Abstract
Microlaryngoscopic interventions are part of daily clinical routine in modern laryngology. In most cases, fulcrum-based laryngoscopy is performed, where endolaryngeal structures are exposed by laryngoscopes of different sizes and kinds. Aim of our study was to describe forces appearing during microlaryngoscopy (MLX) as well as parameters influencing easiness of exposure and given gender differences. Starting from May 2006, 100 consecutive patients scheduled for microlaryngoscopy underwent study procedures. While performing microlaryngoscopy under general anaesthesia by using a device after Kleinsasser, force measurements were obtained with a tension spring balance attached to the laryngoscope holder (F chest). By using the law of the lever and given distances, we calculated dimensions of occurring forces on upper teeth (F teeth) and base of the tongue (F tongue). Mean force (F chest) obtained by measurement with the spring balance in our study cohort was 4.4 kg (43.2 N). Whereas the force exerted on the teeth/toothless upper jaw is 4.4-fold F chest, the force exerted on base of the tongue (F tongue) is the sum of both forces (F teeth + F chest). Thus, the mean force exerted on teeth is 19.4 kg (∼190 N), force exerted on base of the tongue is 23.8 kg (233.5 N). Status of teeth was described as an independent variable and correlated with both easiness of exposure of the operational field, as well with occurring forces. We could not identify gender differences of either kind. Jet anaesthesia did not influence pressure loads or easiness of exposure.
Similar content being viewed by others
References
Brünings W (1912) Direct laryngoscopy, bronchoscopy, and esophagoscopy. Tindall & Cox, London
Hochman I, Zeitels SM, Heaton JT (1999) Analysis of the forces and position required for direct laryngoscopic exposure of the anterior vocal folds. Ann Otol Rhinol Laryngol 108:715–724
Kirstein A (1897) Autoscopy of the larynx and trachea (direct examination without mirrir). FA Davis Co, Philadelphia, pp 57–58
Kleinsasser O (1968a) Microlaryngoscopy and endolaryngeal microsurgery. University Park Press, Baltimore, pp 48–62
Kleinsasser O (1968b) Mikrolaryngoskopie und endolaryngeale Mikrochirurgie. Technik und typische Befunde. 1. Auflage Schattauer Verlag, Stuttgart
Klussmann JP, Knoedgen R, Damm M, Wittekindt C, Eckel HE (2002) Complications of suspension laryngoscopy. Ann Otol Rhinol Laryngol 111(11):972–976
Rosen CA, Filho PA, Scheffel L, Buckmire R (2005) Oropharyngeal complications of suspension laryngoscopy: a prospective study. Laryngoscope 115:1681–1684
Vaughan CW (1993) Vocal fold exposure in phonosurgery. J Voice 7:189–94
Zeitels SM, Burns JA, Dailey SH (2004) Suspension laryngoscopy revisited. Ann Otol Rhinol Laryngol 113:16–22
Zeitels SM, Vaughan CW (1994) External counterpressure and internal distention for optimal laryngoscopic exposure of the anterior glottal commissure. Ann Otol Rhinol Laryngol 103:669–675
Acknowledgments
The authors would like to thank Evelyn Reckenzaun MD, Karl Kiesler MD and Reinhard Tripp MD for taking measurements and providing data for this study.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Gugatschka, M., Gerstenberger, C. & Friedrich, G. Analysis of forces applied during microlaryngoscopy: a descriptive study. Eur Arch Otorhinolaryngol 265, 1083–1087 (2008). https://doi.org/10.1007/s00405-008-0586-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00405-008-0586-z