Does Mandibular Distraction Change the Laryngoscopy Grade in Infants With Robin Sequence?

Surgical Outcome and Treatment Trends in 1289 Infants with Micrognathia: A Multicenter Cohort

BACKGROUND

Studies of infants with micrognathia, especially Robin sequence, are limited by its rarity and both phenotypic and diagnostic variability. Most knowledge of this condition is sourced from small, single-institution samples.

METHODS

This is a cross-sectional study including infants with micrognathia admitted to 38 Children's Hospital Neonatal Consortium centers from 2010 through 2020. Predictor variables included demographic data, birth characteristics, cleft, and syndrome status. Outcome variables included length of stay, death, feeding or respiratory support, and secondary airway operations.

RESULTS

A total of 1289 infants with micrognathia had surgery to correct upper airway obstruction. Mean age and weight at operation were 34.8 ± 1.8 weeks and 3515.4 ± 42 g, respectively. A syndromic diagnosis was made in 150 (11.6%) patients, with Stickler (5.4%) and Treacher Collins (2.2%) syndromes being the most common. Operations included mandibular distraction osteogenesis (MDO) in 66.3%, tracheostomy in 25.4%, and tongue-lip adhesion (TLA) in 8.3%. Patients receiving a tracheostomy had lower birthweight, head circumference, gestational age, and Apgar scores. Patients undergoing MDO were less likely to need a second airway operation compared with patients undergoing TLA (3.5% versus 17.8%; P < 0.001). The proportion of infants feeding exclusively orally at hospital discharge differed significantly, from most to least: MDO, TLA, and tracheostomy. Hospital length of stay was not statistically different for patients who had MDO or TLA, but was longer for those with primary tracheostomy. The mortality rate was low for all operations (0.5%).

CONCLUSIONS

In this surgical patient cohort, MDO was associated with shorter hospital stay, improved oral feeding, and lower rates of secondary airway operations. Prospective multicenter studies are necessary to support these conclusions.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Pharyngeal Airway Changes Following Mandibular Distraction Osteogenesis as Evaluated with Laryngoscopy

PURPOSE

Mandibular distraction osteogenesis (MDO) may improve airway grade in patients with Robin Sequence (RS), but little is known about the response of the oropharyngeal airway to the distraction process in cases of tongue base obstruction (TBAO). This study used drug-induced sleep endoscopy (DISE) to evaluate the impact of MDO on the oropharynx.

METHODS

RS patients with severe obstructive sleep apnea (OSA) were prospectively enrolled, and underwent DISE prior to MDO, and at the time of distractor removal. Laryngoscopy views, glossoptosis degree, polysomnography (PSG) results, oxygen saturations and airway measurements were compared pre- and post-MDO.

RESULTS

Twenty patients met inclusion criteria. At the time of distractor placement, a grade II laryngoscopic view was most frequently observed (63%), and one patient (5%) had a grade I view. Median obstructive apnea hypopnea index (OAHI) improved after MDO (49.1 [30.2-74.0] to 9.1, [3.9-18.0], p ≤ .001). Median oxygen saturation nadir also improved (preoperative 69% [60-76] to 85% [82-91], p ≤ .001). At distractor removal, mean laryngoscopic view improved (p ≤ .002) with no views that were grade 3 or higher. Median intraoperative oropharyngeal width improved, (3.1 mm [2.8-4.4] to 6.0 mm [4.4-6.8], p ≤ .021), as did median cephalometric anteroposterior oropharyngeal width (3.5 mm [2.7-4.1] to 6.3 mm [5.6-8.2], p ≤ .002).

CONCLUSION

Following MDO, RS patients with TBAO have an approximate doubling of oropharyngeal width and an improvement in laryngoscopic grade. These findings likely contribute to improved oxygenation, OAHI and ease of intubation.

Is a Difficult Airway Team Needed for Intubation at Removal of Mandibular Distraction Devices for Infants With Robin Sequence?

PURPOSE

Difficult airway teams (DATs) are typically present to assist intubation at the initial mandibular distraction osteogenesis (MDO) operation for infants with Robin sequence (RS). In some institutions, the RS diagnosis triggers a "difficult airway" label for the infant, requiring DAT presence for future operations. By the time of distractor removal, however, breathing and airway anatomy are significantly improved. The objective of this study was to measure intubation difficulty and perioperative respiratory complications at MDO device removal as a proxy for the necessity for coordination with a DAT.

METHODS

This is a retrospective study including infants with RS from 2013 to 2021 who had MDO during infancy. Patients were excluded if they had a tracheostomy or MDO device failure. Predictor variables included demographic data, comorbidities, and apnea-hypopnea indices (AHIs) from pre- and immediate post-MDO polysomnograms. The primary outcome measures were number of intubation attempts, laryngoscopy grade, and perioperative respiratory events at the distractor removal operation. Descriptive statistics were computed including Fisher's exact, paired sample t-tests, and Wilcoxon rank tests, and P < .05 was considered statistically significant.

RESULTS

The sample included 47 (60% male) patients with a mean age at MDO of 12.0 ± 15.7 weeks. Significant improvement in AHI was seen after MDO (pre-MDO: 26.8 ± 18.4 events/hour; post-MDO 2.78 ± 2.66 events/hour; P < .001). Average number of intubation attempts decreased from 2.09 ± 1.36 to 1.30 ± 0.75 (P < .001) and the most common post-MDO laryngoscopy grade was 1 (69%). There were no intraoperative and 2 (4%) minor postoperative respiratory events, both in patients with repaired congenital cardiac disease and not related to traumatic intubation.

CONCLUSION

Neither difficult intubations nor perioperative respiratory events associated with intubation trauma were seen at distractor removal, suggesting that specialty airway assistance is not routinely needed after successful MDO. DAT presence should be determined on a case-by-case basis based on specific patient risk factors.

Early weight gain in infants with Robin sequence after mandibular distraction

This retrospective cohort study was performed to assess weight gain in infants with Robin sequence (RS) treated by mandibular distraction osteogenesis (MDO). The primary outcome variable was average daily weight gain for the following time periods: (1) birth to MDO (T1), (2) MDO to distractor removal (T2), (3) distractor removal to 6 months later (T3), and (4) 6 months to 12 months following distractor removal (T4). Published growth curves were used for comparison. Differences were assessed using the Wilcoxon matched-pairs signed rank test. Twenty-two infants were included in the study. During T1, the infants had 9.47 ± 12.61 g/day less weight gain than expected (P = 0.001). However, for T2, T3, and T4, the infants demonstrated 3.48 ± 6.17 g/day (P = 0.028), 2.19 ± 4.47 g/day (P = 0.030), and 1.83 ± 3.25 g/day (P = 0.028) more weight gain than expected. Feeding tube use resulted in improved weight gain during T1 (P < 0.001), but was associated with poorer weight gain in T3 (P = 0.003) and T4 (P = 0.001). In conclusion, infants with RS treated by MDO demonstrated poorer weight gain relative to their peers between birth and the MDO operation. However, from the MDO procedure to 12 months post-distractor removal, infants who had MDO showed faster weight gain than their age-matched peers.

Incidence of mandibular distraction osteogenesis in Stickler Syndrome: Variation due to COL2A1 and COL11A1

OBJECTIVE

To determine whether the two most common genetic mutations seen in Stickler Syndrome (SS) (COL2A1 and COL11A1) affect the incidence of mandibular distraction osteogenesis (MDO) and what impact Robin sequence (RS) has on diagnosis. SS is an autosomal dominant connective tissue disorder characterized by almost complete penetrance. COL2A1 and COL11A1 are the two most common mutations seen in SS patients. SS often presents at birth with RS, which is characterized by the triad of micrognathia, glossoptosis, and tongue-based airway obstruction. MDO is one surgical intervention that has been shown to be successful in relieving tongue base obstruction and is the surgical intervention of choice for this condition.

METHODS

A retrospective chart review was performed on all patients with a diagnosis of SS at a tertiary pediatric hospital between January 1, 2003 and December 31, 2018. The included patient charts were reviewed for demographic information, SS mutation, and history of MDO. Forty-six patients had a clinical diagnosis of SS. Of those, 31 met inclusion criteria which involved having a molecular diagnosis of SS and sufficient follow up information to determine if MDO was indicated or performed. Twenty-two of the 31 included patients had a diagnosis of RS (70.96%). Thirteen of the 31 patients (41.94%) included in this study required MDO as a neonate.

RESULTS

Fifty-percent of patients with type I (COL2A1) required MDO as a neonate compared to only 31% of patients with type II (COL11A1), though the difference between the two groups was not statistically significant.

CONCLUSION

The findings of this study suggest that patients with type I mutation may have a higher incidence of MDO than patients with a type II mutation, though further research with larger sample sizes is needed. This information is helpful in counseling those with SS or family history of SS about what they can expect related to RS and need for MDO based on genetic findings.

LEVEL OF EVIDENCE

3.

Laryngoscopy Grade Improvement and Difficult Airway Resolution in Infants With Robin Sequence Undergoing Mandibular Distraction Osteogenesis: A Multi-Institutional Study

OBJECTIVE

Mandibular distraction osteogenesis (MDO) aims to relieve tongue-based airway obstruction in Robin Sequence (RS). We investigated direct laryngoscopy grade (DLG) improvement and difficult airway (DA) resolution following MDO.

DESIGN

Retrospective cohort analysis.

SETTING

Three tertiary care institutions.

PATIENTS

Sixty-four infants with RS who underwent a single MDO procedure in their first year of life were identified from January 2010 to January 2019.

MAIN OUTCOME MEASURES

The primary outcome was DLG pre- and post-MDO. Secondary outcomes included DA designation, pre- and post-MDO polysomnographic assessment for obstructive sleep apnea (OSA), length of stay, need for gastrostomy, and major/minor adverse events.

RESULTS

Median DLG improved from II pre-MDO to I at the time of distractor removal (n = 43, P < .001). No significant change was seen in patients with a third recorded time point (eg, palatoplasty; n = 78, P = .52). Twenty-six (47%) of 55 patients were designated as DA pre-MDO, and 10 (18%) of 55 patients retained the label post-MDO (P < .01). Five (50%) of these 10 patients appeared to be inappropriately retained. Median obstructive apnea-hypopnea index improved from 38.6 (range 31.2-62.8) pre-MDO to 2.9 (range 1-3.9) post-MDO (n = 12; P = .002).

CONCLUSION

Mandibular distraction osteogenesis allowed for DLG improvement that was stably maintained as well as functional improvement in OSA, with minimal morbidity. Difficult airway designation persisted in the electronic record of some infants despite clinical resolution.

Is Intensive Care Unit Admission Necessary After Removal of Mandibular Distraction Devices in Infants With Robin Sequence?

OBJECTIVE

Intensive care unit (ICU) care is routinely required after the operation to initiate mandibular distraction osteogenesis (MDO) in infants with Robin sequence (RS). Many patients are also managed in the ICU after subsequent device removal. It is uncertain if ICU care, which is expensive and limited, is necessary after this second operation. The objective of this study was to evaluate the incidence of respiratory events following device removal. We hypothesized that respiratory events would be infrequent and non-ICU inpatient monitoring would be adequate.

DESIGN

This is a retrospective study of patients with RS from 2013 to 2018.

PATIENTS

Patients were included if they had MDO and distractor removal during the first year of life. Patients were excluded if they had a tracheostomy or remained intubated after distractor removal.

MAIN OUTCOME MEASURE

Postoperative respiratory events.

RESULTS

Twenty-five (60% male) patients were included. Mean age and weight at distractor removal were 142 ± 79 days of life and 5.5 ± 1.1 kg. Mean apnea-hypopnea index after completion of distraction was 1.1 ± 1.5 events/hour. Two (8%) patients experienced postoperative respiratory events that required intervention. In 1 (4% of sample) of these, the event was deemed to have benefited from ICU-level care. Two variables were significantly associated with these events: congenital heart disease (P = .020) and concomitant procedure performed during the same operation (P = .020).

CONCLUSIONS

Intensive care unit-level care is rarely needed after distractor removal in infants with RS. Intensive care unit admission should be considered in patients with congenital cardiac disease and when having multiple operations during the same anesthetic.

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.

Longer upper airway lengths in Robin Sequence: A case-control study using computed tomography

BACKGROUND

Direct laryngoscopy and intubation are often difficult in children with Robin Sequence. Previous research characterizing anatomic airway differences has focused on parameters influencing airway patency; there is a paucity of data pertaining to intubation trajectories and depth. Such information could impact airway management approaches and decrease the incidence of endotracheal tube malpositioning.

AIM

The study goal was to examine whether longitudinal airway parameters pertaining to intubation are different in children with Robin Sequence compared with age-matched controls.

METHOD

This case-control study compared patients with RS <4 years of age who had computed tomography scans of the head and neck to age- and sex-matched controls. Measurements were made of the nasopharynx, oropharynx, hypopharynx, tongue, hyoid, and the front teeth to vocal cord, nares to vocal cord, and nasion-basion distances. Statistical analysis was performed using multiple ANCOVA models with the categorical predictor of Robin Sequence vs control and potential covariates including subject height/length, weight, and age.

RESULTS

Thirty-three patients with Robin Sequence and 33 control subjects were included. After controlling for subject height/length, mean front teeth to vocal cord distance was 1.2 cm longer (95% CI: 0.9 to 1.6 cm, P < .001) and mean nares to vocal cord distance was 0.8 cm longer (95% CI: 0.4 to 1.2 cm, P < .001) in patients with Robin Sequence than in controls. The tongue was positioned on average 0.5 cm higher (95% CI: 0.3 to 0.8, P < .001) and 0.9 cm more posterior (95% CI: 0.6 to 1.0 cm, P < .001) in cases than in controls. Moreover, in patients with Robin Sequence, the hyoid was positioned on average 0.5 cm more inferiorly (95% CI: 0.2 to 0.8 cm, P < .001) and 0.2 cm more posteriorly (95% CI: 0.1 to 0.4 cm, P < .01) than controls.

CONCLUSION

In patients with Robin Sequence under 4 years of age, the mean front teeth to vocal cord distance was found to be 1.2 cm longer while the mean nares to vocal cord distance was found to be 0.8 cm longer controlling for subject length. Clinicians should account for these differences when selecting and placing endotracheal tubes, particularly those with a preformed bend.