[High-frequency thermocoagulation. Use in bronchial endoscopy]

Abstract

High frequency thermocoagulation is a relatively recent technique of destroying tracheobronchial tumour mass. It selects the thermal effect of electrical current whilst avoiding the electrolytic and faradic effects of nerve and muscle stimulation. With gentle coagulation which is generally utilised the tissues are heated to between 70 and 100 degrees with the formation of water vapour and immediate destruction of the tissues. The electrodes are usually unipolar and are either rigid or flexible. The HF current which circulates across the tissues is gathered and evacuated by neutral electrodes. A new generation of fiberoptic bronchoscopes which isolate the exit current may optimise the safety of the procedure. New generators delivering a stable voltage controlled by a microprocessor enable the control of the process of coagulation and adapt the thermal energy delivered to the volume and nature of the tissue to be destroyed. The electrode is put in contact with the tissues. The immediate effects is similar to those described with laser. The simplicity, speed of utilization, minimal morbidity and relatively low cost has made this an interesting technique even in developed countries where the investment budgets are becoming more and more limited.