Abstract TP201: Impact of Microguide Wire Stiffness on Microcatheter and Aspiration Catheter Navigation in Tortuous Vessels

Abstract

Background and Purpose: Endovascular therapies require devices to access treatment sites safely and efficiently. Vessel tortuosity often complicates this navigation, increasing the risk of microguide wire (MGW) or microcatheter (MC) kickback, which may result in unstable device movements or sudden drop of devices. This study aims to elucidate the effect of MGW stiffness variability on the trackability of MC and aspiration catheters (AC). Methods: Using two silicone vascular models, we replicated the M2 segment of the middle cerebral artery (MCA) at an 80-degree branch (MCA model, Fig. A) and a severely tortuous internal carotid artery (ICA model, Fig. B). Experiments were conducted under conditions of 37°C, 60 BPM, and an ICA flow rate of 240 mL/min. In the MCA model, the MC (TrevoTrak21) was advanced from the M1 segment to distal M2 while three MGWs (Synchro SELECT Soft, Standard, Support) were placed at distal M2. In the ICA model, the AC (Zoom 71) was advanced from ICA to M1 with MC and MGW at distal M2. Maximum push force and kickback length were measured while TrevoTrack21 or Zoom71 were advanced at 4 mm/sec for 7 runs per device. One-way ANOVA assessed group differences. Results: In the MCA model, when using the Soft MGW, the MC recorded the highest pushing force at 59.3mN and kickback of 29.87mm. Conversely, the Support MGW demonstrated the least pushing force at 38.2mN (P<0.001) and the shortest kickback length at 17.83mm (P<0.001). For the ICA model, differences in forces across the MGW types were less distinct. However, the kickback length with the Soft MGW at 13.78mm was significantly greater than that with the Standard MGW at 6.26mm and the Support MGW at 6.76mm (P=0.026). Conclusion: Our findings suggest that MGWs with higher stiffness offer more stable guidance, requiring less force in both MC and AC navigation. Moreover, increased MGW stiffness consistently leads to shorter kickback lengths, emphasizing its importance in stable device navigation.