Cryosurgery involves local freezing of tissues for
their controlled destruction or removal. Here we will
discuss the role of cryosurgery in skin diseases. The various cryogens used are Nitrous oxide
(-75°C), Carbon-dioxide snow (-79°C) and liquid Nitrogen (-196°C). We will discuss two
cryosurgical techniques that the author uses in her dermatosurgical practice.
LIQUID NITROGEN CRYOSURGERY
Above are the pictures of the cryocan and the
cryojet. Cryocan is a container that stores liquid nitrogen and cryojet is a hand held unit that
is used to spray the liquid nitrogen over the diseased part. Liquid nitrogen
has a temperature of -196 °C and freezes tissues to -40 to -60 °C.
- What are the indications of liquid nitrogen cryosurgery?
- There are numerous indications but to enumerate a few :
- warts, molluscum contagiosum, pyogenic granuloma, skin tags, seborrhoeic
warts, milia, cystic acne, acne scars and
- Precancreous conditions like leukoplakias, Bowen's disease,
- Cancers of the skin which are very small and have no deep or
- When should liquid nitrogen cryosurgery not be done?
- It should not be preformed in immuno-suppressed conditions
like certain cancers, patients on immunosuppressive drugs, people allergic to
cold temperatures, people having vasospastic disorders and cold intolerance.
- What happens during the treatment?
- The procedure involves spraying liquid nitrogen over
the diseased part leading to freezing of the tissues. This causes a stinging sensation and numbness initially. Later on
there may be varying degree of pain which may need analgesics or
elevation of the part.
- What happens after spraying?
- After a few hours of spraying the area shows colour changes due
to controlled destruction. The part may become dark or red and swollen. A blister
is formed which later turns into an eschar, thus the desired tissue is
destroyed. The blister should not be
disturbed as it prevents infection. The sprayed part takes 1
to 3 weeks to heal. Multiple sessions of cryosurgery may be required till the desired result
- What are the advantages?
- no anaesthesia is required.
- no hospitalization is necessary.
- multiple lesions can be treated at the same time.
- good for small local cancer recurrences.
- it is a no touch technique, hence beneficial while treating HIV
- Are there any complications?
- Hyperpigmentation, hypertrophic scars, milia may be
a few transient problems. Hypopigmentation, scarring could be the long term consequences.