Sleep Outcomes in Neonates with Pierre Robin Sequence Undergoing External Mandibular Distraction: A Longitudinal Analysis.

Abstract

We read with great interest the recent work of Ehsan et al.1 on respiratory and sleep outcomes using polysomnograms as a presurgical and postsurgical intervention to objectively measure treatment success of neonatal mandibular distraction in infants with Robin sequence. Objective assessment of obstructive sleep apnea by polysomnography is essential to the baseline evaluation of airway obstruction in infants with Robin sequence and to assessing the impact of interventions, especially given the high rate of additional anomalies and high mortality rates of 10 to 17 percent.2 The spectrum of obstructive sleep apnea in Robin sequence is broad and may also change with growth or intervention.3 Ehsan et al.1 assessed treatment success of their surgical intervention in a comprehensive way. Their work is an excellent example of how future studies assessing obstructive sleep apnea in Robin sequence should be designed. The authors report on essential variables, including variables derived from full polysomnograms, time of day and duration of polysomnogram recording, age at time of each polysomnogram, and specifically the definition of obstructive sleep apnea based on the polysomnogram results (obstructive sleep apnea if obstructive apnea-hypopnea index was >1). These are all variables necessary to facilitate treatment comparisons across centers and among different interventions. However, for future studies to be able to compare outcomes more comprehensively, we would suggest several aspects that are still missing. First, the exact indication to perform mandibular distraction in their cohort of Robin sequence infants was unclear. The authors state that the decision to proceed with mandibular distraction was determined by the multidisciplinary team collaboratively after comprehensive evaluation, but they do not state what respiratory and/or sleep parameter thresholds from the baseline polysomnograms were used to guide intervention decisions. Second, the authors define the presence of obstructive sleep apnea based on an obstructive apnea-hypopnea index greater than 1 as part of the methodology, but the authors then use index values of less than 40 and greater than 40 to categorize the severity of obstructive sleep apnea in those infants undergoing mandibular distraction osteogenesis based on their institutional practice later in the statistics section and an index value greater than 10 to define those with persistent obstructive sleep apnea after mandibular distraction osteogenesis in their results. This suggests that an obstructive apnea-hypopnea index value greater than 1 is not truly used to define obstructive sleep apnea in their clinical practice and may not be a useful definition in this age group, since in healthy neonates in the first 30 days of age, the median obstructive apnea-hypopnea index was recently reported as 1.8 (range, 0.2 to 12.5 events/hour).4 Third, the authors provide extensive details of their polysomnogram methodology, which is preferable in all future polysomnogram studies in Robin sequence. However, body position during the polysomnogram recording was not reported. Whether the recordings were performed with the patient in the supine or the prone position can heavily influence the respiratory and sleep parameters assessed by polysomnography, and assess the impact of prone positioning.5,6 Further well-designed studies that include clear documentation of these important variables reported by Ehsan et al., and these suggested additional variables, will pave the way to a more standardized, evidence-based approach in the assessment and treatment of obstructive sleep apnea in infants with Robin sequence. DISCLOSURE None of the authors reports any conflicts of interest. None of the authors has a financial interest in relation to the content of this communication. Robrecht J. H. Logjes, M.D.Department of Plastic and Reconstructive SurgeryAmsterdam University Medical CentreAcademic Medical Center and Vrije UniversiteitEmma Children’s HospitalAmsterdam, The Netherlands Joanna E. Maclean, B.Sc.(Hon.), M.D., Ph.D.Department of PediatricsDivision of Pediatric Respirology, Pulmonary, and AsthmaUniversity of AlbertaStollery Children’s HospitalEdmonton, Alberta, Canada Corstiaan C. Breugem, M.D., Ph.D.Department of Plastic and Reconstructive SurgeryUniversity Medical Centre AmsterdamAcademic Medical CenterEmma Children’s HospitalAmsterdam, The Netherlands