No Consensus on the Optimal Approach to Treating Type II Aortic Endoleaks
Interview with Dr. Michael D. Dake, Stanford University School of Medicine, Stanford, CA
There is no consensus as to the best way to treat Type II endoleaks because they can vary considerably and they can be very complex to treat. However, Type I and Type III should almost always be treated when discovered, and treatment of Type II should be reserved to patients with sac enlargement, according to Dr. Michael D. Dake, MD, who is the Thelma and Henry Doelger Professor, Department of Cardiothoracic Surgery at Stanford University School of Medicine, Stanford, California. Dr. Dake, who spoke at #GEST2014 said that open conversions may be necessary but they carry a higher risk for morbidity and for mortality.
"There are significant challenges that are still existing in treatment of endoleaks. Clearly, when you have a number of approaches; there is no one certain right way to do it. So consequently the challenge is to find out which patients really need to be treated early on and which techniques are best for Type II branch."
Endoleaks currently are divided into IV Types:
- Type I- Attachment leak
- Type II - Branch flow
- Type III - Defect in graft or modular disconnection
- Type IV - Fabric porosity
"There is a general consensus that Type I and III endoleaks are serious and associated with a significant risk of rupture and should be treated whenever feasible and treated with endovascular salvage or open conversion. Endovascular treatment of Type I endoleaks include ballooning, extensions with stent grafts and increase radial force by Palmaz stents.
There are currently several approaches to Type II endoleaks and they include observation; laparoscopic clipping of branches; open surgical conversion (partial or complete) and endovascular approaches. Current practices include agents (used alone or in combination); extension cuffs; supplemental bare metal stent expansion, and coils. Interventional radiologists are using liquid embolics (EVOH, glue, etc.); plugs; occluders; blockers; fasteners, staplers and procoagulants (thrombin, fibrin, gel foam, etc).
Delivery routes currently include trans-arterial, trans-caval, sub-graft (between prosthesis and vessel wall) and percutaneous (trans-parietal, retroperitoneal). Embolization is considered the treatment of choice of the Type II endoleaks in the case of growth of the volume of the sac. Many interventions are being carried out too early in some cases where the endoleaks would have resolved spontaneously. My concern is that many techniques may obstruct future imaging.
The big challenge we still have is how best to deal with Type II branch endoleaks. I think Type II's are difficult and they are still the Achilles' heel. There are many new opportunities and I think we are interested in new embolics and in ones that are less expensive and less risky."
He noted that endovascular techniques can be used safely and effectively to treat endoleaks after EVAR (endovascular abdominal aortic repair), but there are many unmet endoleak challenges. "Unfortunately very little data exist and currently it is easy to make claims of effectiveness since there are no clear endpoints determining effectiveness."