Pediatric Obstructive Sleep Apnea : Evaluation of surgical treatments and immunological aspects

Abstract: Pediatric obstructive sleep apnea (OSA) is a sleep-related breathing disorder often caused by  enlargement of the adenoid and the tonsils. The peak prevalence is among children who are two to six years of age, when the lymphatic tissue is  most active. Clinical diagnosis can be challenging, since the symptoms are often unspecific. Polysomnography, the diagnostic gold standard is a complex procedure with limited availability.The standard surgical treatment for OSA is removal of the tonsils (tonsillectomy) together with removal of the adenoid (adenoidectomy). Partial removal of the tonsils together with adenoidectomy, known as adenotonsillotomy, is a treatment accompanied with less postoperative morbidity but a higher risk of reoperation. The aims of this thesis are to evaluate different treatment methods for treating pediatric OSA and to investigate immunological aspects of tonsil hypertrophy.In Paper I, tonsil tissue from children with large tonsils and moderate to severe OSA was compared with tonsil tissue from children with small tonsils and milder OSA. The tissue was analyzed with flow-cytometry using markers for T cells, B cells and ILCs. Patients with enlarged tonsils and more severe OSA had a significant increase of naïve B cells without a difference in the Ki67 proliferation marker. This indicates an impaired differentiation and/or migration of B cells in the larger tonsils.In Paper II, behavior and mental health after adenotonsillectomy or adenotonsillotomy were compared. Together with polysomnography and the questionnaire OSA-18, a strength and difficulties questionnaire (SDQ) was filled out both before and one year after treatment. No significant differences between the treatment groups were seen after one year, in terms of mental health and behavior. Paper III is a long-term follow-up study of a previously published randomized controlled trial of adenotonsillectomy and adenotonsillotomy. Five years after surgery, a new polysomnography was performed on the patients.  The results showed a high dropout rate, and six children were excluded because of re-operation with adenotonsillectomy. No difference in the obstructive apnea hypopnea index was found between the groups five years after surgical intervention.Paper IV is a prospective cohort study of children treated for OSA. The correlations between subjective data from OSA-18, patient-reported outcome measures, and objective data from polysomnography were compared. Significant correlations were shown between changes in objective polysomnography data and changes in OSA-18, with the strongest correlation in the sleep disturbance subscale. The measure of patient-reported outcomes showed a significant but weak correlation.