Combined use of transmyocardial laser revascularization and endothelial progenitor cells enhances neovascularization and regional contractility in a canine model of ischemic hearts / 华中科技大学学报（医学）（英德文版）

The purpose of this study was to determine the combined effect of transmyocardial laser revascularization (TMLR) and the implantation of endothelial progenitor cells (EPCs) on cardiac function of ischemic hearts in canines. The left anterior descending artery (LAD) was occluded to establish the canine model of acute myocardial infarct (AMI). Four weeks later, the animals were randomly divided into four groups: TMLR group, in which transmyocardial laser-induced channels were established at the ischemic region; EPCs+TMLR group, in which EPCs were locally transplanted into laser-induced channels at the ischemic region; EPCs group, in which the EPCs were injected into the ischemic region; control group, in which the AMI animals received neither TMLR nor EPCs. The peripheral blood (50 mL) was sampled in all groups. Mononuclear cells from the peripheral blood were separated and cultured to obtain spindle-shaped attaching (AT) cells in vitro. AT cells were labeled with 1, 1'-dioctadecyl-1 to 3,3, 3',3'-tetramethyl-indocarbocyanine perchlorate (DiI) before injecting into the laser-induced channels or ischemic region. Four weeks after the first operation, TMLR was performed in the TMLR group and EPCs+TMLR group, and at the same time, the EPCs originating from the AT cells were mixed with calcium alginate (CA). Then the EPCs-CA composites were implanted into myocardial channels induced by laser in the EPCs+TMLR group, and into the myocardial infarct area in the EPCs group. All dogs underwent echocardiography at second month after LAD occlusion. Finally the samples of myocardium around the LAD were subjected to histochemical and immunohistologic examinations. The results showed there was no significant difference in the diameter of left atrium and ventricle before treatment among all groups (P>0.05). Eight weeks after modeling, the regional contractility in the LAD territory in the EPCs+TMLR group was increased as compared with control group and TMLR group, but there was no significant difference between control group and TMLR group. Neoangiogenesis was observed in the EPCs+TMLR group, and the fibrosis was seen in the TMLR group. There was no significant difference in neoangiogenesis around the channels induced by laser among EPCs+TMLR, EPCs and TMLR groups. It was concluded that TMLR combined with EPCs could improve the regional and global cardiac function in AMI, and augment neovascularizaiton in channels of ischemic myocardium induced by laser.

Anesthesia for transmyocardial revascularization with autologous bone marrow stem cell transplantation

Transmyocardial Irevascularization with stem cell transplantation is an alternative treatment option for patients with refractory angina who are not suitable candidates for more conventional coronary intervention or surgery. It is done by creating transmyocardial channels that provide blood flow from the left ventricular chamber to areas of ischemic myocardium. The concept behind this technique is these channels causes increase vascular density around the channels that create Platelet activation with Growth factor release that assumes it promote amgioneogenesis when stem cell is transplanted in these channels [1] Innovations in this relatively new procedure include less invasive approaches and using it as an adjunctive or delivery modality for gene therapy. The original work in TMLR was done with a high powered infrared C02 laser. This laser is capable of creating 1 mm diameter channels with a single burst that penetrates the entire depth of the myocardium

Change of Regional Myocardial Blood Flow After Transmyocardial Laser Revascularization in Porcine Model of Chronic Myocardial Ischemia / 대한흉부외과학회지

BACKGROUND: This study was aimed to assess improvement in myocardial perfusion after TMR by measuring regional myocardial blood flow(RMBF) in porcine model of chronic myocardial ischemia. MATERIAL AND METHOD: Ameroid ring was placed around the proximal left circumflex coronary artery in fourteen pigs. After 4 weeks, the control group(7 pigs) underwent rethoracotomy only, and the TMR group(7 pigs) underwent Ho:YAG laser TMR at the circumflex territory. After another 4 weeks, the animals were sacrificed for the measurement of RMBF using colored microspheres. The ratio of RMBF between the circumflex territory and the interventricular septum was calculated and compared. RESULT: At 4 weeks after ameroid constriction, RMBF of the circumflex territory decreased to 46~89% of RMBF of the interventricular septum. In five of six animals in the TMR group, RMBF of the circumflex territory at 8 weeks after ameroid constriction was higher compared with RMBF at 4 weeks after ameroid constriction. However, the improvement was statistically significant only in two animals. In three of the four animals in the control group, RMBF of the circumflex territory also increased at 8 weeks compared with RMBF at 4 weeks. The degree of increase in RMBF was not different between the control and the TMR groups. CONCLUSION: In porcine model of chronic myocardial ischemia, the degree of increase in RMBF of the ischemic area after Ho:YAG TMR was not different from the increase by development of native collateral circulation. Perfusion of ischemic myocardium after TMR is not thought to improve to the degree that can be demonstrated by currently available method of assessment such as radioisotope myocardial scintigraphy.

Transmyocardial Laser Revascularzation for Patients with Recurrent Angina after CABG: Report of 3 cases / 대한흉부외과학회지

Transmycardial laser revascularization has made its position as a sole therapy for patients with chronic angina nonamenable to maximal medical therapy, percutaneous transluminal coronary angioplasty, and coronary artery bypass grafting. We report three cases of transmyocardial laser revascularization as a sole therapy for patients with recurrent angina after CABG.