Holmium laser?induced coronary thrombolysis

Abstract

~Dne role of thrombosis in acute myocardial infarction and unstable ischemic coronary syndromes is well documented [1][2][3]. Revascularization of thrombotic, occluded coronary vessels can be achieved by pharmacologic therapy [4,5], balloon angioplasty [6], transluminal extractional catheter [7], low-frequency ultrasound [8], and coronary artery bypass surgery [9]. Recently, lasers have been introduced as a means of optical thrombolysis [10,11]. Most clinical and basic research data on the application of lasers in this setting is based on in vivo and in vitro studies conducted with an investigational, pulsed-wave, mid-infrared holmium: YAG system. This editorial focuses on current status of holmium laser application for coronary thrombolysis. Means of ThrombolysisNumerous randomized clinical trials have established the advantages of thrombolytic therapy for patients with acute myocardial infarction [5]. Benefits include reduction of mortality [12][13][14][15][16][17][18], limitation of infarct size [19], improvement of left ventricular function [20], and increased patency of the infarct-related vessel [21] when compared with patients with acute infarction not treated with thrombolytic drugs. Despite its merits, pharmacologic therapy achieves vessel patency in only 75% of patients, does not dissolve the underlying atherosclerotic plaque, and can be associated with bleeding complications [5,13,14]. Altogether, pharmacologic thrombolytic therapy remains underutilized, and a large number of patients do not receive it [22][23][24], either because of delayed presentation after the onset of chest pain, age limitations, history of significant hypertension, or lack of inclusive electrocardiographic criteria. Notably, the value of thrombolytic agents is time dependent, with maximal benefit achieved in patients presenting up to 6 hours after the onset of symptoms. The effect of late thrombolysis, that is, treatment beginning more than 6 hours after symptom onset, remains controversial. The LATE study suggested that the time window for thrombolysis with intravenous rtPA should be extended to at least 12 hours [25]. On the other hand, when compared with controls, those presenting later than 12 hours after the onset of chest pain exhibit an excess number of deaths during the first postinfarction day attributed to thrombolytic agents [26].Mechanical reperfusion is a viable alternative to pharmacologic therapy in patients presenting either too late or with contraindications to drug treatment. Infarct-related vessel patency is achieved in more than 90% of patients who undergo balloon angioplasty in this setting [27][28][29]. However, in the presence of a large thrombus, results are oftentimes suboptimal due to distal embolization and incomplete removal of the entire clot, creating the need for intracoronary injection of thrombolytic drugs; hence, the rationale for application of advanced interventional devices, such as laser. Generally, cardiovascular lasers have the potential to selectively ablate atheromatous, coronary plaques ...

Shear-, Sound-, and Light-Sensitive Nanoparticles for Thrombolytic Drug Delivery

“…56 The wavelengths of light for thrombolysis use range from ultraviolet (308 nm) 57 to mid-infrared (holmium 2100 nm). 58 In laser thrombolysis, the laser is transmitted to the thrombi through a catheter. Owing to the absorption of laser energy by the surrounding absorbing liquids, bubbles will be formed at the catheter tip.…”

Application of excimer laser angioplasty in acute myocardial infarction

“…Thrombi are known to readily absorb several wavelengths of light [9,30,31]. There are four major constituents of coronary thrombus, i.e.…”

Acute results, complications, and effect of lesion characteristics on outcome with the solid‐state, pulsed‐wave, mid‐infrared laser angioplasty system: Final multicenter registry report

“…As thrombi avidly absorb light in the mid-infrared optical range [11], the mid-infrared holmium: YAG laser potentially offers a unique revascularization option for patients with thrombotic occlusions [12]. In a recent in vitro study we determined this laser clot-dissolving by a mechanical, nonselective process caused by the formation and propagation of shock waves [13].…”