Evaluating a biaxial radial workflow for flow diverter placement: clinical and technical outcomes using the RIST...

Triaxial systems are widely presumed to enhance support and distal microcatheter stability in the setting of delivery of a flow diverter; however, advances in radial-specific guide catheters may reduce the need for added complexity. This study evaluates procedural and clinical outcomes of a uniform biaxial-only radial workflow using the RIST guide catheter for intracranial flow diverter treatment.

We performed a retrospective, single-center review of all consecutive patients undergoing transradial flow diverter placement for intracranial aneurysms using the RIST system between 2021 and 2024. Primary outcomes were technical success, conversion to triaxial support or femoral access, and intraprocedural complications.

Fifty-three patients were included. Median age was 52 years (IQR, 39-59), and 26% were male. Most aneurysms were unruptured (91%) and located along the internal carotid artery. Flow diverters included Pipeline Shield (66%), FRED X (15%), Pipeline Vantage (13%), Surpass Evolve (3.8%), and Pipeline Flex (1.9%). Three procedures were unsuccessful (technical success rate: 94%), including one requiring conversion to a triaxial system (1.9%); no case required femoral conversion. Intraprocedural complications were rare (3.8%), consisting of one cervical carotid dissection and one episode of severe but reversible radial artery spasm. Median hospital stay was 1 day (IQR, 1-2). No procedure-related mortality was observed.

A radial-first, biaxial-only workflow using the RIST guide catheter provides reliable support for flow diverter deployment with high technical success and infrequent complications. The extremely low need for conversion to triaxial support suggests that contemporary radial-specific guide catheters may preclude routine use of intermediate catheters in most cases. This strategy may reduce procedural complexity and cost without compromising safety.