Abstract Number ‐ 23: In vitro evaluation of thrombectomy techniques: What is the most efficient combined technique?

Abstract

Introduction A combined technique with contact aspiration and stent retriever is widely used for the treatment of patients with acute ischemic stroke due to the potential synergistic effect of the two technologies. However, there are no large studies that conclude the combined technique is more efficient compared to stent retriever only or contact aspiration. One of the issues in combined techniques may be the complexity, and multiple variations of combined techniques exist. We performed an in vitro study using three‐dimensional (3D) flow models and performed clot retrieval in order to explore effective and safe techniques for mechanical thrombectomy. Methods In a 3D silicone flow model with moderate tortuosity, we compared several techniques: 1. a pinching combination method (pull out stent retriever and aspiration catheter as a unit) with several variations of aspiration catheter locations; 2. an ingestion combination method (stent retriever removal through aspiration catheter); 3. stent retriever only; and 4. contact aspiration. We evaluated the success retrieval rates of a thrombus in the M2 branch. In addition, we measured pulling force during each technique to determine the amount of force exerted on the distal MCA vessel. Results The highest clot retrieval rate was achieved with a pinching combination technique with close contact with an aspiration catheter. The pulling force on the distal MCA vessel was high with the techniques that had high clot retrieval rates and low with the techniques that had low success rates. The pulling force was higher when the stent retriever was fully deployed compared with a pinching technique with a stent partially covered with an aspiration catheter. Conclusions In our in vitro model, the pinching combination method showed the highest clot retrieval rate when the aspiration catheter was advanced to the clot and the stent retriever. The pulling force experiments suggested the shorter stent retriever may decrease the rate of subarachnoid hemorrhage due to low pulling force.