Analysis of the new indirect revascularization method by determining objective parameters of clinical chemistry, histo-chemistry and histology

Abstract

This prolonged acute study demonstrates that CO2-TMLR significantly reduces the amount of necrosis in the area at risk, but does not reduce cardiac ischemic markers. In healthy myocardium, TMLR significantly increases myocardial water content and ischemic parameters and induces small ischemic and very small necrotic areas surrounding open laser channels. Generally, the elevated cardiac enzymes and proteins are mainly attributed to the expected rise caused by vaporization of myocardial tissue in all laser groups.

Evaluation of Transmyocardial Laser Revascularization by Following Objective Parameters of Perfusion and Ventricular Function1

“…After TMLR treatment, a non-significant decline of LV function was observed postoperatively in the TMLR group which could be due to an inflammatory reaction, edema, and potentially reversible injury of the myocardium [11,12]. Laser channels significantly decrease global heart function shortly after TMLR in healthy porcine myocardium which demonstrated no recovery 6 hours postoperatively [10], in contrast to human myocardium [12].…”

Microperfusion Enhancement after TMLR in Chronically Ischemic Porcine Hearts

“…Other centers report similar results excepting a significant improvement in regional perfusion and metabolism [3,11]. The exact mechanism which facilitates these subjective and objective transmyocardial laser revascularization-related improvements remains as yet unknown [12,13]. Various acute animal models have provided contradictory results that have led investigators to differing conclusions as to patency, perfusion and global function after transmyocardial laser revascularization [2].…”

“…After investigations were performed, the left anterior descending artery territory (area at risk) was treated with transmyocardial laser revascularization, as reponed elsewhere [6,13]. Drilling took an average of 18 min/animal (laser group 1) and 29 min/animal (laser group 2) to complete.…”

“…As per the protocol described for operation 2, measurement of all parameters was repeated. Histochemical assessment and myocardial water content analysis were performed, as previously described [13].…”

“…where EDL and ESL are end-diastolic length and end-systolic length, respectively. Results were expressed as percent of systolic myocardial shortening relative to control values (baseline at 1 week) to allow comparison between the animals and avoid bias relative to differences in heart size and crystal placement [13]. SMS measurements were recorded before and after transmyocardial laser revascularization at the 2nd operation and at the 3rd operation in all experimental groups, except in the control and ischemic group were SMS measurements where only taken before transmyocardial laser revascularization (2nd) and after the 3rd operation.…”