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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↗

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↗

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↗

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↗

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↗

PubMed1997

Percutaneous coronary angioscopic comparison of thrombus formation during percutaneous coronary angioplasty with ionic and nonionic low osmolality contrast media in unstable angina.

Patients with unstable coronary syndromes are more likely to have a lesion containing thrombus and have a higher procedural complication and restenosis rate. The aim of this study was to evaluate the effect of an ionic (ioxaglate) and a nonionic (iohexol) low osmolality contrast media on thrombus generation using percutaneous intracoronary angioscopy in patients with unstable angina undergoing percutaneous transluminal coronary angioplasty (PTCA). Thirty patients with unstable angina pectoris randomized to either ioxaglate or iohexol (15 patients in each group), underwent percutaneous intracoronary angioscopy before and after PTCA and 15 minutes after PTCA. Angioscopically visible thrombus was defined using the Ermenonville classification and the lesion divided into 3 zones-proximal, mid, and distal. Angiographic filling defects were seen in 3 patients before PTCA, and in 10 after PTCA. Angioscopically visible thrombus was seen in 10 patients before PTCA in the ioxaglate group and 8 in the iohexol group. After PTCA 5 patients (33.3%) in the ioxaglate and 11 (73.6%) in the iohexol group developed new thrombus, p = 0.028. Total thrombi before PTCA were 16 versus 13, after PTCA 25 versus 27, and at 15 minutes after PTCA 23 versus 25, ioxaglate versus iohexol respectively, p = NS. There was no correlation between type or extent of intimal dissection and angioscopically visible new thrombus formation. Angiography underestimated the incidence of intracoronary thrombus before and after PTCA. Nonionic low osmolality contrast medium was associated with significantly more patients developing angioscopically visible new thrombus. This has clinical implications in the choice of contrast medium used in PTCA, particularly in the setting of unstable angina.

Aged↗

PubMed1997

Angioscopic evaluation of rotational atherectomy followed by additional balloon angioplasty versus balloon angioplasty alone in coronary artery disease: a prospective, randomized study.

OBJECTIVES: This study sought to compare, by angioscopy, the morphologic changes induced by rotational atherectomy, followed by additional angioplasty, with those observed after balloon angioplasty alone. BACKGROUND: Rotational atherectomy and balloon angioplasty act by different mechanisms, which could explain the difference in morphologic changes induced by these two techniques. METHODS: The study group included 50 patients with 50 lesions who were randomly assigned to undergo rotational atherectomy (n = 24) or balloon angioplasty (n = 26). Rotational atherectomy with a single burr (approximately equal to 70% of coronary diameter) was systematically followed by additional balloon angioplasty. Angioscopy was performed immediately after the procedure. Abnormal angioscopic findings were 1) flaps, graded from 1 to 3 (1 = intimal flap; 2 = flap protruding into < 50% of the lumen; 3 = flap protruding into > or = 50% of the lumen); 2) thrombi, graded from 1 to 3 (1 = flat deposits; 2 = protruding but nonocclusive thrombus; 3 = occlusive thrombus); 3) subintimal hemorrhage; 4) longitudinal dissection. The two groups were comparable for clinical and angiographic baseline data. RESULTS: On angioscopy, flaps were observed less frequently after rotational atherectomy followed by additional balloon angioplasty (8 [33%] of 24 lesions) than after balloon angioplasty alone (14 [54%] of 26 lesions, p = 0.08) and were also less severe (grade 1 in 6 lesions, grade 2 in 2 and grade 3 in none vs. grade 1 in 4 lesions, grade 2 in 5 and grade 3 in 5). Longitudinal dissections were also significantly less frequent: one versus six (p = 0.05). There was no difference in the incidence of angioscopic thrombi (p = 0.16) or subintimal hemorrhage (p = 0.15), but the power to detect a significant difference was low for these variables (37% and 26%, respectively). CONCLUSIONS: Rotational atherectomy followed by additional balloon angioplasty leads to fewer angioscopic dissections and a trend toward fewer intimal flaps than balloon angioplasty alone. However, our angioscopic differences did not lead to an outcome difference between the two groups.

Aged↗

PubMed1995

An angioscopic method for intraluminal aortic evaluation and stent placement.

PURPOSE: The purpose of this study was to develop an angioscopic technique to visualize the endoluminal surface of the aorta and to guide vascular stent placement. METHODS: A fiberoptic angioscope, fitted with a balloon at its tip, was passed via a carotid arteriotomy into the abdominal aorta of seven anesthetized pigs. Saline solution inflation of the balloon allowed for blood displacement and clear visualization of the endoluminal anatomy. After the left renal artery orifice had been identified with angioscopy, a catheter was inserted via a left femoral sheath to cannulate the orifice under direct visualization. The position of the catheter was verified angiographically. A vascular stent was loaded onto an angioplasty balloon, inserted through a right femoral arteriotomy, positioned by use of angioscopic visualization, and deployed immediately below the left renal artery orifice. RESULTS: The aortic trifurcation and the lumbar and renal artery orifices were clearly visualized in every animal. Vascular stents were placed in seven animals within an average of 3.14 +/- 1.14 mm (mean +/- SEM, range 0 to 8 mm) below the inferior rim of the left renal artery orifice. No stents were positioned above a renal artery orifice or obstructed blood flow. CONCLUSIONS: This angioscopic technique permitted detailed evaluation of aortic endoluminal anatomy and precise implantation of vascular stents. Direct endovascular visualization may facilitate other endovascular procedures, including endovascular grafting.

Angioscopy↗

PubMed1988

Angioscopic thromboembolectomy: preliminary observations with a recent technique.

Video angioscopy was employed in 12 patients to monitor thrombectomy or embolectomy within prosthetic bypass grafts (n = 4), saphenous vein grafts (n = 2), and native femoropopliteal arteries (n = 6). A flexible, 2.8 mm diameter angioscope was introduced into the vessel for confirmation and accurate localization of the diagnosed embolus. A Fogarty embolectomy balloon catheter was passed alongside the angioscope and balloon inflation was visually calibrated to the exact vessel lumen. Thromboembolic debris was then retrieved under direct visualization. Intraoperative angiograms were obtained in all cases and results were compared with the finding at angioscopy. After conventional thrombectomy, angioscopic inspection revealed residual thrombus within the lumen or adherent to the wall in 10 of 12 cases. Residual debris was also identified in tributary vessels in two cases, and the embolectomy catheter was successfully guided into these channels by the tip of the scope. Limb salvage was achieved in all but one patient, with early follow-up of up to 18 months. As a result of this experience we conclude that angioscopic thromboembolectomy has several advantages over the traditional blind technique: (1) accurate detection and localization of thrombus or embolus; (2) monitoring and control of the degree of balloon inflation, thereby preventing vessel wall damage caused by overinflation; (3) detection and retrieval of residual clot after blind embolectomy; (4) manipulation of the balloon catheter to selected vessels; (5) decreased requirement for repeated arteriograms; (6) increased speed, convenience, and accuracy when compared with intraoperative angiography; and (7) avoidance of surgical exposure of the distal popliteal and tibial vessels.

Adult↗

PubMed1995

Angioscopic prediction of successful dilatation and of restenosis in percutaneous transluminal coronary angioplasty. Significance of yellow plaque.

BACKGROUND: Coronary angiography has been used to assess the anatomy of coronary artery and intraluminal pathological changes. However, it has several limitations in its diagnostic quality and sensitivity in the detection of intraluminal details. Angioscopy has enabled coronary artery lumens to be visualized directly and fine intraluminal morphological changes to be detected. The information obtained by angioscopy is expected to provide new insights into the mechanisms and pathophysiology of transluminal coronary angioplasty. METHODS AND RESULTS: Forty-seven patients (39 men and 8 women) with stable angina were enrolled in the present study. Angioscopy was performed before and after angioplasty with a 0.68-mm angioscope with a double-guiding catheter system. The patients who were successfully evaluated by angioscopy were divided into two groups according to the color of the lesion: group 1, mainly yellow; and group 2, white. Angiographic, angioscopic, and clinical parameters in the two groups were compared. Detailed angioscopic findings were obtained in 36 of the 47 patients (77%) before percutaneous transluminal coronary angioplasty (PTCA) and in 24 of the 47 (51%) after PTCA. Yellow plaque were found in 13 of 36 (36%). Age, sex, presence of coronary risk factors, serum cholesterol level, and duration of angina showed no correlation with plaque color. The incidence rates of dissection and thrombi after angioplasty also were not different. Successful dilatation was achieved in 13 of 13 patients (100%) in group 1 and in 21 of 23 (91%) in group 2. The restenosis rate of group 1 was significantly lower than that in group 2 (16.7% versus 57.9%, P < .05). Cox proportional hazards model revealed that plaque color was the independent variable associated with restenosis after PTCA (P = .03). CONCLUSIONS: The restenosis rate after successful balloon angioplasty differs, with the color of the target lesion being significantly higher in patients with solely white plaque. Therefore, angioscopic findings are highly predictive of restenosis.

Angina Pectoris↗