Purpose: This presentation includes a pictorial review of aortic endoleaks by type, discusses surveillance strategies and imaging modalities, and provides optimal treatment strategies for endoleaks by type.
Materials and Methods: Endovascular aortic aneurysm repair (EVAR) is a minimally invasive approach for the treatment of abdominal aortic aneurysms (AAAs). One potential complication of EVAR is the development of endoleaks (continued perfusion of the excluded sac), which could result in rupture. We review the imaging findings of aortic endoleaks of types I to IV. Type I endoleaks result from an inadequate seal at proximal–distal graft attachment sites. Type II endoleaks occur because of retrograde flow of branch vessels that communicate with the excluded sac. Type III is a mechanical failure of the stent graft either (i.e., stent fracture or component separation). Type IV endoleaks are caused by increased porosity of the graft fabric. We also review optimal practice principles for managing endoleaks by type.
Results: Endoleaks are a potential complication of EVARs, occurring in approximately 20% to 50% of cases. Type I endoleaks represent approximately 10% of all endoleaks and most are detected at the time of placement. Treatment options include angioplasty, stent extension, and simple observation. More advanced techniques for type I repair are available for those that are refractory to or not amenable to primary treatment options. Type II endoleaks represent more than half of all endoleaks and are typically associated with slow progression; only approximately 1% are associated with rupture. Initial management is often close surveillance. Sac expansion greater than 5 mm serves as an indicator to pursue intervention. Treatment revolves around embolizing inflow and outflow vessels. Type III and type IV endoleaks were much more common with earlier generation endografts, and their incidence has decreased with improved technology, now each representing about 3% of all endoleaks. Management of type III endoleaks mainly requires deployment of additional stent-grafts. Type IV endoleaks usually resolve within 24 hours. Endoleak of undefined origin is usually treated with graft relining.
Conclusions: EVAR now accounts for nearly 50% to 60% of all AAA treatment. It is important for interventionalists to understand optimal surveillance strategies and imaging modalities. More important, interventionalists must understand when to intervene on endoleaks and optimal treatment options by endoleak type.