Endoleaks : graft extension or coil embolization ?

1. Endoleaks : graft extensionor coil embolization ? Claudio Schönholz,MDAssociate Professor of RadiologyHeart and Vascular Center Medical University of South CarolinaCharleston, SC CANNES 2004

2. Endoleak “Presence of flow at the aneurysmal sac after stent-graft treatment” White GH, May J, Waugh RC, Chaufour X, Yu W. Type III and type IV endoleak: toward a complete definition of blood flow in the sac after endoluminal AAA repair. J Endovasc Surg 1998;5:305309.

3. Endoleak Types • Type I endoleak • Proximal or distal attachment • Type II endoleak • Retrograde branch flow • Type III endoleak • Structural defect or component junction • Type IV endoleak • Trans-graft leakage or porosity

4. Prevention of Type I Endoleak • Case Selection • 20 % oversizing of the endograft. • Generous overlapping of segments. • Graft covers the aorta and common iliac arteries from the renal arteries down to the iliac artery bifurcation.

5. Possible reasons of having low incidence of Type I endoleaks: • No procedure was considered finished until complete sealing of the endograft was obtained. • Sealing of the ends and connections was achieved by applying balloon dilatation, cuffs and malleable stents at the ends ( Extra-large Palmaz) PARODI, JC

6. Type I Endoleak

7. Type I Endoleak

8. Prevention of Type II Endoleak:IMA Embolization

9. Prevention of Type II Endoleak: Lumbar Artery Embolization

10. Prevention of Type II Endoleak: Lumbar Artery Embolization

11. WHEN SHOULD TYPE II ENDOLEAKS BE TREATED? “If the endoleak continues to be present on the 6-month scan, there is a small chance that it will spontaneously thrombose” • Treat a type II endoleak if there is evidence of sac enlargement • Intervene if a type II endoleak is present on the 6-month scan regardless of the status of an aneurysm sac 6-month CT scan

12. ENDOLEAK ANATOMY • Simple: small cavity and has ingress and egress from a single vessel • Complex: multiple ingress and egress vessels

13. Blood enters during systole into the endoleak cavity, swirling around, leaving the endoleak cavity during diastole Physiology similar to a pseudo-aneurysm May spontaneously thrombose prior to the 6-month CT scan ENDOLEAK ANATOMY“Simple”

14. ENDOLEAK ANATOMY“Complex” • Multiple ingress and egress vessels • Behave like arteriovenous malformations • Persists longer than 6 months.

15. How to treat Type II Endoleaks:Embolize the artery feeding the endoleak cavity by a transarterial route ? • This technique has proved ineffective, providing only short-term response if the sac can not be reached by the embolic agent. • Endoleaks will recur by recruiting additional aortic branch vessels.

16. The endoleak cavity acts as an “Arteriovenous malformation nidus,” and thrombosing this nidus is what provides a successful and durable response. Richard A. Baum, MD Do stable type II endoleaks require treatment after EVAR Endovascular Today

17. Type II Endoleak:Embolization with Glue

18. TYPE II ENDOLEAK FROM IMA 67 Years old High Risk Patient. 6.5 cm AAA treated 14 month ago with Gore Excluder Device. CT scan showed Type II Endoleak from IMA and the AAA remain same size. Indication:Endovascular Embolization

22. How to treat Type II Endoleaks:translumbar needle stick ? • Coils and glue to completely thrombose the endoleak cavity • Instead of treating feeding vessels, the endoleaks themselves are being embolized • The connection between ingress and egress vessels, as well as the endoleak cavity, is destroyed

23. Type II Endoleak

24. Translumbar Embolization Translumbar Gelfoam-Thrombin 6 Months FU

25. Translumbar Embolization of Type 2 Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysms • 7 Patients with Type 2 Endoleak • 4 lumbar, 3 IMA • 19-gauge,20cm needle w/5fr.Teflon Sheath • Gianturco Coils (CooK) • 100% Initial Success • No Complications R.A.Baum;C.Cope; R.Fairaman;J.CarpenterJ.Vasc Interv Radiol 2001;12:111-116

26. Type III Endoleak

27. Type III Endoleak

28. Type III Endoleak

29. Management of Endoleaks • Type I: Immediate treatment. Balloon,Cuff, Palmaz or Conversion to Open Procedure. • Sealed Type I: If large Treat ,If small Watch. If size does not decrease Treat. • Type II: Treat after 6 months if aneurysmal size do not decrease. • Late Type I or III: Treat immediately.

30. Obliteration of the Aneurysmal Sac in Abdominal Aortic Aneurysms in an Animal Model Renan Uflacker,MD

31. Pig #3 AAA creation Volume measurement 15 cc’s Post Treatment Endoleak

32. 24 Week FU Pig # 3

33. Results • The treatment of the AAA was technically successful in all animals with total exclusion of the sac • The AAA sac acquired a firm rubberish consistency after treatment • Fibrosis and calcifications were detected within the sac, mostly around the graft and in contact with the aortic wall after 4 to 6 weeks. • There was inflammatory reaction to the Dacron material and to the polymer (to a lesser extent) • Significant adhesion of the AAA with surrounding structures was observed

34. Results • After 4 to 6 weeks there is a tendency for shrinkage of the AAA sac, apparently maximized by the 24th week • There was no sac recanalization in the follow up time ranging from 1 to 24 weeks • The controls at 6 and 12 weeks showed shrinkage of the AAA sac (histology not ready yet)

35. Conclusions • pGlcNAc Glucosamine in the gel form is an unique hemostatic material • Promotes rapid clotting within the AAA sac • Also effective under systemic anticoagulation • Effective aneurysm sac filling with occlusion of branches as necessary • Easy to use and cost effective • It seems to have gradual longer term absorption allowing AAA shrinkage over a period of 24 weeks but not before 6 weeks • Experience is necessary for volumetric measurement • A human trial is warranted