Predictors of Failure in Infant Mandibular Distraction Osteogenesis

Mid-term effect of mandibular distraction osteogenesis on clinical and polysomnography findings of patients with Robin sequence

The study aimed to evaluate the mid-term effect of MDO in children with Robin sequence (RS). In this case series, 13 patients with RS who underwent MDO were followed up for more than 5 years. Data were collected using clinical history and physical examination. Polysomnography was performed and endoscopic evaluations of the airway was performed if patients still presented obstructive signs of upper airways and/or dysphagia. The patients' clinical signs improved in the mid-term after versus before MDO (inspiratory noise, 92,3% vs 30,8%; apnea, 84,6% vs 7,7%; cyanosis, 76,9% vs 0%; desaturations, 69,2% vs 0%; and suprasternal/intercostal retractions, 61,5% vs 0%; p < 0.05). Statistically significant improvement was noted in the following polysomnographic parameters evaluated in the pre and postoperative mid-term: apnea-hypopnea index, total sleep time and desaturation index (p < 0.05). Within the limitations of the study it seems that MDO is an effective surgical option for children with RS, not only in the short term as previously demonstrated, but also in the mid-term.

Prevalence and Management of Laryngomalacia in Patients With Pierre Robin Sequence

OBJECTIVE

To characterize the prevalence and presentation of laryngomalacia and efficacy of supraglottoplasty (SGP) in a cohort of patients with Pierre Robin Sequence (PRS).

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care children's hospital.

PATIENTS, PARTICIPANTS

Consecutive patients with PRS born between January 2010 and June 2018.

MAIN OUTCOME MEASURES

Chart review included demographics, comorbid airway obstruction including laryngomalacia, timing of surgical interventions, clinical symptoms, sleep study data, and modified barium swallow study data.

126 patients with PRS were included; 54% had an associated syndrome, 64% had an overt cleft palate, and 22% had a submucous cleft palate. 64/126 were noted to have laryngomalacia (51%). Patients with concurrent PRS and laryngomalacia were significantly more likely to have submucous cleft palate (P = .005) and present with aspiration with cough (P = .01) compared to patients with PRS without laryngomalacia. Patients with concurrent laryngomalacia and PRS showed a significant decrease in apnea-hypopnea index (AHI) and obstructive AHI (OAHI) after mandibular distraction, with a median AHI and OAHI improvement of 22.3 (P = .001) and 19.8 (P = .002), respectively. Patients who underwent only SGP did not show significant improvement in these parameters (P = .112 for AHI, P = .064 for OAHI).

The prevalence of laryngomalacia in our PRS cohort was 51%. Patients with PRS and laryngomalacia are more likely to present with overt aspiration compared to patients with PRS without laryngomalacia. These data support that laryngomalacia does not appear to be a contraindication to pursuing MDO.

Safety of Mandibular Osteotomies in Infants with Pierre Robin Sequence: Computer-Aided Modeling to Characterize the Risks of Various Techniques

BACKGROUND

Mandibular distraction osteogenesis is effective for the correction of severe tongue-based airway obstruction in infants with Pierre Robin sequence. Involved osteotomies may damage developing tooth buds and/or the inferior alveolar nerve. The authors evaluated the theoretical safety of various osteotomy techniques to better define infantile mandibular anatomy using computer-aided modeling.

METHODS

Seven mandibular osteotomy techniques (oblique, inverted-L, multiangular, walking stick, high oblique, vertical/high inverted-L, and horizontal) were simulated using computed tomography studies from infants with Pierre Robin sequence and without other associated conditions. Software was used to manually segment the mandibular bone, inferior alveolar nerve, and tooth buds.

RESULTS

Sixty-five computed tomography scans were included, yielding 130 hemimandibles. The horizontal osteotomy pattern had significantly lower theoretical risk of tooth bud (p < 0.001) and inferior alveolar nerve involvement (p < 0.001) than all other patterns. Osteotomies with high vertical components (i.e., vertical, walking stick, and multiangular) had lower theoretical tooth bud involvement than the more proximal oblique and inverted-L osteotomies (p < 0.001). Average lingula location was measured at a point 65 percent of the mandibular width from anterior mandibular border and 63 percent of the mandibular height from the inferior mandibular border.

CONCLUSIONS

Surgical planning with computed tomography scans can help evaluate an infant's mandibular anatomy to select an osteotomy that reduces morbidity risks. Regardless of technique, tooth buds and the inferior alveolar nerve are often included in osteotomies. The lingula location in this study demonstrates a position more superior and posterior than that previously described.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Timing and Duration of Facial Nerve Dysfunction After Mandibular Distraction Osteogenesis for Robin Sequence

Objective

Collect data from craniofacial surgeons to analyze mandibular distraction osteogenesis (MDO) protocols, and facial nerve dysfunction (FND) to characterize this common, but poorly documented complication after MDO in infants with Robin Sequence (RS).

Design, Setting, and Participants

A 16-question anonymous survey designed through REDCap was digitally distributed to members of the American Cleft Palate-Craniofacial Association and International Society of Craniofacial Surgery (ISCFS).

Main Outcome Measure(s)

Demographic information, MDO perioperative variables, surgeon experience with FND after MDO for patients with RS, and the timing and duration of FND were analyzed.

Results

Eighty-four responses were collected, with 80 included for analysis. Almost two-thirds of respondent surgeons reported FND as a complication of MDO in patients with RS (51, 63.8%); 58.8% (n   =   47) transient FND and 5% (n   =   4) with permanent facial nerve palsy only. Both transient and permanent FND was documented by 13 (16.3%) respondents. Among respondents, FND was observed immediately following initial device placement/osteotomies in 45.1%, during distraction in 45.1%, during consolidation in 19.6%, and following device removal in 43.1%. Twenty-five of these respondent surgeons reported resolution of FND between 1 and 3 months (53.2%, n   =   25).

Conclusions

FND after MDO in patients with RS was noted by most respondents in this survey study. While most surgeons noted temporary FND, one-fifth reported long-term dysfunction. FND was documented most commonly following device placement/osteotomies or during active distraction. Further research should seek to establish risk factors associated with FND and identify surgical and perioperative prevention strategies

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.

Mandibular Distraction Osteogenesis for Tongue-Based Airway Obstruction Without Micrognathia

PURPOSE

Mandibular distraction osteogenesis (MDO) effectively treats tongue-based airway obstruction (TBAO) in micrognathic patients with Robin Sequence. Mandibular distraction osteogenesis may also address TBAO in certain nonmicrognathic patients who have severe obstructive apnea, although there is no current literature to guide MDO use in these atypical patients. This study describes outcomes of MDO in a series of patients with TBAO without micrognathia.

METHODS

Patients who underwent MDO for TBAO from 2013-20 were reviewed, and patients with micrognathia were excluded. Study subjects received baseline/follow up polysomnography. Polysomnography variables, including Obstructive Apnea Hypopnea Index, oxyhemoglobin saturation nadir (SpO2 nadir), percent sleep time end tidal CO2 greater than 50 mm Hg (%ETCO2 > 50), and respiratory-related arousals were compared before and after MDO. Demographics, syndromic/cleft palate status, airway anomalies, respiratory support, and feeding outcomes were collected.

RESULTS

One hundred and twenty-four patients underwent MDO during this study period; 5 were nonmicrognathic and included in analysis. Sixty percent (n = 3) of the cohort was syndromic: 1 patient each had Trisomy 9, Beckwith Wiedemann syndrome, and duplicated pituitary gland plus syndrome. Forty percent (n = 2) of patients had a cleft palate, 60% (n = 3) had laryngomalacia, and 40% had tracheomalacia. Median (range) age at MDO was 53 days (47-167 days), and median length of distraction was 16 mm (14-20 mm). After MDO, median Obstructive Apnea Hypopnea Index decreased from x̃ = 60.7/h (11.6-109.4) to x̃ = 5.3/h (3.5-19.3) (P = 0.034). SpO2 nadir increased (69% [58-74] to 85% [80-88], P = 0.011), and median %ETCO2 > 50 mm Hg decreased (5.8% [5.2-30.1] to 0.0% [0.0-1.3], P ≤ 0.043). Continuous positive airway pressure was used by all patients immediately after MDO, and at 6 months postoperatively, 1 patient remained on continuous positive airway pressure and 1 patient required supplemental oxygen. At last follow up, no patients had significant residual airway obstruction or required a tracheostomy.

CONCLUSIONS

Mandibular distraction osteogenesis can effectively treat severe TBAO in some patients without micrognathia that would otherwise be candidates for tracheostomy. When used in select patients, MDO significantly improves obstructive sleep apnea and reduces need for ventilatory support, although feeding support is still needed in most patients at 6 months. Further study in a larger cohort will help identify appropriate candidates for MDO and characterize outcomes of unique patient populations.

The Surgical Treatment of Robin Sequence: Neonatal Mandibular Distraction Osteogenesis in the Unfavorable Patient

INTRODUCTION

Neonates with severe Pierre Robin sequence (PRS) can be treated by mandibular distraction osteogenesis (MDO), tongue-lip adhesion, or tracheostomy; however, there is an active debate regarding the indications of MDO in this patient population. Published algorithms identify tracheomalacia, bronchomalacia, laryngomalacia, hypotonic syndromes, and central sleep apnea as contraindications for MDO and indications for tracheostomy, but these comorbidities may exist along a spectrum of severity. The authors propose that appropriately selected neonates with PRS who concurrently express 1 or more of these traditional contraindications may be successfully treated with MDO.

METHODS

The authors performed a 5-year retrospective chart review of all neonates who underwent MDO for treatment of severe PRS. All patients expressed a comorbidity previously identified as an indication for tracheostomy. Pre- and postoperative characteristics were recorded. Apnea/hypopnea index (AHI) before and after MDO were compared using 2-tailed repeated measures t-test.

RESULTS

The authors identified 12 patients with severe PRS and conditions associated with contraindications to MDO: 9 (75.0%) patients had laryngomalacia, 6 (50.0%) patients had tracheomalacia, 2 (16.6%) patients had bronchomalacia, 1 (8.3%) patient had central sleep apnea, and 3 (25.0%) patients had hypotonia. Five (41.7%) patients underwent concurrent gastrostomy tube placement due to feeding insufficiency. Average birthweight was 3.0 kg. Average pre-op AHI was 34.8. Average post-op AHI was 7.3. All patients successfully underwent MDO with avoidance of tracheostomy.

CONCLUSIONS

By employing an interdisciplinary evaluation of patient candidacy, MDO can safely and effectively treat upper airway obstruction and avoid tracheostomy in higher-risk neonatal patients with traditional indications for tracheostomy.

Early Adverse Events Following Pediatric Mandibular Advancement: Analysis of the ACS NSQIP-Pediatric Database

OBJECTIVE

This study aims to assess early adverse events and patient factors associated with complications following mandible distraction osteogenesis (MDO).

MATERIALS AND METHODS

The American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-Pediatric) database, years 2012 to 2019, was queried for patients undergoing mandible advancement via relevant Current Procedural Terminology and postoperative diagnosis codes. Thirty-day adverse events and co-morbidities are assessed.

RESULTS

A total of 208 patients were identified with 17.3% (n = 36) experiencing an adverse event, reoperation (n = 14), and readmission (n = 11) being most common. Patients < 365 days old at the time of operation were more likely to experience an adverse event (26.1% vs 10.8%; P = .005). However, among patients less than 1 year of age, differences in the complication rates between patients  ≤ 28 days and >28 days (30.2% vs 22.2%; P = .47) and those weighing  ≤ 4 kg and >4 kg (31.7% vs 11.5%; P = .063) did not reach statistical significance.

CONCLUSIONS

Adverse events following mandible advancement are relatively common, though often minor. In our analysis of the NSQIP-Pediatric database, neonatal age ( ≤ 28 days) or weight  ≤ 4 kg did not result in a statistically significant increase in complications among patients less than 1 year of age. Providers should consider early intervention in patients who may benefit from MDO.

Robin Sequence: Neonatal Mandibular Distraction

Pierre Robin sequence is defined by the clinical triad: mandibular hypoplasia, glossoptosis, and airway obstruction. Mandibular distraction osteogenesis (MDO) is a standard treatment of Robin sequence associated with severe airway obstruction and is the only intervention that directly corrects the underlying anatomic pathologic condition. Compared with tongue-lip adhesion, MDO has demonstrated more success in treating airway obstruction in infants with Pierre Robin sequence, including patients with syndromic diagnoses and concomitant anomalies. This article provides a current, comprehensive review of neonatal mandibular distraction and offers treatment guidelines based on a combined surgical experience of more than 400 patients.

Craniofacial Development: Neural Crest in Molecular Embryology

Craniofacial development, one of the most complex sequences of developmental events in embryology, features a uniquely transient, pluripotent stem cell-like population known as the neural crest (NC). Neural crest cells (NCCs) originate from the dorsal aspect of the neural tube and migrate along pre-determined routes into the developing branchial arches and frontonasal plate. The exceptional rates of proliferation and migration of NCCs enable their diverse contribution to a wide variety of craniofacial structures. Subsequent differentiation of these cells gives rise to cartilage, bones, and a number of mesenchymally-derived tissues. Deficiencies in any stage of differentiation can result in facial clefts and abnormalities associated with craniofacial syndromes. A small number of conserved signaling pathways are involved in controlling NC differentiation and craniofacial development. They are used in a reiterated fashion to help define precise temporospatial cell and tissue formation. Although many aspects of their cellular and molecular control have yet to be described, it is clear that together they form intricately integrated signaling networks required for spatial orientation and developmental stability and plasticity, which are hallmarks of craniofacial development. Mutations that affect the functions of these signaling pathways are often directly or indirectly identified in congenital syndromes. Clinical applications of NC-derived mesenchymal stem/progenitor cells, persistent into adulthood, hold great promise for tissue repair and regeneration. Realization of NCC potential for regenerative therapies motivates understanding of the intricacies of cell communication and differentiation that underlie the complexities of NC-derived tissues.

Short-term condylar and glenoid fossa changes in infants with Pierre Robin sequence undergoing mandibular distraction osteogenesis

The purpose was to evaluate short-term changes in condylar and glenoid fossa morphology in infants with Pierre Robin sequence (PRS) undergoing early (age <4 months) mandibular distraction osteogenesis (MDO) for the management of severe airway obstruction. Computed tomography data from infants with PRS who had MDO were compared to those of age-matched control infants without facial skeletal dysmorphology. Surface/volume, linear, and angular measurements of the condyle and glenoid fossa were obtained and compared between infants with PRS and controls. Eleven infants with PRS met the inclusion criteria. There were five female and six male subjects with a mean age at the time of MDO of 41±32 days. Prior to MDO, PRS mandibles had a smaller condylar articulating surface area and volume than age-matched control mandibles, with a more laterally positioned condylar axis (P≤0.05). Following MDO, there were significant increases in condylar articulating surface area and volume, approaching those of normal controls, with further lateral translation of the condylar axis (P≤0.05). Condyle and glenoid fossa morphology is largely normalized following early MDO in infants with PRS. The condylar axis translates laterally as a result of MDO; this change is not observed with mandibular growth in infants without PRS.

[The significance of evaluation of sleep respiration in infants with Pierre Robin sequence]

Objective:This study aimed to evaluate the sleep disorders of infants with Pierre Robin sequence by PSG, and to understand the sleep breathing characteristics of them. Method:Seventeen patients with Pierre Robin sequence underwent polysomnography lasting over 7 hours. Sleep apnea and oxygen index was recorded and analyzed. Result:14（82.35%） patients with Pierre Robin sequence presented with apnea, hypopnea and hypoxemia with varying degree. The apnea-hypopnea index（12.39±9.86） and lowest arterial oxygen saturation（84.12±8.12） %were not significantly different between sexes. However, age showed a negative impact with apnea-hypopnea index, which was worse in younger infants. Conclusion:Most patients with the Pierre Robin sequence have sleep apnea and hypoxemia, and appropriate management should be implemented in an early age. Polysomnography can provide objective analysis of the treatment.

Family Experience With Pierre Robin Sequence: A Qualitative Study

OBJECTIVE

To identify concepts and constructs important to parents of children with Pierre Robin Sequence (PRS).

DESIGN

Qualitative study.

SETTING

All children received some care at a tertiary hospital with additional care at outside facilities. Interviews were conducted in nonclinical locations, including remote locations.

PARTICIPANTS

Parents of children <5 years old with a diagnosis of PRS. Prior treatments included observation, positioning, nasal trumpet, mandibular distraction osteogenesis, tracheostomy, and gastrostomy.

INTERVENTION

Semi-structured interviews with individuals (4) and with groups (focus groups, 4) were conducted using open-ended questions and non-leading prompts. Transcripts were analyzed with iterative open and axial coding. Concepts and constructs were identified and refined into codes and central themes. Interviews were conducted until thematic saturation was achieved.

RESULTS

Sixteen parents were interviewed. Their experiences were coded into 5 main themes, which can be summarized as: (1) child's symptoms/well-being, (2) parents' grief/isolation, (3) family stress, (4) relationships with providers, and (5) psychological and technical growth. Difficulty with feeding, weight gain, and breathing problems were core physical issues described by participants with associated intense fear. Participants described frustration from not only lack of care coordination, slow diagnoses, and poor communication but also gratitude for providers who served as advocates. Participants described gradual development of knowledge/competencies.

CONCLUSIONS

Families of children with PRS have experiences that profoundly affect their lives. Child's physical symptoms/well-being and parents' psychosocial well-being provide content for a future PRS-specific quality-of-life instrument. Concepts that emerged also provide a framework to improve parents' experience and enhance their children's quality of care.

Optimal duration of mechanical ventilation and influencing factors following mandibular distraction osteogenesis in infants with Pierre Robin sequence

Mandibular distraction osteogenesis (MDO) is an effective treatment for tongue-based airway obstruction in infants with severe Pierre Robin sequence (PRS). Most infants receiving MDO require postoperative mechanical ventilation (MV) to assist breathing. Optimal MV time for each individual patient and factors influencing the time must be identified to guide clinical decision-making.A retrospective analysis was performed on 75 infants with PRS receiving MDO from November 2016 to August 2018. Twenty-six were females and 47 were males. Data extracted from the hospital information system included sex, age, weight, history of preterm labor, preoperative pulmonary infection, laryngomalacia/tracheomalacia, laryngoscope exposure classification, anesthesia duration, operation duration, postoperative treatment site, situation of distraction, postoperative complications and MV duration. Statistical analyses were conducted to investigate the potential associations of these factors with MV time.Seventy-three PRS syndrome patients received anesthesia for MDO device procedures were considered eligible for study. Patient sex, history of preterm labor, preoperative pulmonary infection, laryngomalacia/tracheomalacia, laryngoscopy exposure difficulty, postoperative treatment site (neonatal or pediatric intensive care unit), ventilator-associated pneumonia, age, weight, anesthesia duration, and operation duration had no significant influence on postsurgical MV time (P > .05). Amount of distraction at the time of extubation had statistically significant influence on postoperative MV time (P < .05). In addition, scatter plots revealed linear relationships between postoperative MV time and amount of distraction at extubation.According to this analysis, amount of distraction was associated with MV time following MDO for severe PRS and roughly 6 days post-surgery is a generally safe extubation time.