562 Adenoid Regrowth after Rapid Maxillary Expansion in Residual Pediatric OSA: Interim analysis of ERMES Randomized Clinical Trial

Abstract

Introduction: Residual pediatric Obstructive Sleep Apnea (OSA) after gold-standard treatment with adenotonsillectomy occurs in nearly 20% of the patients. Treatment alternatives are scarce and based upon low-level evidence. Rapid maxillary expansion is an orthodontic-orthopaedic treatment of maxillary transverse hypoplasia that has shown promising results in pediatric OSA based upon nasal and oral cavity enlargement. Revision adenoidectomy of all-purpose adenotonsillectomies in population-based studies is 4,9%, and a threefold risk in OSA patients has been reported. We present data from an ongoing randomized clinical trial (ERMES) highlighting the importance of nasofibroscopic control of the adenoid tissue in residual pediatric OSA patients. Methods: According to the study protocol of our ongoing randomized clinical trial (Rapid maxillary expansion for treatment of residual pediatric obstructive sleep apnea; Acronym: ERMES; NCT02947464) patients aged 4 to 9 years old with polysomnographic evidence of OSA persistence after adenotonsillectomy were randomized to either rapid maxillary expansion or wahtchful waiting. They underwent fiberoptic nasopharingoscopy in order to stablish the amount of adenoidal tissue present at the time of inclusion and at polysomnographic control twelve months later. The nasopharyngeal occupation was measured in a 1 to 4 scale. Patients that graded 3 or 4 at the initial nasofibroscopy were excluded from the study due to their surgical revision indication; if they developed grade 3 or 4 adenoid hypertrophy and persistence of symptoms at the final assesment they were offered re-adenoidectomy. Results: A total of 5 patients developed an adenoid regrowth amenable for revision surgery: 4 of them within the rapid maxillary expansion group and one in the watchful waiting group. All of them had experienced either worsening or very mild improvement in their apnea hypopnea index (AHI). Conclusion: Adenoid regrowth is a known risk factor for pediatric OSA persistence. The anatomical enlargement of the nasal and oral cavity provided by means of rapid maxillary expansion may trigger such overgrowth in otherwise predisposed residual OSA patients. Fiberoptic nasopharyngoscopy is therefore mandatory in the follow-up of such complex cases, since adenoid regrowth may hinder resolution of OSA and its associated symptoms.