1. Embolization of Giant Angiomyolipoma
Adam S. Fang, MD David S. Wang, MD
Division of Interventional Radiology
Stanford University School of Medicine

2. Disclosures
No relevant disclosures

3. Case
HISTORY OF PRESENT ILLNESS:
27 year old female, 35 weeks pregnant, presented to ER 11/2014 with acute left flank pain.
PAST MEDICAL HISTORY:
None
PAST SURGICAL HISTORY:
D+C x 2
FAMILY HISTORY:
No renal tumors
Uncle with colon cancer
Father died of heart disease
SOCIAL HISTORY:
Has 2 children, youngest age 4. No prior difficulties with pregnancy.

4. Physical Exam & Labs BP: 135/77, Pulse: 75, Resp: 17, SpO2: 98%
Abdomen: soft, NT, ND, no mass palpated
Labs
-Normal UA

5. Renal ultrasound showed a complex left renal mass in the superior pole, measuring 8.2 x 7.0 x 6.1 cm

6. Contrast-enhanced CT and MRI showed a large complex heterogeneous mass in the left upper quadrant emanating from superior pole of left kidney with associated fatty elements and hemorrhage, compatible with a large AML.

7. Left posterior division superior segmental artery supplying the giant AML was embolized with 3 cc mixture of 7:3 ethanol:lipiodol

8. Left anterior division superior segmental artery and lateral branches supplying the AML was embolized with 5 cc mixture of 7:3 ethanol:lipiodol. Contrast is noted pooling within pseudoaneurysm
Contrast-enhanced C-arm CT on injection of the left renal artery
demonstrates a large fat-containing AML within the superior left
kidney. The lesion measures up to approximately 11 cm in diameter,
and appears to be supplied by superior segmental lobar branches of
the posterior and anterior division arteries.
2. Left renal arteriogram (10 degree RAO) delineates the patient's
renal arterial anatomy with supplying branches of the left posterior
division superior segmental lobar artery and left anterior division
superior segmental artery identified.
3. Arteriogram of the distal left posterior division superior
segmental artery demonstrates supply to the AML and no supply to
renal parenchyma.
4. Embolization of the distal left posterior division superior
segmental artery performed to stasis.
5. Post-embolization arteriogram via the distal left posterior
division superior segmental artery demonstrates no antegrade flow.
6. Arteriogram of a lateral branch of the left posterior division
superior segmental artery demonstrates supply to the AML and minimal
supply to renal parenchyma at the lateral periphery.
7. Embolization of a lateral branch of the left posterior division
superior segmental artery performed to stasis.
8. Post-embolization arteriogram via a lateral branch of the left
posterior division superior segmental artery demonstrates no
antegrade flow.
9. Arteriograms of the left anterior division lower and mid
segmental arteries show no supply to the AML.
10. Arteriogram of the left anterior division superior segmental
artery demonstrates supply to the AML and no supply to renal
parenchyma.
11. Embolization of the left anterior division superior segmental
artery performed to stasis.
12. Post-embolization arteriogram via the left anterior division
superior segmental artery demonstrates no antegrade flow. There is
visualization of a small superior left hilar artery, likely
originating from the posterior division, that supplies the AML.
13. Arteriogram left anterior division shows the origin of a few
small hilar branches.
14. Arteriogram of a superior left hilar artery demonstrates
probable supply to the AML via a tiny ascending branch.
15. Successful coil embolization of a tiny superior left hilar
artery performed using a 2 mm x 4 cm Concerto detachable microcoil.
16. Post-embolization arteriogram via a tiny superior left hilar
artery demonstrates no antegrade flow.
17. Post-embolization left renal arteriogram demonstrates no
residual arterial enhancement of the treated lesion except a possible
small focus at the previously treated superolateral branch of the
posterior division superior segmental lobar artery. The rest of the
mid to inferior pole left kidney enhances normally. No capsular,
adrenal, or other possible AML supplying branches are visualized from
the proximal left renal artery.
18. Repeat arteriogram of the distal posterior division superior
segmental lobar artery shows no residual abnormal AML vascularity.
19. Abdominal aortogram demonstrates questionable faint small supply
to the superomedial aspect of the AML via retroperitoneal branches
possibly arising from the left T12 intercostal artery.
20. Noncontrast CACT of the abdomen demonstrates retained lipiodol
throughout the target AML that correlates well with the areas of
internal vascularity seen on initial contrast enhanced CACT. There is
minimal off target embolization of adjacent renal parenchyma in the
lateral mid left kidney. The superomedial aspect of the mass is fat
density and shows no lipiodol uptake. Just inferomedial to this is a
small area of soft tissue density that also does not show lipiodol
uptake but also did not show arterial vascularity on initial contrast
enhanced CACT. It is unclear if this may represent an area of
hemorrhage or is residual angiomyogenic components supplied from
non-renal arterial branches.
21. Right femoral arteriogram demonstrates access overlying the
femoral head above the bifurcation. The access site is appropriate
for closure device.
IMPRESSION
IMPRESSION:
1. Successful selective transarterial embolization of a left superior
giant renal AML angiomyogenic components with ethanol and lipiodol.
PLAN: Admit for overnight observation and pain control. Follow up
with renal mass protocol MRI and serum creatinine level measurement
followed IR clinic visit with Dr. Wang in 3 months.
MEDICATIONS: 300 mcg Fentanyl IV, 5 mg Versed IV, 1 mg Dilaudid IV,
400 mg Ciprofloxacin IV, 300 mcg Nitroglycerin IA, 8 mg Zofran IV.
Lidocaine 1% for local anesthesia.
ISSUES: An interpreter was not required. There was no difficulty
gaining IV access. In the future, general anesthesia will not be
necessary.
Following the procedure, she experienced post-embolization syndrome with fevers, flank pain, and myalgias for approximately 1 week post-procedure
She continues to experience intermittent left flank pain which does not require regular medication management. She also complains of occasional mid-lower back pain but is unsure if it is musculoskeletal in nature or related to her AML

9. Follow-up 3 month contrast-enhanced MRI showed interval decrease in size of the left upper pole giant AML (green). However, there was persistent heterogeneous enhancement.
CT angiogram shows a parasitized vessel (yellow) arising from the left posterior aspect of aorta.

10. Dominant superior and inferior divisions.
Arteriogram of parasitized branch vessel arising from the left posterior aspect of aorta
Large arterial network supplies the upper half of the giant AML.
Dominant superior and inferior divisions.
Distal branches appear to communicate with a network of capsular branches.
Arteriogram of a parasitized branch vessel arising from the left
posterior aspect of aorta demonstrates a large arterial network that
supplies the upper half of the giant AML. It has dominant superior
and inferior divisions. Its distal branches appear to communicate
with a network of probable capsular branches.

11. Superior and distal branches of parasitized vessel arising from left posterior aspect of aorta
Arteriogram of superior and distal branches of parasitized vessel
arising from left posterior aspect of aorta shows supply to AML.
22. Embolization of superior division and its distal branches of
parasitized vessel arising from left posterior aspect of aorta
performed to stasis
Pre-embolization arteriogram of superior and distal branches of parasitized vessel arising from left posterior aspect of aorta shows supply to AML.
Embolization of distal branches of parasitized vessel w/ 6 cc mixture of 7:3 ethanol:lipiodol to stasis

12. No residual arterial enhancement of the AML.
Post-embolization arteriogram of parasitized branch vessel arising from left posterior aspect of aorta
No residual arterial enhancement of the AML.
No antegrade flow in the treated renal artery branches. The rest of the mid to inferior pole left kidney enhances.
Post-embolization

13. The collection was managed with percutaneous drainage.
5 months after embolization, CT showed replacement of the treated AML with a large fluid collection.
The collection was managed with percutaneous drainage.
Thick brown milky fluid was removed.
Analysis of the fluid showed 98% neutrophils, creatinine level of 0.6 mg/dL, triglyceride 34 mg/dL, and negative cultures.
After removal of the drain, the collection recurred 3 months later. This was treated with percutaneous drainage and ethanol sclerosis.

14. Question 1 What size AML are at risk for acute hemorrhage? A. 1.5 cm
B. 2.0 cm
C. 2.5 cm
D. 4.0 cm

15. Answer
What size AML are at risk for acute hemorrhage?
A. 1.5 cm
B. 2.0 cm
C. 2.5 cm
D. 4.0 cm
More than 50% of AML 4 cm or larger hemorrhage and one-third present with acute hemorrhagic shock.1

16. Discussion
Renal angiomyolipomas (AMLs) comprise of vascular, smooth muscle and adipose tissue
80% (sporadic), 20% (tuberous sclerosis complex)
Large AMLs become symptomatic (80%, >4 cm)
Giant AML associated with significant morbidities including insidious flank pain ,renal insufficiency, and eventual renal failure
Risk of hemorrhage increases with size
Treatment options:
-conservative management: AML <4 cm & asymptomatic
-selective transarterial embolization: parenchyma-sparing
-partial or total nephrectomy.

17. Question 3
What is the preferred embolic agents for treating AML with selective transarterial embolization?
A. Gelfoam
B. 7:3 ethanol to Lipiodol
C. Coils
D. Polyvinyl alcohol spheres

18. Answers
What is the the preferred embolic agents for treating AML with selective transarterial embolization?
A. Gelfoam
B. 7:3 ethanol to Lipiodol
C. Coils
D. Polyvinyl alcohol spheres
Ethanol provides permanent occlusion at arteriolar and capillary levels distal to level of collateral inflow and effectively necrotizes tumor tissue.1
Polyvinyl alcohol spheres fail to penetrate capillary level and are less effective agent.1
Coils should never be used as collateral vessels may form around level of occlusion. 1

19. References
Bishay VL, Crino PB, Wein AJ, et al. Embolization of giant renal angiomyolipomas: technique and results. J Vasc Interv Radiol 2010; 21:67-72.
Dickinson M, Ruckle H, Beaghler M, et al. Renal angiomyolipoma: optimal treatment based on size and symptoms. Clin Nephrol 1998; 49:281–286.
Hao LW, Lin CM, Tsai SH. Spontaneous hemorrhagic angiomyolipoma present with massive hematuria leading to urgent nephrectomy. Am J Emerg Med 2008; 26:249.