（1）引导导管内双导管，其中之一是微导管
（2）引导导管内第二个微导管用转向微导管（steerable microcatheter）：The technical tips of steerable 2.9Fr high-flow microcatheter as a second catheter for triple coaxial systems.

这一概念不同于triaxial 共轴系统的概念

Usefulness of the triple coaxial systems using steerable high-flow microcatheter as a second catheter. 

Background

➢Progress in catheter devices are remarkable in recent years, especially with balloon catheters and superselective microcatheter, 

treatment options have expanded more than ever.

➢The steerable microcatheter (SwiftNINJA, Sumitomo Bakelite, TOKYO) was developed as the world‘s first movable  [ˈmuvəbəl] tip microcatheter, and was launched in Japan in April 2016. Since a steerable microcatheter was released, it has improved vessel selectivity [səˌlek'tɪvətɪ] in difficult case.1)

 

➢Procedure with steerable catheter can reduce operative time and radiation exposure. 2)


 

① The steerable microcatheter is greatly improved in vessel selectivity. However, even with the standard(2.4/2.6Fr) or selective(2.0/2.4Fr) steerable microcatheter, we rarely experience the cases that microcatheter cannot be advanced.

 

② To solve this problem, we propose a triple coaxial system with a high-flow steerable microcatheter(2.9Fr Swift NINJA) as a second catheter. The highlights of the triple coaxial system is the steerable microcatheter works like a guiding catheter by locking angle of the movable part at the tip, and it is possible to get strong backup.

③ After inserting the guidewire and the third microcatheter to the periphery, releasing the lock improves followability and enables advancement of the steerable microcatheter.

④ By alternately advancing the steerable microcatheter and the third microcatheter, it is possible to intensify the backup in stages and insert catheter even in difficult vessels. It seems to be really useful to advance the catheter reliably.