Volumetric Changes after Coblation Ablation Tongue (CAT) in Obstructive Sleep Apnea Patients

Background: Obstruction of the tongue is commonly seen in patients with obstructive sleep apnea (OSA). This study proposed whole tongue treatment using coblation ablation tongue (CAT) and aimed to explore the potential association between the dimensions of a tongue and the severity of OSA, to inspect volumetric changes of the tongue after CAT, and to search for factors that influence outcome of tongue volume change. Methods: The prospective study enrolled 12 OSA patients (all male, average age: 35 years, average apnea/hypopnea index (AHI): 45.5 event/h, average body mass index (BMI): 27.0 kg/m²). All patients received multi-level sleep surgery including septomeatoplasty, uvulopalatopharyngoplasty, and CAT. The CAT used a coblation wand to perform uniform multiple ablations (15 points, body −6, base −9) on dorsal tongue. Three dimensions of the tongue (length, height, and width) and tongue volume were measured from head and neck computed tomography. The perioperative changes in the tongue dimension/volume and AHI were assessed at baseline and 3 months after surgery. Result: The baseline tongue length and AHI had a significant correlation (r = 0.60, p = 0.02). The multi-level surgery significantly improved AHI (43.8 vs. 23.7, p = 0.008). The CAT significantly decreased tongue volume from 91.3 to 85.6 cm³ (p = 0.02), with an average tongue volume reduction of 5.7 cm³ per person and 0.38 cm³ per ablation. Further outcome analysis showed surgical success was significantly higher in patients with non-hypertrophic lingual tonsils (grade I/II) than in those with hypertrophic lingual tonsils (grade III/IV) (p = 0.02). Conclusion: Length of the tongue is associated with the severity of OSA. The CAT significantly decreased the tongue volume in OSA patients. A volumetric reduction of 0.38 cm³ per ablation could be useful in the optimal reduction of tongue for OSA. The CAT significantly enlarged the retroglossal airway volume, which is related to the non-hypertrophic lingual tonsil.