The Role of Functional Respiratory Imaging in Treatment Selection of Children With Obstructive Sleep Apnea and Down Syndrome.

STUDY OBJECTIVES: The complexity of the pathogenesis of obstructive sleep apnea (OSA) in children with Down syndrome (DS) is illustrated by a prevalence of residual OSA after adenotonsillectomy. The aim of this study was to investigate whether upper airway imaging combined with computation fluid dynamics could characterize treatment outcome after adenotonsillectomy in these children. METHODS: Children with DS and OSA were prospectively included. All children underwent an evaluation of the upper airway and an ultra-low dose computed tomography scan of the upper airway before adenotonsillectomy. The upper airway tract was extracted from the scan and combined with computational fluid dynamics. Results were evaluated using control polysomnography after adenotonsillectomy. RESULTS: Thirty-three children were included: 18 boys, age 4.3 ± 2.3 years, median body mass index z-score 0.6 (-2.9 to 3.0), and median obstructive apnea-hypopnea index was 15.7 (3-70) events/h. The minimal upper airway cross-sectional area was significantly smaller in children with more severe OSA (P = .03). Nineteen children underwent a second polysomnography after adenotonsillectomy. Seventy-nine percent had persistent OSA (obstructive apneahypopnea index > 2 events/h). A greater than 50% decrease in obstructive apnea-hypopnea index was observed in 79% and these children had a significantly higher volume of the regions below the tonsils. CONCLUSIONS: This is the first study to characterize treatment outcome in children with DS and OSA using computed tomography upper airway imaging. At baseline, children with more severe OSA had a smaller upper airway. Children with a less favorable response to adenotonsillectomy had a smaller volume of regions below the tonsils, which could be due to enlargement of the lingual tonsils, glossoptosis, or macroglossia. COMMENTARY: A commentary on this article appears in this issue on page 501.

Predicting the effect of treatment in paediatric OSA by clinical examination and functional respiratory imaging.

OBJECTIVE: The aim of this study was to investigate whether functional respiratory imaging (FRI) or clinical examination could predict treatment outcome for obstructive sleep apnea (OSA) in normal-weight, non-syndromic children. METHODS: Normal weight children diagnosed with OSA by polysomnography were prospectively included. All children got a thorough evaluation and an ultra-low dose computed tomography scan of the upper airway (UA). A 3-D reconstruction was built combined with computational fluid dynamics for FRI. Decisions on the need and type of surgery were based upon findings during drug-induced sleep endoscopy. A second polysomnography was performed 3-12 months after surgery. RESULTS: Ninety-one children were included: 62 boys, 5.0 ± 2.7 years, and BMI z-score of -0.1 ± 1.2. Children with more severe OSA had a smaller volume of the overlap region between the adenoids and tonsils. Nineteen out of 60 patients had persistent OSA (oAHI >2/h). A lower conductance in the UA and a higher tonsil score predicted successful treatment. CONCLUSIONS: A less constricted airway, as characterized by both FRI and a lower tonsil score, was associated with a less favorable response to (adeno) tonsillectomy. Further studies after treatment using FRI and DISE are warranted to further characterize the UA of these subjects.