An empirical study of modified frontolateral partial laryngectomy without tracheotomy

Voice Outcome of Modified Frontolateral Partial Laryngectomy in Excised Canine Larynges and Finite Element Model

OBJECTIVE

To evaluate vocal parameters after modified frontolateral partial laryngectomy (MFLPL) and frontolateral partial laryngectomy (FLPL) in both excised canine and finite element models.

STUDY DESIGN

FLPL and MFLPL were compared, using a prospective paired case control laboratory study with excised canine larynx and computational modeling.

SETTING

Basic science study conducted in university laboratory.

METHODS

FLPL and MFLPL were performed serially on 9 excised canine larynges. The excised larynx bench apparatus was used to collect phonation threshold pressure (PTP) and high-speed video data. A finite element model was built to compare a normal vocal fold with applied tension, a cut fold with no applied tension (simulating FLPL), and a cut fold with applied tension (simulating MFLPL). Stress values and distributions across the 3 conditions were computed.

RESULTS

The mean PTP increase after MFLPL (15.45-17.46 cmH2O) was not statistically significant. In the excised canine model, fundamental frequency (F0) showed a significant increase for the MFLPL (P = .039). Differences in vibration amplitudes were not statistically significant. Von Mises stress distribution was most similar between the MFLPL model and the normal fold. Maximum von Mises stresses at the midline were 17.56, 21.63, and 5.10 kPa for the normal, MFLPL, and FLPL, respectively, and 47.57, 63.98, and 101.97 kPa at the peripheries.

CONCLUSIONS

From these results, we conclude that MFLPL has the potential to give a better voice outcome while avoiding tracheotomy in partial laryngectomy patients. In vivo study in canines to examine the healing process would lend further evidence-based support for this surgical method.