Abstract
Objective: Application of ultrasound energy by an endarterectomy probe can facilitate the removal of atheromatous plaque, but the effect of this procedure on surrounding vessel structure and function is still a matter of experimental investigations. Methods: To determine whether ultrasound energy impairs the production of nitric oxide (NO) or damages vascular smooth muscle function of epicardial coronary arteries, isolated canine coronary artery segments were exposed to either high or low ultrasonic energy outputs for 15 seconds using an endarterectomy prototype device. After exposition, segments of coronary arteries were studied in organ chambers. For the pharmacological assays, the following drugs had been used: Adenosine diphosphate (ADP), acetylcholine (Ach) and sodium fluoride (NaF sodium) for the endothelium - dependent vasoreactivity study. Sodium nitroprusside (SNP) and isoproterenol (ISO) were used for the evaluation endothelium-independent relaxations. Following exposure to the ultrasonic endarterectomy probe, segments of epicardial coronary artery were studied in organ chambers. Results: Application of high ultrasonic energy power (25 W) impaired endothelium-dependent relaxation to adenosine diphosphate (10-9 - 10-4 M), acetylcholine (10-9 - 10-4 M) and sodium fluoride (0.5 - 9,5 mM) in epicardial coronary arteries. However, low ultrasound energy output (0-10 W) at the tip of the probe did not alter the endothelium-dependent relaxation (either maximal relaxation or EC50) to the same agonists. Vascular smooth muscle relaxation to isoproterenol or sodium nitroprusside was unaltered following exposure to either low or high ultrasonic energy outputs. Conclusion: These experiments demonstrate that ultrasonic energy alters endothelial function of epicardial coronary arteries at high power. However, ultrasound does not alter the ability of vascular smooth muscle of canine epicardial coronary arteries to relax.
Translated title of the contribution | High-frequency ultrasonic waves cause endothelial dysfunction on canine epicardial coronary arteries |
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Original language | Portuguese |
Pages (from-to) | 190-196 |
Number of pages | 7 |
Journal | Brazilian Journal of Cardiovascular Surgery |
Volume | 23 |
Issue number | 2 |
State | Published - Apr 2008 |
Keywords
- Coronary endarterectomy
- Nitric oxide
- Ultrasound
ASJC Scopus subject areas
- Surgery
- Cardiology and Cardiovascular Medicine