Validity about Diameter of Guiding Catheter for Posterior Circulation Derived by MRA Study.

Objective: The development of large-bore aspiration catheters (ACs) has advanced the treatment of mechanical thrombectomy (MT) and their use requires larger guiding catheters (GCs). However, due to the small vessel diameter of the vertebral artery (VA), it can be difficult to cannulate large-bore GC to the VA. This study aims to determine the percentage of VAs that are amenable to GC placement based on the use of a large-bore AC and to clarify the diameters of VAs in the general population using neck MRA.

Methods: Left and right VA diameters were measured in 1394 consecutive adult patients who underwent neck MRA at our hospital between April 2020 and June 2021. Sex and left/right differences in the VA diameters, as well as the conformity ratios of GCs (6, 7, and 8 French) to right and left VAs, were examined.

Results: The patients ranged in age from 18 to 98 years (mean 70.8 ± 13.5 years), with 770 (55.2%) males. The left and right VA mean diameters were 2.82 ± 0.75 mm (range 0-5.1 mm) and 2.65 ± 0.75 mm (range 0-5.3 mm), respectively. The conformity ratios of 6, 7, and 8 French GC to left and right VAs were 85.3% and 79.9%, 74.9% and 68.4%, and 60.9% and 53.7%, respectively.

Conclusion: When performing MT for the posterior circulation system, a large-bore AC of 0.060 inches or larger is usually required, and GC placement of 7-French or larger is necessary. The results of this study showed that 7-French GC placement is achievable in approximately 70% of these cases.