Markus Gugatschka 1

1 ENT University Hospital Graz, Phoniatrics, Graz

Introduction: Considerable forces are exerted on oropharyngeal tissues during microlaryngoscopic procedures. In most cases fulcrum-based laryngoscopy is performed, with laryngoscopes of different sizes and kinds. Aim of our study was to describe forces occurring during microlaryngoscopy as well as parameters influencing easiness of exposure.

Methods: 100 consecutive patients scheduled for microlaryngoscopy underwent study procedures. While performing microlaryngoscopy under general anaesthesia by using a microlaryngoscopy device after Kleinsasser, force measurements were obtained with a tension spring balance attached to the laryngoscope holder. By using the law of the lever we calculated forces on upper teeth and base of the tongue. Measurements were taken in neutral position, during extension of the cervical spine, as well as under moderate and maximum flexion.

Results: Mean force 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 was 4.4 fold the aforementioned, the force exerted to the tongue was the sum of both forces. Elevation of the patient’s head thus flexing the cervical spine reduced the occurring forces significantly. Maximum elevation allowed a full exposure of the anterior commissure in all cases, whereas exposure of the anterior commissure was not possible even with maximum external counterpressure in almost 40% of cases with maximum extended cervical spine.

Conclusion: The forces exerted to the oropharyngeal tissues during microlaryngoscopic interventions are noteworthy. Taking into consideration the magnitude of occurring forces, one can imagine very easily that injuries may appear. Elevation of the patient’s head allows a better exposure during microlaryngoscopy. This manoeuvre reduces the forces on the tissues significantly, and minimises the risk of peri- and postoperative complications.

Jan Vanderwegen 1 , Nora van Ardenne 1 , Gwen Van Nuffelen 1 , Marc De Bodt 1 , Paul Van de Heyning 1

1 UZ Antwerpen, NKO, Edegem

Manal El-Banna 1 , Hesham Abdelfattah 1

1 Faculty of Medicine, otorhinolaryngology, Alexandria

Alfonso Borragan 1 , Luis Buelta 2 , Andrea Ricci Maccarini 3 , Giovanni de Rossi 4

1 Centro de Foniatría y Logopedia, , Santander

2 Cantabria University, Faculty of Medicine, Santander

3 Ospedale “M. Bufalini”, ORL, Cesena

4 Ospedale San Bonifacio di Soave, ORL, Verona