Mechanisms and Results of Transmyocardial Laser Revascularization

Abstract

Transmyocardial laser revascularization (TMR) is a technique that has been performed on over 10,000 patients around the world. Most of the patients were not suffering from heart failure. TMR is principally used for the treatment of angina, but in patients with significant reversible ischemia that is not amenable to conventional therapy, TMR may also improve myocardial function. The results of using TMR as a treatment for angina show a dramatic improvement in symptoms and quality of life. This paper reviews the current status of TMR techniques, mechanisms and results.

Does laser type impact myocardial function following transmyocardial laser revascularization?

“…While evidence of angiogenesis is seen following treatment with both lasers, there is significantly more fibrosis noted in the myocardium that underwent Ho:YAG TMR. This tissue response correlates with the energy distribution and characteristics of the two lasers as demonstrated in the series flash photography of both lasers firing [10] (Fig. 2).…”

Method for inducing the growth of new arteries in the myocardium

“…From the many clinical reports, TMLR seemed to be a promising treatment for patients with end-stage coronary artery disease. 19,20 A hydrogel containing angiogenic growth factors was also used in TMLR, but the hydrogel could not maintain a patent channel. 21 From all the reports related to TMLR, it became obvious that channels created by laser do not remain patent.…”

Transmyocardial Laser Revascularization Combined with Intramyocardial Endothelial Progenitor Cell Transplantation in Patients with Intractable Ischemic Heart Disease Ineligible for Conventional Revascularization: Preliminary Results in a Highly Selected Small Patient Cohort

“…In a certain number of patients, however, conventional therapy is often unsuccessful, leaving these patients with disabling angina pectoris and/or congestive heart failure symptoms. Alternative therapeutic strategies have been evaluated, among them transmyocardial laser revascularization (TMLR) which seems to offer some benefits with regard to the regression of angina [1,2]. However, a significant increase in myocardial perfusion or left ventricular ejection fraction with TMLR has only rarely been reported, a fact which seems to hinder its widespread adoption.…”

“…The presented study provides first evidence that a combined therapy of TMLR and intramyocardial endothelial progenitor cell injection may be beneficial for patients with conventionally intractable angina with a coronary artery status unsuitable for revascularization. The intramyocardial administration of bone marrow-derived endothelial progenitor cells may contribute to the functional regeneration of ischemic myocardium and stimulate neovascularization [4,5,[10][11][12], as TMLR may provide relief from angina with the tissue and injury-induced stimulus and substrate necessary for this regeneration [1,2]. Various possible mechanisms have been proposed to explain the beneficial effects observed after cardiac stem cell transplantation [10,12,13].…”

“…However, as mentioned before, since CABG was performed simultaneously, it was not possible to determine whether the effect was specifically related to the stem cell treatment. There is strong evidence in the literature for the clinical efficacy of TMLR in reducing anginal symptoms [1,2]. The reduction of anginal symptoms is particularly effective if a CO 2 laser is used.…”