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

Disclosures No relevant disclosures

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.

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

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

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.

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

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

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.

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.

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

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

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.

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

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

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.

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

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

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.