Excimer laser-facilitated balloon angioplasty of a nondilatable lesion

Bioresorbable vascular scaffold implantation for severely calcified lesions after excimer laser lesion preparation

Bioresorbable vascular scaffolds (Absorb BVS, Abbott Vascular, Santa Clara, CA) temporarily elute antiproliferative drugs and provide vessel support, which then subsequently resorb to allow restoration of normal vessel function and architecture. To attain the best possible results with BVS, a dedicated implantation technique (PSP: adequate lesion preparation, proper sizing, postdilatation) is considered mandatory, and calcified lesions are one of the most challenging lesion subsets for BVS implantation. In five cases with severe calcifications refractory to balloon predilatation, we performed excimer laser catheter ablation (ELCA: Turbo Elite catheter; Spectranetics Corporation, Colorado Springs, CO, USA), which facilitated adequate lesion expansion with high-pressure noncompliant balloon inflation and BVS implantation. During the follow-up period (481 days [interquartile range: 445-579]), all patients continued dual antiplatelet therapy (DAPT) and there were no cases of cardiac death, myocardial infarction, or scaffold thrombosis. For treatment of severely calcified lesions with bioresorbable scaffolds, ELCA could be considered an effective potential strategy. After the procedure, prolonged DAPT was prescribed.

The use of excimer laser for complex coronary artery lesions

Excimer laser coronary atherectomy (ELCA) has been used for coronary intervention for more than 20 years. Advances in delivery systems for laser energy using the xenon-chlorine pulsed laser catheter deliver higher energy density with lower heat production. The Spectranetics CVX-300 (Spectranetics, Colorado Springs, CO, USA) excimer laser catheter system has been used for the treatment of complex coronary lesions. We report our experience with the use of this advanced system for stenoses for which were unsuitable for standard percutaneous coronary intervention; for example, balloon-resistant lesions, chronic total occlusions, and for underexpanded stents in calcified lesions. ELCA may also be valuable for thrombus-containing lesion. We find ELCA to be indispensable in the catheterization laboratory for specific complex or calcified lesions. Its role should be explored in a large randomized trial of thrombus containing lesions and saphenous vein grafts.

Improved outcome with novel device for low-pressure PTCA in de novo and in-stent lesions

PURPOSE

Complex lesion morphology requiring the use of high pressure to effect lumen expansion and in-stent restenosis (ISR) remain two indications that challenge conventional PTCA balloons. We report on a new PTCA device that is designed to provide precise, low-pressure dilatation of both de novo and in-stent lesions.

METHODS

The FX miniRAIL catheter (FX) has an integral wire positioned external to a dilating balloon and a short, 12-mm guidewire lumen distal to the balloon. The balloon inflates against the guidewire and the external wire to prevent slippage and to introduce high focal longitudinal stresses at low inflation pressures. In this initial study, the FX was used in 37 lesions (25 de novo, 12 in-stent; vessel reference diameter=2.73+/-0.49 mm) in 30 patients. A stepwise inflation protocol and QCA were used to determine the balloon pressure at which the stenosis was resolved (stenosis resolution pressure, SRP).

RESULTS

All lesions (100%) were easily reached, crossed and dilated without complication. The SRP was 4.5+/-2.9 atm, and no balloon slippage was observed. Residual stenosis after FX was 26.39+/-13.29%. Minor dissections (Types A and B) were observed in eight lesions (21.6%). Target lesion revascularization (TLR) and target vessel revascularization (TVR) at follow-up (8.1+/-1.5 months) were 8.3% and 12.5%, respectively.

CONCLUSION

The design of the FX is versatile and appears to provide for a safe, effective and improved low-pressure PTCA technique in de novo and in-stent lesions.

Laser coronary angioplasty: history, present and future

The efficacy of percutaneous transluminal coronary angioplasty (PTCA) is limited by remaining plaque tissue and the development of restenosis. It has been demonstrated that the restenosis rate is low if a large lumen diameter is achieved after coronary intervention. Debulking of coronary stenoses is a concept to increase the luminal diameter after intervention. Laser angioplasty debulks coronary stenoses by ablation of atherosclerotic plaque. Since the first intravascular laser intervention, the technique has been significantly improved by the use of optimized wavelength, the development of flexible optimally spaced multifiber catheters and an additional saline flush technique. These technical advancements allowed a reduction in the incidence of adverse events, such as the number of dissections and perforations, associated with the use of the laser technique. Coronary laser angioplasty is commonly combined with adjunctive balloon angioplasty to optimize the outcome. Laser coronary angioplasty was not followed by a lower restenosis rate compared with plain balloon angioplasty in lesions without stents, however, a randomized comparison of the techniques including the use of the saline flush technique is not available yet. The value of excimer (acronym for excited dimer) laser coronary angioplasty for treatment of in-stent restenosis is still under investigation. So far, nonrandomized single center studies have not suggested a relevant benefit for this technique used for in-stent restenosis. In nonstented lesions there remain niche indications for laser angioplasty such as the treatment of ostial lesions, diffuse lesions or lesions traversable with a guidewire but not with an angioplasty balloon. Laser coronary angioplasty may also be useful after a failed balloon angioplasty and in patients with chronic total occlusions. The potential advantages of combining laser coronary angioplasty with vaporization of thrombus in patients with acute coronary syndromes are currently under evaluation.

Excimer laser facilitated percutaneous coronary intervention of a nondilatable coronary stent

A patient is described in which excimer laser percutaneous coronary intervention is performed inside a suboptimally expanded stent due to nondilatable calcified plaque. The use of excimer laser facilitated full expansion of the stent with a balloon.

Management of resistant coronary lesions by the cutting balloon catheter: initial experience

Resistant coronary lesions remain a challenge for modern angioplasty. Classical approaches include high-pressure inflations, prolonged inflations, or balloon oversizing. More recently, new technologies like rotablator, atherectomy, or laser have been proposed as adjunct to balloon angioplasty for the treatment of these specific lesions. However, all these technologies remain more difficult to handle, costly, and they do not offer long-term benefit over conventional methods. Therefore, a simple device such as the cutting balloon catheter which has been developed from a standard over the wire balloon catheter, may prove to be useful in resistant coronary lesions. We present our single center experience using the new cutting balloon catheter in six resistant lesions.

Excimer laser-facilitated angioplasty for undilatable coronary narrowings

Calcified and fibrotic coronary artery lesions cannot always be dilated with conventional balloon angioplasty even at high pressures. This study examines the success of excimer laser facilitated angioplasty in 38 lesions in 37 patients with lesions that failed balloon angioplasty alone.

Immediate and late outcome of excimer laser and balloon coronary angioplasty: a quantitative angiographic comparison based on matched lesions

OBJECTIVES

This study sought to compare acute lumen changes and late lumen narrowing during and after excimer laser-assisted balloon angioplasty, measured by quantitative coronary angiography, with the immediate and long-term outcome of balloon angioplasty alone.

BACKGROUND

Although excimer laser coronary angioplasty is used as an adjunct or alternative to balloon angioplasty, limited comparative data exist regarding the immediate and long-term efficacy of excimer laser-assisted balloon angioplasty versus balloon angioplasty alone.

METHODS

A series of 53 lesions in 47 consecutive patients successfully treated with excimer laser-assisted balloon angioplasty were individually matched after completion of 6-month follow-up angiography with 53 successfully treated balloon angioplasty lesions according to vessel location, preprocedural minimal lumen diameter and reference diameter. Immediate and long-term angiographic results were assessed by an automated lumen contour detection algorithm.

RESULTS

Before intervention in the laser and balloon angioplasty groups, respectively, minimal lumen diameter (mean +/- SD) was 0.73 +/- 0.47 and 0.74 +/- 0.46 mm, and reference diameter was 2.71 +/- 0.42 and 2.72 +/- 0.41 mm. Laser angioplasty was followed by adjunctive balloon dilation in 50 lesions. Mean balloon diameter at maximal inflation was similar in both treatment groups (2.61 +/- 0.32 and 2.65 +/- 0.38 mm, respectively), resulting in similar minimal lumen diameters after intervention of 1.77 +/- 0.41 and 1.78 +/- 0.34 mm, respectively. At follow-up angiography, minimal lumen diameter after excimer laser-assisted balloon angioplasty was 1.17 +/- 0.63 mm, and that after balloon angioplasty alone was 1.46 +/- 0.67 mm (p = 0.02). The angiographic restenosis rates at follow-up using the 50% diameter stenosis cutoff criterion were 57% and 34%, respectively (p = 0.02).

CONCLUSIONS

Quantitative angiographic analysis of a matched group of 106 successfully treated coronary lesions showed a similar immediate outcome but reduced long-term efficacy of excimer laser-assisted balloon angioplasty compared with that after balloon angioplasty alone.

Quantitative angiographic comparison of elastic recoil after coronary excimer laser-assisted balloon angioplasty and balloon angioplasty alone

OBJECTIVES

Coronary lumen changes during and after excimer laser-assisted balloon angioplasty were measured by quantitative coronary angiography, and the results were compared with the effects of balloon angioplasty alone.

BACKGROUND

Reduction of atherosclerotic tissue mass by laser ablation in the treatment of coronary artery disease may be more effective in enlarging the lumen than balloon angioplasty alone.

METHODS

A series of 57 consecutive coronary lesions successfully treated by xenon chloride excimer laser-assisted balloon angioplasty were individually matched with 57 coronary artery lesions successfully treated by balloon angioplasty alone. The following variables were measured by quantitative coronary analysis: 1) ablation by laser, 2) stretch by balloon dilation, 3) elastic recoil, and 4) acute gain.

RESULTS

Matching by stenosis location, reference diameter and minimal lumen diameter resulted in two comparable groups of 57 lesions with identical baseline stenosis characteristics. Minimal lumen diameter before excimer laser-assisted balloon angioplasty and balloon angioplasty alone were (mean +/- SD) 0.73 +/- 0.44 and 0.74 +/- 0.43 mm, respectively. Laser ablation significantly improved minimal lumen diameter by 0.56 +/- 0.44 mm before adjunctive balloon dilation. In both treatment groups, similar-sized balloon catheters (2.59 +/- 0.35 and 2.56 +/- 0.40 mm, respectively) were used. After laser-assisted balloon angioplasty, elastic recoil was 0.84 +/- 0.30 mm (32% of balloon size), which was identical to that after balloon angioplasty alone, namely, 0.82 +/- 0.32 mm (32%). Consequently, both interventions resulted in similar acute gains of 1.02 +/- 0.52 and 1.00 +/- 0.56 mm, respectively. Minimal lumen diameter after intervention was equal in both groups: 1.75 +/- 0.35 and 1.75 +/- 0.34 mm, respectively. The statistical power of this study in which a 25% difference in elastic recoil (0.2 mm) between groups was considered clinically important was 95%.

CONCLUSIONS

In matched groups of successfully treated coronary lesions, xenon chloride excimer laser ablation did not reduce immediate elastic recoil after adjunctive balloon dilation or improve the final angiographic outcome compared with balloon angioplasty alone using similar-sized balloon catheters.

Multiple balloon rupture during coronary angioplasty. A case report

The authors report a case of coronary angioplasty of the left anterior descending artery complicated by multiple balloon rupture. Various balloon types including polyethylene terephthalate and PE 600 (ACS) ruptured at low atmospheric pressure. During balloon rupture, a septal side branch was dissected with severe intimal staining. The authors postulate that a particular lesion morphology was responsible for balloon rupture. Approaches to such lesions using alternative coronary angioplasty techniques and newer technologies are discussed.

Intravascular ultrasound imaging after excimer laser angioplasty

To help elucidate the mechanism of excimer laser coronary angioplasty (ELCA), intravascular ultrasound (IVUS) imaging was performed in 19 of 29 patients who were treated with ELCA. The results were compared with a non-randomized control group of 18 patients who had IVUS studies both before and after PTCA alone. After ELCA alone, lumen diameter (1.9 x 1.7 mm) and lumen cross-sectional area (CSA) (2.9 mm2) by IVUS were not significantly different from baseline values in the patients before PTCA alone (2.1 x 1.8 mm, 3.2 mm2). After balloon dilatation in the laser treated group, lumen diameter (2.5 x 2.1 mm) and lumen CSA (4.9 mm2) were significantly greater than those post ELCA alone. However, there was no difference in lumen CSA or atheroma CSA in the group treated with excimer laser plus balloon dilatation vs. these measurements in the group treated with PTCA alone. ELCA does not ablate a large amount of atheroma (9% reduction) but creates a pathway to permit easier passage of a PTCA balloon. These quantitative and morphologic results may help explain why the restenosis rate with ELCA is similar to PTCA alone.

Acute complications of excimer laser coronary angioplasty: a detailed analysis of multicenter results. Coinvestigators of the U.S. and European Percutaneous Excimer Laser Coronary Angioplasty (PELCA) Registries

OBJECTIVES

The aim of this study was to document and analyze the incidence and consequences of complications of excimer laser coronary angioplasty.

BACKGROUND

Excimer laser coronary angioplasty has been reported to be a safe and feasible alternative or adjunct to conventional balloon angioplasty, but serious and unique complications have been observed.

METHODS

Data on 1,595 interventions of excimer laser coronary angioplasty in 1,521 patients were analyzed, using a merged data base from the U.S. and European Percutaneous Excimer Laser Coronary Angioplasty (PELCA) registries.

RESULTS

Procedural success was achieved in 89.3% of interventions. Stand-alone laser angioplasty was performed in 17.8% of interventions. Complications included dissection (22.0%), vasospasm (6.1%), filling defects (4.8%), abrupt reclosure (6.1%), embolization (2.3%), perforation (2.4%), arrhythmia (0.7%) and aneurysm formation (0.3%). Major complications were non-Q wave myocardial infarction (2.3%), Q wave myocardial infarction (1.0%), coronary artery bypass grafting (3.1%) and death (0.7%). Logistic regression analysis revealed correlation between dissections and the use of larger catheter size (p = 0.0005), high energy per pulse levels (p = 0.0001 for native vessels), lesion length > 10 mm (p = 0.001) and presence of a side branch (p = 0.01). The incidence of perforations was higher in women (p = 0.004), in treatment of total occlusions (p = 0.02) and in the presence of a side branch (p = 0.03). Fatal complications were correlated with patients with multivessel disease (p < 0.0001), patients with acute myocardial infarction (p = 0.0009) and older patients (> 70 years old, p = 0.004). The incidence of major complications decreased after performance of 50 laser angioplasty procedures at one institution (p = 0.02).

CONCLUSIONS

This analysis defines both the learning curve and the profile of complications for excimer laser angioplasty and provides insight into the selection of appropriate patients and proper performance of the procedure.

Excimer laser-assisted coronary angioplasty for lesions containing thrombus

OBJECTIVES

The purpose of this study was to analyze the success rates for excimer laser-assisted coronary angioplasty performed in patients undergoing angioplasty for lesions containing thrombus.

BACKGROUND

The presence of intracoronary thrombus increases the risk of a poor clinical outcome after balloon angioplasty. The effect of intracoronary thrombus on the safety and efficacy of excimer laser-assisted coronary angioplasty is unknown.

METHODS

Percutaneous excimer laser-assisted coronary angioplasty was attempted in 142 patients, of whom 12 had angiographic evidence of intracoronary thrombus in 14 lesions, defined as a filling defect surrounded by contrast medium or an area of contrast staining.

RESULTS

Clinical success (< 50% residual stenosis without myocardial infarction, death or bypass surgery at any time during hospitalization) was achieved in 7 (58%) of the 12 patients with intracoronary thrombus, compared with 123 (95%) of the 130 patients without thrombus (p = 0.00001). Angiographic and clinical complications were more common in patients with thrombus: embolization (25% vs. 1%, p < 0.001), myocardial infarction (33% vs. 2%, p < 0.001), abrupt closure (17% vs. 4%, p = 0.049). Angiographic restenosis at 6 months was seen at 7 (70%) of 10 treated sites with intracoronary thrombus and at 59 (51%) of 116 sites without thrombus (p = 0.245). Presence of intracoronary thrombus was identified as the most important predictor of clinical success (p = 0.013) by multivariable logistic regression analysis, which controlled for other co-variables, such as lesion complexity or lesion location in a saphenous vein graft.

CONCLUSIONS

This analysis shows that the success of excimer laser-assisted coronary angioplasty is compromised when thrombus is detected angiographically. Further investigation of other strategies is needed to improve the outcome of angioplasty for this challenging problem.

Successful excimer laser angioplasty following unsuccessful primary balloon angioplasty

We report five patients where excimer laser coronary angioplasty facilitated successful balloon dilatation of heavily calcified lesions that could not be dilated by conventional angioplasty techniques alone. In each case, the lesion was crossed successfully with a guide wire. Conventional angioplasty failed because of inability to cross the lesion with a balloon (four lesions) or inability to dilate the lesion with balloon inflation (two lesions). These cases illustrate an indication for excimer laser coronary angioplasty as an adjunctive procedure in heavily calcified coronary stenoses.

Intraluminal vapor bubble induced by excimer laser pulse causes microsecond arterial dilation and invagination leading to extensive wall damage in the rabbit

BACKGROUND

Previous in vitro studies demonstrated that during excimer laser ablation of aortic tissue in saline, a fast-expanding and imploding vapor bubble is formed. The present in vivo study was designed to demonstrate the formation of a fast-expanding intraluminal bubble in flowing blood and to assess any damage to the adjacent arterial wall.

METHODS AND RESULTS

Excimer laser pulses (one to 10, at 55 mJ/mm2 per pulse) were delivered coaxially in the femoral and iliac arteries of nine normal rabbits. Time-resolved flash photography of dissected arteries in situ demonstrated a 50% diameter increase within 75 microseconds after the laser pulse and a subsequent invagination (150-500 microseconds) that corresponded with the temporal course of the bubble expansion (up to 3.2 mm in diameter) and implosion observed in a hemoglobin solution. One day after laser light delivery, light microscopy (47 arterial segments) showed abrasion of the internal elastic lamina, medial necrosis, and extensive dissection planes filled with red blood cells. The degree (up to 100% medial necrosis) and extent of damage (up to 1.9 mm in length) increased with the number of delivered laser pulses.

CONCLUSIONS

In blood, each excimer laser pulse generated a fast-expanding and imploding vapor bubble. In vivo, the intraluminal vapor bubble produced microsecond dilation and invagination of the adjacent arterial segment, which induced dissections and extensive wall damage far beyond the penetration depth of 308-nm laser light (< 100 microns). This unique pattern of extensive wall damage observed in the rabbit might explain the mechanism of dissection observed in humans and might have an impact on the acute and chronic outcome after excimer laser coronary angioplasty.

Rupture and entrapment of a balloon catheter in the left anterior descending artery: fluoroscopic appearance of impending balloon failure

Rupture of an angioplasty balloon in an undilated left anterior descending coronary stenosis resulted in entrapment of the balloon requiring surgical removal. The balloon was found to have a circumferential tear. The fluoroscopic appearance of impending balloon rupture is demonstrated. It is suggested that when faced with an unyielding stenosis, inflation pressure sufficient to cause impending balloon failure should be avoided.

Excimer and holmium yttrium aluminum garnet laser coronary angioplasty

Recently access to the coronary arteries became available to laser angioplasty because of a new technique utilizes a pulsed laser source and multifiber, "over-the-wire" guided catheters. The aim of this study was to evaluate the early and long-term results and the side effects of coronary angioplasty with an excimer or a Ho-YAG laser. Forty consecutive patients were treated with the Ho-YAG laser (group I) and 46 consecutive patients were treated with the excimer laser (group II). The primary laser angioplasty success rate was 55% and 72% (NS) for groups I and II, respectively. This success rate was highest in saphenous vein grafts. It was similar in calcified and noncalcified lesions and in total occlusions and stenoses. It tended to be lower in long lesions than in short ones (40% vs 60%; p < 0.05 and 44% vs 78%; NS for groups I and II, respectively). Laser stand-alone therapy was performed in 5% of patients in group I compared with 22% in group II (p < 0.05). Failures were due to the inability of the laser catheter tip to reach the lesion, to cross the obstruction, or to obtain a significant reduction in stenosis. They were more frequent in patients in group I than in those in group II (45% vs 28%). There were no deaths, no myocardial infarctions, and no need for emergency coronary artery bypass grafting because most patients had total occlusions or a well-protected coronary artery. Complications included acute closure in 8% of patients in group I and in 17% of patients in group II and spasm in 10% and 13% of patients in groups I and II, respectively. Dissection occurred more frequently in patients in group II than in those in group I (28% vs 7%; p < 0.04). The angiographic patency rate at 6-month follow-up was 33% and 29% for patients groups I and II, respectively. Multifiber, wire-guided catheters provide easy access to the coronary arteries. Excimer laser angioplasty is effective but induces a high rate of dissections. Technical improvements are required to ablate more tissue to possibly reduce the restenosis rate. Further studies are needed to elucidate the mechanism of side effects and to reduce the restenosis rate.

Laser facilitated angioplasty and thrombolysis in acute myocardial infarction complicated by prolonged or recurrent chest pain

To date, application of laser angioplasty in acute myocardial infarction (MI) has not been reported. In nine patients with acute myocardial infarction complicated by continuous or recurrent severe ischemia and chest pain, a mid-infrared, solid-state, pulse-wave holmium/thulium:YAG coronary laser was applied. In six of these patients the laser was specifically utilized for the purpose of coronary thrombolysis. In each case a guidewire was placed across the stenosis and a multifiber laser catheter was utilized, emitting 250-600 mJ/pulse at 5 Hz, followed by adjunctive balloon angioplasty. Laser success (defined as ability to cross the lesion, reduction of > or = 20% in stenosis and thrombolysis when a thrombus is present) was achieved in all patients. Final angiograms revealed residual stenosis < or = 30%, adequate thrombolysis and no major complication (MI, perforation, emergency CABGS, CVA, death) in each patient. Clinically, all nine patients improved, survived the acute infarction and were discharged. This initial clinical experience demonstrates the feasibility and safety of holmium/thulium:YAG laser application in thrombolysis and plaque ablation in selected patients who experience acute myocardial infarction complicated by prolonged or recurrent ischemia and chest pain.

Clinical success, complications and restenosis rates with excimer laser coronary angioplasty. The Percutaneous Excimer Laser Coronary Angioplasty Registry

The role of excimer laser angioplasty in treating complex coronary artery disease remains uncertain. A randomized trial comparing this new technology with balloon angioplasty cannot be designed until systematic analysis identifies the lesion types that are likely to benefit from treatment with excimer laser angioplasty. In a cohort of 764 patients who had 858 coronary stenoses treated with excimer laser-facilitated angioplasty, relative risk analysis was used to examine acute success, complications and restenosis rates, and the results were compared with those of balloon angioplasty to identify the lesion types that show the greatest benefit with the new treatment. Clinical success was achieved in 657 patients (86%), as indicated by < or = 50% residual stenosis and no in-hospital complication. A major in-hospital complication (death, bypass surgery, or Q-wave or non-Q-wave myocardial infarction) occurred in 58 patients (7.6%). Follow-up angiography was obtained in 70% of eligible patients. Combining angiographic and noninvasive restenosis rates yielded an overall restenosis rate of 46%. Relative risk analysis showed that major complications occurred frequently in lesions at an arterial bifurcation (odds ratio [OR] 5.96 [2.76, 12.6]; p = 0.001). However, certain complex lesions that are difficult to treat with balloon angioplasty (saphenous vein graft lesions, lesions > 10 mm, ostial lesions, calcified stenoses, total occlusions and unsuccessful balloon dilatations), analyzed together as a group, had lower complication rates by univariate (OR 0.59 [0.35, 1.00]; p = 0.051) and multivariate logistic regression (p = 0.006) analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Wire-guided excimer laser coronary angioplasty: instrument selection, lesion characterization, and operator technique

Laser angioplasty has now been successfully performed on over 2,000 patients worldwide. Two systems (Advanced Interventional Systems, and Spectranetics, Corp.) have now received initial approval from the Food and Drug Administration. As with all new interventional techniques designed as an alternative to balloon angioplasty, there are a variety of instrument related issues that merit consideration in terms of patient selection as well as operator technique. While the ultimate role of laser angioplasty in the percutaneous revascularization of coronary artery disease remains to be established with certainty, laser angioplasty is, in fact, being currently used on a widespread basis as an alternative or an adjunct to balloon angioplasty in a large number of centers worldwide. Industry projections suggest that the use of this technique will increase further over the next decade. Accordingly, the purpose of this article is to discuss specific issues regarding instrumentation, native anatomical considerations, operator technique, and complications that relate specifically to the applied use of this technology as it is currently being used.

Percutaneous angioscopic evaluation of luminal changes induced by excimer laser angioplasty

Angioscopy has been shown to provide more detailed information on lesion morphology before and after interventional procedures than angiography. Therefore to evaluate the effects of laser angioplasty, angioscopy was performed in five patients with peripheral or coronary vascular disease who underwent excimer laser angioplasty. The excimer laser was operated at 308 nm, 135 nsec, 25 Hz, and 40 to 60 mjoules/mm2 and was coupled into multifiber wire-guided catheters of 1.4 to 2.0 mm diameter for coronary lesions and into catheters of 2.2 mm diameter for peripheral lesions. There were three coronary (one left anterior descending, one circumflex, one right coronary artery) and two peripheral (one common iliac artery, one superficial femoral artery) lesions. Angioscopy was successfully performed before and after laser ablation without any complications in all five lesions. The characteristics of angioscopic findings after excimer laser angioplasty consisted of flaps, fractures of plaques, and abundant tissue remnants. There was no apparent thermal injury. Recanalized channels were small and irregular. These results indicate that (1) angioscopy is effective and safe for evaluation of lesion morphology after laser angioplasty; (2) laser ablation does not result in thermal injury; and (3) irregular channels after recanalization and abundant tissue remnants may explain the suboptimal results after laser angioplasty.

Excimer laser coronary angioplasty for failed PTCA

Specific indications for excimer laser coronary angioplasty (ELCA) are yet undefined. We report two specific applications of ELCA when percutaneous transluminal coronary angioplasty (PTCA) failed: (1) to facilitate balloon crossing a long rigid stenosis that could not be crossed after the lesion was wired, and (2) to overcome prominent elastic recoil of the stenosis after PTCA.

Excimer laser-facilitated coronary angioplasty. Relative risk analysis of acute and follow-up results in 200 patients

BACKGROUND

Excimer laser coronary angioplasty has been reported to be a promising treatment for complex coronary artery disease. The purpose of this study was to define the predictors of acute success and restenosis after this experimental intervention.

METHODS AND RESULTS

A cohort of 200 consecutive patients had a minimum of 6 months of follow-up evaluation after treatment of 215 coronary stenoses that were carefully selected for excimer laser coronary angioplasty. At the time of the initial procedure, the laser catheter alone produced a residual stenosis of less than or equal to 50% at 119 of 215 lesions (55.4%). For complete dilatation, 87.9% of the lesions required adjunctive balloon angioplasty. Clinical success was achieved in 183 of the 200 patients (91.5%), as indicated by a reduction by at least 20% of the narrowing of the vessel diameter, less than or equal to 50% residual stenosis, and no in-hospital complication. Complications included abrupt closure (5.0%), myocardial infarction (3.5%), bypass surgery (3.0%), perforation (2.0%), and death (0.0%). Logistic regression analysis showed that lesions at vessel bifurcations (success rate, 66%; adjusted odds ratio [OR] = 0.16; p = 0.002) or in tortuous vessels (success rate, 82%; OR = 0.48; p = 0.004) were associated with decreased clinical success. However, acceptable success rates were achieved in patients with lesions in saphenous vein grafts more than 3 years old (success rate, 94%; OR = 1.40; p = 0.75), in ostial lesions (success rate, 100%; OR = 3.36; p = 0.43), and in lesions longer than 10 mm (success rate, 93.5%; OR = 1.50; p = 0.39). Clinical follow-up was available in 197 of the 200 patients (98.5%) a mean of 5.9 +/- 1.9 months after angioplasty, at which time 31.0% of patients had developed symptoms or evidence of ischemia. No patient died during the study. Follow-up angiography was obtained in 83.1% of eligible patients after a mean [+/- SD] of 5.2 +/- 2.0 months. Angiographic restenosis, defined by greater than 50% stenosis, appeared at 78 of 164 lesions (47.6%). By logistic regression analysis, only lesions in saphenous vein grafts were associated with a decreased rate of restenosis (restenosis rate, 20%; OR = 0.18; p = 0.01).

CONCLUSIONS

This analysis, which defines the profile of risk for excimer laser angioplasty, provides a sound basis for rigorous comparison of adjunctive excimer laser with balloon angioplasty for ostial narrowings, long lesions, and saphenous vein graft stenoses.