1. Transradial Type I Endoleak Ethylene Vinyl Alcohol Copolymer (Onyx) Embolization
Zachary L. Bercu, MD
Acknowledgements: Aaron Fischman, MD
Department of Interventional Radiology, Icahn School of Medicine at Mount Sinai,
New York, New York.
Financial disclosures: None.

2. History CC: “Expanding aneurysm with suspicious post-operative CT”
HPI: 70 y/o male status post abdominal aortic aneurysm (AAA) repair in 2007 admitted for expanding right lower extremity hematoma. During admission, patient underwent emergent proximal and distal endoleak repair with a “snorkel” procedure, stent graft extension, left hypogastric coil embolization and placement of a left common iliac graft. The results of post-operative CT angiography led to interventional radiology referral.

3. History
Relevant past medical and surgical history: Essential hypertension, hypercholesteremia, history of abdominal aortic aneurysm status post endovascular repair (EVAR) (2007), chronic obstructive pulmonary disease, history of myocardial infarction, coronary artery disease status post coronary stent placement x 3, depression
Medications: Hydrochlorothiazide, oxycodone-acetaminophen, heparin, amlodipin, lisinopril, docusate sodium, sennosides, setraline, diphenhydramine, ondansetron
Allergies: Naproxen: reaction unknown
Physical exam: BP: 116/62 P: 75 T: 36.4 °C RR: 19. No acute distress. No wheezing. Abdomen non-tender. Extensive bilateral lower extremity and scrotal edema.
Relevant labs:
9.1
133 94 15
11.3
137
100
INR
1.1 PT
14.4
PTT
38.4
27.8
3.7 27
1.1

4. Original Endoleak Repair

5. CTA

6. Diagnosis and Panel Discussion
Diagnosis: Persistent endoleak (type I?)
Panel discussion: Options include:
Open surgical repair? Patient not a great candidate (multiple comorbidities).
Conventional endovascular repair? Complex anatomy (left external iliac occluded), most recent attempt unsuccessful, “snorkel” already performed.
Fenestrated endovascular graft? Not approved for use in the U.S.
Transradial endovascular repair?
Which embolic agents to use? Coils vs. Glue? Onyx?
Potential complications in general: embolization failure, non-target embolization, paralysis, “closing off” future access/options
Onyx limitations: high radio-opacity (catheter tip obscuration), time consuming, expensive, inability to follow on CT1

7. To perform transradial access, ultrasound guidance was utilized
To perform transradial access, ultrasound guidance was utilized. A 6F hydrophilic Glidesheath was advanced over a wire into the left radial artery units of heparin, 200 mcg of nitroglycerin and 2.5 mg of verapamil were injected. A side flush was started.
Figures 1 and 2.
An angled glidewire was advanced into the aneurysm sac behind the stent graft.
Figures 1 and 2 (cine). Digital subtraction angiography frontal full field-of-view and magnification projections demonstrate a type IA endoleak.
Figure 3 (static). Frontal magnification view demonstrates a type IA endoleak at the proximal edge of the stent graft at the right renal stent snorkel.

8. Figures 3, 4 and 5 (static). An angled Glidewire was used to access the aneurysm sac, after which a total of 4 vials of Onyx and 23 Interlock coils were used before the endoleak ceased filling. An Amplatzer 4 plug was placed at the proximal entry site of the endoleak to complete the seal.

9. 4L ascites drained. No pressures recorded.
Two overlapping 12mm x 80mm SMART stents were placed to cover the tract from the splenic vein to the right hepatic vein. TIPS stent post-dilated to 6 mm, extrahepatic stent post-dilated to 10 mm. Gelfoam used to close the splenic access.
4L ascites drained. No pressures recorded.
Figure 6 (static). Static image from contrast angiography demonstrates no filling of the aneurysm sac.
Figure 7 (cine). Oblique projection completion angiogram again confirms absence of filling of the aneurysm sac. The coil/Onyx mass is highly radio-opaque.

10. Summary
Follow-up: Patient discharged 3 days post-op without perioperative complication. Patient followed with MRA.
Transradial approach well-known in cardiology literature. Common transradial procedures at our institution include: TACE, MAA prior to Y-90, UFE, GI bleed embolizations.
Previous studies of Onyx for type 1 endoleaks:
6 patients, 2 complications: 1 had renal artery graft and leg extension occlusions (thought to be unrelated to Onyx) and the other had late stentgraft migration of Onyx with aneurysm rupture 18 months post-op.2
6 patients, no recurrent endoleaks.1
Conclusion: Transradial Onyx embolization of a Type 1 endoleak may be performed successfully when other options are not available to patients.
References:
1. Chun JY, Morgan R. Transcatheter embolisation of type 1 endoleaks after endovascular aortic aneurysm repair with Onyx: when no other treatment option is feasible. Eur J of Vasc and Endovasc Surg 2013;45(2):
2. Henrikson O, Roos H, Falkenberg M. Ethylene vinyl alcohol copolymer (Onyx) to seal type 1 endoleak. A new technique. Vascular 2011;19(2):77-81.