1. EVAR of AAA EndoVascular Aneurysm Repair of Abdominal Aortic Aneurysm.
EVAR of AAA is widely accepted as a less-invasive alternative to open repair.

2. EVAR of AAA
CT-angiography is the primary imaging technique for evaluating patients after stent graft placement.
The recommended follow-up schedule is at 1, 6 and 12 months and annually thereafter.

3. Complications of EVAR Common Rare Endoleak Graft trombosis
- Graft kinking
- Pseudoaneurysm
- Graft occlusion
- Embolism
- Colon necrosis
- Aortic dissection

4. Endoleaks
Persistent blood flow outside the lumen of the graft but within the aneurysm sac, wich results in incomplete exclusion of the aneurysm sac, and continued communication with the native arterial system.

5. Endoleaks
There is a potential risk for the aneurysm sac expansion with possible rupture and death.
Represents the most common complication of EVAR.

6. Types of endoleaks
Type 1: flow around the proximal (1a) or distal (1b) attachment sites.
Type 2: retrograde flow into the aneurysm sac from patent side branches.
Type 3: graft malfunction or disruption.
Type 4: graft porosity.
Type 5: endotension.

7. Type-2 endoleaks Is the most common identified endoleak.
SMA
Leak
SMA
Is the most common identified endoleak.
Blood flow in the AAA sac arising from branch vessels of the aorta or iliac arteries, most commonly lumbar or inferior mesenteric arteries (IMA); and rarely hypogastric, sacral, gonadal or accessory renal arteries.

8. Type-2 endoleaks
At CT-angiography, appears as focal blushes of contrast during the arterial or venous phase of enhancement.
The back-bleeding vessel can usually be traced; leaks that occur along the ventral aspect of the aneurysmal sac, are usually caused by a patent IMA; while those that occur along the dorsal aspect of the sac are usually caused by a patent lumbar artery.

9. Management of type-2 endoleak
There is controversy regarding the management of this type of endoleak because, although many of them do spontaneously trombose, some remain patent and result in persistent aneurysm expansion.
There are two options: observation or treatment.
Enlargement of the aneurismal sac size (> 5mm) is considered the best indicator to endotension. So:
 Conservative management: serial follow-up imaging
 Interventional management: several options
*At 6-months follow-up angio-CT.
Stable or decreased aneurysmal sac size*
Increased aneurysmal sac size*

10. Proposal follow-up approach
1 month angio-CT
Endoleak and size 
Endoleak without size 
Size  without endoleak
No endoleak
No size 
Annually angio-CT
6 months angio-CT
Angiography to classify the endoleak
Endoleak and/or size 
Size : aneurysm sac size increasment of at least 5 mm

11. Options of treatment Classically there are two different techniques:
Embolize the artery feeding the endoleak cavity via a transarterial route (“outside- in” approach).
Direct translumbar puncture of the aneurysm sac (”inside-out” approach).
But, we have other options of treatment:
Laparoscopic ligation of the feeding vessel.
Open surgical ligation of the feeding vessels.
Transosseous or transcaval puncture of the aneurysm sac.
It is also possible, to perform an embolization of the IMA, prior to the EVAR. But, it has the risk of mesenteric isquemia.

12. Retrograde catheterization of the IMA
Transarterial embolization of the endoleaks emanating from the IMA are accessed through Riolan’s arcade from the superior mesenteric artery (SMA).
The embolization agents are usually placed at the IMA origin, as near the aneurysm sac as possible, to avoid colonic ischemia.

13. Retrograde catheterization of the IMA. Vascular Map.1 2 3 4 6 5 1 2 3 4 5 6
1- Superior Mesenteric Artery; 2- Middle Colic Artery; 3- Marginated Artery; 4- Riolano’s arcade; 5- Left Colic Artery; 6- Inferior Mesenteric Artery

14. Retrograde catheterization of the IMA
1.- Selective catheterization of the superior mesenteric artery (SMA).

15. Retrograde catheterization of the IMA
2.- After the contrast material injection, look for the site of the endoleak.

16. Retrograde catheterization of the IMA
Marginated Artery
Middle Colic Artery
Riolano’s arcade
3.- Supraselective catheterization of the SMA following the Riolano’s arcade, throw the middle colic artery and the marginated artery.
Leak

17. Retrograde catheterization of the IMA
Riolano’s arcade
IMA
Left Colic Artery
4.- Place the catheter in the IMA, as near the aneurysm sac as possible, to avoid colonic ischemia. Liberate the embolization agents.

18. Retrograde catheterization of the IMA
Coils
Coils
Coils
5.- After the placement of the coils, the contrast material injection shows no blood flow.

19. Retrograde catheterization of the IMA
Coils
6.- Angio-CT after the procedure shows the correct placement of the coils and no blood flow within the aneurysm sac.

20. Long- term success of any endovascular stent-graft repair depends on several factors:
Ease of use.
Risk of complication.
Acceptable morbidity and mortality.
It can successfully replace traditional surgical exclusion of the aneurysm and halt or reverse the size of the native aneurysm sac while maintaining long-term integrity

21. Conclusions
Retrograde flow from the IMA contributes to many type-2 endoleaks.
Selective arteriography may be necessary to demonstrate these leaks.
Access to the aneurysm sac is possible with subselective catheterization of the SMA and the middle colic artery.
Retrograde catheterization of the IMA from the SMA is feasible and could be performed safely and successfully using microcatheters in most patients.

22. References
Anuj J. Tolia, Ronnie Landis, Patrick Lamparello, Robert Rosen, and Michael Macari. Type II Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysms: Natural History. Radiology May 2005; 235:
J.M. LaBerge, R. Sawhney, S. D. Wall, et al. Retrograde Catheterization of the Inferior Mesenteric Artery to Treat Endoleaks: Anatomic and Technical Considerations. J Vasc Interv Radiol 2000; 11:
Richard A. Baum, Jeffrey P. Carpenter, Catherine M. Tuite, et al. Diagnosis and Treatment of Inferior Mesenteric Arterial Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysms. Radiology May 2000; 215:
N. B. Amesur, A. B. Zajko, P. D. Orons, M. S. Makaroun. Embolotherapy of Persistent Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysm with the Ancure-Endovascular Technologies Endograft System. J Vasc Interv Radiol 1999; 10:
Barry T. Katzen, Alexandra A. MacLean. Complications if Endovascular Repair od Abdominal Aortic Aneurysms: A Review. Cardiovasc Intervent Radiol 2006; 29:
C. D. Karkos, P. D. Hayes, D. M. Lloyd et al. Combined Laparoscopic and Percutaneous Treatment of a Type II Endoleak Following Endovascular Abdominal Aortic Aneurysm Repair. Cardiovasc Intervent Radiol 2005; 28:
S. W. Stavropoulos, H. Kim, T. W. I. Clark, R. M. Fairman, O. Velazquez, J. P. Carpenter. Embolization of Type 2 Endoleaks after Endovasclar Repair of Abdominal Aortic Aneurysm with Use of Cyanoacrylate with or without Coils. J Vasc Interv Radiol 2005; 16: 22