Techniques to Generate Low Working Temperatures
In dermatological cryosurgery, depending on the type of indication, working temperatures between -70 °C and -196 °C are most commonly used. There are different techniques to generate cold, for instance, thermoelectric cooling, the release of compressed gas like CO2 (-78,5 °C) and N2O (-89 °C) and different liquid gasmixtures. With the exception of N2, CO2 and N2O cold performance are between approx. -30 °C to approx. -55 °C.
Therefore the operational area of these methods is strictly limited and not sufficient for many applications – especially tumours but also other lesions. The liquid phase of N2O (with a constant temperature of -89 °C) is extremely effective.
Technique of the Cryosurgical Treatment
The Cryosuccess unit function is based on cold expansion, whereby liquid N2O (nitrous oxide) is brought directly through a micro capillary to the area to be treated, under a remaining constant temperature of -89 °C (184,4 K). Freezing of the tissue to a depth of 3 mm, by a diameter of 10 mm is reached after an application time of 12 seconds. Patients feel a light «tickle», similar to a mosquito bite. In the following days, normally a necrosis forms, peeling after approx. 10 to 14 days.
Usually pigmentation comes back after a few weeks. However, the re-pigmentation could also take longer depending on the type of skin. Pain is usually not felt but of course the sensitivity for pain is quite individual. Therefore, a higher sensitivity is possible when removing bigger lesions.