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PubMed1992

First clinical experiences with a new angioscopic system for diagnosing peripheral vascular changes.

Conventional angiography allows a global view of regional vascular anatomy but precise information can only be deduced indirectly using contrast medium. The use of the three-dimensional picture of angioscopy, however, allows a direct evaluation of the vascular system. In order to extend our experiences with angioscopy, we employed a new micro-cardio-angioscopic system which consists of four components: a CCD color camera (360,000 pixels); a highly flexible optical probe which can be resterilised (1.4-0.6 mm diameter) incorporating 10,600-6,000 glass fibers, with a viewing angle of 140 degrees, 70 degrees, and 50 degrees and a focusing system that allows a distance from 2 mm to infinity; a high power light source and an insertion catheter with inflatable balloon. Using a known technique (intermittent blood-flow blockage and continual rinsing with NaCl solution), 36 cases involving 27 patients were examined before and after desobliteration of the femoral artery. In 88% of the cases it was possible to control the result of the intervention by angioscopy. Smaller intimal lips, the thrombotic wall, and intimal ruptures were clearly visible. Quantification of the stenoses was also successful in 88% of the cases, and in 8 patients the angioscopic findings deviated from the conventional angiogram. In 14% of the cases, angioscopic examination of the recanalisation result showed that thrombolytic therapy was necessary. Angioscopy offers the possibility of qualitative vascular diagnosis. It is a valuable addition to angiography.

Angioplasty, Laser↗
PubMed1989

Angioscope-assisted occlusion of venous tributaries with prolamine in in situ femoropopliteal bypass: preliminary results of canine experiments.

Ten mongrel dogs underwent left lower extremity in situ femoropopliteal bypass with femoral vein. A 20 to 25 cm myocutaneous bridge was left between femoral and popliteal anastomoses. A 2.8 mm angioscope was introduced intraluminally to visualize venous tributaries (VT). A balloon occlusion catheter was placed alongside the angioscope and directed in each VT. Prolamine was injected into each VT to effect occlusion. Seven dogs were followed up for 1 week and three dogs for 1 month. A total of 34 VT (range one to five per dog) were available for attempted occlusion. Twenty-nine of 84 (85%) VT were able to be occluded based on comparison of pre-VT and post-VT occlusion angiograms. Poor visualization of VT or VT too small to admit the 5F catheter were reasons for failure. We conclude that (1) in the canine model studied angioscope-assisted occlusion of femoropopliteal during bypass is technically feasible, (2) this technical detail makes unnecessary medial thigh dissection for exposure of the vein graft, and (3) during short-term observation prolamine appeared to be a suitable occluding substance.

Anastomosis, Surgical↗
PubMed1992

Femoral vein valvuloplasty: intraoperative angioscopic evaluation and hemodynamic improvement.

Femoral vein valvuloplasty (FVV) is the operation of choice for primary valvular incompetence, but this procedure is highly operator dependent for judging the competence of the valve repair during surgery. We have reviewed our experience with FVV, focusing on the utility of angioscopic-guided valve repair and hemodynamic results. Nine limbs in six patients underwent superficial FVV. There were four men and two women; the average age was 49 years (range 32 to 62 years). All limbs were Society for Vascular Surgery/International Society for Cardiovascular Surgery clinical stage III (venous ulcer), and descending phlebography showed grade 4 reflux in six limbs, grade 3 reflux in one limb, and grade 2 reflux in two limbs. In addition to FVV, five limbs underwent subfascial ligation of incompetent perforators and three limbs underwent ligation and stripping of superficial varicosities. Two limbs underwent polytetrafluoroethylene wrapping of the valvuloplasty. The last five valvuloplasties underwent angioscopic evaluation of the repair, and the last two procedures were closed valvuloplasties (without venotomy). Follow-up averaged 20.3 months (range 2 to 51 months). In all patients ulcers healed without recurrence. There were two perioperative deep vein thromboses in the polytetrafluoroethylene wrapped repairs. All superficial femoral veins were patent by duplex scanning at the time of follow-up. Venous refill time measured by light reflection rheography did not improve after surgery. Venous filling index measured by air plethysmography showed near normalization (3.83 +/- 0.82) after angioscopically guided FVV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

A modified, angioscopically assisted technique for in situ saphenous vein bypass: impact on patency, complications, and length of stay.

PURPOSE: The impact of preoperative saphenous vein mapping and intraoperative angioscopy on the results of in situ saphenous vein bypass is analyzed in this study. METHODS: A new technique developed for in situ saphenous vein bypass (ISVB) was used in 26 patients (group I) and consisted of (1) preoperative duplex scanning and mapping of the saphenous vein and its tributaries, (2) small incisions for dissecting the proximal and distal arteries and veins, (3) ligation of marked tributaries through small incisions, (4) angioscopically directed incision of venous valves with a flexible-tipped valvulotome, and (5) femoral and distal anastomoses. The results were compared with those of 14 patients (group II) in whom the technique was similar except that venous tributaries were identified angioscopically and then ligated and 24 patients (group III) who underwent standard "open" ISVB through one long incision without angioscopy or vein mapping and in whom valvulotomy was carried out with a rigid valvulotome passed through tributaries. RESULTS: In comparing the results of groups I and III, significant reductions in operative intravenous fluid requirements (1930 ml vs 2675 ml; p = 0.04), postoperative length of stay (4.4 days vs 9.1 days; p < 0.001), and wound complications (1 vs 9; p = 0.01) were observed. Angioscopic irrigation fluid volume in group I was less than that in group II (360 ml vs 1014 ml; p < 0.001). At 12 months, the primary graft patency rate in all 64 patients was 91% for femoropopliteal and 89% for femoral-infrapopliteal ISBV and 84% for the 40 patients in groups I and II. CONCLUSIONS: This report demonstrates the effectiveness of our modified technique for ISVB, which helped reduce wound complications and length of stay while satisfactory early graft patency was also maintained.

Aged↗
PubMed1995

Clinical application of coronary angioscopic examination.

BACKGROUND: The coronary artery is examined with angioscopy in addition to coronary arteriogram to evaluate the potential clinical benefit of angioscopy. Changes in the coronary artery can be visualized which might not have been recognized before. METHODS: Coronary angioscopy was applied with Inoue coronary angioscope system, in cases with coronary artery disease. In case of angioplasty, a similar procedure was repeated after intervention. RESULTS: Twenty-one cases of coronary artery disease were examined with angioscopy. Successful visualization was obtained in 15 of them, with the rate to be 71.7%. The coronary angioscopy provided useful information about the coronary tree such as severity of atherosclerosis and integrity of endothelium and intraluminal thrombosis. Angioscopic change was even more remarkable after angioplastic intervention. Almost all cases had intimal abrasion. Damage to atheroma was observed in 77% of the cases, 38.5% had an intimal flap on dilatation site, and more thrombi were observed. CONCLUSIONS: Coronary angioscopic examination is valuable in the observation of coronary atherosclerosis and is especially helpful to evaluate cases of coronary angioplasty and to survey the results of therapy and severity of damage in the management of coronary artery stenosis.

Aged↗
PubMed1994

Randomized prospective study of angioscopically assisted in situ saphenous vein grafting.

PURPOSE: A study was conducted to test the hypothesis that angioscopically assisted valve lysis and vein branch identification during in situ saphenous vein bypass would reduce technical causes of graft failure, local operative morbidity, and hospital stay. METHODS: Patients requiring primary bypass to an infrageniculate artery were randomly assigned to undergo in situ saphenous vein bypass with valvulotomy and branch identification either under angioscopic visualization with use of short intermittent incisions (scope) or under direct vision with use of a continuous incision (no scope). Data on operative details, morbidity, hospital length of stay, and graft patency were collected prospectively and compared. RESULTS: Fifty-nine patients were enrolled (32 scope, 27 no scope). There were no significant differences between study groups in the incidence of diabetes, claudication versus critical ischemia indications for surgery, or popliteal versus infrapopliteal location of distal anastomoses. Rates of wound complications (9.3% and 3.7%), early graft occlusion (6.2% and 7.4%), and mean postoperative hospital stay (8.0 and 8.6 days) were statistically similar for the scope and no scope groups, respectively. Differences in cumulative secondary patency rates at 48 months (79% scope, 91% no scope) were also insignificant. CONCLUSIONS: Use of angioscopy to assist with preparation of the in situ vein for infrageniculate grafting appears to have no impact on local operative morbidity, hospital length of stay, or midterm graft patency.

Aged↗
PubMed1991

In situ femorodistal bypass: novel technique for angioscope-assisted intraluminal side-branch occlusion and valvulotomy. A preliminary report.

To allow and facilitate complete endoluminal vein preparation under angioscopic guidance for in situ femorodistal bypass grafting, a novel instrument was constructed. In experiments in cadavers we developed the occluder valvulotome, consisting of a modified Mills' valvulotome containing a laterally-ending working channel, a retrograde cutting blade and an advanceable Teflon tube within the working channel. Using this instrument in combination with commercially available wire coils, we successfully performed five femorocrural in situ reconstructions with endoluminal valvulotomy and embolization of a total of ten thigh tributaries. The technique allows angioscope-assisted valvulotomy and simultaneous endoluminal tributary occlusion, making long skin incisions and extensive vein dissection obsolete.

Aged↗
PubMed1992

Angioscope-guided neodymium yttrium-aluminium-garnet laser valvulotomy for in situ vein bypass.

Valvulotomy for in situ vein bypass is commonly performed with a valvulotome. Although the procedure can be controlled through an angioscope, the dangers of intimal damage and valve remnants remain. An experimental study was designed to evaluate angioscopic laser valvulotomy compared with standard mechanical valvulotomy (n = 16). Two different laser probes, a bare 400-microns fibre (n = 20) and a 2-mm hot-tip (n = 26) were tested. Results were investigated by histology and scanning electron microscopy. Hot-tip laser valvulotomy achieved significantly better results than the 400-microns fibre. The Insitucat valvulotome yielded the worst results, with valve remnants in all cases and an 88 per cent rate of intimal damage. It is concluded that laser valvulotomy can be performed simply and safely with a very low incidence of valve remnants and intimal damage.

Adult↗
PubMed1994

Angioscopic evaluation of incompletely obstructing coronary intraluminal filling defects: comparison to angiography.

At 66 sites in 40 patients, we evaluated the sensitivity and specificity of coronary angiography in detecting intraluminal filling defects of varying sizes and in characterizing the contents (thrombus, intimal flap, both) of such defects using coronary angioscopy as "the gold standard." Overall angiographic sensitivity for thrombus was 37% and for intimal flap 45%. Specificity for thrombus was 100% and intimal flaps 96%. Angioscopically small flaps were less frequently seen angiographically (28%) than larger sizes (65%, p = 0.03). Angioscopically small thrombi were seen less often angiographically (30%) than larger ones (75%, p = 0.13). Filling defects (intimal flaps, thrombus, both) were characterized correctly in only 37% of sites. Angiography is relatively insensitivity in detecting intraluminal filling defects. Angioscopy may be preferred to or adjunctive with angiography in detecting these lesions.

Angioplasty, Balloon, Coronary↗
PubMed1985

Angioscopic visualization of blood vessel interior in animals and humans.

The purpose of this study is to describe the use of angioscopes in flowing bloodstreams of animals and humans, to demonstrate the ability to precisely deliver laser energy to an intravascular target using visual guidance and to determine the information content and spatial content of angioscopy. Angioscopy was performed in 5 living dogs, 16 cadaver vascular segments, and 14 patients at the time of peripheral or coronary bypass surgery. Five canine femoral artery segments received angioscopically directed intravascular Nd:YAG laser irradiation. We were able to precisely direct the laser irradiation to predetermined intimal targets. Gross tissue injury varied from none to carbonization and vascular perforation, depending on incident energy. Using a variety of flexible fiberoptic endoscopes ranging in diameter from 1.5 to 3.7 mm, we were able to visualize intravascular structures including plaque, suture lines, venous valves, and thrombi in living patients. No patient incurred complications of any sort. We conclude that angioscopy using flexible endoscopes can be performed safely, can provide clinically useful information, and may provide a means for delivering visually directed intravascular laser irradiation.

Animals↗
PubMed1991

Angioscopic assessment of fibrinolysis for impending in situ saphenous vein graft thrombosis.

A failing femorotibial in situ saphenous vein bypass graft was found by angioscopic examination to be lined with white thrombus and was successfully treated by intraoperative lytic therapy rather than by thrombectomy with a balloon catheter. The platelet-fibrin debris was completely cleared by 250,000 units of urokinase. There were no bleeding complications and the potential for mechanical damage to the venous endothelium was prevented. The in vivo angioscopic observations of fibrinolysis are described.

Aged↗
PubMed1988

Hazards of angioscopic examination: documentation of damage to the arterial intima.

The fiberoptic scope is increasingly used in the coronary and peripheral arteries to quantitate the degree and type of arterial obstructive disease and to inspect the results of procedures such as bypass grafting and laser irradiation of obstructive lesions. Since little is known about this instrument's potential complications, we passed a variety of fiberoptic scopes (1.8 to 3.6 mm outer diameter) in fresh postmortem pig coronary arteries and live monkey and canine peripheral arteries, and observed the intraluminal anatomy through the angioscope. No perforations were created, but ridges rising from the vascular luminal surface, avulsion of the endothelial lining, and small flaps attached at one end to the vessel wall were observed. Histologically, subintimal and medial tears were evident. Inserting large diameter scopes or making frequent passes (10 to 100) in coronary arteries increased intravascular injury. The use of small diameter flexible scopes or infrequent passes (less than 10) in the larger iliac and femoral arteries of live monkeys and dogs resulted in a lower frequency of myointimal sloughing or flap formation. Current fiberoptic scopes are not ideal angioscopes; they have a rigid tip, cannot be steered adequately, and are relatively stiff, resulting in a high probability of intraluminal injury, especially when used in small tortuous arteries. To decrease the risk of such injury, we recommend gentle manipulations while passing the scope and use of the smallest diameter scope possible. We further suggest limited use of the fiberscope, or at least limiting the number of passes in small vessels such as coronary arteries.

Animals↗
PubMed1993

Angioscopic evaluation of periprocedural and postprocedural abrupt closure after percutaneous coronary angioplasty.

Abrupt closure remains a significant complication of PTCA. On the basis of the presumption of underlying cause (thrombus, dissection, spasm), various empiric medical and mechanical interventions have been used to prevent and/or treat this event. Despite these measures, however, abrupt closure remains a highly unpredictable occurrence with a substantial incidence of myocardial infarction and angioplasty-related morbidity and mortality. Direct visualization of the site of abrupt closure may allow determination of responsible mechanisms and appropriate treatment strategies. Intracoronary visualization using a new angioscope was carried out in two cases of abrupt closure after percutaneous coronary angioplasty. The angioscope features a movable fiberoptic bundle that provides continuous and uninterrupted imaging of the coronary artery segment incorporating the site of abrupt closure. In one patient with intraprocedural closure angioscopy revealed obstruction of the lumen with extruded plaque material. In a second patient with postprocedural closure, however, imaging at the site of coronary artery occlusion revealed a mass consistent with a large platelet thrombus. Intracoronary evaluation with angioscopy may yield important characteristics that identify lesions at risk for abrupt closure. Further elucidation of the mechanisms underlying abrupt closure may allow more appropriate selection of therapeutic interventions.

Aged↗
PubMed1986

Correlation of coronary angioscopic to angiographic findings in coronary artery disease.

An Olympus ultrathin fiberscope, 1.8 mm outer diameter, was inserted intraluminally into 11 stenoses of the left anterior descending and circumflex coronary arteries in 8 patients at coronary bypass surgery. Intraluminal views were obtained by coupling the angioscope to a color video camera and videotape recorder, and compared with preoperative coronary angiographic findings in right and left anterior oblique views. Atherosclerotic plaque was observed as yellow-white mass attached onto the luminal lining, which may be large enough to virtually obliterate the vascular lumen. Angioscopy provided a topographic view and cross-sectional picture of stenosis not observed by angiography. Single-plane angioscopic cross-sectional stenotic lumens correlated well (r = 0.90, p less than 0.001) with calculated angiographic luminal narrowings. However, with subtotal obstruction, lesion length must be assessed angiographically. Coronary angioscopy can be a useful adjunct to angiography by providing the added dimension of the true cross-sectional view of obstruction.

Coronary Angiography↗
PubMed1991

Angioscopic evaluation of intravascular morphology after coronary endarterectomy.

Coronary endarterectomy in diffuse coronary disease is attended by an increased incidence of perioperative myocardial infarction and vein graft occlusion, which have been partially attributed to the presence of occlusive or thrombogenic intraluminal flaps in the main vessel or its smaller branches. To define the nature and incidence of these features we studied 15 endarterectomized right coronary arteries in 15 patients (12 men, 3 women; age, 55 +/- 7 years [mean +/- standard deviation]) undergoing a coronary operation for multivessel disease. After endarterectomy and distal graft anastomosis, angioscopy was performed using a 1.8-mm Olympus angioscope during graft perfusion with crystalloid solution. The endarterectomy cores were 66 +/- 30 mm in length with 11 major bifurcations and two trifurcations providing 30 major endpoints. At 22 of 30 major endpoints the distal end of the core was smooth and tapered. There were 17 minor side-branch endpoints. Angioscopy revealed the presence of wispish intraluminal fronds and medial bruising in all (100%) arteries. Twenty-nine of the 30 intraluminal endpoints could be visualized. Major intraluminal flaps were seen at the eight nontapered endpoints and six of the 21 smooth tapered endpoints that were visualized. Fifteen minor side branches could be identified angioscopically: a flap was seen at only one side-branch origin. The average examination time was 3.2 +/- 1.1 minutes (7.7% +/- 2.7% of cross-clamp time), and examination required 200 to 250 mL of perfusate. This technique enables immediate and accurate postinterventional assessment of intravascular morphology with minimal prolongation of ischemic time and has shown that small side branches are not compromised by endarterectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1987

Valvulotomy in in situ vein bypasses performed by angioscope-assisted laser probe.

The objective of this study was to evaluate the use of an angioscope-assisted laser hot-tip probe for performing valvulotomies in in situ nonreversed canine veins used for arterial bypasses. In Group 1, 9 valvulotomies were performed in 7 bypass veins with a 2-mm probe activated by 12 W power, resulting in 4 vein perforations, 1 vein thrombosis, and 4 in situ grafts patent at removal after 2-28 days. In Group 2, 10 valvulotomies in 9 bypass veins were performed with a 1.5-mm probe at 14 W with no vein perforations, 3 vein thromboses, and 6 in situ grafts patent at removal after an interval of 1 to 6 weeks. We conclude that valvulotomy within in situ vein bypasses can be successfully performed using a 1.5-mm laser hot-tip probe at 14 W power, with patency of the grafts demonstrated at 6 weeks. Angioscope-assisted laser valvulotomy using a laser probe may significantly reduce the length of incisions and the time required for in situ vein bypasses and improve the technical accuracy of the procedure.

Animals↗
PubMed2005

Association between cardiac troponin T elevation and angioscopic morphology of culprit lesion in patients with non-ST-segment elevation acute coronary syndrome.

BACKGROUND: It is well known that cardiac troponin T (TnT) elevation on admission indicates a high-risk subgroup among patients with non-ST-segment elevation acute coronary syndrome (NSEACS). Although the mechanism of TnT elevation is speculated to be the microthromboembolism from unstable plaques, it has not been clarified. The aim of this study is to clarify the association between the serum TnT elevation and the angioscopically evaluated morphology of culprit lesion in the patients with NSEACS. METHODS: Among 113 patients with NSEACS who had significant coronary stenosis, 62 patients with successful angioscopic examination were prospectively and consecutively enrolled from October 2001 to August 2002. Patients were divided into 2 groups according to the serum TnT level measured before percutaneous coronary intervention: TnT-positive or TnT-negative group. Thrombus and plaque color at culprit lesion were evaluated by angioscopy and were compared between the groups. Plaque color was determined as yellow or white, and thrombus as none, small, or large. Three different definitions for TnT-positive (> or =0.1, > or =0.03, and > or =0.01 ng/mL) were used and the sensitivity and specificity for detecting thrombus was compared. RESULTS: Prevalence of thrombus, large thrombus, and yellow plaque were all higher in TnT-positive than in TnT-negative group for 3 different cutoff values of TnT. Angiographic slow-flow occurred more frequently after percutaneous coronary intervention in TnT-positive than in TnT-negative group for 3 different cutoff values of TnT. Sensitivity/specificity of detecting large thrombus were 33%/100%, 44%/91%, and 56%/83% when TnT-positive was defined as TnT > or = 0.1, > or =0.03, and > or =0.01 ng/mL, respectively. CONCLUSIONS: Serum TnT level was significantly associated with the prevalence of thrombus and yellow plaque at the culprit lesions of NSEACS. Troponin T, when positive was defined as > or =0.01 ng/mL, still have a high specificity for detecting intracoronary thrombus.

Aged↗
PubMed2005

Serial angioscopic findings after successful intracoronary brachytherapy for in-stent restenosis.

The intracoronary changes that occur after brachytherapy for in-stent restenosis (ISR) have yet to be fully established. The purpose of this study in patients who had ISR was to examine the serial angioscopic changes in intracoronary lesions that occurred after brachytherapy. Forty-four patients who had ISR (49 lesions) underwent balloon angioplasty (n = 34) or directional atherectomy (n = 15), followed by intracoronary brachytherapy using a beta-emitting phosphorus-32 source wire. Angioscopic investigations were performed 3 and 9 months after brachytherapy. Uncovered stents were detected in 63.3% of lesions at 3 months. A significant decrease (p = 0.028) in this prevalence occurred over the next 6 months, with 36% of lesions having uncovered stents at 9 months. At 3 months, 33% of the lesions had visible erosion or ulceration and superficial thrombus. The prevalence of these characteristics was decreased at 9 months, although 17% of the lesions were still ulcerated or eroded at that time. Protruding thrombus was not observed in any lesion at 3 and 9 months. In conclusion, uncovered stents and intimal erosions or ulcerations were still present 9 months after brachytherapy in 36% and 17% of lesions, respectively. These results suggest that the healing process was not completed 9 months after brachytherapy in approximately 33% of lesions.

Aged↗