Direct laryngoscopy and description of a self-retaining attachment for the laryngoscope.

Modern direct laryngoscopy had its inception with the introduction by Killian (cited by Le Jeune 1 ) in 1911 of his suspension laryngoscope. Since that time there have been in use four main types of laryngoscopes for direct laryngoscopy. They can be designated as the suspension, bivalve speculum, chest support, and handle-tube types, and a representative of each class is illustrated in Figure 1. A brief discussion of the introduction and mechanical features of each type of instrument may help to clarify the use of the laryngoscope attachment which I shall presently describe. According to Lewy, 2 Kirstein introduced direct laryngoscopy in 1896, and in 1902 von Hacker inserted a rigid tube into the trachea. The suspension laryngoscope introduced by Killian marked a milestone in the history of laryngology, but the instrument was difficult to use. Atkinson 3 described the Killian laryngoscope as follows: "The spatula had to be accompanied by