Fig. 2

a. Loading slit type introducers from the middle of a catheter is difficult because of the overlap of wrapping structures.

b, c. Widening the slit reduces the overlap, making the catheter introducer easy to load from the middle of a catheter. This is done by rubbing the unslit side using a metal stick such as a microguidewire introducer or a microguidewire shaper.

d. Overly opened slit: cannot hold a microcatheter

e. Adequately opened slit

f. Unopened slit: before processing