CHANGE OF TEMPERATURE OF CANNULA AND ITS INFLUENCE ON MUSCLES, VESSELS, AND NERVES DURING ULTRASONIC LIPOSUCTION

Lee, Dong Hun; Cho, Byung Chae; Lee, Jung Hyung; Baek, Bong Su

Abstract

It has been suspected that the cannula of the ultrasonic generator became heated during liposuction, and that the heated cannula might possibly damage the soft tissues such as vessels, nerves and muscles. To confirm these suspicions, the actual temperature of the cannula was measured after being switched on, and the influence of the heated cannula on the soft tissues of 30 rabbits was studied macroscopically and microscopically. When the cooling system of ultrasonic generator was not operated, the temperature of a cannula tip increased to 100degrees C in 10 seconds, and the temperature of a cannula shaft did not increase over 40 degrees C. When the cooling system of the ultrasonic generator was operated, the temperature of the cannula tip increased to 70 degrees C in 20 seconds and to 100 degrees C in 1 minute. The stronger ultrasonic power was, the higher the temperature of the cannula tip was. When the heated cannnula tip touched the muscles, vesseles and nerves directly, the arterial and venous walls were perforated in about 20 seconds and 10 seconds, respectively. Gross changes of the muscles, such as color change and depression of the contacted area, were seen in about 30 seconds, and histological changes occurred in about 3 seconds. When adding the Klein solution, an infiltration solution for increasing the destructive effects of the ultrasound, the onset time of tissue damage was significantly shortened in vessels and nerves, but there was no significant difference in muscles. Although there was no finding of damage by the ultrasonic wave itself on the vessels, nerves, and muscles during ultrasonic liposuction, this study confirmed that the heated cannula could damage vessels, nerves, and muscles. Thus we must try to avoid placing the cannula at certain areas for more than 10 seconds douring the ultrasonic liposuction.