Tracheal ulceration and obstruction associated with flexible Bivona tracheostomy tubes.

An adjustable length tracheostomy tube, Bivona, which assumes a curve on insertion, has a tendency to straighten itself in situ. The straightening force, measured electronically, was maximal (0.21 Newton) when a tube was bent 90 degrees. We observed particular clinical disadvantages of these tubes--that of tracheal ulceration (1 case), distortion of soft tracheal graft tissue (1 case) and airway obstruction when the tip embedded into the tracheal wall (1 case).