Findings on MR Sleep Studies as Biomarkers to Predict Outcome of Genioglossus Advancement in the Treatment of Obstructive Sleep Apnea in Children and Young Adults

Abstract

Genioglossus advancement, an operation to pull the tongue anteriorly, is a treatment of obstructive sleep apnea (OSA) secondary to glossoptosis. MRI predictors to identify which children will benefit from genioglossus advancement would be helpful for planning. We reviewed imaging findings on MR sleep studies as biomarkers to predict success or failure of genioglossus advancement in the treatment of OSA in children and young adults. Twenty-eight patients who had undergone genioglossus advancement and preoperative MRI were identified. For each subject, genioglossus advancement, which was performed to treat OSA, was categorized as a success or failure on the basis of polysomnography and clinical criteria. Static and dynamic cine MR sequences were retrospectively evaluated for multiple parameters including measurements of the size of the tongue and of the bony confines of the supraglottic airway, the ratio of tongue size to bony confines size, static size and dynamic changes of the retroglossal airway, tonsil size, and soft palate thickness. Radiologists were blinded to the outcome of genioglossus advancement (i.e., success or failure category). Numeric biomarkers were compared in an analysis-of-covariance model adjusting for patient age. Genioglossus advancement was successful for the treatment of OSA in 17 patients and failed in 11 patients. The relative size of the tongue (tongue-bony confines ratio) was larger in patients with a successful surgical outcome than in those for whom the procedure failed (mean ratio, 0.51 vs 0.46; p = 0.023). Smaller adenoids were associated with a successful outcome (mean size of adenoids, 9.1 vs 12.4 mm; p = 0.049). No other biomarker-including absolute tongue size and airway size or dynamic airway motion-was significant. The relative (not absolute) tongue size and small size of the adenoid tonsils on MRI were predictors of success of genioglossus advancement for the treatment of glossoptosis causing OSA. These findings may be helpful in guiding surgical decision making in children with OSA.