Excimer laser coronary angioplasty: the New Approaches to Coronary Intervention (NACI) experience.

In the New Approaches to Coronary Intervention (NACI) registry, 887 patients were electively treated with excimer laser coronary angioplasty (ELCA) for coronary artery disease. The Advanced Interventional System (AIS) system was used in 487 cases; the Spectranetics system, in 400. The mean age was 63.4 years. Most patients had unstable angina (60.3%); 43.7% had a prior myocardial infarction; and 18.6% were high risk or inoperable patients. Mean ejection fraction was 55.4%. A total of 1,000 lesions were treated in the 887 patients. Of the 1,000 lesions treated with ELCA in the 887 patients, 36% were in the right coronary artery; 33%, left anterior descending; 13%, circumflex; 3%, left main; and 16.6%, vein graft. By angiographic core laboratory analysis available for 752 (85%) patients with 839 lesions, lesions were 12.76 mm long. The minimum lumen diameter increased to 1.29 mm after the laser and finally to 1.95 mm after adjunctive percutaneous transluminal coronary angioplasty (PTCA) (which was performed in 93% of all lesions), with a final residual stenosis of 32.1% and Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in 95%. Dissections of grades B, C, or D were seen after 22.0% of initial laser attempts, and postlaser perforations were noted in 2.6%. Additional such dissections accumulated after adjunctive PTCA but the perforation rate remained low. Procedural success was achieved in 84% of patients, but 1.2% died, 0.7% experienced Q-wave myocardial infarction (MI), and 2.7% required emergency bypass surgery. Multiple logistic regression analysis could not identify any independent predictors of these in-hospital complications. One-year mortality was 5.7% and the cumulative incidence of Q-wave MI was 1.5%. Coronary artery bypass graft (CABG) surgery was performed in 15.0% of patients whereas 25.5% required repeat percutaneous intervention with a target lesion revascularization rate of 31%. Independent predictors of death, Q-wave MI, or target lesion revascularization (which, combined, occurred in 35.6% of patients) were the absence of prior MI, ELCA in the circumflex, perforation after the procedure, and small (<2 mm) final minimal lumen diameter. Considering the large number of patients with high-risk lesions, laser angioplasty was performed with excellent procedural success rates and a reasonable incidence of major complications.

Light-guiding effect in a two-fluid model of laser angioplasty.

Mixing and optical characteristics of blood and optical fluid, utilized in laser angioplasty, are investigated with a two-fluid model. Transport equations are solved for the zone-averaged variables of each fluid with allowance for momentum transport at the interface. The predicted volume fractions of the fluids are used as weight functions to calculate the mixture refractive index. A set of light rays are traced through the fluids to the plaque, utilizing the mixture refractive index. The results indicate significant effect of flow characteristics on the focusing of the rays.

[Cardiac interventions in Switzerland]. / Herzeingriffe in der Schweiz 1995.

For the year 1995, as for the previous 10 years, a survey of cardiac invasive and surgical procedures in Switzerland was carried out by a standardised questionnaire. At the 25 Swiss centres (10 public non academic, 10 private and 5 academic centres) a total of 11,198 coronary revascularisation procedures were performed, the majority of them (60%) by percutaneous transluminal coronary angioplasty (PTCA). Of all PTCAs, 89% were single vessel interventions. PTCA for ongoing infarction accounted for 6% of all PTCAs. The use of coronary stents has increased to 28% of all angioplasties. Other devices like directional atherectomy and rotablations have lost ground (41 cases). Thirteen interventions with intracoronary laser catheters were recorded. Among the new diagnostic tools, only coronary ultrasound has been used regularly (191 cases). Percutaneous balloon valvuloplasties (64 cases) and catheter closure of congenital shunt defects (32 cases) remained rare interventions. Procedure related mortality for PTCA was 0.7%, infarction occurred in 1.1% and emergency coronary artery bypass grafting (CABG) became necessary in 0.7%. For the first time, the total number of CABGs (4485) decreased. Among the 2077 non-coronary operations, 56% were performed for valve disease and 44% for congenital heart disease. Heart transplantation was performed in 44 patients. The majority of interventional catheter procedures were performed at the 5 university centres whereas the majority of CABGs were carried out at private centres. Four centres performed diagnostic procedures, exclusively. In-house surgical stand-by for PTCA was present in 17 of the 21 interventional centres.

The changing face of coronary interventional practice. The Mayo Clinic experience.

BACKGROUND: Devices designed to facilitate or replace conventional percutaneous transluminal coronary angioplasty have been introduced in recent years. OBJECTIVES: To characterize the changes in percutaneous coronary interventional practice over 16 years and to assess the relative use of these new devices. METHODS: We performed a retrospective analysis of all patients who underwent percutaneous coronary revascularization at Mayo Clinic, Rochester, Minn, during a 16-year period (1980-1995) and characterized the changes in procedural and clinical factors. RESULTS: The number of coronary interventional procedures performed increased from 38 in 1980 to 1284 in 1995. Atherectomy and laser angioplasty were incorporated in 1988; their use peaked in 1994 (17% of procedures) but decreased to 9.9% by 1995. In contrast, the use of intracoronary stents has increased steadily since 1990. By 1995, intracoronary stents were placed in 48.2% of procedures. The success rate improved from 55.3% in 1980 to 91.4% in 1995, although patients were older (51 +/- 10 [mean +/- SD] years in 1980 vs 63 +/- 12 years in 1995), had more extensive coronary artery disease (0% with multivessel disease in 1980 vs 47.4% in 1995), had more complex lesions, and often underwent intervention in the peri-infarction setting (2.6% of procedures in 1980 vs 17% in 1995). The rate of referral to emergency coronary bypass surgery after percutaneous procedures declined from 5.2% in 1980 to 0.4% in 1995. CONCLUSIONS: Current coronary interventional practice is expanding and improving. In contrast to intracoronary stents that have greatly affected current practice, other new devices are used infrequently. Conventional angioplasty, with or without intracoronary stents, remains the dominant treatment strategy.

Incorporation of endovascular training into a vascular fellowship program.

BACKGROUND: Despite expanding indications for endovascular therapy of peripheral vascular disease, vascular surgeons have largely remained bystanders in the use of this form of treatment for the disease, which is the focus of their profession. Lack of access to training in endovascular techniques is a major obstacle to increasing involvement by vascular surgeons. This paper reports our experience in the endovascular training of vascular surgical fellows without the involvement of radiologists. METHODS: The results of vascular surgery fellows receiving instruction in endovascular diagnostic and therapeutic procedures from vascular surgery faculty were reviewed. RESULTS: Endovascular training of vascular surgery fellows exceeded the case levels recommended by all involved societies. A diverse case mix of 355 endovascular diagnostic procedures were performed with a major complication rate of 0.3% and no procedure-related deaths. Two hundred six endovascular interventions were performed, with an initial technical success rate of 96.6%, a 30-day success rate of 93%, no major complications, and an overall intervention-related mortality rate of less than 1%. CONCLUSIONS: Vascular surgery fellows can receive endovascular training by vascular surgery faculty without the involvement of radiologists and can do so with acceptable success and complication rates. This experience is sufficient to qualify them to perform and teach endovascular therapy in their future practices.

Chronic total obstruction and short-term outcome: the Excimer Laser Coronary Angioplasty Registry experience.

Percutaneous transluminal coronary angioplasty for chronic total obstructions is associated with significantly decreased success rates in comparison with those for dilation of subtotal stenoses. Failure usually results from inability to cross the occlusive lesion with a guidewire, although it may result from inability to pass the balloon catheter after the guidewire has been passed. In the Excimer Laser Coronary Angioplasty Registry, 172 chronic total obstructions were treated in 162 patients (10.3% of the 1,569 patients entered). For chronic total obstructions, passage of a guidewire is a prerequisite for laser angioplasty. Once a guidewire crossed an occlusion, the overall laser success rate for treatment of chronic total obstructions was 83%; the extent of stenosis decreased from 100% to 55 +/- 26%. Success was independent of length of the occlusive lesion. In 74% of patients, adjunctive percutaneous transluminal coronary angioplasty was used after laser angioplasty. A final procedural success, defined as residual stenosis of less than 50% and no major complication (coronary artery bypass grafting, myocardial infarction, or death), was achieved in 90%. Major complications were infrequent; 1.2% of patients required coronary artery bypass grafting, and 1.9% had a Q-wave myocardial infarction. Only one death occurred. The use of laser angioplasty may be of particular value when chronic total obstructions can be crossed with a guidewire but not with a conventional balloon catheter or when the occlusion is confirmed to be extremely long.

[Laser versus rotation angioplasty in the recanalization of chronic femoropopliteal arterial occlusions]. / Laser- versus Rotationsangioplastie bei der Rekanalisation chronischer femoropoplitealer Arterienverschlüsse.

Between June 1987 and July 1989 laser angioplasty, and between July 1989 and December 1991 rotation angioplasty was used as the method of choice for the recanalisation of chronic (minimal duration 3 months) arterial occlusions in the femoro-popliteal region. The technical success rate and final results following supplementary balloon dilatation were identical and there was no significant difference between the two groups (laser 87%, rotation 87.7%). For long occlusions (more than 150 mm), the success rate for rotation angioplasty was 60% and significantly higher than for laser angioplasty at 40%. Complication rates for rotation angioplasty were 24.3%, higher than laser angioplasty with 20.3%. This was due to the higher incidence of emboli of 12.1% compared with the laser technique of 7.3%. Cumulative patency rates after two years showed no significant difference (uncorrelated/correlated: laser 53.4%/67.8%; rotation 56.6%/67.5%). Using lytic and aspiration techniques, the higher incidence of embolisation during rotation angioplasty had no adverse effect on final outcome. If both methods are available, it is advisable to treat long occlusions by rotation angioplasty because of the high immediate success rate, whereas short occlusions are best dealt by laser angioplasty because of the lower incidence of embolisation.

Limb perfusion. An objective measure of hemodynamic improvement after angioplasty.

Forty-four patients undergoing femoropopliteal angioplasty were studied by magnetic resonance blood flowmetry to determine quantitative limb perfusion. Baseline limb perfusion averaged 0.52 +/- 0.15 mL/min per 100 cc of tissue. Perfusion values for successful angioplasties rose within 72 hours to a mean of 1.40 +/- 0.31 mL/min per 100 cc of tissue. There were five early failures (less than 30 days), in which perfusion fell to 0.54 +/- 0.10 mL/min per 100 cc of tissue; at 6 months, 12 additional angioplasties had failed, with limb perfusion values of 0.68 +/- 0.16 mL/min per 100 cc of tissue. At 6 months, perfusion in four additional limbs had decreased to between 0.7 and 1.0 mL/min per 100 cc of tissue, with a mean change of 0.59 mL/min per 100 cc of tissue; duplex ultrasound imaging at these sites showed restenoses ranging from 50% to 75%. We conclude that lower-leg limb perfusion appears to be a reliable measure of hemodynamic improvement after femoropopliteal angioplasty and may provide an early indicator of impending failure.