

OBJECTIVE: To describe the morphological changes occurring in the months following percutaneous transluminal coronary angioplasty (PTCA) of unstable plaques. BACKGROUND: Coronary angioscopy is a relatively new technique to assess plaque morphology. Previous angioscopic studies have shown that unstable coronary lesions are characterized by complex morphology, evidence of plaque rupture, and intraluminal thrombi. No serial angioscopic studies have investigated the effects of PTCA on plaque morphology at such lesions. METHODS: We studied 15 patients who underwent successful PTCA for an unstable coronary syndrome (unstable angina: n = 5; recent myocardial infarction: n = 10). Angioscopy was performed immediately before PTCA in 14 patients, immediately after PTCA in 13 patients, and at follow-up (225 +/- 62 days after PTCA) in all patients. RESULTS: Pre-PTCA, plaque morphology was defined as complex in 18%, ulcerated in 27%; the vessel was totally occluded in 18% of cases. Plaque colour was yellow in 75% of patients. A thrombus was identified at the lesion site in 71% of patients. Immediately post-PTCA, small surface disruptions and dissections were observed in 62% of patients. Plaque colour was yellow in 85% of cases. Seventy-seven percent of patients had an angioscopically visible thrombus at the PTCA site. At follow-up, however, plaque shape was almost uniformly classified as smooth concentric (93%); plaque colour was white in 93%; no thrombus was observed. CONCLUSIONS: These results demonstrate the healing of unstable plaques in the months following PTCA. The angioscopic appearance at 6 months is that of a stable plaque (smooth concentric, white, without thrombus). Whether this stable angioscopic appearance predicts long-term clinical stability remains to be determined.

Adult↗
PubMed2001

Histopathologic validation of in-vivo angioscopic observation of coronary thrombus after angioplasty in a porcine model.

BACKGROUND: Coronary angioscopy has been reported to be superior to angiography and intravascular ultrasound for detecting intracoronary thrombus. However, in-vivo histopathologic validation of angioscopic detection of intracoronary thrombus had not been performed. OBJECTIVE: To perform histopathologic validation of in-vivo angioscopic detection of coronary thrombus. DESIGN: An experimental, blinded comparison of angioscopy and histopathology. METHODS: Coronary angioscopy was performed from 0 to 14 days after angioplasty in 39 porcine coronary arteries. When thrombus was detected by angioscopy, it was subclassified into white, mixed red-white, or red thrombus according to color. By histopathology the presence of thrombus was determined and subclassified into platelet-rich, mixed platelet-erythrocyte, or erythrocyte-rich thrombus. RESULTS: Angioscopy correctly classified 19 of 21 coronary thrombi (sensitivity 90%) but incorrectly classified nine of 18 arteries without formation of thrombus as having a thrombus (specificity 50%). Positive and negative predictive values were 68 and 82%, respectively. The angioscopic subclassification of thrombus into white, mixed red-white, or red thrombi was not correlated to the corresponding histopathologic morphology (platelet-rich, mixed platelet-erythrocyte, or erythrocyte-rich) of the observed thrombi (chi2 test: P = 0.5). CONCLUSIONS: Angioscopic detection of thrombus in vivo had high sensitivity and negative predictive value but low-to-moderate specificity and positive predictive value. Visual assessment of color of angioscopically detected thrombi seemed not to reflect histopathologic morphology of thrombus according to the definitions used in the present study.

Angioplasty, Balloon↗
PubMed1992

A serial observation of coronary thrombi in vivo by a new percutaneous transluminal coronary angioscope.

This study was undertaken to observe coronary thrombus formation serially from an antegrade perspective by means of a new thin flexible angioscope that has an inflatable balloon at the distal tip and an angulation mechanism. To test its capabilities, thrombi were induced in the left anterior descending coronary artery of 11 dogs by copper coils, and the thrombi were then observed through this angioscope, which had been introduced into the coronary artery by a guide catheter. Five minutes after insertion of the copper coil, fibrin-like material and white components of the thrombi were seen massing around the copper coil. Then, thin, mixed thrombotic white and red components formed around the copper coil. At fifteen minutes after the copper coil insertion, the thrombi grew in size. Ten minutes later, the thrombi finally obstructed the coronary lumen in most dogs. The red and white appearance of these thrombi was confirmed macroscopically, and the microscopic findings of these occluding thrombi revealed a fibrinous network with platelet aggregates and blood cell coagulation. Though ordinary angiography cannot reveal the precise features of the various coronary thrombi, this new angioscope was able to discern them from the antegrade perspective. The capabilities of this angioscope, which enabled these findings, should prove helpful in evaluating the stages of human coronary thrombosis. Of additional benefit, this angioscope can be used clinically for cardiac catheterization.

Animals↗
PubMed1994

In vivo angioscopic visualization of right heart structure in dogs by means of a balloon-tipped fiberoptic endoscope: potential role in percutaneous ablative procedures.

We designed an angioscopic system that consisted of a fiberoptic endoscope enclosed in a polyurethane thin-wall tube with a latex balloon attached to its distal end. In 10 anesthetized closed-chest dogs the angioscope was placed in the right heart via a femoral vein. By inflating the balloon with 5 to 10 ml of normal saline solution to displace the blood, the endocardial structure of the right heart was visualized. Under fluoroscopic guidance and direct vision, an ablation catheter was placed inside the coronary sinus or in its vicinity, and radiofrequency energy was delivered through the catheter tip to create a lesion. The appearance and anatomic location of the lesion and the endocardial structure as seen through the angioscope correlated well with the results of postmortem examination. There were no or minimal changes in heart rate, blood pressure, or cardiac output by inflating the balloon to a volume of 15 ml in the right atrium or right ventricular cavity. An inflated balloon may produce single or repetitive atrial or ventricular arrhythmias, but not sustained tachyarrhythmia. Our study demonstrates that in vivo visualization of the interior of the right heart is feasible and that our angioscope can be used to assist placement of catheter at a specific location in the right atrium and to verify its location with no or minimal hemodynamic effects and without causing significant arrhythmias.

Angioscopes↗
PubMed1991

Coronary angioscopy: a monorail angioscope with movable guide wire.

A new angioscope was devised for easier visualization of the coronary artery. In its tip, the angioscope (Olympus) with an outer diameter of 0.8 mm had a metal lumen, through which a 0.014-in steerable guide wire passed. Using a 8F guiding catheter and a guide wire, it was introduced into the distal coronary artery. With injection of warmed saline through the guiding catheter, the coronary segments were visualized. In the attempted 70 vessels (32 left anterior descending [LAD], 10 right coronary [RCA], 28 left circumflex [LCX]) from 48 patients, 60 vessels (86%) were successfully examined. Twenty-two patients who underwent attempted examination of both LAD and LCX; both coronary arteries were visualized in 19 patients (86%). In the proximal site of the lesion, 40 patients have the diagonal branch or the obtuse marginal branch. In 34 patients (85%) the angioscope was inserted beyond these branches. In 12 very tortuous vessels, eight vessels (67%) were examined. In conclusion, the new monorail coronary angioscope with movable guide wire is useful to examine the stenotic lesions of the coronary artery.

Angioplasty, Balloon, Coronary↗
PubMed1993

Angioscope-assisted endovascular occlusion of venous tributaries: preclinical studies.

The feasibility of angioscope-assisted occlusion of venous tributaries from within a vein using a steerable 'shaped-memory' nickel-titanium (nitinol) alloy catheter and occlusion coils was evaluated. An initial series of tests was designed to establish the necessary pressure (275 p.s.i., 1897.5 kPa), time (1.5 s) and volume (2.5 ml normal saline) requirements for hydraulic delivery of platinum occlusion coils from the nitinol catheter through a 3-Fr tracking catheter. In a second series, 25 side branches of the saphenous vein in 11 amputated limbs were visualized angioscopically and cannulated with the nitinol catheter under angioscopic and fluoroscopic surveillance to determine whether the catheter tip could be positioned and coils deployed. In a third series of studies, ten canine femoral vein tributaries were successfully cannulated with an 8-Fr nitinol catheter and 19 occlusion coils delivered under angioscopic surveillance. Fluoroscopy verified coil placement and all embolized venous tributaries were thrombosed. An ideal approach for femoropopliteal in situ saphenous vein bypass would allow the surgeon to divide saphenous vein valves while occluding venous side branches from within the saphenous vein. These initial studies demonstrate that the nitinol catheter can occlude venous tributaries from within a vein by coil embolization. Further development of this technique for clinical investigation is warranted.

Angioscopes↗
PubMed1989

Experimental and clinical applications of angioscopic guidance for laser angioplasty.

The role of angioscopic monitoring and aiming for control of laser intervention in the vascular system was initially investigated in 48 vessels in 33 dogs, and the techniques were then applied to 30 patients undergoing intraoperative or percutaneous laser-probe angioplasty treatment for long atherosclerotic occlusions of the femoral and popliteal arteries or well-localized lesions of the superficial femoral artery. Experimental bare argon fiber laser application in 20 normal canine arteries in vivo demonstrated that small-diameter laser fibers could be accurately aimed by manipulations of the scope. However, advancement of the fiber resulted universally in perforation, with extravasation and thermal damage of surrounding tissues after 2 seconds of argon laser energy at low power. In 28 canine and 2 human veins, angioscopically guided metallic-tipped laserprobes were used to divide 82 valve cusps in preparation for in-situ bypass, with satisfactory aiming and monitoring achieved expeditiously by manipulations of the angioscope. We conclude that angioscopic aiming of lasers is feasible in normal vessels or localized lesions. In contrast, angioscopy has a restricted role for guidance of laser angioplasty in atherosclerotic, occluded arteries, and does not prevent perforation. Postprocedural inspection allows immediate detection of complications and may avert or predict poor outcome.

Angioplasty, Balloon↗
PubMed1994

Angioscopic versus angiographic detection of intimal dissection and intracoronary thrombus.

OBJECTIVES: This study was undertaken to compare coronary angioscopy with angiography for the detection of intimal dissection and intracoronary thrombus. BACKGROUND: It has been demonstrated previously that coronary angioscopy provides more intravascular detail than cineangiography. Both imaging methods have to be compared directly to assess the additional diagnostic value of angioscopy. METHODS: The angiograms and videotapes of 52 patients who had undergone angioscopy were reviewed independently by two observers unaware of other findings. Classic angiographic definitions were used for dissection and thrombus. Angioscopic dissection was defined as visible cracks or fissures on the lumen surface or mobile protruding structures that are contiguous with the vessel wall. Angioscopic thrombus was defined as a red, white or mixed red and white intraluminal mass. RESULTS: Angiography and angioscopy were in agreement in 40.4% of cases in the absence of thrombus and in 11.5% in the presence of thrombus. No fewer than 25 (48.1%) angioscopically observed thrombi remained undetected at angiography. With angioscopy as the standard, although the specificity of angiography for thrombus was 100%, sensitivity was very low at 19%. Angioscopic dissection was present in 40 patients (76.9%) versus angiographic dissection in 15 patients (28.8%). With regard to dissection, there was no correlation between the two imaging methods (r phi = 0.15, p = 0.29). CONCLUSIONS: Coronary angiography underestimates the presence of intracoronary thrombus. Angioscopy and angiography are complementary techniques for detecting and grading intimal dissections.

Adult↗
PubMed2006

Angioscopic evaluation of neointima coverage: sirolimus drug-eluting stent versus bare metal stent.

BACKGROUND: The process of neointima formation after bare metal stent (BMS) implantation has been previously elucidated by angioscopic observations; however, that after drug-eluting stent (DES) implantation has not been clarified. Therefore, we compared the angioscopic appearance of neointima over DESs with that over BMSs 6 months after implantation. METHODS AND RESULTS: Patients who received an implantation of a BMS (n = 13) or a sirolimus DES (n = 24) were included in this study. Angiographic and angioscopic examinations were performed at 6 months. The color of the stented lesion (white or yellow), coverage of stent by neointima (not covered, covered by a thin layer, or buried under neointima), and thrombus at the stented lesion (presence or absence) were angioscopically evaluated. Of the 24 lesions in which a DES was implanted, 11 (46%) had a part where the stent strut had no coverage, 21 (88%) had a part where it was covered by a thin layer, and 11 (46%) had a part where it was buried under neointima. Of the 13 lesions in which a BMS was implanted, 1 (8%) lesion had a part where the stent strut had no coverage, 4 (31%) lesions had a part where it was covered by a thin layer, and 13 (100%) lesions had a part where it was buried under neointima. The prevalence of a stent buried under neointima (46% vs 100%, P = .001) was lower and that of thrombus (42% vs 8%, P = .03) was higher in DES-implanted lesions as compared with BMS-implanted lesions. The prevalence of thrombus (64% vs 17%, P = .005) was higher in the yellow area than in the white area when a DES was implanted. CONCLUSION: Sirolimus DESs, as compared with BMSs, were poorly covered by neointima and were accompanied by thrombus especially when there was a yellow plaque under the stents. Thus, the thrombogenic potential in DES-implanted lesions may be sustained by the inhibition of neointima formation over thrombogenic plaques.

Aged↗