Angioplasty of the proximal left anterior descending coronary artery: initial success and long-term follow-up.
(9/33)
From 1984 to 1987, 537 consecutive patients (mean age 58 years; range 34 to 79) underwent angioplasty for proximal left anterior descending coronary artery disease. The procedure was clinically successful in 516 (96.1%). Procedural complications included myocardial infarction (2.2%; Q wave 0.9%, non-Q wave 1.3%), in-hospital bypass surgery (3%) and death (0.4%). Follow-up was obtained in 534 patients (99.8%) for a mean duration of 44 months (range 8 to 75). Follow-up cardiac catheterization, performed in 391 patients (76%), demonstrated a 39.6% angiographic restenosis rate. Ninety-eight (19%) of the patients with a clinically successful result required additional revascularization for recurrent left anterior descending artery disease by angioplasty (12.8%) or coronary artery bypass grafting (4.7%), or both (1.5%). During follow-up there was a 2.5% incidence rate of myocardial infarction (anterior myocardial infarction 1.6%), and 27 patients (5.2%) died, 14 (2.7%) of cardiac causes. The actuarial 5-year cardiac survival rate was 97%, freedom from cardiac death and myocardial infarction was 94% and freedom from cardiac death, myocardial infarction, coronary artery bypass surgery and repeat left anterior descending artery angioplasty was 77%. At last follow-up 76% of patients were free of angina and 88% reported sustained functional improvement. Angioplasty is an effective treatment for proximal left anterior descending coronary artery disease that has a high success rate, low incidence of procedural complications and provides excellent long-term cardiac survival, freedom from cardiac events and sustained functional improvement. (+info)
Pulsed laser and thermal ablation of atherosclerotic plaque: morphometrically defined surface thrombogenicity in studies using an annular perfusion chamber.
(10/33)
Although clinical trials using laser and thermal angioplasty devices have been underway, the effects of pulsed laser and thermal ablation of atherosclerotic plaque on surface thrombogenicity are poorly understood. This study examined the changes in platelet adherence and thrombus formation on freshly harvested atherosclerotic aorta segments from Watanabe-heritable hyperlipidemic rabbits after ablation by two pulsed laser sources (308-nm xenon chloride excimer and 2,940-nm erbium:yttrium-aluminum-garnet [YAG] lasers) and a prototype catalytic hot-tip catheter. Specimens were placed in a modified Baumgartner annular chamber and perfused with citrated whole human blood, followed by quantitative morphometric analysis to determine the percent surface coverage by adherent platelets and thrombi in the treated and contiguous control areas. Pulsed excimer laser ablation of plaque did not change platelet adherence or thrombus formation in the treated versus control zones. However, photothermal plaque ablation with a pulsed erbium:YAG laser resulted in a 67% reduction in platelet adherence, compared with levels in control areas (from 16.7 +/- 2.2% to 5.5 +/- 1.8%; p less than 0.005). Similarly, after plaque ablation using a catalytic thermal angioplasty device, there was a 74% reduction in platelet adherence (from 29.2 +/- 5.1% to 7.7 +/- 1.6%; p less than 0.005) and a virtual absence of platelet thrombi (from 8.6 +/- 2.3% to 0.03 +/- 0.03%; p less than 0.005). This reduced surface thrombogenicity after plaque ablation with either an erbium:YAG laser or a catalytic hot-tip catheter suggests that thermal modifications in the arterial surface ultrastructure or thermal denaturation of surface proteins, or both, may be responsible for reduced platelet adherence. These in vitro findings indicate that controlled thermal plaque ablation by catheter-based techniques may elicit endovascular responses that can reduce early thrombus formation during angioplasty procedures. (+info)
Novel approach to the analysis of restenosis after the use of three new coronary devices.
(11/33)
Restenosis after coronary intervention has remained a vexing problem despite the introduction of nearly 24 newer coronary interventional devices. To more clearly evaluate the potential impact of three such new devices on restenosis, coronary lumen diameters were measured before, immediately after and at 6 months after intervention, and restenosis was analyzed using continuous geometric techniques. Lumen diameters were measured before and immediately after intervention in 223 coronary vessels treated with one of three new devices: a single Palmaz-Schatz stent (n = 87), directional atherectomy (n = 125) and laser balloon angioplasty (n = 11); 184 (83%) of the patients underwent follow-up angiography 6 months after treatment. The immediate increase in lumen diameter produced by the intervention (acute gain) and the subsequent reduction in lumen diameter between the time of intervention to 6 month follow-up study (late loss) were examined. For each of the three interventions, the restenosis rate at follow-up study was analyzed using a traditional dichotomous definition (greater than or equal to 50% diameter stenosis), as well as a novel graphic technique. Although the apparent restenosis rates differed significantly among the three interventions (19% for stents, 31% for atherectomy and 50% for laser balloon angioplasty; p = 0.02), late loss among the three interventions was equivalent (average 1 mm; p = 0.91). There were, however, marked differences in the acute gain achieved by the three interventions: 2.6 mm for stents, 2.2 mm for atherectomy and 2 mm for laser balloon angioplasty; p less than 0.001). It was these differences in acute gain rather than late loss that explained the observed differences in restenosis rate.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Origin of arterial wall dissections induced by pulsed excimer and mid-infrared laser ablation in the pig.
(12/33)
To study adjacent tissue damage after delivery of holmium, thulium and excimer laser pulses, porcine thoracic aortas were irradiated in vivo. After 3 days, microscopic analysis of 67 craters produced by all three lasers demonstrated large dissections extending from the craters. The mean diameter of the dissections was smaller for excimer-induced craters (1.38 +/- 0.42 mm; n = 22) than for holmium-induced (2.7 +/- 0.87 mm; n = 22) and thulium-induced (2.37 +/- 0.42 mm; n = 14) craters (p less than 0.01 vs. mid-infrared dissections). In addition, microscopic analysis demonstrated necrosis adjacent to the crater. The lateral necrotic zones of the thulium-induced craters were smaller than the holmium- and excimer-induced necrotic zones (p less than 0.01). To identify the origin of the excessive tissue tearing, laser-saline and laser-tissue interaction were compared in vitro by time-resolved flash photography. In saline solution, the mid-infrared lasers showed bubble formation on a microsecond time scale. The excimer laser produced similar bubbles in the vicinity of tissue. For all three lasers, elevation of the tissue surface was shown during in vitro ablation. Dimension (diameter up to 4 mm) and time course (rise time of 100 to 300 microseconds) of bubble formation and tissue elevation were strikingly similar. Thus, tissue dissections are caused by the expansion of a vapor bubble within the target tissue. Coronary dissections after excimer and mid-infrared laser angioplasty might be related to the forceful bubble expansion. (+info)
Diffuse phlegmonous phlebitis after endovenous laser treatment of the greater saphenous vein.
(13/33)
Endovenous laser treatment (EVLT) has become a valuable and safe option in the treatment of varicose veins. Although long-term results are lacking, most patients seem to benefit in the short-term from EVLT. Reported postoperative complications are limited, consisting usually of pain, ecchymosis, induration, phlebitis, or spot skin burn injuries. The most feared complication is an extension of the saphenous thrombus into the femoral vein, with possible pulmonary embolism. Here we report a septic thrombophlebitis after EVLT resulting in a phlegmonous infection of the whole leg that was treated by surgical drainage. Aggressive local therapy and antibiotic treatment resulted in complete resolution of symptoms and eventual satisfactory healing. (+info)
A proposed alternative mechanism of action for transmyocardial revascularization prefaced by a review of the accepted explanations.
(14/33)
Laser transmyocardial revascularization, a procedure originally intended to simulate the perfusion mechanism of the reptilian heart, has evolved into an effective but poorly understood treatment for angina when traditional revascularization is not an option. Herein, we review the explanations that have been proposed over the years and suggest a new one. We hypothesize that the long-term mechanism of action of transmyocardial revascularization is the redistribution of stresses on the ventricular wall through the creation of fibrous transmyocardial scars, which penetrate the various layers of muscle that surround the left ventricular cavity. The stress redistribution of a load in an otherwise unchanged ventricular wall reduces the wall stress per unit of wall volume, which in turn decreases the workload for the hyperkinetic compensating areas. This reduces both oxygen demand and local metabolite production, lowering the level of angina. (+info)
Outcome of extensive coronary artery dissection during coronary angioplasty.
(15/33)
A total of 32 (3.6%) patients of 880 undergoing coronary angioplasty during a nine year period at one hospital had extensive dissection (defined as a dissection extending beyond the limits of the dilated angioplasty balloon) in the coronary artery in which the angioplasty procedure was performed. Two (6.25%) of the 32 patients (both of whom were undergoing angioplasty because of unstable angina that was refractory to medical treatment) died as a consequence of the coronary artery dissection. Twelve (38%) needed immediate coronary artery bypass surgery and 11 (34%) had a myocardial infarction, which in four was minor in extent. During follow up, 20 of the 32 patients were successfully managed by medical treatment; only two needed further angioplasty procedures. There were no late deaths. Extensive coronary artery dissection is a serious complication of coronary angioplasty, with a high early mortality and a high incidence of infarction and requirement for bypass surgery. None the less, patients with extensive dissection who are free from the manifestations of acute ischaemia at the end of the procedure can be managed conservatively and have a good immediate and medium term outlook. Attempts should be made to stabilise extensive dissection during coronary angioplasty so that surgical intervention can be delayed or avoided altogether if possible. (+info)
Endovenous laser and echo-guided foam ablation in great saphenous vein reflux: one-year follow-up results.
(16/33)