FIG 1. Excel 14 catheter, demonstrating 7-mm length and manually steam-shaped 90° angle curve. Although the initial measured tip angle measured 98° (I), the tip angle decreased to 75° following coaxial microcatheter insertion through a guiding catheter (CI). The tip angle was further reduced to 46° following guidewire manipulation (GW). The tip angle recovered to approximately 60° after the second (C2) and fifth GDC withdrawals and insertions (C5). The change rate of the catheter-tip angles, once exposed to straightening forces, is graphically depicted as a percentage straightening when compared with the initial baseline-shaped angle.