What is Thermal Cautery?
The use of thermal cautery to stop bleeding is an ancient practice. As early as 3000 B.C., tools heated in a fire were used to reduce hemorrhaging in accidental injuries. The first units to utilize electrical energy for the heating of cautery instruments date back to the early 1900s. The thermal cautery unit is now a well established surgical instrument.
The Geiger TCU.
The Geiger Thermal Cautery Unit (TCU) utilizes an electrically heated tip to coagulate tissue and to control bleeding. When the cautery tip is applied to tissue for coagulation, several changes occur. Cells vaporize, removing water from the tissue, causing the tissue to shrink and the blood vessels to contract; and/or the protein from the blood cells and the tissue to form a coagulum.
How is it Different from Electrosurgery?
Thermal cautery is often confused with electrosurgery. In electrosurgery, a high frequency current flows from the electrosurgical unit through a small active electrode applied to the tissue, and back to the electrosurgical unit through a second, larger return electrode. The electrosurgical heating effect that causes tissue destruction is produced by the electrical resistance of tissue to the high-frequency current.
Without the Zap.
With thermal cautery, however, no current flows through the patient. The tip of the cautery instrument becomes heated by the passage of an electric current through a high resistance wire. The heat transferred from the tip by conduction coagulates the tissue.