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BACKGROUND: Venous thromboembolism (VTE), encompassing both deep vein thrombosis (DVT) and pulmonary embolism (PE), is a leading cause of morbidity and mortality worldwide. METHODS: GARFIELD-VTE is a prospective, non-interventional observational study of real-world treatment practices. We aimed to capture the 36-month clinical outcomes of 10,679 patients with objectively confirmed VTE enrolled between May 2014 and January 2017 from 415 sites in 28 countries. FINDINGS: A total of 6582 (61.6 %) patients had DVT alone, 4097 (38.4 %) had PE ± DVT. At baseline, 98.1 % of patients received anticoagulation (AC) with or without other modalities of therapy. The proportion of patients on AC therapy decreased over time: 87.6 % at 3 months, 73.0 % at 6 months, 54.2 % at 12 months and 42.0 % at 36 months. At 12-months follow-up, the incidences (95 % confidence interval [CI]) of all-cause mortality, recurrent VTE and major bleeding were 6.5 (7.0-8.1), 5.4 (4.9-5.9) and 2.7 (2.4-3.0) per 100 person-years, respectively. At 36-months, these decreased to 4.4 (4.2-4.7), 3.5 (3.2-2.7) and 1.4 (1.3-1.6) per 100 person-years, respectively. Over 36-months, the rate of all-cause mortality and major bleeds were highest in patients treated with parenteral therapy (PAR) versus oral anti-coagulants (OAC) and no OAC, and the rate of recurrent VTE was highest in patients on no OAC versus those on PAR and OAC. The most frequent cause of death after 36-month follow-up was cancer (n = 565, 48.6 %), followed by cardiac (n = 94, 8.1 %), and VTE (n = 38, 3.2 %). Most recurrent VTE events were DVT alone (n = 564, 63.3 %), with the remainder PE, (n = 236, 27.3 %), or PE in combination with DVT (n = 63, 7.3 %). INTERPRETATION: GARFIELD-VTE provides a global perspective of anticoagulation patterns and highlights the accumulation of events within the first 12 months after diagnosis. These findings may help identify treatment gaps for subsequent interventions to improve patient outcomes in this patient population. ispartof: THROMBOSIS RESEARCH vol:222 pages:31-39 ispartof: location:United States status: published

This paper studies the (Ramsey) optimal taxation of labor income when wage inequality is rising, as has been the case in many developed economies in recent decades. The tax schedule is a linear or affine function of labor income every period. Workers are ax-ante heterogenous in their initial productivity/wage and its growth rate. An increasing profile of tax rates over time (postponing taxation) redistributes resources to the workers whose productivity grows at a below-average rate, because their income constitutes a smaller share of the tax base in later periods. For a given path of government expenditures and transfers, postponing labor taxation is associated with an increase in the stock of government debt. A quantitative example studies the optimal policy in a model with two types of workers, calibrated to match the increasing wage inequality in the US since the 1980s. The low-skilled workers are characterised by a lower initial productivity and its growth rate than the high-skilled workers. The solution is sensitive to the Pareto weights in the social planner’s function. With equal Pareto weights on both types the optimal policy redistributes resources to the low-skilled workers by postponing taxation of labor income and increasing the stock of government debt. Over a 30-year period the optimal increase in the labor tax rate is significant, and the government debt/GDP ratio increases by 156 percentage points (linear tax schedule), or 71 percentage points (affine tax schedule). The actually observed increase in debt/GDP ratio between 1980 and 2010 (34 percentage points) is optimal if the Pareto weight on the high-skilled workers is 2-4 times the weight on the low-skilled workers.

Background Parenteral anticoagulants and vitamin K antagonists (VKAs) have constituted the cornerstone of venous thromboembolism (VTE) treatment. Meanwhile, direct oral anticoagulants (DOACs) provide physicians with an alternative. The Global Anticoagulant Registry in the FIELD (GARFIELD)-VTE observes real-world treatment practices. Objectives Describe initial anticoagulation (AC) treatment patterns in VTE patients who received parenteral AC, VKAs, and/or DOACs within ±30 days of diagnosis. Methods VTE patients were categorized into parenteral AC only, parenteral AC with transition to VKA, VKA only, parenteral AC with transition to DOAC, and DOAC only. Results A total of 9647 patients were initiated on AC treatment alone. 4781 (49.6%) patients received DOACs ± parenteral ACs; 3187 (33.0%), VKA ± parenteral ACs; and 1679 (17.4%) parenteral ACs alone. Rivaroxaban was the most frequently used DOAC (79.4%). DOACs were more frequently used in North America/Australia (58.1%), Europe (52.2%), and Asia (47.6%) than in Latin America (29.7%) and the Middle East/South Africa (32.5%). In patients with suspected VTE, most received parenteral AC monotherapy (67.7%). Patients with deep vein thrombosis were more likely to receive DOACs alone than those with pulmonary embolism with or without deep vein thrombosis (36.2% vs 25.9%). Active cancer patients received parenteral AC alone (58.9%), with 25.5% receiving DOAC ± parenteral AC and 12.8% parenteral AC and VKA. A total of 46.5% of pregnant patients received parenteral AC monotherapy, 34.0% were treated with VKA ± parenteral AC, and 19.5% received a DOAC (± parenteral AC). Conclusion AC treatment patterns vary by patient population, geographic region and site of VTE. Guidelines for AC therapy are not always adhered to.

Introduction: Lymphocyte subpopulations are identified by the uniform CD classification (Cluster of Differentiation) and can be accurately differentiated with monoclonal antibodies using the method of flow cytometry. With the aid of cordocentesis it is possible to perform studies on the status and development of cellular immunity as early as in the second trimester of pregnancy. Objective: To compare lymphocyte subpopulations present in fetuses with chromosomal abnormalities (Down’s syndrome (DS), Edwards’ syndrome (ES)) and fetuses with normal karyotype. Study Design: Prospective observational study. Methods: We examined a total of 61 pregnant women with an average age of 31.5 years (20– 46 years). Results: In fetuses with DS we found a significant decrease in B lymphocytes (CD19),a decrease in the subpopulations of multi-reactive B-cells (CD5+CD19+, B-CLL),and a decrease in the index of CD4/CD8 and class II HLA-DR. In contrast, the representation of NK cells expressing /CD3-CD (16 + 56)+/ was greatly increased. In ES we found a decrease in T lymphocytes (CD3), a decrease in T-helper lymphocytes (monocytes CD4), a decreased index of CD4/CD8 and a greater representation of NK cells /CD3-CD (16 + 56)+/. Conclusion: We determined the normal values of lymphocyte subpopulations in physiological fetuses. We demonstrated that the immunological defect of the affected fetuses is already present antenatally, and can be reliably diagnosed in the second trimester of pregnancy.

Carlo Patrono (Chairperson)* (Italy), Fedor Bachmann (Switzerland), Colin Baigent (UK), Christopher Bode (Germany), Raffaele De Caterina (Italy), Bernard Charbonnier (France), Desmond Fitzgerald (Ireland), Jack Hirsh (Canada), Steen Husted (Denmark), Jan Kvasnicka (Czech Republic), Gilles Montalescot (France), Luis Alberto Garcia Rodriguez (Spain), Freek Verheugt (The Netherlands), Jozef Vermylen (Belgium), Lars Wallentin (Sweden)

Colorectal surgery particularly as a treatment option for colorectal cancer comprises considerable and ever expanding spectrum of surgical procedures. Seniors (over 65 years of age) form the majority of patients operated for benign or malignant colon disease. High age in general poses one of the significant risks of the operation. The study analyses overall stress caused to patients by laparoscopy and laparotomy surgical procedures.Literature analysis of surgical stress in patients and prospective study of our patients' data collected over the period of four years. Comparable indicators: objectification of pre-operative stress and risks, per-operative cardiac and circulatory parameters, course of the lesion healing process, laboratory reactions of acute phase proteins, morbidity and lethality related to the surgery treatment.Comparable results of tissue response examinations demonstrated no fundamental difference between laparoscopic and laparotomic operations performed on otherwise healthy younger individuals. Laparoscopic surgery, however, appears to be fully appropriate treatment modality in majority of patients suffering from colorectal disease, even in senior age. In advanced or complicated stages of the disease the open-section surgery still remains more efficient.Age itself cannot be generally denoted as a fundamental risk factor. Co-morbid conditions, however, represent considerable risk, especially in high age patients. Laparoscopic surgery may well be applied even in senior age patients with no contra-indications. Yet, its application requires perfectly mastered laparoscopic technique and rational approach. Success of the operation in high-risk patients depends on close interdisciplinary cooperation, especially with anaesthetists.

Factor V Leiden (G1691A) and prothrombin gene (FII G20210A) mutations are independent risk factors of venous thrombosis and this risk is further increased by the combined genotype 4G/4G PAI-1.The primary objective was to identify the frequency of mutations of minor alleles and genotypes of FVL, FII G20210A and PAI-1 4G/5G in healthy Caucasians in the Prague and Central Bohemia regions. The secondary objective was to identify the occurrence of their mutual combinations.Genotyping was performed in 1,450 healthy individuals (blood donors, 981 men and 469 women) using robotic DNA isolation and subsequent PCR and melting curve analysis (Light Cycler 480 System, Roche).The minor allele frequencies in FV Leiden and FII G20210A mutations were 4.5% and 1.3% respectively. The frequency of the 4G PAI-1 allele was 55.9%. The genotype frequencies were as follows: GG 91.10%, GA 8.83% and AA 0.07% for FV Leiden; GG 97.38%, GA 2.55% and AA 0.07% for FII G20210A and 4G/4G 30.69%, 4G/5G 50.34% and 5G/5G 18.97% for PAI-1. No differences in these frequencies were found between the genders. The occurrence of the combined heterozygous FII and heterozygous FV Leiden mutations was 0.14%. The PAI-1 4G/4G genotype was combined with the heterozygous FV leiden mutation in 2.83% of cases and with the heterozygous FII mutation in 0.62% of cases.The found frequencies of genotypes and alleles confirm a relatively high prevalence of hereditary thrombophilia in the Czech Republic.

A novel radiofrequency ablative system (40 msec-train pulses with twenty 200 msecpulses at the carrier frequency of 750 KHz and 1 Hz repetition rate) aimed at recanalizing totally occluded peripheral arteries was investigated by means of in vitro tissue ablation from human postmorten arterial wall samples. The samples were submitted to irradiation with a guidewire 150 cm long, maximum diameter of ceramic tip 0.033 inch positioned perpendicular to the tissue surface in saline, contrast medium or blood using varying generator power. Ablation efficacy was determined as the depth of vaporization per pulse delivered. Electrical current for the train duration was measured as voltage at the 1 ohm-resistor. In saline, the ablation efficacy increased from 8 to 65 μm/pulse with generator power increasing from 11 W to 27.5 W. There was no significant difference in the ablation efficacy between saline and blood. In contrast medium, the ablation efficacy was significantly lower. For the same generator power, the electrical current varied during the ablation procedure from 1.3 ± 0.2 A at the beginning of the procedure to 1.1 ± 0.2 A after the first pulses and to 2.0 A before artery wall perforation occurred. Neither tissue ablation nor current variations were observed when radiofrequency energy was emitted on calcified tissue. The diameter of craters was 0.89 ± 0.1 mm (range: 0.85–0.96 mm). No major thermal injury such as carbonization or charring was observed. Thus. (1) radiofrequency energy emitted through a guidewire is reliable and effective for the ablation of arterial tissue; (2) the depth of penetration is related to the generator power; (3) the ablation efficacy is greater in saline and blood than in contrast medium; (4) the system is not effective in highly calcified tissue; and (5) the procedure may be monitored by electrical current measurements. © Wiley-Liss, Inc.

The immediate and early angiographic results in lesions treated solely with percutaneous coronary excimer laser angioplasty were compared with those obtained after combined laser and balloon angioplasty to determine whether early recoil may occur after coronary excimer laser angioplasty. The excimer laser was operated at 308 nm, 25 Hz, 40–60 mJ/mm2/pulse and 135 nsec/pulse and coupled onto multifiber wire-guided catheters of 1.4- to 2.0-mm diameter. Thirty-five consecutive patients (32 men and 3 women; mean age 56 ± 8 years) were studied. Ten patients were treated with laser angioplasty alone (group I), and 25 patients were treated using laser angioplasty followed by balloon dilatation (group II). In group I, the minimal luminal diameter increased from 1.89 ± 0.50 mm immediately after the procedure to 2.17 ± 0.51 mm at the early follow-up (P < 0.01), whereas in group II, the minimal luminal diameter decreased from 1.89 ± 0.45 mm to 1.50 ± 0.60 mm (P < 0.005). At the early follow-up, the minimal luminal diameter of group II was significantly smaller than that of group I (1.50 ± 0.60 vs 2.17 ± 0.51 mm; P < 0.05). These data demonstrate that coronary excimer laser angioplasty alone results in less severe early recoil than adjunctive balloon angioplasty. (J Interven Cardiol 1994; 7:221–228)

Coronary laser angioplasty is limited by a high rate of dissection and the occurrence of abrupt closure and perforation. The aim of this study was to visualize the mechanical effects of pulsed lasers on two chamber in vitro models. These models consisted of 1 or 2 agar layers and calcium carbonate inclusions (1-layer model) or lipid (2-layer model) simulating lipid or calcified tissue. The inclusions were irradiated with a holmium-yttrium-aluminum-garnet (Ho-YAG) laser or a xenon chloride excimer laser. The Ho-YAG laser demonstrated dissection-like expansions of the target and perforation-like cracks. The size of dissection was obtained using an the empirical formula of energy (E) and the maximal expansion distance (Dmax) of the targets, Dmax = 0.15E0,87-1,17. The excimer laser showed rare and short perforation-like cracks and little dissection-like expansion of the gaseous products originating from the ablation of material. Ho-YAG laser ablation is likely to induce target tissue dissections and/or perforations. Excimer laser ablates targets with less traumatic effects than Ho-YAG laser. © 1993 Wiley-Liss, Inc.

Venous thromboembolism is a common serious clinical condition, in which genetic factors play an important role, too. The objective of this review is to summarize current knowledge regarding the hereditary thrombophilias and submit their simple classification. Recommended Consensus of the Czech Societies on Thrombosis and Haemostasis, Haematology and Medical Genetics for genetic testing in specific patients' groups at venous thromboembolism high-risk situation is also presented.

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.

We report two cases of coronary artery aneurysmal formation as long term consequences of Ho: YAG and excimer laser coronary angioplasty. This case report suggests that pulsed laser angioplasty may result in severe vessel wall damage that may lead ultimately to aneurysmal formation.

This study attempted to determine whether anatomic findings at angioscopy were associated with adverse early angiographic outcomes following excimer laser-assisted coronary angioplasty. Predictive factors of either coronary abrupt vessel closure or early (or =24 hours) restenosis after percutaneous coronary angioplasty, including clinical and angiographic variables, have been widely evaluated. The role of angioscopic findings may contribute to identification of patients at risk for early poor outcome. Thirty-seven patients with severe lesions, including 23 total occlusions which underwent successful percutaneous transluminal coronary angioplasty (PTCA) with laser irradiation and adjunctive balloon dilatation (n = 35), or stand alone laser (n = 2), had concomitant angioscopic imaging of the target vessel. All patients had a 24-hour angiographic follow up. Early unfavorable outcome (n = 15) was defined as abrupt vessel closure or restenosis (or = 50% stenosis) at 24 hours. By multivariate logistic regression analysis, immediate post-PTCA residual percent stenosis was associated with a poor outcome (restenosis: 33 +/- 22% vs no restenosis: 21 +/- 14%, p = 0.05). Angioscopic red thrombus aspect was the most significant correlate for early closure or restenosis (7 of 15 patients with unfavorable outcome vs 2 of 22 patients with favorable outcome, odds ratio, 22.9; p0.01) and was associated with a significantly higher early minimal lumen diameter loss (1 +/- 0.8 mm in the presence of a red thrombus vs 0.3 +/- 0.5 mm without thrombus, p0.005). Red thrombus appearance is associated with an unfavorable early angiographic outcome in patients who undergo laser-assisted coronary angioplasty.

A pulsatile blood flow model was used to estimate the influence of position of Doppler guide wires with 12 MHz forward looking ultrasound transducers on the average spectral peak velocity. Three 0.014-inch and three 0.018-inch Doppler guide wires were positioned in plastic tubes ranging from 1.7 mm to 8.0 mm internal diameter. Blood flow of 50, 100 and 200 ml/min was adjusted using a roller-pump. The flow velocity was lower by 54% near the wall than in the center of large tubes (diameter 8.0 mm). In tubes of 2.9 mm and 4.2 mm in diameter the maximum variations were 11% and 22.5% for the 0.014-inch guide wire and 7.5% and 20% for the 0.018-inch guide wire, respectively. No variance in velocity related to wire position was observed in small (1.7 mm) tubes. The system was not sensitive to angular displacement of the guide wire in the range of +/- 30 degree(s). These results demonstrate that intravascular Doppler ultrasound flowmeter may be accurately utilized for measurements of blood flow velocity in small coronary arteries without any need to reposition the guidewire.

Hemopump is a ventricular assist device which is aimed at improving the management of high- risk patients for PTCA. The aim of the study was to access coronary blood flow velocity during hemopump. The hemopump was inserted percutaneously into the femoral artery. Coronary blood flow was measured with a 12 MHz Doppler-tipped guidewire proximal and distal to the stenosis before, during and after PTCA. Coronary vascular reserve was assessed by intracoronary 12 mg bolus injection of Papaverine. Collateral flow was assessed during balloon occlusion by inverted velocity signals below baseline. Eight patients aged 59 +/- 11 yrs, with unstable angina, a last patent vessel and/or major left ventricular dysfunction (EF < 0.20) had hemopump during PTCA of stenosis (86 +/- 14%) of the LAD (n equals 4) or the LCX (n equals 4). Collateral flow was slightly increased (+25 +/- 18%) by the Hemopump. Hemopump did not strongly affect coronary flow velocity, did not significantly increase collateral flow and increased slightly coronary vascular reserve.

The accuracy and reliability of intracoronary Doppler measurements were thought to depend in part on the site of measurement and to the position of the sensor relative to the arterial wall and size. To obviate this drawback Doppler velocity measurements were performed during a constant mechanically-driven pull-back at a speed of 1 mm/sec from the distal to the proximal segment of coronary arteries. Coronary blood flow velocity was measured using a 15 MHz Doppler-tipped 0.014-in guidewire with a plot trend recorded throughout the pull-back. Continuous assessment of the time-average peak velocity (APV cm/sec) was performed in 10 male singlevessel diseased patients, aged 56 ± 9 years, submitted to PTCA for a 79 ± 15 percent stenosis diameter of the left anterior descending (n = 6) or the left circumflex coronary (n ± 4) artery. The dynamic velocity measurements were also performed in the other angiographically normal left coronary artery for comparison with the trend in the stenotic arteries. APV was measured each second in the normal segments to calculate 95% confidence interval (CI). If the APV was ≥ 3 times outside the limits of CI when crossing the stenosis, the lesion was considered significant. Coronary angiogram was used as a reference for the assessment of sensitivity and specificity. Results In the angiographically normal arteries and in the non-diseased segments APVvaried smoothly. On the contrary, in the stenosed segments APV varied sharply depicting a “Manhattan-like” tracing (figure). Download : Download high-res image (70KB) Download : Download full-size image Conclusions 1. During pull-back of Doppler-tipped guidewire, velocity remains stable in non stenotic coronary segments. 2. Stenosis is associated with high changes in velocity which may reflect turbulent flow. 3. Dynamic velocity assessment may be useful for the detection of coronary stenosis.

Fabrice S. Larrazet,Patrick J. Dupouy, Jean-Luc Dubois Rande, Akira Hirosaka,Jan Kvasnicka, Herbert J GeschwindUnite d'Hemodynamique et de Cardiologie Interventionnelle,Service d'Explorations Fonctionnelles : INSERM U2,University Hospital Henri Mondor, University of Paris XII,Creteil 94010, France.

Objectives. Percutaneous intracoronary angioscopy was used to study the morphologic changes occurring in coronary arteries after balloon or laser angioplasty. Background. Angioscopy is thought to provide details of the coronary vessel lumen and the inner wall. Methods. Coronary lesions were studied in 44 patients with a 4.5F Imagecath angioscope before and after each interventional procedure. Balloon and laser angioplasty were performed in 21 (group I) and 23 patients (group II), respectively. There was no difference in age, gender or angiographic lesion appearance before the procedure between the two groups. Results. Circumferential visualization of the target lesion was successfully completed in 17 group I and 19 group II patients. A larger lumen than that observed at baseline was seen in all 17 group I and in 13 of the 19 group II patients. Tissue remnants were observed in all group I and II patients. Laser irradiation resulted in characteristic sharp-edged craters. Dissection was identified in 2 of 19 patients before versus 9 of 19 patients after balloon angioplasty (p < 0.05) and in 0 of 23 patients before versus 4 of 23 patients after laser angioplasty (p = NS). Subintimal hemorrhage was observed in 3 of 19 patients before versus 11 of 19 patients after balloon angioplasty (p < 0.05) and in 2 of 23 patients before versus 4 of 23 patients after laser angioplasty (p = NS). The frequency of hemorrhage was higher in group I than in group II (11 of 19 vs. 4 of 23, respectively, p < 0.02). Conclusions. Angioscopy provides valuable information on lesion morphology after coronary interventions. Balloon dilation results in a high rate of dissection and subintimal hemorrhage. Laser angioplasty is able to ablate obstructing tissue and results in a lower rate of subintimal hemorrhage than balloon dilation.

Excimer laser coronary angioplasty has been shown to result in high acute success rate. However, long term follow up has shown significant restenosis. To evaluate the restenosis predictive factors, we analyzed data from patients treated by excimer laser angioplasty in four French clinical centers. A cohort of 166 patients, 140 men and 26 women with mean age of 58 +/- 11 years, was enrolled in the study. Total occlusions, tubular, ostial and calcified lesions, unsuccessful balloon dilatation and/or restenosis were considered as indications for laser angioplasty. Follow-up angiography six months after the procedure was achieved in 80 patients. In conclusion, excimer laser angioplasty is associated with a high initial success rate and an acceptable major complications rate. However the use of this method is limited by significant restenosis rate.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Despite recent technological advances in laser catheter technology and the use of guidewire guidance,clinical studies still reveal an important number of arterial wall dissections and less commonly perforations following coronary laser angi361. The aim of the study was to establish a simple model of atherosclerotic arterial wall and to assess themechanical effects induced by holmium-yttrium-aluminium-garnet (Ho-YAG) laser and XeC1 excimer laser(Ex).The first model of arterial wall designed for dissection simulation consisted of two-layered agar withlipid inclusions, while the second model simulating perforation consisted of one agar layer with calciumcarbonate inclusions. Both were irradiated with laser energy doses comparable to those currently used inlaser angioplasty through 1 .4 to 2.0 mm diameter carheters. The effects of Ho-YAG and Ex were comparedin terms of the maximal distances of expanded inclusions (Dmax) and target lesions appearance.Ho-YAG irradiation of the two-layers model resulted in disruption of the agar layers and circular and/orradial expansion of the lipid inclusions into the space between them. Ex created craters with limited or no

This study was designed to assess the depth and extent of chronic lesions induced by clinically relevant doses of excimer or Ho:YAG laser irradiation in an animal model of normal arterial wall. Normal iliac arteries of 14 male New Zealand rabbits were irradiated with excimer laser and 7 contralateral sites were irradiated with Ho:YAG laser. The lasers were coupled to a 1.4 and 1.5 mm multifiber wire guided catheter for excimer and Ho:YAG laser, respectively. The catheter was introduced through the carotid artery and positioned coaxially over the guide wire into the common iliac artery. After 28 days the irradiated sites were excised for light microscopy. Arterial wall lesions were assessed at the site of irradiation and at 30 mm antegrade to the site of intervention. (1) Excimer and Ho:YAG induce chronic arterial wall damage, which may result in accelerated restenosis. (2) Ho:YAG results in deeper and more extensive lesions than excimer. (3) Both lasers induce an initial vasodilation in the irradiated vessel which disappears at follow-up.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

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%; p0.05 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 (p0.05). 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%; p0.04). 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.

This study was performed to assess the ablational properties of 1.4-, 1.7-, and 2.0-mm wire-guided multiple fiber catheters coupled to a XeCl excimer laser. Samples of postmortem human aorta were irradiated in blood at fluences of 40, 50, and 60 mJ/mm2. Our results indicate that: 1) an increase in the active irradiation coverage results in an increase in the ablation efficiency; 2) the ablation efficiency is not fluence related using the 1.4- or 1.7-mm multiple fiber catheter but efficiency is fluence dependent using the 2.0-mm multiple fiber catheter; 3) the depth of tissue ablated with a multiple fiber catheter depends primarily upon the proportion of the active irradiation coverage at the catheter tip: 4) the 2.0-mm multiple fiber catheter induces craters surrounded by a larger zone of tissue damage than that observed with the 1.4- or 1.7mm multiple fiber catheter; and 5) the 2.0-mm multiple fiber catheter should be used cautiously for laser angioplasty because of its high penetration and its risk of arterial wall damage. (J Interven Cardiol 1992; 5:263–273)

Pulsed laser coronary angioplasty with an excimer or a holmium-yttrium-aluminum-garnet (Ho:YAG) laser may become an alternative treatment for patients with coronary artery disease. However, little is known about its acute consequences on the normal arterial wall. This study was designed to examine the acute histologic consequences of these two pulsed lasers on the arterial wall of normal iliac arteries in rabbits. Irradiation with each laser was performed in 15 normal iliac sites on eight male New Zealand white rabbits. The excimer laser was operated at 308 nm, 25 Hz, 50 mJ/mm2/pulse, and 135 nsec/pulse and the Ho:YAG laser was operated at 2.1 micrometers , 3/5 Hz, 400 mJ/pulse, and 250 microsecond(s) ec/pulse. The excimer and Ho:YAG laser were coupled into a multifiber wire-guided catheter of 1.4 and 1.5 mm diameter, respectively. The sites irradiated with excimer or Ho:YAG laser had the same kinds of histologic features, consisting of exfoliation of the endothelium, disorganization of internal elastic lamina, localized necrosis of vascular smooth muscle cells, and fissures in the medial layer. However, the sites irradiated with excimer laser had lower grading scores than those irradiated with Ho:YAG laser (p < 0.05). Laser irradiation with excimer or Ho:YAG laser of normal arteries results in localized mechanical vascular injury.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Angioscopy has proved 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 - 60 mJ/mm2 and was coupled into multifiber wire-guided catheters of 1.4 to 2.0 mm diameter for coronary lesions and 2.2 mm 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.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Recently, access to the coronary arteries became available to laser angioplasty based upon a new concept which 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 using an excimer or a Holmium:YAG laser. Forty consecutive patients were treated with the Holmium: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 71.7% for group I and II, respectively. It was similar in calcified and in non-calcified lesions and in total occlusions and stenoses. Laser stand-alone therapy was obtained in 5.0% of group I patients versus 21.7% in group II patients (p < 0.05). Failures were due to the inability for 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 group I than in group II patients (45% versus 28.3%). Complications included acute closure in 7.5% of group I and 17.1% of group II patients and spasm in 10.0% and 13.0% of group I and group II patients, respectively. Dissection occurred more frequently in group II than in group I patients (28.3% versus 7.5%, p < 0.04). The angiographic patency rate at 6 month follow up was 33% and 29% for group I and group II patients, respectively. Multifiber, wire-guided catheters provide an easy access to the coronary arteries. Excimer laser angioplasty using large, densely packed catheters 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 ar needed to elucidate the mechanism of side effects to reduce their impact on restenosis rate.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Excimer lasers are being extensively used for coronary angioplasty along with multifiber over-the-wire catheters. To determine whether another wavelength could be an alternative, the laser-tissue interaction and the clinical usefulness of an infrared laser were studied. The laser consisted of a Holmium YAG pulsed laser coupled into a multifiber catheter. Experimental data from our laboratory showed that this solid stale laser had the ability to cut calcified tissue, to be preferentially absorbed by atheroma, and to ablate tissue even when the catheter tip was positioned at a distance from the target. These results were obtained with only minimal thermal effects. After assessment of the efficacy and safety of this technique, laser angioplasty was performed in 53 consecutive patients with totally occluded (40%) or stenosed (mean percent 94) coronary arteries with a mean length of 6 mm. The primary laser and the procedure success rate were 64% and 94%, respectively. Failures were due to inability to advance the catheter against the lesion or to cross the obstruction. Stand-alone laser therapy could be achieved in only 18% of patients. In previous dilatation failures, laser irradiation allowed for subsequent balloon angioplasty to be successfully performed at a lower inflation pressure than that used in the failed dilatation. Complications included abrupt (during the procedure) and early (within 24 hours) vessel closure in 19% of cases, dissection without hemodynamic consequence in 28% and spasm. Reoccluded arteries could all be recanalized with dilatation. There was no death, myocardial infarction, and no urgent coronary artery bypass surgery (CABG). Thus, infrared laser angioplasty is effective in difficult lesions for dilatation. The results are obtained with a reliable, easy to use and to maintain laser source.

This study was designed to examine the acute response of normal arterial wall to pulsed laser irradiation. Irradiation with an Excimer or a Holmium YAG laser was performed in 15 normal iliac sites of 8 male New Zealand white rabbits. The excimer laser was operated at 308 nm, 25 Hz, 50 mj/mm2/pulse, and 135 nsec/pulse and the Ho:YAG laser was operated at 2.1 μm, 3.5 Hz, 400 mj/ pulse, 250 μsec/pulse. The excimer and Ho:YAG laser were coupled into a multifiber wire-guided catheter of 1.4 and 1.5 mm diameter, respectively. The mean luminal diameter increased similarly from 2.01 ± 0.29 to 2.46 ± 0.27 mm (P < 0.0005) and from 2.09 ± 0.53 to 2.45 ± 0.30 mm (P < 0.005) after excimer and Ho:YAG laser irradiation, respectively. Perforation occurred in 3 of 15 Ho:YAG irradiated sites and 0 of 15 excimer laser irradiated sites. The sites irradiated with excimer or Ho:YAG laser had similar histologic features, consisting of shedding of the endothelium, disorganization of internal elastic lamina, localized necrosis of vascular smooth muscle cells, and fissures in the medial layer. However, the sites irradiated with excimer laser had lower grading scores than those irradiated with the Ho:YAG laser (P

Percutaneous transluminal laser angioplasty with a pulsed Nd:YAG laser (1,064 nm wavelength, 100 jig pulse duration, up to 0.4 J per pulse, 10 Hz repetition rate) coupled to optical fibers with sapphire tips of 1.8, 2.2 and 2.9 mm diameter was performed in 17 chronic occlusions of iliac, femoral, popliteal and fibular arteries in 15 patients. Clinically the procedure was successful in 14 cases. The probe formed a primary channel of at least 2.0 mm width which was further dilated by conventional balloon catheter. Ankle/brachial systolic pressure index (ABPI) increased from 0.46 0.13 to 0.84 0.21 after the procedure. Two failures were due to an extensive dissection which occurred after balloon angioplasty and resulted in an early reocclusion. In the remaining case a balloon catheter could not be introduced through the 30 cm long primary channel which reoccluded shortly after the recanalization. The initial patency rate was 82 % and in 5 patients followed for more then 6 months the ABPI showed only a minor decrease. These first results are encouraging and it is likely that this method could become an important alternative to conventional balloon angioplasty.