FOR A long time a simple instrument that would enable an assistant to watch the various steps of bronchoscopy and esophagoscopy has been needed. Such an instrument could be especially useful for teaching purposes.
A prototype of the instrument, which is called an endoscopic side-viewer, was constructed in 1963 and consisted of two tubes connected together to form an "L" and a semitransparent mirror placed at an angle of 45° to the endoscope and bisecting the 90° angle formed by the two tubes (Fig 1). The main branch of the instrument serves the surgeon and the other may be used for simultaneous observation by the assistant. This prototype was modified to fit the fiber-optic bronchoscopes and esophagoscopes (Fig 2). Also a transparent cover closing the side branch was manufactured, for use when general anesthesia is given.
We hope that the use of the side-viewer will both facilitate the teaching