International Journal of Pediatric Otorhinolaryngology 138 (2020) 110332 Contents lists available at ScienceDirect International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl 2016 ESPO Congress Management of obstructive sleep apnea in children with achondroplasia: Outcomes of surgical interventions Kayce L. Booth a, Dylan A. Levy a, David R. White a, Jeremy D. Meier b, Phayvanh P. Pecha a,* a – Department of Otolaryngology Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA b – Division of Otolaryngology Head and Neck Surgery, University of Utah School of Medicine, Salt Lake City, UT, USA ARTICLE INFO ABSTRACT Keywords: Introduction: Children with achondroplasia are predisposed to obstructive sleep apnea (OSA), however little is Achondroplasia known regarding surgical interventions and outcomes for this condition. The aim of this study was to evaluate Adenotonsillectomy the severity of OSA in children with achondroplasia and report outcomes of surgical interventions using poly- Sleep-disordered breathing somnography (PSG) parameters. Obstructive sleep apnea Methods: Retrospective chart review of children with achondroplasia with documented OSA from 2002 to 2018 Polysomnography that had pre- and post-operative PSG results. Additional data extracted included age, gender, and type of surgical interventions. The primary outcome was change in postoperative obstructive apnea hypopnea index (OAHI). Results: Twenty-two children with achondroplasia were identified that underwent formal PSG before and after – confirmed OSA. The median age was 12 months (range 4 days 15.3 years, IQR 2 years) at time of initial PSG evaluation. The majority (72.7%) of patients had severe OSA with a median preoperative OAHI of 14.25 (IQR 9.4). The most common surgical intervention was adenotonsillectomy (n = 15). Multilevel surgical intervention was required in 9 (41.0%) patients. Post-operatively, 16 (72.7%) children experienced a reduction in OAHI, of which four (18.2%) had complete OSA resolution. OAHI scores increased in six (27.3%) children. Patients with the most severe OSA at baseline had greater improvements in post-operative OAHI (P < 0.01). Neither type nor number of surgical interventions was associated with improved outcomes (P = 0.51, P = 0.89 respectively). Conclusions: Treatment of OSA in children with achondroplasia remains challenging. Although reduction of OAHI is possible, caregivers should be counseled about the likelihood of persistent OSA and the potential for multilevel airway surgery. 1. Introduction combination with hypotonia of the airway musculature, hypertrophic lymphoid tissue, and restrictive lung disease from thoracic bony de- Achondroplasia is the most common type of skeletal dysplasia, esti- formities, predispose this population to sleep-disordered breathing mated to affect more than 250,000 individuals worldwide with an (SDB) [4,5]. The most common manifestation of SDB is obstructive sleep – incidence of 1 in 10,000 30,000 births [1]. The phenotype is caused by a apnea (OSA), which is estimated to affect approximately 20% of chil- mutation in the fibroblast growth factor receptor 3 (FGFR3), a trans- dren with achondroplasia [6,7]. Central sleep apnea secondary to brain membrane protein expressed in proliferating chondrocytes responsible stem compression from foramen magnum stenosis may further compli- – for endochondral ossification 2[ ]. Achondroplasia is inherited in an cate sleeping disorders in this population [8 10]. autosomal dominant pattern or can be the result of de novo genetic Despite the complex sleep patterns for children with achondroplasia, mutations [3]. In addition to short stature secondary to rhizomelic management recommendations specific to this population have not been shortening of the limbs, patients with achondroplasia have distinct facial well reported [11]. Previous studies have focused on adenotonsillec- features characterized by macrocephaly, frontal bossing, midface hy- tomy (AT) alone as treatment for OSA in children with achondroplasia, poplasia, and a depressed nasal bridge [4]. but few have examined the effectiveness of multilevel surgical in- Previous research has established that these structural features, in terventions [7,8]. Furthermore, studies lack objective measures such as * Corresponding author. Department of Otolaryngology-Head & Neck Surgery, Medical University of South Carolina, 135 Rutledge Ave., MSC 550, Charleston, SC, 29425, USA. E-mail address: [email protected] (P.P. Pecha). https://doi.org/10.1016/j.ijporl.2020.110332 Received 16 June 2020; Received in revised form 23 August 2020; Accepted 23 August 2020 Available online 27 August 2020 0165-5876/© 2020 Elsevier B.V. All rights reserved. K.L. Booth et al. International Journal of Pediatric Otorhinolaryngology 138 (2020) 110332 obstructive apnea-hypopnea index (OAHI) from formal poly- Table 1 somnography (PSG) to assess unbiased postoperative changes. The Patient characteristics and surgical interventions. present study aims to evaluate the severity of OSA in children with N (%) achondroplasia, report our experience and outcomes with multilevel – Median age at time of PSG, months (range; IQR) 12.5 (0.13 184; 24) sleep surgeries in cases of persistent OSA, and postoperative changes on Sex PSG following surgery. Male 13 (59.1) Female 9 (40.9) 2. Materials and methods OSA severity Mild 3 (13.6) Moderate 3 (13.6) 2.1. Patient selection Severe 16 (72.7) Number of surgical interventions Following Institutional Review Board approval by the University of 1 13 (59.1) Utah and the Medical University of South Carolina, a retrospective chart 2 9 (40.9) Surgery type review was conducted on patients under the age of 18 years with In- Adenotonsillectomy only 11 ternational Classification of Diseases Ninth(ICD-9) and Tenth Edition (ICD- + Lingual tonsillectomy 1 10) diagnosis codes for chondrodystrophy (756.4 and G47.33) from + Uvulopalatopharyngoplasty 1 + 2002 to 2018. We identified children with a confirmed diagnosis of Palatopharyngoplasty 1 + Supraglottoplasty 1 achondroplasia that were evaluated for SDB. Only children who un- Adenoidectomy only 0 derwent surgical intervention and had both pre- and post-operative PSG + Tonsillectomy 3 results available were included in the final analyses. Patients that had + Lingual tonsillectomy 1 other forms of chondrodysplasias, children treated solely with positive Supraglottoplasty only 2 + pressure (either continuous or bi-level), and those without pre- and Tonsillectomy 1 postoperative sleep studies were excluded. Abbreviations: PSG, polysomnography; IQR, interquartile range; OSA, obstruc- tive sleep apnea. 2.2. Outcomes Table 2 Patient charts were reviewed for patient demographics, PSG results, Individual patient characteristics including surgery type and change in pre- and surgical interventions and follow-up duration. The OAHI, defined as the postoperative polysomnography studies. number of obstructive apnea and hypopnea events per hour of sleep, was Δ Δ Δ compared between the first pre-operative PSG obtained before any Patient Sex Age (mo) Surgery OAHI CAHI SpO2 intervention to the final PSG results following the last surgical inter- 1 M 137 AT 6.34 NA 22 vention. Oxygen saturation nadir (spO2) was defined as the lowest ox- 2 M 13 AT, DISE 1.35 1.86 6 3 M 63 AT 4.8 0.12 1 ygen level reached during the sleep study. PSG were considered normal 4 F 16 AT, DISE 8.1 0.3 22 in the case of a nadir greater than 92% and apnea-hypopnea index of less 5 F 17 AT 2.3 3.1 10.3 than 1.5 events per hour (h). Mild obstructive sleep apnea was defined as 6 M 59 AT, DISE 10.5 14 1 an OAHI >1.5 and < 5 events/h, moderate sleep apnea as an OAHI ≥5 7 F 34 AT 11.2 0 7.9 and <10 events/h, and severe sleep apnea as an OAHI ≥10 events/h 8 F 12 AT, DISE 15.1 0.6 1 9 F 0.13 AT 13.1 2.3 7 [12]. The primary outcome measure was reduction in OAHI on 10 M 11 AT, DISE 18.6 1.6 6 ≥ post-operative PSG, with a 50% reduction defined as a meaningful 11 M 11 AT, DISE 10.9 0 23 – improvement in SDB [13 15]. 12 M 4 AT, LT, DISE 0.7 12.9 30 Categorical variables were summarized by frequency and percent- 13 M 184 AT, UPP, DISE 31.9 0.6 23 14 M 15 AT, PP 7.02 4.4 14.3 age. All continuous variables were assessed for normality using the ± 15 F 3 A, T, DISE 8.7 NA 11 Shapiro-Wilk test and reported as mean standard deviation (SD) or as 16 M 6 A, T 3.0 2.5 0 the median with interquartile range (IQR: 25th and 75th) where 17 M 7 A, T 13.7 0.34 12 appropriate. Comparisons between normally distributed variables were 18 F 24 A, LT 8.1 NA 8 performed using the One Way Analysis of Variance (ANOVA) or the 19 M 31 T, SGP, DISE 5.6 0.3 3.3 < 20 M 3 SGP, DISE 31.8 4.4 7.7 Kruskal-Wallis test for non-parametric data. A P value 0.05 was 21 F 8 SGP 30.9 10.5 10 considered statistically significant and all statistical analysis was per- 22 F 11 SGP, DISE, AT 14.5 4.8 17.5 formed using SPSS 24.0 (IBM Corporation, Armonk, NY). Δ Abbreviations: , change in; OAHI, obstructive apnea-hypopnea index; CAHI, central apnea-hypopnea index; SpO2, oxygen saturation nadir; AT, adeno- 3. Results tonsillectomy; A, adenoidectomy; T, tonsillectomy; LT, lingual tonsillectomy; UPP, uvulopalatopharyngoplasty; PP, palatopharyngoplasty; DISE, drug- 3.1. Patient population induced sleep endoscopy; SGP, supraglottoplasty; M, male; F, female; NA, not available; mo, months. The combined chart review included 77 patients with achondro- plasia, of which 32 had obstructive sleep apnea diagnosed with formal had moderate OSA (13.6%) with a mean OAHI of 8.2 ± 1.6. The majority PSG. Five children were managed with positive pressure without sur- (72.7%) had severe OSA with a mean OAHI of 25.2 ± 26.2.