J R Soc Med 2001;94:196-201
© 2001 Royal Society of Medicine
The history of cryosurgery
S M Cooper MRCP MRCGP
R P R Dawber FRCP
Department of Dermatology, Oxford Radcliffe Hospitals, Oxford OX3 7LJ,
UK
Correspondence to: Dr S M Cooper, Department of Dermatology, Churchill
Hospital, Headington, Oxford OX3 7LJ, UK E-mail:
NeilCCooper{at}msn.com
 |
INTRODUCTION
|
|---|
The controlled destruction of tissue by freezing is today widely
practised
in medicine. Terms for it include cryotherapy, cryocautery,
cryocongelation
and cryogenic surgery, but cryosurgery (literally,
cold handiwork) seems most
appropriate. Cryosurgery is a cheap,
easy, and safe treatment suitable for
both hospital and office
based practice. Its major advantage is excellent
cosmetic results
with minimal scarring.
The benefits of cold have been appreciated for many thousands of years. The
ancient Egyptians, and later Hippocrates, were aware of the analgesic and
anti-inflammatory properties of cold. Over the past 200 years cold treatment
has evolved from generalized application such as hydrotherapy
(Figure 1) to specific, focal
destruction of tissue—today's cryosurgery.
|
THE BEGINNINGS OF CRYOSURGERY
|
|---|
James Arnott (1797-1883), an English physician, published on
the use of
cold between 1819 and
1879
1,2.
He was the senior
physician of Brighton Infirmary but moved to London on
winning
fame. His brother, a scientist, had already gained fame and
fortune as
inventor of the slow combustion stove. Arnott was
the first person to use
extreme cold locally for the destruction
of tissue. He used a mixture of salt
and crushed ice (`two parts
finely pounded ice and one part of chloride of
sodium'
1) for
palliation
of tumours, with resultant reduction of pain and local haemorrhage.
He
stated that a very low temperature will arrest every inflammation
which is
near enough to the surface to be accessible to its
influence
1.
He
designed his own equipment, consisting of a waterproof cushion
applied to the
skin, two long flexible tubes to convey water
to and from the affected part
and a reservoir for the ice/water
mixture and a sump. He exhibited this at the
Great Exhibition
of London in 1851 and won a prize medal for his
effort
2. (The
Great
Exhibition was a showcase for the Empire's scientific
prowess not unlike the
Millennium Dome but with considerably
more style.) Arnott treated breast
cancer, uterine cancers and
some skin cancers. Although palliation was his
main aim he recognized
the potential of cold for curing cancer, stating that
the cases
he had seen `are therefore, by no means unfavourable to the
supposition
of the curability of cancer by congelation'. He advocated cold
treatment
for acne, neuralgia and headaches, achieving temperatures of
-24°C.
In addition he recognized the analgesic `benumbing' effect of
cold,
recommending the use of cold to anaesthetize skin before
operation. He was
concerned about the safety of the new anaesthetic
agents that were being
introduced and advocated the use of cold
as an alternative. This was to become
a lifelong crusade that
was ultimately unsuccessful, but his contribution to
the development
of cryosurgery was crucial.
|
FIRST USE OF REFRIGERANTS
|
|---|
Salt/ice mixtures were not capable of reducing tissue temperatures
sufficiently
to treat tumours effectively. It was not until refrigerants
came
into use that lower tissue temperatures could be achieved.
In the late 1800s,
at a time of tremendous scientific advance,
there was an interest in
liquefying gases. Cailletet, on Christmas
Eve 1877, demonstrated at the French
Academy of Science that
oxygen and carbon monoxide could be liquefied under
high pressure
3.
Pictet
also demonstrated the liquefaction of oxygen but used a mechanical
refrigeration
cascade
4.
Von Linde
was responsible for the first commercial production
of liquid air in 1895,
which led the way to its widespread introduction.
|
LIQUID AIR AND LIQUID OXYGEN
|
|---|
Campbell White, of New York, was the first person to employ
refrigerants
for medical use. He reported his success in 1899,
advocating liquid air for
the treatment of a large range of
conditions including lupus erythematosus,
herpes zoster, chancroid,
naevi, warts, varicose leg ulcers, carbuncles and
epitheliomas
5,6.
He
recognized `the efficiency of liquid air in the treatment of
carcinoma' and
enthusiastically stated `I can truly say today
that I believe that
epithelioma, treated early in its existence
by liquid air, will always be
cured
6'.
Whitehouse7
reviewed the effects of liquid air on normal skin, finding it to be especially
useful for epitheliomata, lupus erythematosus and vascular naevi. He stated
that liquid air `outranks some of the remedies on which we have placed great
reliance7'. He
treated recurrences of epitheliomata after radiotherapy and found liquid air
to be more successful than repeat radiotherapy. Bowen and
Towle8 reported the
successful use of liquid air for vascular lesions in 1907. Liquid oxygen had a
limited vogue in the 1920s and 1930s. It has similar properties to liquid air,
achieving temperatures of -182.9°C, but was chiefly used for acne.
|
CARBONIC ACID SNOW
|
|---|
Around the time that liquid air was being investigated, William
Pusey
9 of Chicago
popularized the use of carbon dioxide snow (or carbonic
acid snow) in
preference to a salt and ice mixture. He advocated
carbon dioxide snow because
of its easy availability (thanks
to its use by manufacturers of mineral
waters). Liquid air was
very difficult to obtain at this time. The liquid
carbon dioxide
gas was supplied in steel cylinders under pressure. When the
gas
was allowed to escape, rapid expansion caused a fall in temperature
(the
Joule—Thompson effect) and a fine snow was formed.
The snow was easily
compressed into various shapes, known as
pencils, suitable for different
treatments. Pusey's first reported
case
9 was the
treatment of a large black hairy naevus on a young girl's
face. Impressive
before-and-after photographs showed the successful
depigmentation of the
lesion. This was one of the first demonstrations
of the extraordinary
sensitivity of melanocytes to cold. He
successfully treated other naevi, warts
and lupus erythematosus.
Pusey stated of carbon dioxide snow that `we have
found a destructive
application whose action can be accurately gauged and is
therefore
controllable'. He recognized the low scarring potential of
cryosurgery
although he attributed this to regeneration of residual epidermal
cells
rather than to collagen's resistance to cold.
Hall-Edwards, of Birmingham, first described his carbon dioxide collection
model in The Lancet in
191110.
Hall-Edward's monograph, written later in 1913, detailed the uses of carbon
dioxide and methods of
collection11
(Figure 2). His contribution to
cryosurgery was all the more remarkable because he was a respected
radiotherapist in charge of much of the Midlands. He would have been well
aware of the place of cryosurgery in relation to X-ray use. He detailed many
conditions in which treatment was effective but was particularly struck by its
efficacy in rodent ulcers. At the same time Cranston-Low, a physician in the
Edinburgh skin department, was likewise promoting the use of carbon dioxide
snow12. He observed
that `thrombosis, direct injury to tissues, and the inflammatory exudate
probably all act together' to produce the effects of freezing.
Solid carbon dioxide applied directly to the skin cannot get the surface
temperature below -79°C. This is insufficient for deeper freezing of
tissue necessary for treatment of malignancies, when a temperature of
-50°C at a tissue depth of 3 mm is required. Nevertheless it proved very
successful for a wide variety of benign skin conditions and remained popular
until the 1960s. Carbon dioxide slush, a mixture of carbon dioxide and
acetone, was used extensively for acne. As the use of carbon dioxide snow
became more widespread so did the range of conditions treated. De Quervain
reported the successful use of carbonic snow for bladder papillomas and
bladder cancers in
191713.
|
DEBATE ON THE BEST REFRIGERANT
|
|---|
The debate on the best cryogen to use persisted for much of
the first half
of the twentieth century. Reviewing the uses
of liquid air and carbon dioxide
snow in 1910,
Gold
14 concluded
`there
is no hesitancy in saying liquid air is far preferable' although
he
acknowledged the difficulty in obtaining liquid air at that
time. In 1929
Irvine and
Turnacliffe
15
similarly favoured liquid
air and oxygen over carbon dioxide snow, but the
controversy
continued into the 1960s. Irvine and
Turnacliffe
15
reported
liquid air treatment of seborrhoeic keratoses, senile keratoses,
lichen
simplex, poison ivy dermatitis and herpes zoster. They found
liquid
oxygen very useful for warts, declaring that `it offers
a practically sure,
quick and painless method for removal of
all types of warts, including the
plantar type'. The debate
was at times acrimonious. Pusey, an ardent advocate
of carbon
dioxide snow, said in reply to Irvine's paper, `I do not want
to
throw any question on Dr Irvine's results with liquid air
but for any method
of treatment to convince me of its adequacy
in warts, I want about 10,000
cases'
15.
|
APPLICATION AND STORAGE
|
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Refrigerants were generally applied either by painting directly
onto the
skin or by use of cotton wool twisted around a piece
of cane that had been
dipped into liquid air. Some ingenious
devices were developed including
Campbell White's roller for
treatment of
erysipelas
6.
Grimmett
16
highlighted the limitations
of a cotton wool applicator, showing that the
depth of freeze
was insufficient to treat tumours. Whitehouse (1864-1938), a
New
York dermatologist, developed a spray in 1907 which allowed
much lower
minimum
temperatures
7. His
simple design consisted
of two glass tubes inserted into a cork stopper of a
laboratory
wash bottle, operated by finger control. Whitehouse used his
spray
to treat skin lesions including cancers but abandoned
it because of the
difficulty in limiting the area of the spray.
The great advantage of liquid
air over salt/ice mixtures was
the lower temperatures that could be achieved,
allowing tumours
to be treated, but a disadvantage was the difficulty in
obtaining
and transporting it. Sir James Dewar solved the problems of
transportation
and storage by inventing a flask made of two walls of glass
with
a vacuum
between
11. Even
today the containers used for refrigerants
have much the same design.
|
LIQUID NITROGEN
|
|---|
Allington is generally thought to have been first to use liquid
nitrogen,
in 1950
17. He
recognized that the properties of liquid
nitrogen were very similar to those
of liquid air and oxygen.
After the Second World War, liquid nitrogen became
freely available
and was preferable to liquid oxygen with its explosive
potential.
He used a cotton swab for treating various benign lesions but
poor
heat transfer between swab and skin meant this method was
insufficient for
tumour treatment.
The contribution of Dr Irving S Cooper to cryosurgery was
immense18,19.
An American neurosurgeon based in New York, in 1913 he designed a liquid
nitrogen probe that was capable of achieving temperatures of -196°C. With
it he treated Parkinson's disease and other movement disorders by freezing the
thalamus, in addition to previously inoperable brain tumours. Although Cooper
was controversial in his lifetime because of his showmanship, his work led to
an explosion of interest in liquid nitrogen and its eventual acceptance as a
standard treatment in many specialties. More general use of cryosurgery was
facilitated by the development of devices suitable for office based practice.
Torre20 developed a
liquid nitrogen spray in 1965 and Zacarian a hand-held device, the Kryospray,
in 196720. Zacarian
popularized the use of this
equipment21.
Zacarian's spray allowed one-handed operation with trigger type control, and
interchangeable tips permitted variations in spray diameter. Zacarian also
developed copper probes that allowed tissue-freezing to depths of up to 7 mm.
His contributions to cryosurgery equipment, understanding of the science of
the cryolesion and the published work on cryosurgery was very great.
Amoils22 developed
a liquid nitrogen probe that achieved cooling by expansion. He performed
cataract extraction (cryoextraction) successfully but cooling was slow and
temperatures were not low enough for tumour work. This system is still widely
used in gynaecology and ophthalmology. The use of liquid nitrogen spread
through different
specialties21. Rand
performed a transphenoidal hypophysectomy with liquid nitrogen, Gage treated
oral cancers and Cahan performed cryosurgery of the uterus with a liquid
nitrogen probe. The use of liquid nitrogen in Great Britain took off when
Zacarian donated the first hand-held liquid nitrogen spray to the Oxford
dermatology department in the 1970s. This centre became the focus of
cryosurgical research in Britain.
|
CRYOBIOLOGY
|
|---|
The past 50 years have seen great advances in knowledge of the
biological
effects of freezing. Almost all research has concerned
the effects of liquid
nitrogen. The development of temperature
probes that can be inserted into skin
has allowed measurement
of tissue temperatures during freezing. An accurate
picture
of the shape and depth of iceball formation with different lengths
of
freeze has been built up, allowing development of guidelines
for freezing
times (best established for cutaneous
lesions
23).
For
malignant lesions freezing times are longer than for benign
lesions since
destruction of all malignant cells is vital. Tissue
temperatures must be below
-50°C for adequate treatment
of tumours. A 30-second spot freeze, counted
30 seconds after
an iceball formation, is capable of achieving a tissue
temperature
of -50°C in the centre of the ice ball and is usually the
minimum
time necessary for tumour
work
3. Other
research has concentrated
on determining the sensitivity of individual cell
types to freezing.
Melanocytes are most sensitive, hence the depigmentation of
skin
often seen after cutaneous cryosurgery. Collagen is the most
resilient
tissue, and indeed preservation of the normal structure
of collagen bundles is
observed on electron microscopy even
after the deep freezes necessary for
tumour work. This explains
why there is so little
scarring
24.
Cartilage necrosis is extremely
rare, so cryosurgery is particularly suitable
in areas where
maintenance of elasticity and function are important—such
as
the ear, around the eyes and the
nose
25.
|
WHICH REFRIGERANT?
|
|---|
Liquid nitrogen is by far the most popular cryogen in current
use. Its
popularity is due to the low temperatures achievable
(-197°C), which make
it suitable for both benign and malignant
lesions. Its effects are predictable
and well documented. Carbon
dioxide still enjoys some popularity because of
its easy storage
but is really only suitable for the occasional user and for
treatment
of benign lesions. Nitrous oxide is favoured by many gynaecologists
and
oral surgeons. Storage presents no problems but the large cylinders
required
are not easily portable. Only a probe method is suitable because
spraying
results in formation of solid crystals of nitrous oxide. A lowest
temperature
of -89°C makes nitrous oxide unsuitable for malignant lesions.
Freons
(fluorinated hydrocarbons with a low boiling point) have been
used in
dermatological practice since 1955 when Wilson advocated
their use for firming
skin before
dermabrasion
27.
Freon 12 has
been used for acne pits and is especially useful when a large
surface
area needs to be treated. The major advantages of freons are
their
portability and easy storage but their disadvantages are
insufficiently low
temperatures for tumour work, potential toxicity
in inhaled air and their role
in depleting the ozone layer.
Currently a spray-on non-fluorinated hydrocarbon
can be prescribed
(the Histofreezer, Thames Laboratories UK) but this is
unlikely
to achieve temperatures low enough to be highly effective.
|
DERMATOLOGICAL CRYOSURGERY
|
|---|
Cryosurgery is now indispensable in a dermatology department.
Benign
lesions amenable to treatment include viral warts, seborrhoeic
keratoses,
molluscum contagiosum, spider angiomata and digital
myxoid
cysts
23. The
efficacy of treatment of viral warts is
approximately 75% if lesions are
treated every two to three
weeks, in line with other methods of
treatment
28.
However, when
cryosurgery is contemplated for benign lesions it is especially
important
to consider the possible side-effects of pain, blistering and
hypopigmentation.
Cryosurgery is highly effective for premalignant solar keratoses and
Bowen's disease. Cure rates after cryosurgery of Bowen's disease are
comparable with those of excision, curettage and
cautery29. Basal
cell carcinomas are commonly treated by cryosurgery and the cure rates also
compare very favourably with those of surgical treatments, in carefully
selected patients. Other tumours that can be effectively treated are squamous
cell carcinomas and lentigo
maligna23.
|
THE WIDER APPLICATION OF CRYOSURGERY
|
|---|
Many other specialties have embraced and refined the technique
of
cryosurgery. Eye surgeons have used it extensively. The first
report of
retinal tears treated by freezing came from
Bietti
30 in 1933,
and when Bellowes reviewed cryotherapy of ocular diseases
in 1966 he included
cryoextraction of cataracts and treatments
for glaucoma and
tumours
30.
Cryosurgery still has an important
place in modern ophthalmological practice,
particularly for
eyelash ablation in
trichiasis
31,
treatment of retinopathy of
prematurity
32 and
retinal detachment.
In gynaecology the use of cold treatment goes back as far as 1883, when
Openchowski13
treated chronic cervicitis with cold water irrigation. Temple
Fay33, in
Philadelphia, applied both local and general cold treatment for cervical
tumours during the 1940s and in 1964
Cahan34 developed
the liquid nitrogen probe for the treatment of uterine fibroids and cervical
neoplasia. There has been some interest in cryosurgical treatment of cervical
intraepithelial neoplasia but this is losing favour. Cryosurgery of vulval
intraepithelial neoplasia is followed by early recurrence and is not to be
recommended35.
Palliation of surgically unresectable vulval squamous cell tumours can be very
beneficial, with reduction of pain and tumour
size36.
General surgeons have used freezing as an adjunct to surgery.
Allen37, in 1938,
recognized that limbs packed in ice for 3 hours could be subsequently
amputated without an anaesthetic agent, and as recently as 1985 a review
article37 described
the use of freezing to delay an otherwise urgent amputation and allow more
time for stabilization of a critically ill patient. A recent study of
palliative treatment for primary rectal carcinoma showed complete relief of
symptoms in 62%38.
Patients selected were unable to undergo surgical treatment either because of
prohibitive operative risk or because of unresectable tumour. Cryosurgery has
been shown to be an effective treatment for
haemorrhoids39 and
may be a useful alternative to surgical haemorrhoidectomy in countries where
health resources are limited. Unresectable tracheobronchial carcinomas have
been managed by
cryosurgery40, with
haemoptysis alleviated in over 90%.
Other areas of current interest include a nephronsparing treatment option
for kidney
cancers41 and
cryosurgical treatment of prostatic
cancer42. In
prostate cancer, impotence and incontinence are less frequent with cryosurgery
than with radical prostatectomy or radiotherapy. Further studies will be
necessary to assess longterm cure rates. Hepatic cryosurgery for either
metastatic carcinoma or primary hepatocellular carcinoma, via cryoprobe, gives
results similar to those of surgical resection. The major advantage is the
ability to treat widespread lesions, whereas surgical resection is limited to
isolated or small foci of
tumour43. Also,
cryosurgery has been used for bone tumours for 30 years and still has a
role44.
After nearly two centuries, the technique of cryotherapy remains widely
applicable. At a time when surgical excision is in the ascendant this simple
method, with its cosmetic and functional benefits, should not be
neglected.
|
REFERENCES
|
|---|
-
Arnott J. On the Treatment of Cancer by the Regulated
Application of an Anaesthetic Temperature. London: Churchill,1851
-
Bird H. James Arnott, MD (Aberdeen), 1797-1883, a pioneer in
refrigeration. Anaesthesia1949; 4:10
-17
-
Cailletet L. Recherches sur la
liquéfaction des gaz. Ann Chemie
Physique 1878;15:132
-44
-
Pictet R. Mémoire sur la
liquéfaction de
l'oxygène. Am Chemie
Physique 1878;13:145
-227
-
White AC. Liquid air: its application in medicine and surgery.
Med Rec1899; 56:109
-12
-
White AC. Possibilities of liquid air to the physician.
JAMA1901; 36:426
-9
-
Whitehouse H. Liquid air in dermatology: its indications and
limitations. JAMA1907; 49:371
-7
-
Bowen JT, Towle HP. Liquid air in dermatology. Med Surg
J 1907;157:561
-
Pusey W. The use of carbon dioxide snow in the treatment of naevi
and other lesions of the skin. JAMA1935; 49:1354
-6
-
Edwards JH. The therapeutic effects of carbon dioxide snow: methods
of collecting and application. Lancet1911; ii:87
-90
-
Hall-Edwards J. Carbon Dioxide Snow: its Therapeutic
Uses. London: Simpkin, Marshall, Hamilton, Kent,1913
-
Cranston-Low R. Carbonic Acid Snow as a Therapeutic
Agent in the Treatment of Disease of the Skin. Edinburgh/London:
William Green, 1911
-
Bracco D. The historic development of cryosurgery. Clin
Dermatol 190;8:1
-4
-
Gold J. Liquid air and carbonic acid snow: therapeutic results
obtained by dermatologists. NY Med J1910; 92:1276
-7
-
Irvine H, Turnacliffe D. Liquid oxygen in dermatology.
Arch Dermatol Syphilol1929; 19:270
-80
-
Grimmett R. Liquid nitrogen therapy. Histologic observations.
Arch Dermatol1961; 83:563
-7
-
Allington H. Liquid nitrogen in the treatment of skin diseases.
Calif Med1950; 72:153
-5[Medline]
-
Cooper IS. Cryogenic surgery. A new method of destruction or
extirpation of benign or malignant tissues. N Engl J
Med 1963;263:741
-9
-
Das K, Benzil DL, Rovit RL. Irving S Cooper (1922-1985): a pioneer
in functional neurosurgery. J Neurosurg1998; 89:865
-73[Medline]
-
Zacarian S. Cryogenics: the cryolesion and the pathogenesis of
cryonecrosis. In: Zacarian SA, ed. Cryosurgery for Skin Cancer and
Cutaneous Disorders. St Louis: Mosby, 1985;1
-30
-
Kuflik EG, Gage AA. History. In: Kuflik EG, Gage AA, eds
Cryosurgical Treatment for Skin Cancer. New York:
Igaku-Shoin 1990: 1-13
-
Amoils SP. The Joule Thomson cryoprobe. Arch
Ophthalmol 1967;78:201
-7[Medline]
-
Dawber R, Colver G, Jackson A. Cutaneous Cryosurgery:
Principles and Practice. London: Martin Dunitz,1997
-
Shepherd JP, Dawber RPR. Wound healing and scarring after
cryosurgery. Cryobiology1984; 21:157
-69[Medline]
-
Dawber RPR. Cold kills! Clin Exp Dermatol1988; 13:137
-50[Medline]
-
Dawber RPR, Colver G, Jackson A. Historic and scientific basis of
cryosurgery. In: Cutaneous Cryosurgery. Principles and
Practice. London: Martin Dunitz, 1997:15
-26
-
Wilson JW, Ayers SW, Luikart R. Dichlorotetrafluorethane for
surgical planning. Arch Dermatol1955; 71:253
-
Bunney MH, Nolan MW, Williams DA. An assessment of methods of
treating viral warts by comparative treatment trials based on a standard
design. Br J Dermatol1976; 94:667
-9[Medline]
-
Ball S, Dawber RPR. Treatment of Bowen's disease with particular
emphasis on the problem of lower leg lesions. Austr J
Dermatol 1998;39:63
-8
-
Bellowes JG. Cryotherapy of Ocular
Diseases. Philadelphia: Lippincott, 1966
-
Bartley GB, Bullock JD, Olsen TG, et al. An experimental
study to compare methods of eyelash ablation.
Ophthalmology1987; 94:1286
-9[Medline]
-
Anderson CC, Phelps DL. Peripheral retinal ablation for threshold
retinopathy of prematurity in preterm infants. Cochrane Database
Syst Rev 2000;2:CD001693
-
Gage AA. History of cryosurgery. Semin Surg
Oncol 1998;14:99
-109[Medline]
-
Cahan WG. Cryosurgery of the uterus: description of technique and
potential application. Am J Obstet Gynecol1964; 88:410
-14[Medline]
-
Marren P, Dawber RPR, Wojnarowska F. Failure of cryosurgery to
eradicate vulval intraepithelial neoplasia: a pilot study. J Eur
Acad Dermatol Venerol1993; 2:247
-51
-
Almeido Gongalves JC. Cryovulvectomy—a new surgical technique
for advanced cancer. Skin Cancer1986; 1:17
-32
-
Hunsaker R, Schwartz J, Keasy B, et al. Dry ice
cryoamputation: a 12 year experience. J Vasc Surg1985; 2:812
-16[Medline]
-
Meijer S, Rahusen FD, Van der Plas LG. Palliative cryosurgery for
rectal carcinoma. Int J Colorect Dis1999; 14:177
-80[Medline]
-
Dennison AR, Paraskevopoulos JA, Kerrigan DD, et al. New
thoughts on the aetiology of haemorrhoids and the development of non-operative
methods for their management. Minerva Chir1996; 51:209
-16[Medline]
-
Maiwand MO. The role of cryosurgery in palliation of
tracheobronchial carcinoma. Eur J Cardio-Thorac Surg1999; 15:764
-8[Abstract/Free Full Text]
-
Gill IS, Novick AC. Renal cryosurgery.
Urology1999; 54:215
-9[Medline]
-
Badalament RA, Bahn DK, Kim H. Patient-reported complications after
cryoablation therapy for prostatic cancer. Urology1999; 54:295
-9[Medline]
-
Saliken JC, McKinnon G, Gray RR, et al. Liver cryosurgery
with curative intent: can we realize the promise? Can Assoc
Radiologists J1999; 50:295
-7
-
Bickels J, Meller I, Shmookler BM, et al. The role and
biology of cryosurgery in the treatment of bone tumours. A review.
Acta Orthop Scand1999; 70:308
-15[Medline]
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INTRODUCTION
THE BEGINNINGS OF CRYOSURGERY
