New design of a tracheostomy-cricothyroidostomy tube.

In an attempt to minimize late airway stenosis, a new tube with an oval cross-section has been developed. Two to three tracheal cartilage arches are usually incised anteriorly, partially excised or inadvertently broken to fit a tracheostomy tube. The risk of post-tracheostomy stenosis seems to be greater when several cartilages have been involved. If an oval tube with the shortest diameter in its symmetry plane is used, the tissue defect along the longitudinal axis of the trachea will be shorter than that caused by a round tube. When such a stoma is healing, the adjacent intact tracheal cartilages, which are located fairly close to each other, will support the bridging scar tissue, thereby preventing collapse of the tracheal wall. The tubes come in three lengths to fit most neck sizes. An oval trial tube with the same length as the shortest one has been used for cricothyroidostomy--the aim being to spread the cricoid and thyroid cartilages apart as little as possible. A series of 23 patients were treated with this tube. At follow-up, no stenosis was found at flexible fiberoptic laryngo-tracheoscopy. Fifteen patients reported no voice change, and five, who were singers, experienced lower pitch, but four of them were still singing. None of these five patients had speech problems. The other three patients had voice problems when speaking. One of these had chronic bronchitis and another had had a stroke. The third one had a rough voice. The voice problems were milder than those reported from previous series.