Objectives: The purpose of this study was to create virtual 3D views of the interaction between contrast-enhanced thrombi and three different types of stent retrievers.
Materials and methods: Artificial thrombi with and without contrast agent were created and introduced into a silicone tube with saline solution. The stent retrievers (Aperio (A), Solitaire FR (B), Revive (C)) were released around the thrombi. For each retriever, two sets (0 min, 5 min) of flat panel computed tomography (CT) data were acquired on a Siemens Axiom Artis Zee biplane angiography system and reconstructed using syngo InSpace 3D software.
Results: The filaments of all three stent retrievers were displaced by the thrombus immediately after deployment. Another study series after 5 min showed further expansion of the stents into the thrombus. A tends to appose best around obstacles. A and B allow cushion-like bulging of clot material into the stent lumen. C showed only moderate curvilinear bulging and a minor degree of interaction in between stent filaments and thrombus.
Conclusions: Flexible design allows better apposition of the device to the surface of the thrombus. A relatively strong longitudinal structure combined with large gaps in between the stent filaments seems to favor migration into the clot. The main capture mechanism seems to be engagement of the clot between the crossings of stent struts.