Coronary excimer laser angioplasty: reduced complications and indium-111 platelet accumulation compared with thermal laser angioplasty

The relative safety and thrombogenicity of pulsed excimer and thermal laser angioplasty systems were compared in 20 normal coronary artery segments in a total of seven pigs. Using similar over the wire catheter systems and laser delivery periods of 3 to 5 s, thermal laser angioplasty was achieved with a 1.3 mm metal probe heated with 10 W of continuous argon laser energy and excimer laser angioplasty was performed with a 4.5F excimer laser catheter consisting of 13 concentrically arranged 200 microns fiber optics delivering 35 to 40 mJ/mm2 of xenon chloride (308 nm) excimer laser irradiation at a repetition rate of 25 to 30 Hz and a pulse duration of 120 ns. On angiography, the incidence of vessel perforation (1 in 10 versus 3 in 10) and abrupt vessel closure (0 in 10 versus 2 in 10) was less with excimer compared with thermal laser angioplasty. Macroscopically, there was a greater incidence of mural and occlusive thrombus formation after thermal laser than after pulsed excimer laser angioplasty. Histologic examination confirmed that this thrombogenicity was associated with greater charring and coagulation necrosis of the media. Quantitative indium-111-labeled platelet deposition was significantly increased after thermal laser angioplasty (median 87.2 x 10(6)/cm length) compared with excimer-treated (0.4 x 10(6)/cm length) or control (1.2 x 10(6)cm length) segments (p less than 0.001). Thus, excimer laser angioplasty was found to result in fewer complications and, as a consequence, less thrombosis and platelet accumulation than did thermal laser angioplasty.     

Angiographic and histologic consequences of laser thermal angioplasty: comparison with balloon angioplasty

The angiographic and histologic consequences of laser thermal angioplasty were examined and compared with those of conventional balloon angioplasty in an atherosclerotic rabbit iliac artery preparation immediately and 4 weeks after the procedure. Nineteen vessels in 13 rabbits underwent either laser thermal or balloon angioplasty in random order. Laser thermal angioplasty was performed in a total of nine vessels with either a 1.5 or 2.0 mm laser-heated metallic-capped fiber by delivery of 6 or 8 W, respectively, of argon laser energy for 5 sec duration during continuous advancement through the stenosis. Balloon angioplasty was performed in a total of 10 stenotic lesions with a 2.5 mm balloon catheter. The immediate enlargement of the angiographic luminal diameters was similar for both procedures: from 1.0 +/- 0.2 to 1.9 +/- 0.2 mm for laser thermal angioplasty vs 1.0 +/- 0.1 to 2.0 +/- 0.2 mm for balloon angioplasty. However, 4 weeks later the vessels treated with laser thermal angioplasty had less restenosis, defined as a 20% or greater reduction in luminal diameter (two of nine vessels [22%] vs 10 of 10 vessels [100%]; p less than .001), and a significantly larger mean luminal diameter (1.6 +/- 0.5 vs 1.0 +/- 0.4 mm) than those treated with conventional balloon angioplasty (p less than .02). Histologic examination 4 weeks after the procedure revealed less fibrocellular proliferation after laser thermal angioplasty, whereas those vessels treated with balloon angioplasty demonstrated evidence of prior fracture and dissection of the vessel wall with more of a fibrocellular proliferative response.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary perforation after excimer laser coronary angioplasty: The excimer laser coronary angioplasty registry experience

Objective. This study assessed the frequency of perforation with excimer coronary angioplasty.Background. Coronary artery perforation after conventional percutaneous trasluminal coronary angioplasty is extremely rare. Because laser coronary angioplasty involves actual tissue ablation, it has an Increased potential for perforation.Methods. All patients in the Excimer Laser Coronary Angioplasty Registry were included in this prospective study. Those who had a perforation related to the procedure were compared with those who did not have this complication.Results. Of 2,759 consecutive patients in the Excimer Laser Coronary Angioplasty Registry, 36 (1.3%) had perforation. In these patients, the left anterior descending coronary artery was the most frequently treated vessel (53%). There were no differences in fiber sizes between patients with and those without perforation. Among the patients with perforation, 36.1% required coronary artery bypass surgery, 16.7% experienced an infarction and 5.6% had a fatal outcome. Among the patients without perforation, the rates were 3.1%, 3.8% and 0.6%, respectively. However, 41.7% of the patients with documented coronary artery perforation did not need coronary artery bypass surgery or experience myocardial infarction or death. No angiographic characteristics distinguished lesions with from those without perforation. The frequency of coronary artery perforation declined over time with increasing operator experience, from 1.6% in the first 1,888 patients to only 0.4% in the last 1,000 patients (p = 0.002).Conclusions. With increasing operator experience, the rate of perforation with excimer laser coronary angioplasty has decreased. When perforation occurs, subsequent event rates increase.     

Experimental angioplasty: circumferential distribution of laser thermal energy with a laser probe

A new laser probe that converts argon laser energy to heat in a metallic cap on a fiberoptic fiber was compared with a bare argon laser fiberoptic catheter system for the dissolution of atherosclerotic obstructions under fluoroscopic guidance in 24 atherosclerotic rabbits. Twelve animals were randomly assigned to receive treatment with either a bare fiberoptic system or a laser probe coupled to an argon laser. Both fibers had similar outer (0.9 mm) and core (400 mu) diameters. Pulses of 1 watt for 1 second's duration were delivered from the tip of the fiberoptic system, while pulses of 6 watts for 2 seconds' duration were delivered to the laser probe. The results of angiography indicated that widening of luminal stenosis was seen in only 2 of 12 animals treated with the fiberoptic system compared with 8 of 12 animals treated with the laser probe. Perforation of the vessel wall occurred more frequently with the fiberoptic fiber (9 of 12 animals) as compared with the laser probe (1 of 12 animals). Histologic examination of direct laser radiation with the fiberoptic fiber revealed a small localized laser defect along one side of the vessel wall associated with charring, a gradient of thermal injury and considerable thrombus formation. In contrast, those vessels treated with the laser probe showed histologic evidence of thermal injury distributed evenly around the entire luminal circumference. This was associated with minimal charring, a gradient of thermal injury and thinner, flatter thrombus formation. Carbonization of the metallic tip and adherence of atherosclerotic debris with secondary vessel tearing were potential adverse effects of the laser probe.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary angioplasty at the time of initial cardiac catheterization

Following initial diagnostic cardiac catheterization in 20 patients with unstable angina, percutaneous transluminal angioplasty (PTCA) was successfully performed either immediately (15 patients) or later in the day (five patients). This approach offers certain clinical and financial advantages. PTCA immediately following diagnostic catheterization should probably only be performed by experienced operators and only when excellent cooperation with cardiovascular surgeons is possible.     

Laser angioplasty in miniature swine: advantages of a modified fiber tip delivery system

Laser angioplasty using a spherical lensed fiber-tip laser delivery catheter and a 200 mum bare silica fiber tip was performed in occluded atherosclerotic iliac arteries of miniature swine. Group I consisted of 8 animals with 11 totally occluded arteries in which the bare silica fiber was used. Group II included 22 animals with occlusive lesions in 41 arteries in which the silica lens tip was used. In vivo laser angioplasty was performed in both groups using an argon ion laser delivering 2 to 3 watts of power in 1 to 5 second intervals. Successful recanalization occurred in 7/11 (64%) in group I arteries and 35/41 (85%) in group II arteries. Vascular perforation occurred in 36% (4/11) in group I compared to 10% (4/41) in group II (P less than 0.05). Mechanical perforation due to the bare fiber alone accounted for 50% of the perforations in group I and did not occur with the silica lens-tip device (group II). We conclude that the atraumatic lensed fiber is more effective in recanalizing occlusive lesions and is a safer delivery system than the bare silica fiber.     

Coronary angioplasty performed at the same time as diagnostic coronarography

To evaluate the results of coronary angioplasty performed during the diagnostic coronary angiogram, we have compared 185 of these procedures with the characteristics of 446 consecutive angioplasties accomplished in a separate procedure from the diagnostic angiogram. There were no differences in the clinical characteristics in both groups, but more angioplasties during diagnosis were indicated after a myocardial infarction (23% vs 10%, p less than 0.001), whereas less angioplasties in this group had prior stable angina (12% vs 21%, p less than 0.025). In addition, a greater number of the angioplasties during diagnosis were used in the treatment of restenosis (24% vs 5%, p less than 0.001), and the procedure was performed as a clinical emergency in 28% vs 2%, p less than 0.001. The initial angiographic success, and the final angioplasty success in the absence of mayor complications was 93% vs 88%, p less than 0.1, and 81% vs 82%, in the angioplasties performed during diagnosis and as a separate procedure, respectively. Therefore, in our experience, the angioplasty performed during the diagnostic coronary angiogram is an effective means of treatment in patients with coronary artery disease, in particular those after myocardial infarction or those presenting with restenosis, yielding a similar rate of success both, per lesion and per procedure, than the conventional approach, the angioplasty in a separate independent procedure. These results suggest that angioplasty performed during diagnosis probably could be extended to a greater number of patients.     

Coronary angioplasty: results with expanded indications

We reviewed 600 consecutive percutaneous transluminal coronary angioplasty procedures in 530 patients. There were 475 men (89%) and 55 women (11%) with a mean age of 55 +/- 9 years. Primary success per patient was 87%. Major acute complications occurred in 58 patients (10%): 2 deaths, vessel or side branch occlusion in 44 patients and ventricular fibrillation in 12 patients. Clinical follow-up was available in 344 of the first 348 patients (99%) at 12 +/- 6 months. Of these, 242 patients (70%) underwent control angiography at 12 +/- 6 months. Including repeat angioplasty, 82% of patients (281/344) with primary success were improved by at least one New York Heart Association functional class. Coronary events among the patients with no improvement were one sudden death, one myocardial infarction, and 16 bypass operations. Four subgroups of special interest were analysed: multivessel angioplasty (100 patients), angioplasty for chronic total occlusion (100 patients), angioplasty for evolving myocardial infarction (50 patients), and repeat coronary angioplasty (70 patients). Primary success rates were 87, 56, 84 and 90%, complication rates 9, 0, 9, and 3%, and recurrence rates 41, 48, 23, and 48%, respectively. At follow-up, improvement by at least one New York Heart Association class was observed in 77, 85, 88, and 80% of patients, respectively. Successful coronary angioplasty including repeat procedures achieved a long-term clinical success in about 80% of patients.     

Coronary angioplasty at the time of initial diagnostic coronary angiography in patients with unstable angina

Of the last 200 consecutive patients undergoing PTCA procedures at our institution, 29 (15%) had unstable angina; and angioplasty was performed at the time of diagnostic coronary arteriography. There were 26 males and three females with an age range of 31-82 (mean 57) years. Factors favoring PTCA at the time of initial coronary arteriography included clinical indications for revascularization, appropriate anatomy based on high-quality fluoroscopy, and availability of emergency surgery if required. Of 34 coronary lesions in 29 patients, 19 involved the anterior branch of the left anterior descending coronary artery (LAD), eight the circumflex branch (Cx); and seven the right coronary artery (RCA). Five patients had two vessels dilated (one LAD + RCA, two LAD + Cx, and two RCA + Cx). Of the coronary artery lesions, 19 were concentric, seven were eccentric, 20 were single and discrete, six were long or multiple in the same vessel; eight vessels were totally occluded, and in nine patients there was good collateral circulation. Twenty-nine (85%) arteries were successfully dilated. Of the unsuccessful cases, one was from failure to cross a totally occluded lesion, and three residual lesions and/or postdilatation pressure gradients remained significant. One patient required emergency aortocoronary bypass surgery because of total occlusion of the LAD immediately post-PTCA. There were no postprocedural myocardial infarcts or deaths. It is concluded that, in selected patients with unstable angina, PTCA can be performed successfully and with low risk at the time of initial diagnostic coronary arteriography. This approach offers certain clinical financial advantages.     

Excimer laser angioplasty in the atherosclerotic rabbit: comparison with balloon angioplasty.

The early and late results of excimer laser angioplasty and balloon angioplasty were compared in atherosclerotic rabbit iliac arteries. Immediately after laser angioplasty (n = 13) with a bare 600 microns fiber, there was a 33% increase in angiographically measured minimum lumen diameter; after balloon angioplasty (n = 12), there was a 53% increase. Restenosis (defined as loss of at least 50% of the gain achieved by angioplasty) occurred in none of six laser-treated rabbits studied 1 month later, compared with four of six balloon-treated rabbits (p = 0.06). Planimetric measurements of cross sections of the arterial wall 1 month after angioplasty showed less intimal and medial tissue in laser-treated (1.8 +/- 0.2 mm2) than in the balloon-treated rabbits (3.0 +/- 0.4 mm2; p less than 0.05). Typical thermal effects were absent on microscopic examination of laser angioplasty sites. It is concluded that in this animal model, excimer laser irradiation results in an immediate increase in lumen diameter comparable with balloon angioplasty, but is associated with less residual atheromatous tissue than balloon angioplasty and a trend toward a lower rate of restenosis.     

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)     

Coronary angioplasty in the aged

The safety and clinical efficacy of percutaneous transluminal coronary angioplasty (PTCA) in elderly patients has not been established. PTCA was attempted in 34 patients aged 65 or more (mean age 67.4). Patients were referred for angioplasty because of significant symptomatic ischemic heart disease with either stable, unstable angina or chest pain after myocardial infarction. Primary success was achieved in 29 patients (85.3%). Significant complications were encountered in three patients (8.8%): two emergency surgical procedures (5.8%), one transmural infarction (3%). In two patients (5.8%) the PTCA failed because the balloon dilating catheter didn't cross the tight stenosis. Follow-up data (mean 13.8 +/- 10.3 months) are available: 22 (73.4%) are asymptomatic. A clinically apparent recurrence occurred in 8 patients (26.6%). Coronary angiography was performed in 19 patients (63.3%) 6.3 +/- 2.4 months after PTCA. Angiographic restenosis occurred in 10 patients (52.6%). All patients with restenosis were ridilated with completely success. In conclusion, PTCA can be performed in elderly patients with a good success rate, an acceptable complication rate, a relatively low clinically apparent recurrence rate, and should be considered as a therapeutic modality for selected geriatric patients.     

Coronary angioplasty in unstable angina and stable angina: a comparison of success and complications

One hundred and five patients with unstable angina and 175 with chronic stable angina were treated by primary percutaneous transluminal coronary angioplasty. Patients with unstable angina had had symptoms for a shorter time and were more likely to have angiographically complex lesions and lesions less than 10 mm in length than patients with chronic stable angina. Other baseline variables were not significantly different in the two groups. The overall primary success rate was similar in both groups (87% v 86%). Nine of the 14 unsuccessful procedures in those with unstable angina and nine of the 24 unsuccessful procedures in those with stable angina were the result of acute occlusion. These results led to a 9% frequency of procedure related myocardial infarction in patients with unstable angina and a 5% rate in those with stable angina (NS). The procedure related infarct rate tended to be higher in patients with unstable angina who had coronary angioplasty soon after an episode of unstable angina (mean 10 days) than in those in whom it was delayed (mean 35 days) (12% v 3%) (NS). In patients with unstable angina who had had a previous myocardial infarction procedure related infarction was significantly more common (18%) than in patients with no previous myocardial infarction (3%). The difference between those with and without previous infarction was also significant in patients with stable angina (10% v 3%).     

Experimental argon laser thermal angioplasty as an adjunct to balloon angioplasty in peripheral arteriosclerotic disease

Laser thermal recanalization has been used clinically as an adjunct to balloon angioplasty in the treatment of peripheral arteriosclerotic disease, with improved initial success rates in total peripheral occlusions and greater 1 yr vessel patency suggested, as compared to balloon angioplasty alone. However, the morphological effects of laser-assisted balloon angioplasty are unknown. Therefore, the goals of the present study were to evaluate 1) the angiographic and histologic effects of laser thermal recanalization followed by balloon angioplasty and 2) the hypothesis that balloon-catheter-induced neointimal fracture could be sealed by subsequent laser thermal angioplasty in an experimental rabbit iliac artery atherosclerotic model. In Group 1 (7 vessels), a 1.5 mm metal capped argon laser fiberoptic was introduced via femoral arteriotomy and 10 W of thermal power was applied to the iliac artery stenosis for 5 sec while maintaining constant back-and-forth motion. Thereafter, balloon angioplasty was performed in the same vessel segment with a 2.5 mm balloon catheter inflated 3 times at 5 atm for 30 sec each. Mean angiographic luminal diameter increased from 1.1 mm to 2.0 mm after both procedures, and mean final post balloon dissection grade was 0.6 on a scale of 0, 1+, and 2+. Perforation occurred once with the laser probe and once with the balloon catheter. Histologic examination of these vessels was characterized by irregular thermal erosions with minimal reactive thrombosis. In Group 2 (10 vessels), the sequence was reversed, with laser thermal angioplasty following balloon dilation. Mean angiographic luminal diameter improved from 1.2 mm to 1.8 mm after both procedures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary angioplasty in a patient with dextrocardia

This report, concerning the procedures applied to a patient with dextrocardia, describes how such a patient was able to undergo a normal diagnostic catheterization. These data should be added to the limited data on interventional procedures in patients who have this anomaly.     

Coronary angioplasty in unstable angina and stable angina: a comparison of success and complications.

One hundred and five patients with unstable angina and 175 with chronic stable angina were treated by primary percutaneous transluminal coronary angioplasty. Patients with unstable angina had had symptoms for a shorter time and were more likely to have angiographically complex lesions and lesions less than 10 mm in length than patients with chronic stable angina. Other baseline variables were not significantly different in the two groups. The overall primary success rate was similar in both groups (87% v 86%). Nine of the 14 unsuccessful procedures in those with unstable angina and nine of the 24 unsuccessful procedures in those with stable angina were the result of acute occlusion. These results led to a 9% frequency of procedure related myocardial infarction in patients with unstable angina and a 5% rate in those with stable angina (NS). The procedure related infarct rate tended to be higher in patients with unstable angina who had coronary angioplasty soon after an episode of unstable angina (mean 10 days) than in those in whom it was delayed (mean 35 days) (12% v 3%) (NS). In patients with unstable angina who had had a previous myocardial infarction procedure related infarction was significantly more common (18%) than in patients with no previous myocardial infarction (3%). The difference between those with and without previous infarction was also significant in patients with stable angina (10% v 3%).