Risk Factors of Residual Obstructive Sleep Apnea After Adenotonsillectomy in Children: Systematic Review

<i>Background and objective:</i> Obstructive sleep apnea (OSA) is a common pediatric sleep disorder, most often caused by adenotonsillar hypertrophy. Although adenotonsillectomy (AT) is the standard first-line treatment, a substantial proportion of children experience residual OSA (rOSA). This systematic review aimed to synthesize current evidence on risk factors associated with rOSA in children following AT. <i>Materials and Methods:</i> A systematic review was conducted in accordance with PRISMA guidelines. PubMed and the Cochrane Library were searched without date restrictions using English-language terms related to rOSA, children, and adenotonsillectomy. Studies assessing postoperative persistence of OSA and associated risk factors were included. <i>Results:</i> Thirteen studies published between 2010 and 2024 met the inclusion criteria. The reported prevalence of rOSA varied widely (18.6-85.0%), reflecting heterogeneity in study design, patient populations, baseline disease severity, and follow-up methods. Obesity emerged as the most consistently identified risk factor, with significantly higher rOSA rates reported among children with elevated body mass index. Age also influenced outcomes, with both very young (<3 years) and older (>7 years) children demonstrating an increased likelihood of persistent disease. Comorbid conditions, particularly asthma and Down syndrome, were associated with poorer postoperative improvement. Additional contributors included craniofacial or developmental abnormalities and higher preoperative apnea-hypopnea index. Limited evidence also suggested that socioeconomic and environmental factors may affect postoperative outcomes. <i>Conclusions:</i> Residual OSA is common following adenotonsillectomy in children. Obesity, age, and comorbidities are key predictors, underscoring the need for comprehensive preoperative risk stratification and structured postoperative follow-up.