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AB
C
D
Chapter22:Management of small renalmasses
Figure 22.3 A 70-year-old man presented
with a right lower-pole renal mass, which
was amenable to radiofrequency ablation
(RFA). (A) Axial computed tomography
(CT) image at RFA shows the mass (black
arrow) lies within 1 mm of the colon (white
arrow), increasing the risk of colonic injury
during ablation. Hence, hydrodissection
was performed to displace the colon and
minimize risk of injury. (B) A 20-gauge
Chiba needle (arrow) was placed between
the kidney and the colon. (C) Sterile 5%
dextrose (black arrow) was instilled within
the tissue planes to separate the colon
(white arrow) from the kidney (arrowhead).
(D) Axial image from a contrast-enhanced
CT scan performed immediately following
ablation shows dissolution of instilled
dextrose. However, the colon (white
arrow) and the kidney (black arrow)
remain separated. (E) Axial image from
a contrast-enhanced CT performed
1 month after ablation demonstrates a
region of non-enhancement (arrow) at
the site of ablation consistent with treated
tumor. There are no regions of abnormal
enhancement to suggest residual disease.
E
more oen seen in central tumors, where the proximity of large
hilar vessels predisposes them to injury and bleeding. Other
complications, such as ureteral strictures and urinoma formation secondary to urine leaks, are rare but more oen seen in
central tumor ablations.
9,38,39,58
Ureteral strictures are more
common with medial tumors in the lower pole. Inadvertent
injury can also be inicted upon adjacent organs, particularly
the colon, which can result in abscess and/or stula formation.12 Tumor seeding of electrode track has been reported as a
rare complication in the treatment of liver tumors.
59,60
Asingle
case of skin seeding was reported in the series by Mayo-Smith
39
etal.
Treatment of metastatic disease
Surgical and RFA options
Palliative treatment with RFA, although rare, has been performed in patients with debilitating hematuria due to invasion
of the collecting system.
e role of local therapies like percutaneous ablation in
patients with metastatic RCC is limited due to the disseminated nature of the disease. Although cytoreductive nephrectomy is sometimes performed even in the setting of metastatic
disease, the role of percutaneous ablation in the treatment of
61
209
Section VI:Renal cell carcinoma
CD
B
Figure 22.4 A 67-year-old woman
underwent contrast-enhanced computed
tomography (CT) scan for evaluation
of abdominal pain. (A) Axial image
demonstrates a 3.5-cm exophytic mass
(arrow) arising from the middle pole of the
left kidney. Due to significant heart disease,
the patient was not an ideal candidate
A
for surgery and underwent treatment by
percutaneous radiofrequency ablation
(RFA). (B) Axial CT image at RFA shows
the needle electrode placed within the
mass. Multiple overlapping ablations were
performed (not shown). (C) Postablation,
the patient was transferred to a recovery
area, where she complained of increasing
left-sided abdominal pain. Axial image from
a repeat CT scan performed 4 hours after
ablation demonstrates a left subcapsular
hematoma (arrow) causing mass effect
on the left renal parenchyma. She was
admitted for overnight observation.
Her hematocrit was stable, and the pain
responded to medication. One day after
treatment, the pain had decreased in
intensity, and the patient was discharged
in stable condition. (D) Axial image from
a contrast-enhanced CT scan performed
1 month after ablation showed no
evidence of residual disease and minimal
decrease in size of hematoma (arrow).
The patient was pain-free. Follow-up
scans performed 3 and 6 months after
treatment (not shown) showed no residual
disease and gradual decrease in size of the
hematoma.
Table 22.3 Summary of results reported in various larger trials of renal cell carcinoma treated with percutaneous radiofrequency (RF) ablation
Tumors treated completely after RF ablation
Author Number of tumors Size % No.
Zagoria et al., 2004
Gervais et al., 2005
Mayo Smith et al., 2003
Farrell et al., 2003
Su et al., 2003
Pavlovich et al., 2002
Ogan et al., 2002
Total 263 91.2 (240/263)
the primary mass is limited by the larger size of most primary
renal masses once metastases have appeared. In isolated cases,
focal ablation of a single painful osseous metastasis that has
failed conventional pain management may result in substantial pain relief.62 Adetailed review of ablation of bone metastases is beyond the scope of this chapter.
those patients with limited metastases such as one or two small
42
24 < 3 cm 100 (11/11)
> 3 cm 69 (9/13)
24
100 < 3 cm 100 (52/52)
3–5 cm 92 (36/39)
> 3 cm 25 (2/8)
39
38
40
50
41
32 97 (31/32)
35 100 (35/35)
35 94 (33/35)
21 79 (19/24)
16 93 (12/13)
pulmonary metastases, RFA has been eective in achieving
local control.64 Likewise, Gervais et al. reported two cases of
isolated lymph node metastases in which complete necrosis
was achieved by RFA.65 e number of patients with metastatic
RCC suitable for percutaneous ablation is a small minority of
62,63
In addition, for
all patients with stage IV disease, and ablation in these cases is
palliative rather than potentially curative.
210
Chapter22:Management of small renalmasses
Medical therapies
RCC is notoriously resistant to medical therapies, and these
are oered only for locally advanced or widely metastatic
RCC. Response to chemotherapy is poor, and a number of
immunomodulatory therapies are currently being evaluated. Prominent among these is interferon-α, being used for
clear-cell RCC. It has a response rate of about 14% and few
side eects.66 High-dose interleukin-2 is approved by the
Food and Drug Administration for treating advanced-stage
RCC; however, limited availability and debilitating side
eects (capillary leak syndrome) compromise the eectiveness of interleukin-2.
Numerous targeted agents can be employed singly or in
sequence. ese include tyrosine kinase inhibitors sunitinib,
pazopenib, axitinib, and sorafenib; the mammalian target of
rapamycin inhibitors temsirolimus and evirolimus, and the
vascular endothelial growth factor inhibitor bevacizumab.
67
8. Gervais DA, Arellano RS, McGovern FJ, etal. Radiofrequency
ablation of renal cell carcinoma:Part2, lessons learned
with ablation of 100 tumors. AJR Am J Roentgenol 2005;
185:72–80.
9. Gervais DA, McGovern FJ, Arellano RS, etal. Renal cell
carcinoma:Clinical experience and technical success with
radio-frequency ablation of 42 tumors. Radiology 2003;
226:417–424.
10. Novick AC. Nephron-sparing surgery for renal cell carcinoma.
Annu Rev Med 2002; 53:393–407.
11. Chiou YY, Hwang JI, Chou YH, etal. Percutaneous
radiofrequency ablation of renal cell carcinoma. J Chin Med
Assoc 2005; 68:221–225.
12. Silverman SG, Tuncali K, vanSonnenberg E, etal. Renal
tumors:MR imaging-guided percutaneous cryotherapy– initial
experience in 23 patients. Radiology 2005; 236:716–724.
13. Goldberg SN, Gazelle GS, Mueller PR. ermal ablation
therapy for focal malignancy:Aunied approach to underlying
principles, techniques, and diagnostic imaging guidance. AJR
Conclusion
erapeutic options for RCC continue to expand, with percutaneous techniques being the latest newcomers. Each modality
has specic clinical applications, and reaching the right therapeutic decision is a complex process. is requires close collaboration between urologists and interventional radiologists
in order to appropriately guide patients while providing adequate information about all viable treatment options available.
Percutaneous ablation is safe, with proven short-term success.
Long-term survival and disease-free data are awaited, and until
then it is best suited for patients who are not ideal candidates
for surgery. Small exophytic tumors up to 4cm are best suited
for treatment with percutaneous ablation.
Am J Roentgenol 2000; 174:323–331.
14. Tacke J, Mahnken A, Roggan A, etal. Multipolar radiofrequency
ablation:First clinical results. Rofo 2004; 176:324–329.
15. Tacke J, Mahnken AH, Gunther RW. Percutaneous thermal
ablation of renal neoplasms. Rofo 2005; 177:1631–1640.
16. Lee JM, Han JK, Choi SH, etal. Comparison of renal ablation with
monopolar radiofrequency and hypertonic-saline-augmented
bipolar radiofrequency:In vitro and in vivo experimental studies.
AJR Am J Roentgenol 2005; 184:897–905.
17. Lee FT Jr., Haemmerich D, Wright AS, etal. Multiple probe
radiofrequency ablation:Pilot study in an animal model. J Vasc
Interv Radiol 2003; 14:1437–1442.
18. Hsu TH, Fidler ME, Gill IS. Radiofrequency ablation of the
kidney:Acute and chronic histology in porcine model. Urology
2000; 56:872–875.
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32. Homann NE, Bischof JC. e cryobiology of cryosurgical
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33. Rupp CC, Homann NE, Schmidlin FR, etal. Cryosurgical
changes in the porcine kidney:Histologic analysis with thermal
history correlation. Cryobiology 2002; 45:167–182.
34. Chosy SG, Nakada SY, Lee FT, Jr., etal. Monitoring renal
cryosurgery:Predictors of tissue necrosis in swine. J Urol 1998;
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35. Campbell SC, Krishnamurthi V, Chow G, etal. Renal
cryosurgery:Experimental evaluation of treatment parameters.
Urology 1998; 52:29–33; discussion,33–34.
36. Woolley ML, Schulsinger DA, Durand DB, etal. Eect of
freezing parameters (freeze cycle and thaw process) on tissue
destruction following renal cryoablation. J Endourol 2002;
16:519–522.
37. Ahrar K, Matin S, Wood CG, etal. Percutaneous radiofrequency
ablation of renal tumors:Technique, complications, and
outcomes. J Vasc Interv Radiol 2005; 16:679–688.
38. Farrell MA, Charboneau WJ, DiMarco DS, etal.
Imaging-guided radiofrequency ablation of solid renal tumors.
AJR Am J Roentgenol 2003; 180:1509–1513.
39. Mayo-Smith WW, Dupuy DE, Parikh PM, etal. Imaging-guided
percutaneous radiofrequency ablation of solid renal
masses:Techniques and outcomes of 38 treatment sessions
in 32 consecutive patients. AJR Am J Roentgenol 2003;
180:1503–1508.
40. Su LM, Jarrett TW, Chan DY, etal. Percutaneous computed
tomography-guided radiofrequency ablation of renal masses in
high surgical risk patients:Preliminary results. Urology 2003;
61:26–33.
41. Ogan K, Jacomides L, Dolmatch BL, etal. Percutaneous
radiofrequency ablation of renal tumors:Technique, limitations,
and morbidity. Urology 2002; 60:954–958.
42. Zagoria RJ, Hawkins AD, Clark PE, etal. Percutaneous
CT-guided radiofrequency ablation of renal neoplasms:Factors
inuencing success. AJR Am J Roentgenol 2004; 183:201–207.
43. Shingleton WB, Sewell PE Jr. Cryoablation of renal tumours in
patients with solitary kidneys. BJU Int 2003; 92:237–239.
44. Shingleton WB, Sewell PE, Jr. Percutaneous renal cryoablation
of renal tumors in patients with von Hippel–Lindau disease. J
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cryoablation with magnetic resonance imaging guidance. J Urol
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46. Farrell MA, Charboneau JW, Callstrom MR, etal. Paranephric
water instillation:Atechnique to prevent bowel injury during
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47. Kariya Z, Yamakado K, Nakatuka A, etal. Radiofrequency
ablation with and without balloon occlusion of the renal
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48. Raman SS, Aziz D, Chang X, etal. Minimizing diaphragmatic
injury during radiofrequency ablation:Ecacy of
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49. Goldberg SN, Gazelle GS, Compton CC, etal. Treatment
of intrahepatic malignancy with radiofrequency ablation:
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50. Pavlovich CP, Walther MM, Choyke PL, etal. Percutaneous
radio frequency ablation of small renal tumors:Initial results. J
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51. Roy-Choudhury SH, Cast JE, Cooksey G, etal. Early experience
with percutaneous radiofrequency ablation of small solid renal
masses. AJR Am J Roentgenol 2003; 180:1055–1061.
52. Veltri A, De Fazio G, Maltana V, etal. Percutaneous US-guided
RF thermal ablation for malignant renal tumors:Preliminary
results in 13 patients. Eur Radiol 2004; 14:2303–2310.
53. Gill IS, Remer EM, Hasan WA, etal. Renal
cryoablation:Outcome at 3years. J Urol 2005; 173:1903–1907.
54. Moreland AJ, Ziemlewicz TJ, Best SL, etal. High-powered
microwave ablation of T1a renal cell carcinoma:Safety and
initial clinical evaluation. J Endourol 2014; 28:1046–1052.
55. Yu J, Liang P, Yu XL, etal. US-guided percutaneous microwave
ablation of renal cell carcinoma:Intermediate-term results.
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56. Yu J, Liang P, Yu XL, etal. US-guided percutaeneous microwave
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270:880–887.
57. Guan W, Bai J, Liu J, etal. Microwave ablation versus partial
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58. Johnson DB, Solomon SB, Su LM, etal. Dening the
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59. Llovet JM, Vilana R, Bru C, etal. Increased risk of tumor
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212
Chapter22:Management of small renalmasses
63. Goetz MP, Callstrom MR, Charboneau JW, etal. Percutaneous
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213
Section VI
Chapter
Embolotherapy in the management of renal cell carcinoma
23
Ricardo Garcia-Mónaco
Introduction
Renal cell carcinoma (RCC) accounts for approximately 4%
of cancers and 2% of cancer mortality in the United States.1
Historically, most patients presented with advanced-stage
disease with clinical symptoms of a palpable mass, hematuria, and ank pain. However, in the last 15years, renal masses
have been increasingly diagnosed as an incidental nding at
cross-sectional abdominal imaging.2 At present, more than
60% of renal cancers are discovered in asymptomatic patients
undergoing evaluation for unrelated conditions.
3
Surgical resection is the standard treatment for RCC. Radical
nephrectomy and partial nephrectomy (PN:nephron-sparing
surgery) are the most used techniques, depending mainly on
the tumor size. ermal ablative techniques (cryoablation,
radiofrequency, or microwave ablation) are promising alternative treatments for non-surgical candidates with small renal
tumors.
4
Embolotherapy for renal tumors has been used since the
1970s for symptomatic hematuria, palliation, or preoperative
infarction of renal tumors. e evolution of the endovascular
techniques, as well as the renement of angiographic technology, allows a more accurate and safe embolization. As a consequence, embolotherapy for renal cancer has also evolved and
expanded its indications.
State-of-the-art embolization in renal cancer is indicated in
three clinical scenarios:preoperative, in selected cases of radical or PN; postoperative, in cases of vascular injuries and/or
hemorrhage following PN and as a palliative treatment.
is chapter reviews basic concept of renal tumor embolization as well as its indication and clinical role in the modern
therapeutic approach ofRCC.
Basic concepts
e interventional oncologist (IO) should not only commit on
the technique of renal embolization but also in the oncology
care of the patient, as a member of the multidisciplinary care
group. Clinical consultation, pretherapeutic patient evaluation,
as well as postembolization care and patient follow-up are mandatory for good clinical practice.
Before performing the renal embolization a thorough
clinical and imaging workup of the patient is mandatory. At
consultation the IO must know the patient’s clinical history and
laboratory tests– mainly platelets, coagulation, and renal function. It is also important to be familiar with the patient’s medication and to carefully review the patient’s images for a better
planning of the embolization. Indeed, most patients referred for
embolization for renal cancer are studied by contrast-enhanced
multiple detector computed tomography (CT) or magnetic
resonance (MR) scans where not only the tumor but also the
supplying vessels are depicted.
To perform a correct and safe embolization, knowledge of
the vascular functional renal anatomy is of utmost importance.
e anatomy of the renal vessels has been extensively described
in the literature.5 Although the arterial anatomy varies significantly among individuals, in most cases each kidney is supplied by a single renal artery arising from the abdominal aorta
at L1–L2 level. However, multiple renal arteries supplying an
individual kidney may be detected in 30% of the population.
5
e main renal artery frequently divides into anterior and
posterior branches. e posterior division is the smaller of the
two and appears as a branch of the main renal artery, whereas
the anterior division appears as a continuation of the main renal
5,6
ar tery.
e anterior branch divides into segmental arteries
and provides blood supply to four of the ve vascular segments
in the kidney. e segmental renal arteries further branch o to
form lobar, interlobar, arcuate, and interlobular arteries.
5,6
ere are several perforating arteries that conform collateral pathways between the intraparenchymal vessels of the
renal artery and the renal capsular arteries.5 e latter may
arise from the inferior adrenal artery, the main renal artery,
the gonadal artery, and the aorta, or even from an accessory or
aberrant lower pole artery. ese vessels form a rich capsular
network that anastomoses freely with perforating arteries and
other retroperitoneal arteries and also with internal iliac, intercostal, and mesenteric arteries.5 us, depending on the tumor
extension, dierent vessels from the renal or extrarenal arteries
may supply a giventumor.
Angiography of the abdominal aorta and the renal arteries
before embolization is recommended not to miss an aberrant
or extrarenal vessel that may supply the tumor, especially in the
case of large tumors. Most RCCs are hypervascular, with neovascularization, enlarged feeding arteries, vessel tapering, and
dierent degrees of arteriovenous shunting. Venous invasion
Interventional Oncology, Second Edition, ed. Jean-François H.Geschwind and Michael C.Soulen. Published by Cambridge University Press.
©Cambridge University Press2016
214
Chapter23:Embolotherapy in the management of renal cell carcinoma
may be observed at angiography in the renal vein or inferior
vena cava in large tumors. In small tumors not all of these signs
are present, normal vascularization is also possible, and even
hypovascular patterns are not uncommon.
glue (cyanoacrylate) have been used to occlude tumor capillaries and aerent vessels. Cumulative experience with n-butyl
cyanoacrylate suggests that it is probably the embolization
material of choice for preoperative renal devascularization.10
is material allows rapid and denitive distal occlusion of a
Embolization technique
Embolization of renal cancer should be performed in an appropriate vascular suite, with state-of-the-art angiography equipment including digital subtraction angiography, road mapping,
and high-quality uoroscopy. Cone-beam CT could be helpful
to prevent non-target embolization and gain therapeutic ecacy, especially in small hypovascular tumors.
e embolization procedure is usually performed under
conscious sedation or general anesthesia but it could also be
performed under local anesthesia. Adequate patient intravenous hydration is of outmost importance to prevent renal
impairment and should be kept till patient discharge. Most
IOs will keep the patient in hospital for 24hours for proper
preparation before the procedure and correct posttreatment
medicalcare.
e embolization technique, choice of catheters, and
embolic material dier according to the indication of embolization, the therapeutic goal, and the tumor vascular architecture.
In large tumors the procedure could be performed with 4F or
5F catheters, but the use of microcatheters is still advisable to
reach peripheral or extrarenal vessels. In small tumors the use
of microcatheters is mandatory, not only because of the small
caliber of the aerent vessels but also to prevent non-target
embolization.
Most commonly used embolic agents are microspheres and
cyanoacrylates, sometimes used in association with Gelfoam,
coils, or vascular plugs. Other embolic agents, such as alcohol
mixed with Lipiodol and balloons, have been reported but are
not commonly used in modern practice.
e individual embolization techniques and choice of
embolic material for each broad indication will be addressed
later in each clinical setting.
Preoperative embolization
Radical nephrectomy
Radical nephrectomy remains the standard of care for locally
advanced or inltrative high-risk tumors. It may be performed
using an open or lapascopic approach. Preoperative embolization to facilitate radical nephrectomy has been used for many
years in selected cases. Most common indications are large
(>9cm) extensively vascularized tumors with associated renal
vein thrombosis.7 e aim of preoperative embolization is to
facilitate surgery by decreasing intraoperative blood loss and
providing a better cleavage plane. Proper tumor devascularization allows a better intraoperative pedicle approach and early
ligation of the renal vein.7 Both the duration of surgery and
the blood transfusion requirements may be reduced provided
there is proper embolization.
8,9
Dierent embolic materials have been reported for preoperative embolization:ethanol, particulate agents, Gelfoam, and
voluminous vascular bed and causes necrosis in perivascular
tissue. Even though glue appears to be the embolic agent of
choice, many interventional radiologists use a combination of
agents to achieve complete devascularization of target tumors.
Preoperative embolization should not only include the
renal tumor and parenchyma but also any extrarenal feedings
and the main renal artery. Coils or plugs are the most common material used to occlude large vessels. When occluding
the renal pedicle a residual stump of the proximal renal artery
should be spared to allow surgical clamping (Figure 23.1).
Postembolization aortography is recommended to check if
all vessels have been embolized according to the surgeon’s
expectations.
ere are no randomized control trials to establish the ecacy of embolization before radical nephrectomy and its indication. Some authors reported excellent results in retrospective
series, with an increased overall 5-year survival benet compared to non-embolized patients,11 but other reports did not
show survival benets.12 However, comparison of published
studies is not possible because the technique, the embolic material, and both the size and type of tumors dier. Anyway, in
clinical practice most urologists agree that preoperative embolization is helpful in selected patients, mainly those with large
tumors involving the renal veins. Best results are obtained with
state-of-the-art embolization techniques, including microcatheters and glue as the preferred embolic agent.10 Timing
between embolization and nephrectomy has not been established. Some urologists prefer 1- or 2-week intervals to avoid
postembolization renal edema and to allow shrinkage of the
tumor. Most commonly, nephrectomy is performed the morning aer or even on the same day as embolization, as we prefer
at our institution.
Partial nephrectomy
Although radical nephrectomy had long been held as the mainstay of treatment for RCC regardless of tumor size, it has shown
a higher incidence of deaths in patients with T1 renal tumors
compared to PN.13 e higher risk of postsurgical chronic kidney disease and of cardiovascular morbidity and mortality was
advocated as the cause of this observation.13 Indeed, over the
past two decades, a wealth of data has accrued that attests to
the oncologic safety and superior functional outcomes of PN
compared to radical nephrectomy.2 erefore urologists have
steadily shied towards the use of PN, especially for small
renal tumors that represent as many as 60% of renal tumors
in clinical practice. Indeed, the American Urologic Association
guidelines specify PN as the reference standard for management of clinical T1 masses given the importance of functional
preservation.
PN can be conducted using open, laparoscopic, or robotic
techniques and needs more technical expertise than radical
nephrectomy to ensure oncologic safety and to minimize the
14
215
Section VI:Renal cell carcinoma
AB
D
E F
C
G
Figure 23.1 A 62-year-old male with hematuria and right flank pain treated with radical nephrectomy after preoperative embolization. Uneventful postoperative
recovery and follow-up at 6 months. (A) Contrast-enhanced computed tomography (CT) shows giant right renal carcinoma with hypervascularization, central
necrosis, and invasion of both renal vein and inferior vena cava. (B) Anteroposterior (AP) aortogram shows the same findings as on CT and better depiction of
afferent renal and extrarenal vessels. (C) Renal angiography (arterial phase) shows enlarged segmental arteries supplying the tumor with neovascularization
and areas of necrosis. (D) Renal angiography (venous phase) shows tumor tissue, areas of necrosis and invasion to both renal vein and inferior vena cava.
(E) Postembolization renal angiogram after occlusion of segmental arteries and capillary tumor vessels with cyanoacrylate shows decreased tumor vascularity.
Residual peripheral tumor enhancement supplied mainly by capsular arteries. (F) Postembolization renal angiogram after occlusion of capsular arteries and
peripheral tumor supply with cyanoacrylate. Notice the stump of the main renal artery after plug occlusion. (G) AP aortogram after complete tumor embolization
does not show tumor enhancement or vascular tumor supply. Patency of normal retroperitoneal and splanchnic arteries. Compare with B. (H) Contrast-enhanced
CT shows nephrectomy and tumor remission at 6 months follow-up. Compare with A.
potential complications. Blood control during tumor removal
is one of the major challenges of PN, due to the high vascularity of renal cancer. Surgeons usually clamp the renal artery
and vein during excision and reconstruction to minimize
blood loss and to allow for visualization of the tissues within a
bloodless eld. Warm renal ischemia is induced by clamping,
but considered safe for a duration of 20–25 minutes. However,
patients with pre-existing chronic kidney disease and additional risk factors such as obesity or diabetes may exhibit functional decline with shorter warm ischemia times (WIT).15 In
H
addition, for less-experienced surgeons or complicated cases,
WIT may extend far beyond 20minutes, thus undermining the
advantages of PN.2 To overcome the risks of vascular clamping
and WIT, new intraoperative techniques such as microsurgical
clipping of tumor arterial feeders16 or preoperative embolization have been introduced.
17,18
Interesting enough to the IO is that preoperative embolization may avoid vascular clamping, thus precluding renal
warm ischemia and functional loss. Indeed, minimal blood
loss of the surgical eld, easily controlled by the surgeon, may
216
Chapter23:Embolotherapy in the management of renal cell carcinoma
EF
BC
A
D
GH
Figure 23.2 A 45-year-old male with incidental finding of a small renal mass. The patient was treated with laparoscopic partial nephrectomy without clamping.
Zero warm ischemia times during surgery and normal kidney function at follow-up. (A) Contrast-enhanced computed tomography (CT) shows a heterogeneous
renal tumor in the posterior valve of the left kidney. (B) Renal angiogram (arterial phase) barely shows the tumor. (C) Renal angiogram (venous phase) better
depicts the tumor. (D) Superselective angiography of renal carcinoma before embolization. (E) Plain X-ray after embolization of the tumor with microspheres and
cyanoacrylate clearly shows the tumor and the afferent artery. The latter was glued for better recognition during surgery. (F) Postembolization renal angiogram
shows patency of all renal vessels except the tumor area. Compare with B. (G) Laparoscopic view of the tumor (T) immediately before removal. (H) Laparoscopic
view after complete tumor removal. (I) Contrast-enhanced CT at 6-month follow-up shows the left kidney after complete tumor removal. Compare with A.
be expected aer proper embolization of tertiary or more distal arterial branches.17 e embolization should comprise not
only the tumor vasculature but also the involved arterial feeders and a minimum area of the surrounding healthy parenchyma (Figure23.2), which would be involved, however, in the
suture performed to close the parenchymal defect aer tumor
removal.
18
To achieve this goal the use of microcatheters is mandatory,
not only because of the small caliber of the aerent vessels but
also to prevent non-target embolization. e preferred embolic
materials are particulate agents and/or cyanoacrylate, the latter allowing better intraoperative visualization of the aerent
tumor arteries. e use of cone-beam CT could be helpful,
especially to localize small hypovascular tumors (Figure23.3).
Aer proper embolization there is no need for any regional
vascular control or clamping, because the bleeding is oen
minimal and a denite boundary between the healthy and
necrotic parenchyma, with a clear view of the cleavage plane,
can easily be identied. us, intraoperative ultrasonography
and other techniques to delineate the extent of the tumor are
unnecessary.
Preoperative embolization is usually performed the day
before or the same day as surgery or even at the same step of
surgery if a hybrid operating room is available. It allows PN
to be performed without clamping hilum vessels and so avoiding ischemic damage that is the main limiting step of this procedure for an experienced surgeon. Oncological outcome is
comparable to that of open approach, and functional results
I
217
Section VI:Renal cell carcinoma
A
BC
DEF
Figure 23.3 A 48-year-old male with hematuria and a small renal mass treated with open partial nephrectomy. Normal kidney functions at follow-up.
(A) Contrast-enhanced computed tomography (CT) shows a central hypovascular renal carcinoma in the right kidney. (B) Renal angiography fails to demonstrate
the hypovascular tumor. (C) Superselective segmental renal angiogram shows vessel displacement and a non-vascular area, probably corresponding to the
hypovascular tumor. (D) Cone-beam CT after superselective angiography in the same segmental artery showed in C precisely locates the hypovascular tumor
and the surrounding parenchyma, thus confirming accurate catheter position for target embolization. (E) Postembolization cone-beam CT three-dimensional
angiogram confirms embolic material deposition in the tumor and surrounding tissue. (F) Histology of excised tumor shows renal carcinoma necrosis and the
microspheres inside the blood vessels.
are encouraging, thanks to the optimal preservation of renal
function.
2,18
CT– frequently shows a vascular injury such as a pseudoaneurysm, arteriovenous stula, or renal hematoma.
Angiography and embolization should be promptly per-
Postoperative embolization
PN remains far more technically challenging than radical
nephrectomy, particularly when performed under laparoscopy or robotic assistance. As a consequence, increase in
surgery-associated morbidity is likely, the most worrying being
postoperative bleeding.
e incidence of severe bleeding aer PN was reported
to be in the range of 4.2–6% for laparoscopic techniques, 6%
for open surgery, and 8% for robot-assisted procedures.
19,20
remains as a serious complication, more common aer PN of
large and centrally located tumors.
19,20
Most common symptoms are gross hematuria or bleeding
from a surgical drain frequently associated with acute ank
pain. e time of onset is variable, from the rst to the 30th day
aer operation, with half of the patients presenting with symptoms within the rst postoperative week.19 Most patients are
hemodynamically stable, and cross-sectional image– usually
formed in such cases. e use of microcatheters is mandatory to keep as much functional parenchyma as possible aer
embolization. e embolic material will depend on the angioarchitecture of the vascular injury, with cyanoacrylate, coils,
and microcoils the most commonly used (Figure23.4).
e treatment is highly ecacious and typically associated
with minimal loss of renal function, thus very rewarding not
only to the patient but also to the urologist involved in the surgical management.
It
21
Palliative embolization
Palliative embolization is an alternative to surgery in patients
with symptomatic and inoperable renal cancer due to distant
metastases, comorbidities, or patients’ reluctance to undergo
surgery.22 Treatment is indicated in patients with ank pain
and/or hematuria with or without anemia, with excellent
results in terms of symptomatic control and quality of life.
218