Bilateral Transradial Approach for Coil Embolization of Basilar Artery Aneurysms Associated with an Unfavorable Vertebral Artery Anatomy : Initial Experience with Role-sharing Technique.

PURPOSE An unfavorable vertebral artery (VA) anatomy occasionally inhibits a successful VA cannulation due to flow stagnation after catheterization. To preserve antegrade VA flow, we developed bilateral transradial catheter systems, referred to as the role-sharing technique, for coil embolization of basilar artery (BA) aneurysms associated with an unfavorable VA anatomy. This study aimed to evaluate the feasibility and safety of coil embolization using the role-sharing technique for BA aneurysms. METHODS We retrospectively analyzed an institutional database of consecutive patients with BA aneurysm who underwent coil embolization using the role-sharing technique between July 2019 and January 2020. The study included seven consecutive patients. Bilateral transradial VA cannulation was performed using 3.2F catheters (TACTICS; Technocrat Corporation, Aichi, Japan) via 4F guiding sheaths placed in the subclavian artery. The following catheter systems were used: the triaxial system (4F guiding sheath/TACTICS/coil or stent delivery microcatheter) that has a specialized role in embolization and the biaxial system (4F guiding sheath/TACTICS) that has a specialized role in contrast injection during embolization procedure. The procedural success and procedure-related or vascular access site complications were assessed. RESULTS All patients underwent a successful embolization procedure using the bilateral transradial catheter systems and none of them presented with flow stagnation, system instability, or other complications. CONCLUSION The role-sharing technique was shown to be a feasible and safe method for coil embolization of BA aneurysms associated with an unfavorable VA anatomy. This method may increase the success rate of transradial coil embolization for BA aneurysms.