Palliative and curative bronchoscopic treatment modalities are currently feasible in patients with airway obstruction due to extra and intraluminal lesions. Nd-YAG laser, photodynamic therapy, brachytherapy, airway stents, cryotherapy and more recently HF thermocoagulation are commonly used, Nd-YAG laser has become without doubt a standard technique for managing tracheobronchial obstructions; it produces immediate relief of bronchial obstruction and this is its main advantage over other modalities. Nevertheless, laser therapy requires significant training and complications sometimes occur. Developing equivalent techniques seems absolutely necessary, such as cryotherapy and HF thermocoagulation. The cost and nature of the effect of the different techniques are determining factors in deciding on which equipment to use. Since 1984, we have a large experience of cryotherapy. We started to use electrocautery 10 years later, and we treated less than one hundred patients. However, it seems interesting to compare these two techniques, and this comparison may guide for an appropriate choice in terms of indications and purchase. It is probably difficult because each technique presents advantages and inconveniences. The mechanisms of cryosurgery and electrocautery are different and thereby the indications may be different. But it would be sometimes useful to use both techniques successively during the same endoscopy.
The effect of cryosurgery is delayed, and for this reason this technique is not indicated for the treatment of acute respiratory distress needing emergency treatment. On contrary, HF thermocoagulation has an immediate debulking effect, more efficient if the section mode is used. It is really a "laser-like" effect but this cutting function may be dangerous. In fact, electric arcs form and thereby it is not possible to deliver oxygen during the procedure because of an important risk of fire, and perforation should be a complication. In case of partial obstruction, without emergency, the techniques are equivalent. For a total bronchial obstruction, cryotherapy will be more appropriate and which may be tried without risk. And if it is not efficient, it is also not dangerous and several sessions may be carried out. It is the same for infiltrating stenosis. No perforation occurs after cryotherapy; electrocautery is not a good choice if an extended coagulation must be carried out.
We performed with Dr. Marquette (Lille - France) an experimental study in 50 pigs. No complications occurred after points of coagulation on the trachea or bronchi, nor after a tangential coagulation of several centimeters along the trachea. But major problems occurred after a circumferential coagulation of the left main bronchus: important stenosis and the pigs died of lung sepsis.
A cartilage disruption was found after electrocautery. For this reason, we recommend to be careful in indications of extending or infiltrating tumors invading the bronchial wall. Extraluminal compressions are contra indications for both techniques.
For hemophtysis from accessible lesions, we prefer to use thermocoagulation even if cryotherapy is also efficient. In fact, it is possible to reach bleeding lesions of the upper lobes with flexible electrodes, which is not always possible with flexible cryoprobes, and the haemostatic effect of cryo often occurs some hours or one day later.
Both techniques are efficient to destroy granulation tissues.
Fibrotic stenosis do not usually respond to cryotherapy, but it may be tried as occasional responses do occur. HF thermocoagulation is more efficient using the cutting programme of the generator.
A syngergistic or potentiating effect is obtained with the combined treatment of cryo plus radiotherapy and particularly cryo + chemotherapy.
There is no special maintenance for electrocautery. It is sometimes difficult to obtain pure nitrous oxide in some countries, but liquid nitrogen is easily available and cheaper.
The teaching is very easy for both techniques.
The devices are relatively cheap but it seems necessary to use a special insulated fibreoptic bronchoscope with electrocautery.
It seems that thermocoagulation should be more dangerous and one of the main advantages of cryotherapy is the very low morbidity of the technique.
The two techniques are efficient, simple, easy to perform, cost-effective.
If there are some specific indications, they may be also combined during the same endoscopic session.