Impact of prone positioning in infants with Pierre Robin sequence: a polysomnography study

The Evolution of Robin Sequence Treatment Based on the Biomimetic Interdisciplinary Approach: A Historical Review

The Robin sequence is a congenital anomaly characterized by a triad of features: micrognathia, glossoptosis, and airway obstruction. This comprehensive historical review maps the evolution of approaches and appliances for its treatment from the past to the current modern possibilities of an interdisciplinary combination of modern engineering, medicine, materials, and computer science combined approach with emphasis on designing appliances inspired by nature and individual human anatomy. Current biomimetic designs are clinically applied, resulting in appliances that are more efficient, comfortable, sustainable, and safer than legacy traditional designs. This review maps the treatment modalities that have been used for patients with a Robin sequence over the years. Early management of the Robin sequence focused primarily on airway maintenance and feeding support, while current management strategies involve both nonsurgical and surgical interventions and biomimetic biocompatible personalized appliances. The goal of this paper was to provide a review of the evolution of management strategies for patients with the Robin sequence that led to the current interdisciplinary biomimetic approaches impacting the future of Robin Sequence treatment with biomimetics at the forefront.

Obstructive sleep apnea is position dependent in young infants

BACKGROUND

Obstructive sleep apnea in infants with Pierre Robin sequence is sleep-position dependent. The influence of sleep position on obstructive events is not established in other infants.

METHODS

We re-evaluated ten-year pediatric sleep center data in infants aged less than six months, with polysomnography performed in different sleep positions. We excluded infants with syndromes, genetic defects, or structural anomalies.

RESULTS

Comparison of breathing between supine and side sleeping positions was performed for 72 infants at the median corrected age of 4 weeks (interquartile range (IQR) 2-8 weeks). Of the infants, 74% were male, 35% were born prematurely, and 35% underwent study because of a life-threatening event or for being a SIDS sibling. Upper airway obstruction was more frequent (obstructive apnea-hypopnea index (OAHI), p < 0.001), 95th-percentile end-tidal carbon dioxide levels were higher (p = 0.004), and the work of breathing was heavier (p = 0.002) in the supine than in the side position. Median OAHI in the supine position was 8 h^-1 (IQR 4-20 h^-1), and in the side position was 4 h^-1 (IQR 0-10 h^-1).

CONCLUSIONS

Obstructive upper airway events in young infants are more frequent when supine than when sleeping on the side.

IMPACT

The effect of sleep position on obstructive sleep apnea is not well established in infants other than in those with Pierre Robin sequence. A tendency for upper airway obstruction is position dependent in most infants aged less than 6 months. Upper airway obstruction is more common, end-tidal carbon dioxide 95th-percentile values higher, and breathing more laborious in the supine than in the side-sleeping position. Upper airway obstruction and obstructive events have high REM sleep predominance. As part of obstructive sleep apnea treatment in young infants, side-sleeping positioning may prove useful.

Pierre Robin and breathing: What to do and when?

Robin sequence is characterized by mandibular retrognathia, airway obstruction, and glossoptosis; 80%-90% also have a cleft palate. Various treatment approaches exist, and although controlled studies are rare, objective assessment of treatment outcomes that address the leading clinical issues, namely obstructive sleep apnea and failure to thrive, are essential. Sleep-disordered breathing may be detected using cardiorespiratory polygraphy or polysomnography. Pulse oximetry alone may miss infants with frequent obstructive apneas, yet no intermittent hypoxia. Among conservative treatment options, the Tubingen Palatal Plate with a velar extension shifting the tongue base forward is the only approach that corrects the underlying anatomy and that has undergone appropriate evaluation. Of the surgical treatment options, which are not necessarily the first line of therapy, mandibular distraction osteogenesis (MDO) is effective and has been most extensively adopted. Notwithstanding, it is puzzling that MDO is frequently used in some countries, yet hardly ever in others, despite similar tracheostomy rates. Thus, prospective multicenter studies with side-by-side comparisons aimed at identifying an optimal treatment paradigm for this potentially life-threatening condition are urgently needed.

Obstructive Sleep Apnea in Neonates

Neonates have distinctive anatomic and physiologic features that predispose them to obstructive sleep apnea (OSA). The overall prevalence of neonatal OSA is unknown, although an increase in prevalence has been reported in neonates with craniofacial malformations, neurological disorders, and airway malformations. If remained unrecognized and untreated, neonatal OSA can lead to impaired growth and development, cardiovascular morbidity, and can even be life threatening. Polysomnography and direct visualization of the airway are essential diagnostic modalities in neonatal OSA. Treatment of neonatal OSA is based on the severity of OSA and associated co-morbidities. This may include medical and surgical interventions individualized for the affected neonate. Based on this, it is expected that infants with OSA have more significant healthcare utilization.

Airway and Feeding Outcomes in Pierre Robin Sequence: A Comparison of Three Management Strategies

BACKGROUND

Controversy remains regarding optimal management of Pierre Robin sequence (PRS). The goal of this study was to compare airway and feeding outcomes in infants with PRS who underwent surgical intervention, specifically mandibular distraction osteogenesis (MDO) or tongue-lip adhesion (TLA), or who had conservative management (CM) without surgery.

METHODS

All consecutive patients treated for PRS at a pediatric academic medical center, with at least one year follow-up, were included. Patients who underwent tracheostomy as an index procedure were excluded. Patients were divided into those who underwent MDO, TLA or CM. Feeding status and data from initial and follow-up polysomnograms were collected. Comparisons between groups were made using the Kruskal-Wallis test, followed by Mann-Whitney pairwise comparison with a Bonferroni correction, when appropriate.

RESULTS

67 neonates were included. 19 underwent TLA, 29 underwent MDO and 19 underwent CM. The proportions of syndromic patients were similar between groups. Patients undergoing CM had the lowest baseline AHI (9.1), but there were no significant differences between TLA (20.1) and MDO (25.4). At follow-up, the three groups had similar mean AHI (MDO 1.3, TLA 4.2, CM 4.5). A similar proportion of patients achieved AHI 5 or less (TLA 89.5%, MDO 96.6%, CM 84.2%). At one year, there were no significant differences in weight percentiles or in risk of failure-to-thrive between groups. One patient from the TLA group required a tracheostomy.

CONCLUSION

The three treatment modalities achieved high airway and feeding success rates. All three modalities should have a place in the armamentarium of the craniofacial surgeon.

Positioning as a conservative treatment option in infants with micrognathia and/or cleft

Evaluation and management of airway obstruction in prone position were reviewed from studies in infants with micrognathia and/or cleft palate, using polysomnography (PSG) or similar measures, and comparing prone against other positions. Most studies identified were case series from specialist referral centres. Airway obstruction appears more severe on PSG than clinical assessment, but there is no consensus for PSG definitions of mild, moderate or severe airway obstruction. Infants show individual variability in responses to positioning; sleep quality tends to improve when prone, but 22-25% have better respiratory outcomes when supine. Most centres recommend home monitoring if advising that an infant be placed prone to manage their airway obstruction. In conclusion, in case series, success rates for managing infant airway obstruction by prone positioning vary from 12 to 76%. PSG studies comparing prone with other sleep positions can help differentiate which infants show improved airway obstruction and/or sleep quality when positioned prone.

Pierre Robin sequence causes position-dependent obstructive sleep apnoea in infants

INTRODUCTION

Obstructive sleep apnoea (OSA) and feeding difficulties are key problems for Pierre Robin sequence (PRS) infants. OSA management varies between treatment centres. Sleep positioning represents the traditional OSA treatment, although its effectiveness remains insufficiently evaluated.

DESIGN

To complete a polysomnographic (PSG) evaluation of effect of sleep position on OSA in PRS infants less than 3 months of age. We analysed a 10-year national reference centre dataset of 76 PRS infants. PSG was performed as daytime recordings for 67 in the supine, side and prone sleeping position when possible. In most cases, recording included one cycle of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep in each position.

RESULTS

One-third of infants (9/76, 12%) had severe OSA needing treatment intervention prior to PSG. During PSG, OSA with an obstructive apnoea and hypopnoea index (OAHI) >5 per hour was noted in 82% (55/67) of infants. OSA was most severe in the supine and mildest in the side or in the prone positions. The median OAHI in the supine, side and prone positions were 31, 16 and 19 per hour of sleep (p=0.003). For 68% (52/67) of the infants, either no treatment or positional treatment alone was considered sufficient.

CONCLUSIONS

The incidence of OSA was 84% (64/76) including the nine infants with severe OSA diagnosed prior to PSG. For the most infants, the OSA was sleep position dependent. Our study results support the use of PSG in the evaluation of OSA and the use of sleep positioning as a part of OSA treatment.

Objective measurements for upper airway obstruction in infants with Robin sequence: what are we measuring? A systematic review

STUDY OBJECTIVES

Identifying optimal treatment for infants with Robin sequence (RS) is challenging due to substantial variability in the presentation of upper airway obstruction (UAO) in this population. Objective assessments of UAO and treatments are not standardized. A systematic review of objective measures of UAO was conducted as step towards evidence based clinical decision making for RS.

METHODS

A literature search was performed in Pubmed and Embase databases (1990-2020) following PRISMA-guidelines. Articles reporting on RS and UAO-treatment were included if the following objective measures were studied: oximetry, polysomnography and blood gas. Quality was appraised by methodological index for non-randomized studies (MINORS, range:0-24).

RESULTS

A total of 91 articles met inclusion criteria. Mean MINORS-score was 7.1 (range:3-14). Polysomnography was most frequently used (76%) followed by oximetry (20%) and blood gas (11%). Sleep position of the infant was reported in 35% of studies, with supine position most frequently, and monitoring time in 42%, including overnight recordings in more than half. Of 71 studies that evaluated UAO-interventions, the majority used polysomnography (90%), of which 61% did not specify the polysomnography technique. Reported polysomnography metrics included oxygen saturation (61%), apnea-hypopnea index (52%), carbon dioxide levels (31%), obstructive-apnea-hypopnea index (27%), and oxygen-desaturation-index (16%). Only 42 studies reported indications for UAO-intervention, with oximetry and polysomnography thresholds used equally (both 40%). In total, 34 distinct indications for treatment were identified.

CONCLUSIONS

This systematic review demonstrates a lack of standardization, interpretation and reporting of assessment and treatment indications for UAO in RS. An international, multidisciplinary consensus protocol is needed to guide clinicians on optimal UAO assessment in RS.

Treatment of infants with craniofacial malformations

Infants with craniofacial malformations (CFMs) are at increased risk of various clinical problems, including respiratory and feeding disorders, the result of which may be long-lasting. An improvement in clinical care can be achieved by prenatal diagnosis and interdisciplinary birth preparation. Feeding problems may particularly be stressful for the family and require a team approach involving nursing staff, speech therapists and nutritional specialists to anticipate, avoid and treat sequelae such as failure to thrive or recurrent aspirations. Special techniques (eg, optimisation of breast feeding, alternative feeding methods or manual orofacial therapy) may be used individually to improve feeding competence; supplemental nutrition via a nasogastric or gastrostomy tube may be temporarily necessary to ensure adequate weight gain. The high prevalence of respiratory disorders in infants with craniofacial abnormalities requires anticipation and screening to prevent growth failure and neurological deficits. Treatment of upper airway obstruction varies widely, strategies can be divided into non-surgical and surgical, and in those aimed at widening the pharyngeal space (eg, prone position, palatal plates, craniofacial surgery) and those bridging the narrow upper airway (eg, nasopharyngeal airway, modified palatal plate, pneumatic airway stenting, tracheostomy). The complex management of an infant with CFM should be performed by a multidisciplinary team to offer specialised support and care for affected families.

The Hypoplasic Mandible: What Makes it Different From the Healthy Child?

OBJECTIVE

This study aimed to analyze the morphology of the hypoplasic mandible and its evolution during the growth period to better understand how it differs from the pediatric healthy mandible.

METHOD

Three-dimensional mandibular models of hypoplasic and healthy children aged from 39 gestational weeks to 7 years old were analyzed with a morphometric method including data clustering. Morphological distinctions between pathological and healthy mandibles were highlighted. Bilateral and unilateral mandibular hypoplasia were distinguished.

RESULTS

The study sample was composed of 31 hypoplasic children and as many sex- and age-matched healthy children. Morphological distinctions between pathological and healthy mandibles were highlighted only from the first year of life. In bilateral hypoplasia, the overall mandibular dimensions were reduced while there was only a ramus asymmetry in unilateral mandibular hypoplasia (mean ± SD of the difference between the Grp03c and Grp03b subgroups: 6.80 ± 6.37 - P value = 1.64e^-3 for the height of the left ramus versus 0.18 ± 4.18 - P value = .82 for the height of the right ramus). Supervised classification trees were built to identify the pathology and discriminate unilateral from bilateral mandibular hypoplasia (prediction rates = 81% and 84%, respectively).

CONCLUSIONS

Based on a morphometric analysis, we demonstrated that mandibular hypoplasia significantly impacts the mandibular morphology only from the first year of life, with a distinction between bilateral and unilateral hypoplasia.

The role of sleep laboratory polygraphy in the evaluation of obstructive sleep apnea syndrome in Robin infants

OBJECTIVE/BACKGROUND

Currently, obstructive sleep apnea syndrome (OSAS) management in Robin sequence (RS) infants has not been standardized. Sleep laboratory polysomnography (PSG) is the gold standard for OSAS diagnosis, however, access is restricted. This study aimed to compare the respiratory indexes measured in a sleep laboratory using PSG as well as a possible alternative, polygraphy (PG).

PATIENTS/METHODS

This retrospective study was conducted between 2015 and 2017 in a tertiary hospital. PSG performed in RS infants in the sleep laboratory was analysed by a single reviewer. After sleep data removal, anonymized raw data were analysed to obtain only PG data. Respiratory indexes were compared for (i) PSG and PG and (ii) patients with or without OSAS clinical signs.

RESULTS

Among the 20 RS (median [IQR] age: 43 [25-114] days at evaluation), 70% of the patients had OSAS clinical signs but all of them had severe OSAS. The median mixed obstructive apnea hypopnea index was not significantly different between PSG and PG (27/h [18-38] versus 26/h [18-56], p = 0.43). The median obstructive apnea index was higher with no significant difference between PG and PSG (19/h [15-31] versus 7/h [4-25], p = 0.05). The median obstructive hypopnea index was significantly lower on PG than on PSG (2/h [0-3] versus 8/h [8-19], p = 0.01). No difference on PSG or PG was observed for patients with and without clinical signs of OSAS.

CONCLUSION

Although PSG remains the gold standard for OSA evaluation, a PG seems to be a useful alternative to measure OSA in RS infants because of their OSAS severity. This evaluation should be recommended in all RS infants, even in the absence of OSAS clinical signs.

CLINICAL TRIAL REGISTRATION

Not applicable.

The Tübingen palatal plate approach to Robin sequence: Summary of current evidence

Various treatments, many of them considerably invasive, are currently applied to infants with Robin sequence (RS) and accompanying upper airway obstruction (UAO). We present a narrative review of our data on the Tübingen palatal plate (TPP) which show the following: a) in a randomized trial, the TPP was superior to a sham procedure in alleviating UAO; b) children treated with the TPP in infancy showed an intellectual development within the reference range; c) prone positioning is no alternative, as it is ineffective and associated with an increased risk of sudden death; d) the TPP reduces the mixed-obstructive apnea index to near-normal values, both in isolated and most (83%) syndromic RS, e) of 443 infants (129 syndromic) treated with the TPP in our center, 23 (5%) ultimately received a tracheostomy (all with syndromic RS), f) recent data suggest that the TPP may induce mandibular catch-up growth, g) the TPP may also help to reduce respiratory complications following cleft closure in RS, and h) TPP treatment is applied by various centers around the world, although it is unclear if its effectiveness is invariably controlled by endoscopy and sleep studies, although both are necessary. Given these data from peer-reviewed studies, it may be questioned whether the "First do no harm" principle is always adhered to when subjecting RS infants to more invasive procedures such as mandibular distraction osteogenesis or tongue-lip adhesion.