Passability and Impassability of Microcatheters Through the Neuroform Atlas Stent During the Trans-cell Approach: An Experimental Evaluation.

ABSTRACT

BACKGROUND: Trans-cell approach for the Neuroform Atlas stent (Stryker Neurovascular, Fremont, CA) is occasionally unsuccessful as a microcatheter can become stuck in the struts. This study aimed to evaluate the passability and impassability of 0.0165-inch microcatheters through the Neuroform Atlas stent using a simplified benchtop model. METHODS: The distal struts of the target cell, referred to as the concave or convex crown, were found to interfere with microcatheter advancement during the trans-cell approach. The procedure was performed across each crown using the 1.7-Fr SL-10 and 1.6-Fr Headway Duo microcatheters (MicroVention-Terumo, Aliso Viejo, CA), and it was repeated 20 times. We evaluated the procedural success rate, passability of each microcatheter using the maximum moving distance of the target crown in successful procedures, and device behaviors. RESULTS: The procedural success rate across the concave crown was significantly higher than that across the convex crown in both microcatheters. The maximum moving distance of the concave crown was significantly shorter in the Headway Duo microcatheter than in the SL-10 microcatheter. All procedures across the convex crown were not successful because the sharp end of the crown fell into the interspace inside the microcatheter tip, which is referred to as the crown jackpot phenomenon. The trapped microcatheter was never released from the crown unless it was pulled back proximally. CONCLUSIONS: Target crowns and microcatheters affected the use of the trans-cell approach through the Neuroform Atlas stent. The passability was excellent in a lower profile 0.0165-inch microcatheter. Moreover, neurointerventionalists must be knowledgeable of the crown jackpot phenomenon, which might cause fatal stent migration.