SMALL RENAL MASS

MANAGEMENT OF
SMALL RENAL MASS
(SRM)
Dept of Urology
Govt Royapettah Hospital and Kilpauk Medical College
Chennai

Moderators:
Professors:
◼ Prof. Dr. G. Sivasankar, M.S., M.Ch.,
◼ Prof. Dr. A. Senthilvel, M.S., M.Ch.,
Asst Professors:
◼ Dr. J. Sivabalan, M.S., M.Ch.,
◼ Dr. R. Bhargavi, M.S., M.Ch.,
◼ Dr. S. Raju, M.S., M.Ch.,
◼ Dr. K. Muthurathinam, M.S., M.Ch.,
◼ Dr. D. Tamilselvan, M.S., M.Ch.,
◼ Dr. K. Senthilkumar, M.S., M.Ch.
Dept of Urology, GRH and
KMC, Chennai.
2

INTRODUCTION
◼ Renal cell carcinoma accounts for 3% of all adult cancers.
◼ Incidence of RCC has increased by about 3% per year since 1970s.
◼ With more pervasive use of noninvasive imaging for evaluation of
nonspecific symptom complexes, more than 50% of RCCs are now
detected incidentally (Pantuck et al, 2000)
◼ Small (<4 cm), solid, sporadic, apparently organ
confined tumor – Small Renal Mass (SRM).
3
Dept of Urology, GRH and KMC,
Chennai.

◼ Management of RCC has undergone paradigm shift over last two decades.
◼ Allowed urologists to explore alternative and less invasive forms of therapy
– nephron sparing surgery(NSS) & renal ablative technologies (Pinto, 2009).
◼ Ultimate goals for management of early-stage RCC-
◼ Cancer-specific survival,
◼ Preservation of renal function,
◼ Avoidance of treatment-related morbidity
◼ Patient-centered quality-of-life outcomes -
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Chennai.

5
Chennai.

◼ NSS provides cancer control comparable with radical
nephrectomy in selected pts with a small (4 cm or less) localized
RCC. (Uzzo&Novick,J.Urol 2001;166:6).
◼ Open partial nephrectomy with its excellent 5 and 10 yrs
oncologic follow-up data is the gold standard.
6
Chennai.

DIAGNOSIS
◼ SRMs detected with renal ultrasound or excretory urography be further
investigated using high quality computerized tomography
◼ A 3 ( TRIPLE ) -phase study, including non-contrast, early
vascular and delayed excretory phases used.
◼ Enhancement of >15 HU and no fat(-20HU) to be demonstrated in
delayed images.
◼ MRI in pts with compromised renal
function or allergic to iv contrast media.
7
Chennai.

CLASSIFICATION OF SRM
◼ Benign SRM: 20%
◼ Incidence of benign pathology is higher in young to middle-
aged women
◼ Potentially Aggressive: 20-25%
◼ Indolent SRM: 60%
8
Chennai.

Histologic Findings in 21st Century
Duchene et al. UTSW, Urology 62: 827, 2003
Modern series 1999 - 2002
TUMOR SIZE– Strong indicator of malignancy.
Each 1 cm increase in tumor size was associated with a 16% increase in the odds of
malignancy such that 22% of all tumors <4 cm are benign
9
Chennai.

◼ Although RCC is by far the most common diagnosis, no clinical
or radiographic feature can predict malignancy.
◼ Prediction of potentially aggressive histology, which is the
critical determinant for clinical management.
◼ More recently,
◼ Advanced molecular imaging using
◼ Radiolabeled antibody to marker expressed by clear cell RCC
◼ Positron emission tomography for detection of Iodine 124
labeled chimeric antibody to carbonic anhydrase IX
◼ Sensitivity was 94% and specificity was 100% for identification of clear
cell RCC.
10
Chennai.

◼ CT scans for right renal mass
using antibodies to carbonic
anhydrase IX (G250
antibody).
◼ Note in the lower picture the
uptake of tracer.
◼ Surgical pathology confirmed
RCC (clear cell)
11
Chennai.

ROLE OF BIOPSY IN SRM
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Chennai.

◼ In the past RMB was largely abandoned due to concerns about
false-negative results and fear of catastrophic complications.
◼ Diagnostic accuracy of RMB in studies before 2001 averaged 82%,
this has increased to 90%.
◼ Performed in the outpatient setting under radiographic (ultrasound,
CT, MRI) guidance with minimal morbidity.
◼ Fewer than 1% of patients experience bleeding or other complications
leading to clinical intervention.
◼ Needle tract seeding, which is a major concern with infiltrative renal
masses such as high grade urothelial carcinoma, is decidedly rare with
well circumscribed SRMs. ( < 0.01%)
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Chennai.

◼ Rationale for the management strategy, Aids in counseling and
decision making.
◼ Stratification of oncologic risk.
Benign Vs malignant histology ( >90% ).
Tumor histology and tumor grade (70% -80%).
◼ Standard of care in SRM especially in ruling out abscess,
lymphoma & metastasis.
◼ Molecular analysis further improves the accuracy.
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Chennai.

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Chennai.

DIFFERENTIAL DIAGNOSIS
◼ RCC is by far the most common diagnosis
◼ Oncocytoma
◼ Fat-poor angiomyolipoma
◼ Metanephric adenoma
◼ Mixed epithelial and stromal tumor
◼ Urothelial carcinoma
◼ Metastatic tumor, Lymphoma, Abscess,
Infarct, Vascular malformation and Pseudotumor.
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Chennai.

Treatment options
◼ Radical Nephrectomy
◼ Partial Nephrectomy
◼ Thermal Ablation
◼ Active survelliance
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Chennai.

SURGICAL MANAGEMENT
18
Chennai.

Radical nephrectomy
◼ Radical nephrectomy
◼ Gold Standard curative operation
◼ Described by Robson in 1963
◼ Surgical Principles:
◼ Early ligation of the renal artery & vein
◼ Removal of the kidney outside Gerota’s fascia
◼ Removal of ipslateral adrenal gland
◼ Complete lymphadenectomy from the crus of diaphragm
to aortic bifurcation
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Chennai.

◼ RN, even when adrenalectomy and lymphadenectomy are
excluded, represents therapeutic overkill.
◼ Should only be performed when the involved kidney has poor
function or when truly necessary.
◼ RN has significant negative impact on renal function and
contributes to the development of chronic kidney disease.
◼ CKD is an important contributor to overall mortality because of the
dose related increase in cardiovascular events.
◼ CKD is present in >30% of patients before nephrectomy for presumed
cancer, and develops in majority of these older pts after RN.
20
Chennai.

◼ Laparoscopic RN, first described in 1991, served as the backbone for
subsequent minimally invasive treatments for SRMs.
◼ Decision to use a transperitoneal,retroperitoneal, robot assisted or hand
assisted technique for LRN depends largely on the surgeon.
◼ LRN offers several short-term advantages over ORN in terms of
morbidity and convalescence, and appears to have comparable
oncologic outcomes for localized RCC.
◼ What is concerning regarding LRN is its widespread use for
SRMs, many of which are amenable to nephron-sparing approach
that would permit greater preservation of renal function.
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Chennai.

NEPHRON SPARING SURGERY
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Chennai.

Partial nephrectomy
◼ PN, in which the uninvolved portion of the kidney is preserved after
removal of the tumor with a small rim of normal parenchyma.
◼ PN has also been performed electively at several centers of excellence
for decades for other patients with SRMs
◼ Cumulated evidence from series indicates that PN is associated with
oncologic outcomes comparable to those of RN.
◼ More importantly, recent evidence suggests that patients undergoing
PN survive longer than those undergoing RN, perhaps due to greater
preservation of renal function.
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Chennai.

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Chennai.

INDICATIONS FOR SURGERY
◼ Situations in which radical nephrectomy would render the
patient anephric, with subsequent immediate need for
dialysis
◼ Bilateral RCC or RCC involving a solitary functioning
kidney
◼ unilateral RCC and a functioning opposite kidney when
the opposite kidney is affected by a condition that might
threaten its future function, such as calculus disease,
chronic pyelonephritis, renal artery stenosis, ureteral
reflux, or systemic diseases (e.g., diabetes and
nephrosclerosis)
◼ provide effective curative treatment >>In RCC
single, small (less than 4 cm), and localized
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Chennai.

PREOP EVALUATION
◼ Patient should be evaluated prior to partial nephrectomy that
include
detailed history and physical examination
◼ laboratory evaluation
◼ Radiographic testing -to rule out locally extensive or metastatic
disease[chest x-ray abd-CT]
◼ Partial nephrectomy requires a more detailed understanding of renal
anatomy than radical nephrectomy. Therefore, more extensive and
invasive preoperative imaging studies are often obtained before
partial nephrectomy
◼ Arteriography
◼ Venography
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Chennai.

◼ Arteriography is most useful for nonperipheral tumors
encompassing two or more renal arterial segments
◼ Selective renal venography is performed in patients
with large or centrally located tumors to evaluate for
intrarenal venous thrombosis and assess the adequacy
of venous drainage of the planned renal remnant
◼ Differential renal function can be assessed by isotope
renography
◼ Patients should receive organism-specific antibiotic
therapy preoperatively 27
Chennai.

PREOP EVALUATION
◼ Three-dimensional volume-rendered CT,gives the
renal parenchymal and vascular anatomy,also
demonstrating involvement of the collecting
system
28
Chennai.

Three-dimensional CT scan shows tumor in upper part of left kidney
with renal arterial and venous supply 29
Chennai.

SELECTION OF INCISION
◼ For infants and children, the anterior subcostal incision
provides the best exposure
◼ For adolescents and adults, lateral approach (11th- or 12th-rib
supracostal incision) is most commonly used.
Disadvantages
◼ The flexion required for the flank position decreases vital capacity
and venous return to the heart, and thus it may not be tolerated by
obese patients
◼ Flank wounds are more prone to muscular weakness due to
stretching of the intercostal nerves
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Chennai.

Advantages
◼ The direct exposure
◼ The pleura and peritoneum,if entered, are readily repaired
◼ If the exposure proves to be limited, it can be increased by
segmental resection of the overlying ribs
◼ Good visualization of the kidney making inspection and
repair easy
◼ The pelvis is well exposed when the kidney is rotated
anteriorly
◼ Closure in layers with dependent drainage makes a secure
wound
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Chennai.

◼ Thoracoabdominal incision provide better access to the renal area for large
tumors,upper pole tumor
Anterior approach [ transverse subcostal or midline ] provides superior exposure to
the vascular pedicle of the kidney for renal trauma and neoplasm
Disadvantages
◼ An anterior approach is more difficult than those through the flank
◼ Risks of injury to the viscera and later formation of intestinal adhesions
◼ Difficult to approach the upper pole and the renal pelvis
◼ Chances of peritoneal cavity contamination
◼ Wound separation is more common than in flank incisions
◼ A posterior approach through a dorsal lumbotomy
is quicker and carries less morbidity but provides more
limited exposure
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Chennai.

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Renal venous anatomy
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Chennai.

INTRAOPERATIVE RENAL
ISCHEMIA
◼ Temporary occlusion of the renal artery is
necessary in NSS
◼ Temporary arterial occlusion not only diminishes
intraoperative renal bleeding but also improves
access to intrarenal structures by causing the
kidney to contract and by reducing renal tissue
turgor
36
Chennai.

Mechanisms of Renal Ischemic Injury
pathophysiologic process of renal ischemia
◼ reductions in glomerular filtration rate due to
persistent vasoconstriction
◼ and activation of tubuloglomerular feedback
◼ ischemia > loss of cell polarity in the proximal
tubule with mislocalization of the Na+,K+-ATPase
resulting decreased sodium reabsorption in the
proximalubule>enhanced delivery of solute to the
macula densa > activation of tubuloglomerular
feedback 37
Chennai.

◼ Renal artery occlusion cause reductions in
medullary blood flow with reduction in oxygen
delivery to the tubular structures
◼ This will lead to cellular injury due to imbalance
between oxygen delivery and demand
◼ Endothelial injury due to leukocyte
activation[cytokines, chemokines, eicosanoids]
and release of vasoactive substances >>
swelling and injury of the endothelial cell
38
Chennai.

Renal Tolerance to Warm Ischemia
◼ The extent of renal damage after normothermic arterial occlusion
depends on the duration of the ischemic insult
◼ The warm ischemic time is 30 minutes
◼ If it beyond 30 minutes, the recovery of renal function is either
incomplete or absent
◼ It affects mostly the proximal tubular cells,whereas the
glomeruli and blood vessels are generally spared
◼ The solitary kidney is more resistant to ischemic damage than the
paired kidney
◼ Presence of an extensive collateral vascular supply increases the
tolerance to temporary arterial occlusion
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Chennai.

◼ The method employed to achieve vascular control of the kidney is
the important determinant of renal ischemic damage
◼ The impairment is least when the renal artery alone is
continuously occluded
◼ Continuous occlusion of the renal artery and vein for an equivalent
time interval is more damaging,because it prevents retrograde
perfusion of the kidney through the renal vein and may also
produce venous congestion of the kidney
◼ Intermittent clamping of the renal artery is also more damaging than
continuous arterial occlusion,because of the release and trapping of
vasoconstrictor agents within the kidney
◼ Manual renal compression to control intraoperative hemorrhage is
more deleterious than simple arterial occlusion
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Chennai.

Prevention of Ischemic Renal
Damage
General measures
◼ preoperative and intraoperative hydration
◼ prevention of hypotension
◼ avoidance of unnecessary manipulation or traction on the
renal artery
◼ intraoperative administration of mannitol
These factors ensure optimal perfusion with an absence of
cortical vasospasm at the time of arterial occlusion, which
allows uniform restoration of blood flow throughout the
kidney when the renal artery is unclamped
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Chennai.

◼ Mannitol is most effective when it is given 5 to 15 minutes before
arterial occlusion
◼ It increases renal plasma flow, decreases intrarenal vascular
resistance, minimizes intracellular edema, and promotes an osmotic
diuresis when renal circulation is restored
Protective measures
◼ Local hypothermia is the most effective and commonly employed
method
◼ Lowering renal temperature reduces energy-dependent metabolic
activity of the cortical cells, with a resultant decrease in both the
consumption of oxygen and the breakdown of adenosine
triphosphate
◼ The optimum temperature for hypothermic in situ renal
preservation is 15°C
42
Chennai.

◼ But it is difficult to achieve uniform cooling to
this level [15`C] because of the temperature of
adjacent tissues and need to exposed a portion of
the kidney to perform the operation
◼ but temperature of 20°C to 25°C is easier to
maintain with renal preservative effect
◼ This level of hypothermia provides complete renal
protection from arterial occlusion of up to 3 hours
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Chennai.

In situ renal hypothermia
◼ external surface cooling
◼ perfusion of the kidney with a cold solution instilled
into the renal artery[invasive]
◼ These two methods are equally effective
◼ Surface cooling of the kidney is a simpler and
widely used method
◼ surrounding the kidney with a cold solution [or]
applying an external cooling device to the kidney
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Chennai.

Another method is ice-slush cooling
◼ The mobilized kidney is surrounded with a rubber sheet
on which sterile ice slush is placed to completely immerse
the kidney
◼ This method is to keep the entire kidney covered with ice
for 10 to 15 minutes immediately after the renal artery is
occluded
◼ This amount of time is needed to obtain core renal
cooling to a temperature of 20°C
◼ Extent up to 2- 4 hrs without ischemic injury
◼ Another approach to in situ renal preservation that does
not involve hypothermia is pretreatment with one or more
pharmacologic agents
◼ renal-dose dopamine,inosine,captopril,and adenosine
triphosphate–magnesium chloride 45
Chennai.

PARTIAL NEPHRECTOMY FOR
MALIGNANT DISEASE
Factors increases partial nephrectomy, or nephron-sparing
surgery in RCC
◼ Advances in renal imaging
◼ Improved surgical techniques
◼ Increasing numbers of low-stage RCCs
◼ Good long-term survival
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Chennai.

Timing of surgery in bilateral
RCC
◼ Kidney most amenable to partial nephrectomy
first
◼ After 1 month, second partial nephrectomy or a
radical nephrectomy on the opposite kidney
◼ In bilateral, small, synchronous RCCs, bilateral
simultaneous partial nephrectomies are also
performed.
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Chennai.

TYPES OF PARTIAL NEPHRECTOMY
◼ Simple enucleation
◼ Polar segmental nephrectomy
◼ Wedge resection
◼ Transverse resection
◼ Extracorporeal partial nephrectomy with renal
autotransplantation 48
Chennai.

Basic principles in partial nephrectomy
◼ early vascular control
◼ avoidance of ischemic renal damage
◼ complete tumor excision with free margins
◼ precise closure of the collecting system
◼ careful hemostasis
◼ closure or coverage of the renal defect with
adjacent fat, fascia, peritoneum, or Oxycel
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Chennai.

PARTIAL NEPHRECTOMY
◼ The kidney is mobilized within Gerota's fascia while the
perirenal fat around the tumor is left intact
◼ the parenchyma around the tumor is divided with a
combination of sharp and blunt dissection
◼ renal arterial and venous branches supplying the tumor
identified and ligated
◼ After excision of the tumor, the remaining transected
blood vessels on the renal surface are secured with figure-
of-eight 4-0 chromic sutures 50
Chennai.

51
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◼ Residual collecting system defects are closed with
interrupted or continuous 4-0 chromic sutures
◼ At this point, with the renal artery still clamped but with
the renal vein open, the anesthesiologist is asked to
hyperinflate the lungs and thereby raise the central and
renal venous pressures. This forces blood out through
residual, unsecured, transected veins on the renal surface
and thereby facilitates their detection.Once identified,
these veins are secured with interrupted figure-of-eight 4-0
chromic sutures
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◼ The kidney is closed approximating the transected cortical
margins with simple interrupted 3-0 chromic sutures with
Oxycel at the base of the defect
◼ The kidney is fixed to the posterior musculature with interrupted 3-
0 chromic sutures to prevent postoperative movement or rotation
of the kidney
◼ Drain is left in place for at least 7 days
◼ Ureteral stent is placed only when major reconstruction of the
intrarenal collecting system has been performed
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Chennai.

SEGMENTAL POLAR NEPHRECTOMY
◼ Indicated in tumor confined to the upper or
lower pole of the kidney
◼ performed by isolation and ligation of the
segmental apical or basilar arterial branch
◼ The apical artery is dissected, ligated, and divided
◼ An ischemic line of demarcation appears on the
surface of the kidney and outlines the segment to
be excised
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Chennai.

segmental (apical) polar nephrectomy
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Chennai.

WEDGE RESECTION
◼ Indicated in peripheral tumors on the surface
of the kidney, particu-larly ones that are larger
or not confined to either renal pole
◼ This technique is associated with heavier bleeding
◼ It should be done with temporary renal arterial
occlusion and surface hypothermia.
◼ In a wedge resection, the tumor is removed with
margin of normal renal parenchyma
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Chennai.

wedge resection for a peripheral tumor
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Chennai.

Transverse Resection
◼ It is done to remove large tumors that involve
the upper or lower portion of the kidney
◼ Major branches of the renal artery and vein
supplying the tumor-bearing portion of the kidney
are identified in the renal hilum, ligated, and
divided
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Chennai.

Transverse resection for a tumor
involving the upper half of the kidney
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Chennai.

SIMPLE ENUCLEATION
◼ simple enucleation means circumferential incision of the
renal parenchyma around the tumor and simple excision
of tumor with maximal preservation of normal
parenchyma
◼ Higher risk of leaving residual malignant cells in the
kidney
◼ Enucleation is indicated only in von Hippel–Lindau
disease and multiple low-stage encapsulated tumors
involving both kidneys
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Chennai.

EXTRACORPOREAL PARTIAL NEPHRECTOMY AND
AUTOTRANSPLANTATION
◼ It was described by Calne 1973, Gittes and McCullough
1975
◼ Indicated in large complex tumors involving the renal
hilum
ADVANTAGES
◼ optimum exposure
◼ bloodless surgical field
◼ maximum conservation of renal parenchyma
◼ greater protection of the kidney from prolonged ischemia
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Chennai.

DISADVANTAGES
◼ longer operative time need for vascular and ureteral
anastomoses
◼ increased risk of temporary and permanent renal failure
PROCEDURE
◼ It is performed through a single midline incision
◼ The kidney is mobilized and removed outside Gerota's
fascia with ligation and division of the renal artery and
vein
◼ The removed kidney is flushed with 500 mL of a chilled
intracellular electrolyte solution and submerged in ice-
slush saline solution to maintain hypothermia
64
Chennai.

A, The kidney is removed outside Gerota's fascia.
B, The tumor is excised extracorporeally
C, Pulsatile perfusion or reflushing is used to identify transected blood vessels
D, The kidney is closed on itself
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Chennai.

◼ After the tumor has been completely resected, the renal
remnant may be reflushed or placed on the pulsatile
perfusion unit to facilitate identification and suture ligation
of remaining bleeding points
◼ The defect is closed by suturing the kidney on itself
◼ Autotransplantation into the iliac fossa is done by the
same vascular technique as for renal allotransplantation.
◼ Urinary continuity may be restored with
ureteroneocystostomy or pyeloureterostomy with internal
ureteral stent
◼ Drain is positioned extraperitoneally in the iliac fossa
66
Chennai.

COMPLICATIONS
◼ Hemorrhage
◼ Urinary fistula
◼ Ureteral obstruction
◼ Renal insufficiency
◼ Infection
Unusual complications
◼ Transient hypertension
◼ Aneurysm or arteriovenous fistula in the remaining
parenchyma
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THERMAL ABLATION
◼ Advanced age .
◼ Significant comorbities.
◼ Local recurrence after previous NSS.
◼ Multifocal tumors
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CRYOABLATION
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Chennai.

Introduction
◼ First known report of renal cryotherapy in human was by Uchida
et al (Br J Urol,75:132,1995).
◼ An energy-based tissue ablation.
◼ One of the most studied ablative technique.
◼ The aim is to achieve targeted destruction of a predetermined
volume of tissue (the tumor and a surrounding margin of healthy
parenchyma).
◼ Can be done laparoscopic or percutaneous.
◼ Various modalities available, differ in the type of ablation energy.
70
Chennai.

M/A
◼ The targeted tissue is rapidly frozen in situ, followed by sloughing of the
devitalized tissue and healing by secondary intention over time.
◼ Essential features:
Rapid freezing, slow thawing, and repetition of the
freeze-thaw cycle.
◼ Cytonecrosis is the result of two step process:
1- Rapid intracellular ice formation
2- Delayed microcirculatory failure during the thaw phase of the cycle.
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Chennai.

M/A
◼ Cryolesion created by a
3.4 mm diameter
cryoprobe.
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Chennai.

Indications
◼ Small lesions ( Less than 4cm).
- Larger lesions will require 2 or more probes,
technically difficult, might leave residual tumor.
◼ Solitary lesion.
◼ Located away from the collecting system.
◼ Elderly pts.
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Chennai.

Contraindications
◼ Coagulopathy.
◼ Significant post op. adhesions.
◼ Intrarenal, centrally located tumor.
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Chennai.

Technique
◼ Open,laparoscopic or percutanous.
◼ Real-time imaging of the tumor.
CT/MRI not proven reliable modality for detection the
progression of the ice-ball.
USS with color Doppler appears promising.
◼ Pre-plan the angle and depth of the probe.
◼ Needle biopsy of the tumor.
◼ Insert the cryoprobe to the center of tumor, and advance up to or
just beyond the inner(deep) margin of tumor.
◼ Cryolesion should be 1cm larger than tumor.
◼ Use lap. USS, or MRI compatible cryosystem for percutanous route.
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Chennai.

◼ Argon gas>> Rapid freezing at the tip of the probe (temperatures < -80
degrees C)
◼ Helium gas >> Releases heat as it is depressurized >> Rapid thawing
◼ 2 freeze/thaw cycles
◼ Directly:
◼ Dehydration>>Damages enzymes, organelles, cell membrane
◼ Intracellular ice formation
◼ Indirectly:
◼ Targeting small blood vessels>> Hypoxic microenvironment
◼ Temperature of -40 degrees C must be achieved
throughout the tumor 76
Chennai.

1. Identify the lesion;2. Cryoablation needles placed inside the lesion;3. Monitoring ice
ball growth with real-time ultra-sound guidance;4. Lesion completely engulfed in ice
77
Chennai.

(A) Laparoscopic access and identification of the renal mass. (B) Placement of
the 3.0-mm cryoprobe into the biopsy tract. (C) End of freeze cycle, with iceball
formation. (D) Placement of collagen plug. A drain is subsequently placed
through the lateral port site.
78
Chennai.

Cryotherapy
Placement of the cryoprobe. The conical tip of the cryoprobe must be positioned at, or just
beyond, the inner margin of the tumor. Ultrasonic guidance for cryoprobe positioning is
obtained by placing the ultrasound probe on the opposite surface of the kidney. 79
Chennai.

Cryotherapy
Cryotherapy performed under laparoscopic visualization and real-time
ultrasonographic control.
The ice ball extends approximately 1 cm beyond the tumor margin.
80
Chennai.

Complications
◼ Potential complications include:
- Urinary fistula.
- Post-op hemorrhage.
- Injury to the collecting system.
- Injury to the adjacent structures (bowel, liver ).
81
Chennai.

Clinical points
◼ Renal artery clamping does not facilitate the freezing process, and has
no clinical significance, as evident by canine model.
◼ Cryoinjury to the collecting system with the ice ball in the absence of
physical puncture with the probe tip does not seem to result in
urinary extravasations.
◼ Cryoablation does not lead to significant systemic hypothermia, or
hypertension.
◼ The ischemic necrotic renal cryolesion, which remains in situ does not
have significant impact on the renal function over long term follow-
up of up to 20 months.
82
Chennai.

◼ Most clinically applied procedure among all probe-ablative
techniques.
◼ Important critique: Lack of histologic data after cryoablation to
ascertain completeness of tumor destruction or to verify surgical
margins.
◼ Needs long term F/U with MRI/CT scanning complimented by
needle biopsy evaluation.
◼ Should be still developmental, and limited to selected pts.
83
Chennai.

RADIOFREQUENCY ABLATION (RFA)
◼ RFA: How Does It Work?
◼ Radiofrequency waves >>> Friction of water>>> Heat >>>
Destroys Tumor
◼ Cell death resulting from RFA begins after 5 minutes of exposure to
temperature more than 50 degrees C
◼ Homogeneous RFA electrode temperature (50-100 degrees C)
84
Chennai.

Techniques
◼ Laparoscopic or percutaneous.
◼ RFA can be performed using a dry or wet technique.
◼ In the wet type: hypertonic saline is used, which promotes centrifugal
dissipation of the RF energy, resulting in rapid creation of larger
radiolesions without the early tissue desiccation as seen in the dry type.
◼ USS, CT, or MRI is used to roughly monitor the boundaries of
the treatment.
◼ Post operatively monitoring by loss of contrast enhancement on CT scan.
85
Chennai.

RFA
RF probe, with its
semicircular umbrella-
shaped tines.
86
Chennai.

RFA
Gross photograph of a
radiolesion at day 7 denotes clear
horizontal demarcation of the
nonviable radioablated lower
pole.
(From Hsu TH, Fidler ME, Gill
IS. Radiofrequency ablation of
the kidney: acute and chronic
histology in porcine model.
Urology 2000;56:872).
87
Chennai.

Pre-ablation 3 Months Post
12 Months Post
Lesion Progression:
1. Wedge/spherical
non-enhancing
2. Gradual contraction
residual scar
(Matsumoto et al. J Urol, 172:45, 2004)
RFA Results
88
Chennai.

◼ RFA still developmental for renal use.
◼ Long term prospective trials still lacking.
◼ So far for monitoring the RFA intensity intra-op., there is no
imaging modality that can in real time ensure a sufficient extent
of tissue ablation while avoiding injury to normal adjacent
parenchyma.
89
Chennai.

◼ How Do We Follow Up after Ablation?
◼ Medical history, physical examination, chest imaging with
conventional radiography or CT, blood work
◼ Contrast enhanced CT or MRI within 6 weeks of initial
therapy, and then at 6, 12, 18 and 24 months
◼ Biopsy of suspicious residual tissue?
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Active surveillance
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Chennai.

INDICATIONS FOR ACTIVE
SURVEILLANCE
◼ ABSOLUTE: (33 – 66% Observational studies)
◼ Not surgical candidates due to severe co-morbidities
◼ RELATIVE
◼ Chronic stable co-morbidities
◼ ELECTIVE
◼ Pt wishes period of observation
92
Chennai.

◼ No interventions, no surgery, and no procedures that are invasive–
active surveillance.
◼ Initially imaging at 3-6 months intervals in the first year, subsequently
imaging at 6-12 months.
◼ Patients to be aware that only small studies with active surveillance,
and with short follow-up of 2-3 years.
◼ Very small potential for spread or metastases while on active
surveillance
93
Chennai.

Disadvantages to Active
Surveillance
◼ Real metastatic potential
◼ Patient longevity variable and not accurately predictable
◼ Cost of frequent surveillance studies (+ biopsy?)
◼ Anxiety
94
Chennai.

◼ How Often Do Renal Masses Metastasize and When?
◼ 18 Studies with active surveillance
◼ 880 patients included
◼ 18 patients experienced metastases during active surveillance (2%)
◼ Mean time of 40.2 months (almost 3.5 years)
◼ “How fast does a mass really grow?”
◼ 23% do not grow at all within 2 years or so.
◼ Growth rate was about 2mm per year for the
patients who did not have spread, and about 6mm
per year for patients who did have spread.
95
Chennai.

◼ When and Who Left Active Surveillance?
◼ 54.6% Remained on Active Surveillance
◼ 45.5% Delayed intervention @ 2 years
◼ Patient concern/anxiety (57.2%)
◼ Increase in mass size (35.7%)
◼ Improvement in medical conditions (7.1%)
96
Chennai.

FUTURE TRENDS
◼ Extracorporeal High-Intensity Focused Ultrasonography (HIFU)
◼ Radiation Therapy – CYPER KNIFE ( SRS )
◼ Microwave Thermotherapy (MWT)
◼ Laser Interstitial Thermal Therapy (LITT)
◼ Chemoablation and Combined Chemoablation with RFA
◼ Targeted Embolization and Ablation
97
Chennai.

HIFU
◼ Potentially the least invasive tumor ablation technique
◼ Employs beams of ablative US frequency,generated by piezoelectric
element, focused by a paraboloid reflector.
◼ This beam is focused on the lesion, like ESWL, US lithotripsy.
◼ Resulting in thermal destruction - tissue cooking
(Temp. raise by 70-80 °C in the target lesion).
◼ Initially used for BPH and Pca.
◼ Lots of concerns in regard to incomplete tumor ablation, and
superficial skin burns.
98
Chennai.

◼ Several studies report the use of HIFU to treat benign and malignant
kidney tumors of animals, and one report in human HIFU offers
complete noninvasive ablation.
◼ Challenges include control over energy deposition, monitoring of
treatment, adjustment for target movement.
◼ Data on safety, histologic effect, clinical efficacy still lacking.
99
Chennai.

Stereotactic radiosurgery ( SRS ) –
◼ CyberKnife is a 6-MV frameless linear accelerator mounted on a
computer-controlled robotic arm.
◼ An image guidance system as described above is employed to
continually monitor movement of the target organ and deliver high-
dose radiation in a focused fashion
◼ Although its use should still be considered experimental, with
improved treatment protocols and well-designed prospective trials,
SRS may ultimately play a significant role in the treatment of RCC
100
Chennai.

◼ MWT delivers energy through flexible antennae that are inserted
directly into target lesion.
◼ Microwave energy creates an electromagnetic field that causes rapid
ion oscillation and frictional heat.
◼ Similar in design and technique to RFA, MWT is capable of achieving
treatment temperatures (>60° C) with greater rapidity.
◼ LITT employs
◼ Specialized laser fibers to delivery energy directly into tissue
◼ Fibers emit laser light that is converted to heat.
◼ Treatment temperatures of >55° C are achieved, & tissue necrosis results.
101
Chennai.

Chemoablation &
Combined Chemoablation with RFA
◼ Currently, injectable chemoablation agents are difficult to reproducibly
control and provide inferior tissue necrosis.
◼ Combined RFA/injectable chemoablation remains investigational.
◼ 95% ethanol
◼ 24% hypertonic saline gel and
◼ 50% acetic acid gel
102
Chennai.

Targeted Embolization and Ablation
◼ Owing to the heat-sink phenomenon with RFA, highly vascular
central lesions or lesions positioned adjacent to the renal
hilum are often inadequately ablated
◼ Selective embolization should allow for more homogenous
heating and improved tissue necrosis.
◼ Use of targeted Angioembolization prior to RFA remains
investigational.
103
Chennai.

◼ Role of in-situ ablation in the management of SRMs is rapidly evolving.
◼ Once experimental & only for pts with significant comorbidities, now
considered viable alternatives to extirpative management.
◼ In-situ ablation confers less treatment-related morbidity than either
open or laparoscopic partial nephrectomy and offers superior renal
preservation compared with open or laparoscopic nephrectomy.
◼ Cryoablation and RFA are technically less challenging than other
nephron-sparing approaches.
104
Chennai.

◼ Recent meta-analyses demonstrate inferior local tumor control
compared with partial and radical nephrectomy, but with
equivalent or superior cancer-specific and overall survival.
◼ Ultimately, the decision to treat a SRMs with an ablative
technology should take into account
➢ Tumor-related characteristics,
➢ Patient demographics and comorbidities, and
➢ The values and desires of the patient.
105
Chennai.

106
Chennai.

107
Chennai.

108
Chennai.

Take Home
◼ Algorithm
◼ Should include benign tumor potential in discussion – 15-20%, biopsy
◼ Active Surveillance = Option #1 for poor health/elderly (< 4cm)
◼ If treat, Nephron-Sparing Surgery is standard option
◼ Radical nephrectomy should be rare!
◼ Ablation truly minimally invasive
◼ Partial Nephrectomy gold standard for healthy patients
109
Chennai.

110
Chennai.

SMALL RENAL MASS

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