The left panel shows the tracheal dilator correctly advanced, following the guiding catheter and guidewire. However, if the guiding catheter is inadvertantly withdrawn into the dilator during dilation (right panel), force is directed to the posterior tracheal wall and can result in perforation.
Reproduced with permission from Trottier, SJ, Hazard, PB, Sakabu, SA, et al, Chest 1999; 115:1383.
