Expansion sphincter pharyngoplasty: analyzing the technique based on anatomy

The purpose of this study is to evaluate the effect of the different surgical techniques of expansion sphincter pharyngoplasty (ESP) on the dimensions of the oropharyngeal airway.

The techniques that were evaluated included the preservation and transection of the palatopharyngeus (PP) and superior pharyngeal constrictor (SPC) muscle attachment and transposition of the PP muscle to the hamulus of the medial pterygoid plate and the palatal musculature. Surgical techniques were applied in twenty half heads.

The preservation of the PP-SPC attachment inhibited the transposition of the PP muscle to the hamulus and resulted in comparable enlargement in the medial-lateral dimension in the oropharyngeal airway when the PP muscle was transposed to the palatal musculature. After transection of the PP-SPC attachment, significant enlargement was observed in anterior-posterior and medial-lateral directions in the oropharyngeal airway when the PP muscle was transposed both to the hamulus and the palatal musculature. The distances measured after both the transposition techniques were similar.

The present study is a basic study demonstrating how different techniques of ESP affect the position of the soft palate. The PP-SPC attachment can be transected in the patients with anterior-posterior palatal and lateral wall collapse to pull the soft palate anteriorly in addition to prevent the lateral wall collapse. The PP-SPC attachment can be preserved in the patients with only lateral wall collapse. Nevertheless, the clinical consequences of these static changes need to be evaluated in clinical studies.