High frequency thermocoagulation. Use in endoscopic bronchoscopy

High frequency thermocoagulation is a relatively recent technique of destro ying tracheobronchial tumour mass. It selects the thermal effect of electri cal current whilst avoiding the electrolytic and faradic effects of nerve a nd muscle stimulation. With gentle coagulation which is generally utilised and tissue are heated to between 70 degrees and 100 degrees with the format ion of water vapour and immediate destruction of the tissues. The electrode s are usually unipolar and are either rigid or flexible. The HF current whi ch circulates across the tissues is gathered and evacuated by neutral elect rodes. A new generation of fiberoptic bronchoscopes which isolates the exit current may optimise the safety of the procedure. New generators deliverin g a stable voltage controlled by a microprocessor enable the control of the process of coagulation and adapt the thermal energy delivered to the volum e 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 utilisation, minimal morbidity and relativ ely low cost has made this an interesting technique even in developped coun tries where the investment budgets are becoming more and more limited.