MORPHOMETRY OF THE GLOTTIS - AN ANATOMICAL BASIS FOR AIRWAY-RESTORING PROCEDURES IN BILATERAL RECURRENT NERVE PARALYSIS

Dimensions of laryngeal and tracheal cross-sectional areas are not well explored and yet are of definite interest in endoscopic airway restorative surgery for the treatment of bilateral vocal cord paralysis. Twenty fresh, intact human larynges were shock-frozen in liquid nitrogen. Four-millimetre horizontal sections were then produced with a slicing machine. Cross-sectional areas of the vocal cords and arytenoids were measured using a computer-aided morphometry device. In addition, casts of 14 larynges were available for morphometric investigation as well as video-laryngoscopic images of 50 volunteers. The results demonstrate that the glottis is the narrowest part of the larynx even in healthy subjects. Its diameter is reduced approximately by the factor 4 in the bilaterally paralysed larynx. Cordectomy potentially offers more enlargement of the glottic airway (169+/-20 mm2 in males and 138+/-22 mm2 in females) than arytenoidectomy (42+/-12 MM2 in males and 34+/-6 mm2 in females). The knowledge of morphometric details of the glottic plane should contribute to an individualized planning of airway restoring surgery in bilateral vocal cord paralysis.