Multilevel surgery is defined as an

Multilevel surgery is defined as any combination of invasive surgical procedures of different collapsible segments of the upper airway. These procedures are restricted to the same four levels: Velum (soft palate and uvula), Oro- pharynx (including tonsils), base of Tongue and Epiglottis, as designated in DISE VOTE classification. In this per-spective, multilevel surgery is a logical and consequent extension and translation of the sites, severity and direction of the obstruction(s) as assessed by DISE, while the disease severity of the patient is taken into account at the same time. While in multilevel surgery almost always at least one palatal and one base of tongue procedure are included, the rare combination of a tonsillar and epiglottis procedure would fall within the definition as well.