P-023 Optimizing radial force of stent retrievers to minimize vessel wall injury: mechanical bench testing of radial force generated by a novel braided stent retriever compared to laser-cut stent retrievers in the M1 and m2 vessels

Abstract

Purpose Stent Retrievers are an important part of the stroke tool kit in achieving high recanalization rates and favorable clinical outcomes in patients with acute ischemic stroke due to large vessel occlusions (LVOs). However, recent reports have raised concern about the risk of vessel wall injury (VWI) when pulling out current laser-cut stent retrievers during active strut apposition to the vessel walls. Development of braided stent retrievers may be gentler on the fragile brain vessels and more optimized (with regards to radial force) for vessel diameters seen in proximal LVOs (such as in M1) and distal LVOs (such as in M2) compared to existing laser-cut stent retrievers. Methods Mechanical bench testing of radial force (RF) generated by stent retrievers was performed using a radial compression station mounted on a Tensile Testing Machine (Blockwise Engineering, Phoenix, AZ). The total radial force (RF) in Newtons (N) generated in vessel diameters (d) (Range 2.25 to 3 mm) seen in proximal LVOs (˜M1), and vessel diameters (d) (Range 1.5 to 2.24 mm) seen in distal LVOs (˜M2) was measured (figure 1). Radial Force of less than or equal to 1N was grouped as ‘low’ and radial force greater than 1N was grouped as ‘high’ for this analysis. Results The results of the radial force testing are shown in the table 1. The total radial force (RF) of all laser-cut stent retrievers studied were all higher in the M2 vessels (>1N) compared to M1 vessels (≤1N), whereas the total radial force (RF) of the braided stent retrievers were uniformly low in both the M1 (≤1N) and M2 (≤1N) vessels. Choosing a stent retriever with lower OD does not translate to lower radial force. As a result, sizing of stent retrievers to target vessels should not only factor the OD of the devices but also the total radial force in the target vessel diameter. Conclusion Novel braided stent retrievers have lower radial force compared to existing laser-cut stent retrievers in the M1 and M2 vessel diameters. Further studies in-vivoneed to assess the impact of lower radial force on minimizing VWI. Disclosures J. Katz: None. A. Abou-Chebl: None. V. Janardhan: 4; C; Insera Therapeutics, Inc. V. Janardhan: 4; C; Insera Therapeutics, Inc.