Renal
Cryoablation
1.
"RADIOFREQUENCY ABLATION OF RENAL TUMORS"
Author:
Mahnken AH, Gunther RW,Tacke J
Institution:
Department of Diagnostic Radiology,Aachen
University
of Technology in Aachen, Germany
Date/Publication:
August 2004, Eur Radiol.Vol. 14 (8)
Indication:
Renal
Key
Words: Kidney, thermal ablation, radiofrequency
Summary:
Thermal
ablation is a minimally invasive and nephron sparing
procedure
that is ideally suited for patients with a single kidney,
multiple
tumors or contraindications for resective surgery.
Although
cryotherapy is the most extensively studied technique
RF
has become the most accepted.This is largely due to the
technical
simplicity of the procedure and equipment needed to
perform
it.This is counterintuitive given the clinical evidence
presented
in the paper.All publications in the medical literature
regarding
renal RF and cryoablation were surveyed. A total of
276
RF patients were found with an average follow up of 7.7
months.The
disease free rate of this group was 81.8%.This is significantly
lower
than the 97.2% disease free rate of the 154
patients
who underwent cryoablation with an average follow-up
of
14.4 months. It is surprising that RF's technical simplicity has
overshadowed
its efficacy limitation which yields a recurrence
rate
over six times that of cryoablation (18.2% for RF versus
2.8%
for cryoablation).
2.
"CRYOTHERAPY AND RADIOFREQUENCY ABLATION: PATHOPHYSIOLOGIC
BASIS
AND LABORATORY STUDIES"
Author:
Finelli A, Rewcastle JC, Jewett MAS
Institution:
Department of Surgical Oncology, Princess Margaret
Hospital
and University of Toronto, Ontario and Department of
Radiology,
University of Calgary,Alberta, Canada
Date/Publication:
2003, Current Opinion in Urology Vol. 13
Indication:
Renal
Key
Words: Renal, radiofrequency ablation, cryotherapy
Summary:
With
an increase in the diagnosis of incidental and slow growing
renal
tumors, novel energy-base treatments, such as radiofrequency
and
cryotherapy, present important options for renal cancer
patients
as less invasive treatments. Cryoablation is the most
studied
modality and its ability to both directly and indirectly
damage
cells is generally understood. Recent data suggests that
an
active thaw can be used instead of the previously accepted
passive
thaw since it can effectively cryoablate renal tissue as
well
as significantly reduce overall operative time. Clinical experience
is
needed to further refine knowledge about optimal
freezing
temperature and freeze-thaw cycles. Radiofrequency
ablation
is an effective means of destroying cancerous tissue but
targeting
this energy has been difficult. Challenges monitoring
interstitial
needle placement and visualization during the procedure
also
limit radiofrequency's application.
3.
"LAPAROSCOPIC RENAL CRYOABLATION IN 32 PATIENTS"
Author:
Gill IS, Novick AC, Meraney AM, Chen RN, Hobart MG,
Sung
GT, Hale J, Schweizer DK, Remer EM
Institution:
Department of Urology and Radiology, Cleveland
Clinic
Foundation in Cleveland, Ohio and Department of
Urology,
Cleveland Clinic Florida in Fort Lauderdale, Florida
Date/Publication:
November 2000, Urology Vol. 56 (5)
Indication:
Renal
Patient
Selection: Enhancing renal mass had to be 4 cm or less,
circumscribed,
and peripherally located
Number
of Patients: 32 total (22 retroperitoneal and 10
transperitoneal)
Length
of Follow-up: 16.2 months
Efficacy:
23 of 23 show no evidence of renal cell carcinoma at
3
to 6 months postoperatively
Measurement
of Efficacy: CT-directed needle biopsy of the
cryolesion
Morbidity:
3.1% superficial liver laceration, 3.1% perirenal
hematoma,
3.1% herpes esophagitis
Key
Words: renal, cryotherapy, short-term efficacy
Summary:
Renal
cryoablation has been performed by open, percutaneous,
and
laparoscopic techniques. Complete necrosis is thought to be
achieved
at -19.4oC or lower.To ensure complete cell death, the
iceball
must extend well beyond the visible margins of the targeted
tumor.The
primary criticism of renal cryoablation is the
lack
of histologic data about the completeness of tumor destruction
and
the adequacy of negative surgical margins.While laparoscopic
renal
cryoablation is still in development, the early results
from
this study are very encouraging. Of the 23 patients who
underwent
CT-directed needle biopsy of the cryolesion at 3 to 6
months
postoperatively, none of the patients showed evidence of
renal
cell. Longer follow-up is needed but the initial experience
is
cautiously optimistic.
4.
"PRELIMINARY EXPERIENCE WITH CRYOABLATION OF RENAL
LESIONS
SMALLER THAN FOUR CENTIMETERS"
Author:
Khorsandi M, Foy RC, Chong W, Hoenig DM, Cohen JK,
Rukstalis
DB
Institution:
MCP Hahnemann University in Philadelphia, PA
Date/Publication:
May 2002, J Am Osteopath Assoc.Vol. 102 (5)
Indication:
Renal
Patient
Selection: Patients had lesions smaller than 4 cm in
diameter
Number
of Patients: 17
Length
of Follow-up: 30 months
Efficacy:
94%
Measurement
of Efficacy: reduction of lesion size
Morbidity:
12% capsular fracture, 6% diarrhea, 6% congestive
heart
failure, 17.6% fever, 6% intravenous infiltration, 6% ileus,
12%
wound separation, 1% syncope
Key
Words: open renal cryoablation, low morbidity, efficacy
Summary:
The
widespread use of imaging instruments (MRI, CT scan, and
ultrasound)
has caused an increase in the number of small renal
lesions
being detected.Therefore, nephron-sparing procedures
are
being used more frequently on small lesions when the localized
cancer
is present bilaterally or in a patient with an anatomic
or
functional solitary kidney. Renal cryoablation is advantageous
because
it is as effective as surgery but with fewer morbidities.
In
this study, the open renal approach was used since it allows
complete
mobilization, access to any part of the kidney, and continual
ultrasound
monitoring. Lesions greater than 4 cm were not
treated
due to fear of undertreating the lesion.The only attributable
complication
in the study was capsular fracture found in two
patients.
However, both of these fractures resulted from the use
of
more than one cryoprobe, and when the switch to only one
cryoprobe
was made there were no more incidences of capsular
fracture.
Follow-up studies demonstrate infarction and a reduction
of
lesion size in 15 to 16 cases.
5.
"RETROPERITONEAL LAPAROSCOPIC CRYOABLATION OF SMALL
RENAL
TUMORS: INTERMEDIATE RESULTS"
Author:
Lee DI, McGinnis DE, Feld R, Strup SE
Institution:
Department of Urology, University of California,
Irvine
Medical Center in Orange, CA; Bryn Mawr Hospital in Bryn
Mawr,
PA; Department of Radiology and Urology,Thomas
Jefferson
University School of Medicine in Philadelphia, PA
Date/Publication:
January 2003, Urology Vol. 61 (1)
Indication:
Renal
Patient
Selection: Preoperative CT or MRI showing a solid or
complex
renal mass less than 4 cm in size
Number
of Patients: 20
Length
of Follow-up: up to 3 years
Efficacy:
95%
Measurement
of Efficacy: reduction of lesion size
Morbidity:
5% (1/20) pancreatic injury
6.
"RENAL CRYOTHERAPY: 2003 CLINICAL STATUS"
Author:
Lowry PS, Nakada SY
Institution:
University of Wisconsin Medical School in Madison,
Wisconsin
Date/Publication:
2003, Current Opinion in Urology Vol. 13
Indication:
Renal
Patient
Selection: Patients had lesions smaller than 4 cm in
diameter
Number
of Patients: 18
Length
of Follow-up: 3 months
Efficacy:
100%
Measurement
of Efficacy: decrease in lesion size
Key
Words: renal cryosurgery, nephron-sparing surgery,
laparoscopy
Summary:
Clinical
studies have shown that long-term cancer control and
renal
function after partial nephrectomy has equivalent results to
radical
nephrectomy. Cryoablation of small renal masses represents
an
alternative method for performing nephron-sparing surgery.
Cryoablation
may be performed under open conditions, but
laparoscopy
provides equivalent efficacy with less morbidity.
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N
The
major disadvantages of LPN techniques are high morbidities,
limitations
in which tumors can be treated, and the need for
highly
skilled and experienced surgeons for some techniques.
Ablative
technologies minimize the risk and morbidity traditionally
associated
with open or laparoscopic partial nephrectomy.
Ablative
technologies include cryoablation, RF ablation, and highintensity
focused
ultrasound (HIFU). HIFU is ideal for treatment
of
small renal tumors but problems of imprecise targeting and
thermal
burns prevent its use. RF show promising short term
results
with low morbidities, but its use is recommended for
small
tumors (<3 cm) only. Cryoablation has shown very promising
short
term results with high efficacy and minimal morbidity,
but
a longer follow-up is necessary. However, if cryoablation is
able
to withstand the test of time, it may be the least morbid
technique
for its delivery to small renal tumors. Exploration into
these
techniques is important since treatment of renal cancer
will
ultimately shift from open to minimally invasive methods.
9.
"CLINICAL EXPERIENCE WITH OPEN RENAL CRYOABALTION"
Author:
Rukstalis DB, Khorsandi M, Garcia FU, Hoenig DM,
Cohen
JK
Institution:
Division of Urology, MCP Hahnemann University
School
of Medicine, Philadelphia and Allegheny General Hospital
in
Pittsburgh, PA
Date/Publication:
January 2001, Urology Vol. 57 (1)
Indication:
Renal
Patient
Selection: Radiologic (CT or MRI) identification of at
least
one solid or indeterminate renal mass less than 4 cm in size
Number
of Patients: 29
Length
of Follow-up: 16 months
Efficacy:
91.3%
Measurement
of Efficacy: Either complete resolution of the
treated
mass or only a residual nonenhancing cyst
Key
Words: open renal cryoablation, efficacy, safety
9
work
approximately two weeks after the procedure.The efficacious
results
demonstrate that laparoscopic renal cryosurgery is
a
viable and safe treatment, especially for small incidental lesions
and
patients with many comorbidities.The maximum lesion size
should
be around 3 to 4 cm. Cryosurgery has many advantages
over
partial nephrectomy including less blood loss, no renal hilar
clamping,
no technically difficult suturing, no urine leaks,
decreased
need for ureteral stenting, and is effective in patients
on
anticoagulation. It is also easier to treat less exophytic tumors
because
of ultrasonic monitoring of the iceball. One probe can
be
used to treat tumors up to 2 cm while larger tumors can be
treated
with triangulation. Larger tumors should be treated with
laparoscopic
partial nephrectomy or laparoscopic radical
nephrectomy.
8.
"MINIMALLY INVASIVE MANAGEMENT OF THE SMALL RENAL
TUMOR:
REVIEW OF LAPAROSCOPIC PARTIAL NEPHRECTOMY AND
ABLATIVE
TECHNIQUES"
Author:
Ogan K, Cadeddu JA
Institution:
The Clinical Center for Minimally Invasive Urologic
Cancer
Treatment, Department of Urology,The University of
Texas
Southwestern Medical Center in Dallas,Texas
Date/Publication:
November 2002, Journal of Endourology
Vol.16
(9)
Indication:
Renal
Key
Words: laparoscopic partial nephrectomy techniques, ablative
techniques
Summary:
The
establishment of nephron-sparing surgery and the emergence
of
laparoscopic partial nephrectomy are the two most
profound
changes in renal cancer.This article outlines the various
LPN
and ablative techniques currently in development. LPN
techniques
include duplication of the open technique, handassisted
laparoscopic
partial nephrectomy, double-loop renal
tourniquet,
cable-tie tourniquet, ultrasound shears, RF-assisted
LPN,
microwave tissue coagulator, laser surgery, and endosnare.
8
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11.
"EFFECT OF INTENTIONAL CRYO-INJURY TO THE RENAL
COLLECTING
SYSTEM"
Author:
Sung GT,Gill IS, Hsu TH, Meraney AM, Skacel M, Brainard
JA,
Remer EM
Institution:
Urological Institute and Departments of Pathology
and
Radiology, Cleveland Clinic Foundation in Cleveland, Ohio
Date/Publication:
February 2003, Journal of Urology Vol. 170
Indication:
Renal
Patient
Selection: all female swine weighing 35 to 47 kg
Number
of Patients: 12
Length
of Follow-up: 1 month
Key
Words: warming of pelvicaliceal system, bilateral renal
cryoablation
Summary:
This
study evaluates whether continuous irrigation of the renal
pelvicaliceal
system with warm saline protects it against cryoinjury.
The
protective effect of local warming of vital hollow
structures,
such as the urethra during prostate cryoablation, is
well
described in recent literature.This same effect was tested in
the
pelvicaliceal system by warming all 12 right kidneys and
leaving
all 12 left kidneys without warming. However, the results
demonstrate
that continuous irrigation of the ureter and renal
pelvis
with warm saline during cryoablation do not provide any
cryoprotective
advantage to the calix at risk.The data suggests
that
mere extension of the ice ball into the intact pelvicaliceal
system
does not seem to result in urinary extravasation or caliceal
fistula
formation.This type of injury appears to be associated
with
favorable,watertight healing characteristics.This study
has
clinical relevance for facilitating cryoablation of a small,
localized
central or polar renal tumor located in proximity to the
pelvicaliceal
system.
11
Summary:
Data
from this study demonstrates that open renal cryoablation
is
a safe and efficacious surgical technique for the destruction of
renal
cancer.The open transperitoneal approach facilitates renal
exploration,
ultrasound imaging, and cryoablation with multiple
probes
without significant morbidity. Data shows little blood loss
in
the procedure and a median hospital stay of 3 days indicating
that
this technique is well tolerated and likely to be competitive
with
other methods in terms of cost.Additional advantages
include
the ability to inspect the renal unit and convert the procedure
to
radical nephrectomy if necessary. Since one tumor was
not
completely eradicated, the study has emphasized the need
for
precise temperature monitoring during the procedure for
lesions
larger than 3 cm. It is recommended that reliable tissue
destruction
is achieved at temperatures less than -40oC
10.
"LAPAROSCOPIC CRYOTHERAPY FOR RENAL TUMORS"
Author:
Spaliviero M, Moinzadeh A, Gill IS
Institution:
Glickman Urological Institute in Cleveland, Ohio
Date/Publication:
April 2004,Technology in Cancer Research
and
Treatment Vol. 3 (2) Indication: Renal
Key
Words: laparoscopic cryotherapy, low morbidity, short-term
results
Summary:
This
study looks at key laboratory and clinical discoveries and the
future
direction of renal cryotherapy. Laboratory experience
demonstrates
that the temperature of the cooling probe, freeze
time,
and vascularity of the tissue all play a significant role in size
and
growth of the ice ball. Clinical experience demonstrates that
renal
cryosurgery has a major role in treatment of small (< 3cm)
solid
tumors in patients with medical comorbidity.Advantages compared
to
partial nephrectomy are reduced blood loss, no renal hilar
clamping
and warm ischemia requirement, and no need for suturerepairing
of
renal parenchyma and collecting system.The primary
limitation
of cryo is the lack of pathologic confirmation of negative
surgical
margins and complete kill throughout the tumor. Longterm
follow-ups
are needed to confirm its efficacy and durability.
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