Faculty Collaboration Database

Physiology, histology, and 2-week morphology of acute transmyocardial channels made with a CO2 laser. Ann Thorac Surg 1997 May;63(5):1275-83

Date

05/01/1997

Pubmed ID

9146314

DOI

10.1016/s0003-4975(97)00102-1

Scopus ID

2-s2.0-0031149819 (requires institutional sign-in at Scopus site)   107 Citations

Abstract

BACKGROUND: Transmyocardial revascularization with a CO2 laser appears to improve symptoms in patients with refractory angina. However, it remains controversial as to whether blood flow through the channels is the mechanism of benefit, especially in the acute setting.

METHODS AND RESULTS: Three protocols were used to test whether blood flows through transmyocardial CO2 laser revascularization channels. First, channels were made in excised, cross-perfused dog hearts (n = 5) using a CO2 laser (The Heart Laser; PLC Systems Inc, Milford, MA; 40 J/pulse) followed by ligation of the proximal left anterior descending coronary artery. Colored microspheres injected into the left ventricular chamber failed to detect any significant transmyocardial blood flow. In the second protocol (n = 4), laser channels were created in the left anterior descending artery territory, the left anterior descending artery was ligated, and the hearts were excised after 24 hours. Triphenyltetrazolium chloride staining revealed that no viable myocardium was detected around the laser channels in the ischemic myocardium. Finally, channels examined 2 weeks after creation in normal (n = 6) or ischemic (n = 4) myocardium did not maintain their original caliber but were invaded by granulation tissue, which included a large amount of smaller vascular spaces and vessels of various sizes.

CONCLUSIONS: Transmyocardial laser revascularization channels made with this CO2 laser did not provide acute myocardial perfusion or preserve myocardial viability in the face of acute ischemia. Channel morphology changes dramatically within the first 2 weeks. To the degree that these findings pertain to human myocardium, the results suggest that transmyocardial blood flow may not be the mechanism of benefit of this procedure, particularly in the acute setting.

Author List

Kohmoto T, Fisher PE, Gu A, Zhu SM, DeRosa CM, Smith CR, Burkhoff D

Author

Takushi Kohmoto MD, PhD Professor in the Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Carbon Dioxide
Cell Survival
Cerebrovascular Circulation
Collateral Circulation
Dogs
Heart
In Vitro Techniques
Laser Therapy
Microspheres
Myocardial Revascularization
Myocardium
Regional Blood Flow