VETY CRYOSURGERY

1. CRYOSURGERY
PRESENTED BY- $UCHITRA B. SURYAVANSHIPATIL
(Dept.of vety surgery & radiology,AKOLA)
Subbmited to- DR.FAHREEN FANI

2. Cryosurgery (cryotherapy) is the
application of extreme cold to destroy abnormal or
diseased tissue.
 The term comes from the Greek words cryo
("icy cold") and surgery meaning "hand work" or
"handiwork".
Cryosurgery has been historically used to treat a
number of diseases and disorders, especially
variety of benign and malignant skin conditions.

3. HISTORY OF CRYOSURGERY
 James Arnott, in 19th century, stated that a very
low temperature will arrest every inflammation
which is near enough to the surface.
 The first cryogens were liquid air and
compressed carbon dioxide snow.
 In 1961, Cooper and Lee developed the first
cryotherapy probe system, involving the
circulation of liquid nitrogen through a closed
metal tube placed in direct contact with the
target tissue.

4. Cryogens -
 Liquid nitrogen (most commonly used) : -196°C
 Nitrous oxide : - 89°C
 Solidified CO2 (dry ice, CO2 snow) : -78°C
 Chlorodifluoromethane : -41°C
 Dimethyl ether and propane : -24°C (42°f)
 Argon

5. Liquid nitrogen
 Cryogun used to spray liquid nitrogen
 A common method of freezing lesions is using liquid nitrogen as the
cooling solution. The super-cooled liquid may be sprayed on the
diseased tissue, circulated through a tube called a cryoprobe, or
simply dabbed on with a cotton or foam swab.
Carbon dioxide
 Less frequently, doctors use carbon dioxide"snow" formed into a
cylinder or mixed with acetone to form a slush that is applied directly
to the treated tissue.
Argon
 Recent advances in technology have allowed for the use of argon gas
to drive ice formation using a principle known as the Joule-Thomson
effect. This gives physicians excellent control of the ice, and
minimizing complications using ultra-thin 17 gauge cryoneedles.
 Dimethyl ether – propane
 A mixture of dimethyl ether and propane is used in some preparations
such as Dr. Scholl's Freeze Away. The mixture is stored in an aerosol
spray type container at room temperature and drops to −41 °C when
dispensed. The mixture is often dispensed into a straw with a cotton-
tipped swab.

6. Mechanism of cryosurgery
o The destructive effect of freezing tissue has been categorized
into two major mechanisms
 Immediate cell destruction
 Delayed cell destruction

8. Application techniques
 Probe freezing: It is done by direct application of a probe tip
to the lesion. The cryogen circulates through the probe tip and
super cools it, when allowed to contact the target tissue. Probe
freezing can be accomplished by one of the two mechanisms:
contact freezing and penetration freezing.
 In contact freezing, firm contact is made between the
cryoprobe and the target tissue.
 While in penetration freezing probe penetrates the target
tissue, providing a large area of direct contact.
 Spray freezing: It is done by direct application of the liquid
nitrogen to the tissue and is the most destructive method.
Liquid nitrogen is delivered to the target tissue at such a
volume and velocity that it evaporates at the edge of the
lesion. The spray orifice allows deeper and faster tissue
penetration than the probe tip but the probe method is safer
and more precise.

9. Controlling parameters during
cryosurgery
o cooling rate
o Temperature
o Thawing rate
o Freeze duration
o Repetitive freeze- thaw cycle

10. Cooling rate
• In cryosurgery, rapid cooling rate i.e. more than 500C/min
produces intracellular ice- crystals which is more destructive
• Such higher rates of cooling can only be achieved close to
the cryoprobe
Temperature
• Mazur stated that the lethal temperature range is between -
50C to -500C.
• The treatment of tumor requires a tissue temperature at which
all the abnormal cells are certainly dead.

11.  From the review of all experimental studies the end point
temperature below -40 0C has been considered prime factor
for tissue destruction

12. Thawing rate
• Thawing rate should be slow and continued for longer time
period; rapid thaw rates allow cell survival.
Repetitive freeze- thaw cycle
• Rapid freezing and slow thawing do not guarantee effective cell
destruction.
• Use of repeated freeze-thaw cycle is also beneficial in treatment
of cancerous tumor

14. Bio-heat Equation
o Several heat transfer mechanisms occur during
cryosurgery, including conduction, convection, metabolism
and phase change.
o Heat transfer by conduction has been assumed to be the
primary heat transfer process during cryosurgery since the
cryoprobe operates at an extremely low temperature.
o Bio-heat transfer is the study of heat transfer in biological
system.
o The fundamental heat transfer equation in biological tissue
was firstly suggested by Pennes.

15. Pennes suggested that the rate of heat transfer between blood and tissue is
proportional to the product of the volumetric perfusion rate and the
difference between the arterial blood temperature and the local tissue
temperature. He expressed that relationship as follows
Where,
hb is the rate of heat transfer per unit volume of tissue,
V is the perfusion rate per unit volume of tissue,
ρb is the density of blood,
cb is the specific heat of blood,
K is a factor that accounts for incomplete thermal equilibrium between
blood and tissue
(0<K<1, for some cases K = 0)
Ta is the temperature of arterial blood, and
T is the local tissue temperature

16. Procedure
o Warts, moles, skin tags, solar keratoses, and small skin
cancers are candidates for cryosurgical treatment.
o Several internal disorders are also treated with cryosurgery,
including liver cancer, prostate cancer, cervical disorders
and, more commonly in the past, hemorrhoids.
o Cryosurgery works by taking advantage of the destructive
force of freezing temperatures on cells. At low
temperatures, ice crystals form inside the cells, which can
tear them apart. More damage occurs when blood
vessels supplying the diseased tissue freeze

17. • The application of liquefied N₂0
sprayed directly on the skin will
bring temperature fully under
control (nitrous oxide always
evaporates at (-)127⁰
• Sophisticated micro-applicator
technology enables an
unprecedented level of accuracy of
treatment from 1mm. The
prevention of trauma to surrounding
tissue will assure patient’s comfort
• The pressure of the spray at 721 psi
will give maximum control over
depth of freezing and will guarantee
the results of the treatment.

18. Why Pressure
• The penetration of the ice crystal into the lesion as a result of cryosurgery
with the CryoProbe will go faster and deeper with minimal surface trauma.
• The freezing rate of CryoProbe is 1mm
per 5 seconds
• Depth of treatment: the CryoProbe freezes up to a maximum 5 mm cell
structure

19. o In this approach, several hollow
probes (needles) are placed in direct
contact with target tissue.
o The doctor guides them into the
gland(tumor) using Trans-Rectal
Ultra-Sound (TRUS).
o This type of procedure requires spinal or
epidural anesthesia (where the lower
half of your body is numbed) or general
anesthesia.

20. Very cold gases are then passed through the needles,
creating ice balls that destroy the gland(tumor).

21. o After the procedure, there will be some bruising and soreness
in the area where the probes were inserted. Patients might need
to stay in the hospital overnight, but many patients leave the
same day.
o The most common method of freezing lesions is using liquid
nitrogen as the cooling solution. The super-cooled liquid may be
sprayed on the diseased tissue, circulated through a tube called a
cryoprobe.

23. Benefits of Cyrosurgery in Veterinary Medicine
 Painless
 No Preparation
 No post op care
 No open wounds – No Bleeding
 No suturing
 No general anthesia – safe for older animals
 Rapid treatment time – only seconds
 Cost Effective
 Pressure to treat lesion
 Pinpoint Accuracy

24. Accurate Pinpoint Precision,
Freezing Power
and Pressure with the touch of your
Fingertip!

25. Cryogun used to spray
liquid nitrogen
Manufacturers have devised various metal
attachments to serve as heat-conducting
probes for cryotherapy. Copper, because
of its high conductivity, is typically used

26. CryoProbe’s different micro applicators
tips allow pinpoint accuracy to treat skin
lesions from 1mm to 8mm in size!
Blue dot applicator
Applications 1-3 mm
White dot applicator
Applications 2-4 mm
Green dot applicator
Applications 3-6 mm
Yellow dot applicator
Applications 4-10 mm

27. Lesions
With the CryoProbe you will be able to treat (but not limited) to the
following lesions successfully:
• Perianal Adenomas
• Epuli
• Pappilomas
• Lick Granulomas
• Warts
• Small Sarcoids
• Eye Lid Tumors
You will be able to quickly and easily treat skin lesions that you could not
treat before without undesired side effects!

28. Treat a lesion with pinpoint accuracy

31. Skin Tumor before treatment

34. Total recovery after 6 weeks.

35. Plantar-Wart
Papilloma situated at the
posterior face of the carpus

36. Papilloma in frozen condition

37. Frozen condition before 2nd freeze

38. Partial necrose at control visit

39. Fall of the papilloma with total
recovery after 4 weeks

40. an ulcerous
skin lesion on the top of the head.

41. Cryotherapy was chosen as the treatment for Nat because it causes little
discomfort
requires no preparation and no follow up care.
Since the CryoProbe has a penetration rate of freezing into the tissue @
1mm per 5 seconds, a 20-30 second treatment is performed on the lesion
that is estimated to be 3 to 4mm deep.

44. After second freeze

45. Although not required Nat came back after treatment for a check up at 5
weeks. A very nice result was achieved with the easy and practical
CryoProbe treatment modality

46. Disadvantages of Cryosurgery
As with the advantages of cryosurgery, the disadvantages can also be categorized
into those for the clinician and those for the patient.
Disadvantages for the clinician include the following:
 Liquid nitrogen needs to be delivered and stored. A liquid nitrogen generator
may be purchased. If that is not done, nitrous oxide tanks or other supplies will
need to be replenished as needed.
 The clinician must be certain of the diagnosis because no tissue will be sent for
pathology.
 Cryosurgery is not as accurate as a scalpel or laser in cosmetic work.
Disadvantages for the patient include:
 Erythema and swelling are the norm. Blistering is common.
 Pain, especially throbbing pain around the nail folds.
 Pain with walking if plantar warts are treated.
 May require multiple visits.
 Hypopigmentation.
 Damage to adjacent structures such as joints and bones may lead to lameness
and fracture.
 Risk of uncontrolled freezing - resulting in destruction of normal tissue.