Cryosurgery of eyelid actinic keratosis and the effect of adrenaline in local anesthetics - temperature mapping using IR thermography.

PURPOSE: The efficacy of cryosurgery is believed to depend on the thaw time. The presence of adrenaline in local anesthetics affects blood perfusion, and may thus also affect the thaw time. The aim of the present study was to use IR thermography to monitor the tissue temperature during cryosurgery of actinic keratosis, and to assess the effect of adrenaline in local anesthetics.

METHODS

Twelve patients with actinic keratosis in the periorbital region underwent cryosurgery. The temperature was continuously mapped using a high-precision IR camera and was also visually assessed by the surgeon. The results obtained when employing local anesthetics with and without adrenaline were compared.

RESULTS

The temperature change during thawing showed a triphasic pattern. The thaw time was significantly longer when using an anesthetic with adrenaline. This was observed with both IR thermography and by visual observation.

CONCLUSIONS

The findings indicate that a longer freezing time may be needed when using a local anesthetic without adrenaline to achieve the same cryo-effect as when using a local anesthetic with adrenaline. A larger clinical trial is needed on the effects of using local anesthetics with and without adrenaline to treat actinic keratosis, for example, the clearance rate, before recommendations can be made concerning their use.