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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R E N A L C R Y O A B L A T I O N R E N A L C R Y O A B L A T I O 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

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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.

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R E N A L C R Y O A B L A T I O N R E N A L C R Y O A B L A T I O N

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.

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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.