Cryotherapy/
Cryosurgery
Patient
Selection Criteria
Candidates for cryosurgery are patients who are considered unresectable
(inoperable), but have no evidence of disease outside the liver. However,
it must be expected that the liver lesions can be completely destroyed
by cryosurgery alone or in combination with resection, as cryotherapy
is not an appropriate palliative procedure (symptom relief without curing
the disease).
Description
of Procedure
Cryosurgery
is a major surgical operation, using general anesthesia and requiring
a large incision in the abdomen. (Occasionally, these procedures are
done with a laparoscope, but usually they are done with open surgery.)
The purpose of the cryosurgery is to destroy all present tumors (including
a margin of healthy tissue) by freezing them. Cryoprobes are placed
directly into the liver and supercooled liquid nitrogen / argon gas flows through
the probes to freeze the intended area. This results in cellular crystallization,
cell shrinkage and membrane damage. Thawing results in further damage
as the area becomes hypotonic and smaller crystals re-crystallize to
larger ones. Usually, two freeze-thaw cycles are done in each area because
it has been shown to produce a better destruction of cancer cells than
a single cycle.
Risks/Side
Effects/Complications
Mortality
rates for patients undergoing cryosurgery range from 0% to 4% in most
published studies. Major complications have been reported in the range
of 0-23% of patients. The most common complications are:
- Transient
elevation of liver enzymes (short-term increase)
- Coagulopathy
(problems with blood clotting)
- Leukocytosis
(high white blood cell count)
- Mild
fever
- Pleural
effusion (fluid around the lungs)
- Hypothermia
(cold body temperature)
Other complications
include, but are not limited to:
- Bleeding
during the procedure / liver surface cracking
- Injury
to nearby structures
- Gas
embolism (air in a blood vessel)
- Cardiac
arrhythmia
- Delayed
bleeding
- Thrombocytopenia
(reduced platelets in the blood)
- Prolonged
prothrombin time (bleeding time)
- Disseminated
intravascular coagulation
- Myoglobinuria
- Acute
renal failure
- Ascites
(fluid in the abdomen)
- Bile
leakage
- Infection/abscess
- Liver
failure
- Cryoshock
syndrome -- thrombocytopenia, disseminated intravascular coagulation,
renal failure, hepatic failure, and adult respiratory distress syndrome
– potentially fatal multisystem failure
Recovery
time and life style changes
Because
cryosurgery is done as an open abdominal surgical procedure with general
anesthesia, the average hospital stay is five to seven days, if there
are no complications. The abdominal incision wound needs to be cleaned
three times each day for about the first two weeks following surgery.
Patients generally should not drive for at least two weeks after this
surgery. In addition, patients are usually advised to limit their physical
activity and not to do any heavy lifting for up to three months after
surgery. If the cyrosurgery is done laparoscopically, using a scope
inserted through a small incision, recovery time and lifestyle changes
are decreased.
Effectiveness
With cryosurgery,
survival rates for patients with HCC have been reported to be 56 to
60% at one year, 24 to 36% at two years, and 10-23% at three years.
For patients with colorectal metastases to the liver, survival rates
range from 62-77% at one year and from 50-65% at two years. One study
reported only a 5% survival rate at three years. Local recurrence has
been reported to be 10% for metastatic patients undergoing cryosurgery.
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2001 RITA Medical
Systems, Inc. | Contact Us | Disclaimer
| Last modified: Friday, October 10, 2003
