The effects of clinical factors on airway outcomes of mandibular distraction osteogenesis in children with Pierre Robin sequence

Mandibular Distraction in Patients With Pierre Robin Sequence: A Multisurgeon Experience

OBJECTIVE

Mandibular distraction osteogenesis (MDO) is rapidly becoming a standard of care for management of patients with severe Pierre Robin sequence. The tongue is brought forward to alleviate airway obstruction. This study will look at an institutional, multisurgeon experience with MDO over 10 years.

DESIGN

A retrospective chart review was conducted.

SETTING

All patients who underwent MDO at the authors' institution from 2012 to 2022 were included. Three craniofacial surgeons performed all interventions.

PATIENTS

Demographics, preoperative and postoperative respiratory and feeding status, and distraction data were collected for 27 patients meeting inclusion criteria.

MAIN OUTCOME MEASURES

Primary outcomes were avoidance of a gastrostomy tube, avoidance of a tracheostomy, discharge from hospital on room air, and complications. A significance value of 0.05 was utilized.

RESULTS

The average age at MDO was 135 days, mean activation phase was 13.6 days, mean distraction length was 14.9 mm, and mean consolidation phase was 64.2 days. A longer activation phase was associated with discharge with a gastrostomy tube and a shorter activation phase was associated with discharge on full oral feeds. The ability to discharge on room air was associated with a shorter latency phase, shorter activation phase, and decreased distance of distraction.

CONCLUSIONS

The goal of MDO is to achieve full oral feeds with no respiratory support. Several different latency periods were used in this study, and a short latency period was demonstrated to be safe.

[The condition of the mandibular bone regenerate in the remote period after compression-distraction osteosynthesis]

THE STUDY OBJECTIVE

Was to assess the qualitative and quantitative characteristics of the bone regenerate in the distant period following compression-distraction osteosynthesis.

MATERIAL AND METHODS

Results from the treatment of 30 patients with mandibular micrognathia, were analyzed. Compression-distraction osteosynthesis (CDO) was performed in the area of the mandibular angle. The patients were divided into two groups: group 1 consisted of 16 patients with congenital micrognathia, and group 2 comprised 14 patients with acquired (post-traumatic) micrognathia. For the assessment of qualitative and quantitative characteristics of the bone regenerate, three-dimensional modeling, morphometric measurements of the regenerate, and evaluation of bone density using the Hounsfield scale through multislice computed tomography were used.

RESULTS AND DISCUSSION

The study of the bone regenerate parameters in group 1 yielded the following results: the length of the bone regenerate decreased by 2.14%; the thickness of the bone regenerate increased by 8.75%; the height of the bone regenerate increased by 1.75%. In group 2, the values were 3.14; 3 and 3.76%, correspondingly. In patients of group 1, the length of the mandibular branch increased by 4%; the length of the mandibular body increased by 5.35%. In group 2, the length of the mandibular branch increased by 1.94%; the length of the mandibular body increased by 2.2%. The density of the cortical bone of the regenerate corresponds to the density of the intact bone, while the density of the cancellous bone is slightly reduced.

CONCLUSION

Qualitative and quantitative characteristics of bone regenerate in the long-term period after CDO correspond to the parameters of intact bone. CDO can be considered not only as a preparatory stage for reconstructive operations after the growth of the skull bones has completed, but also as an independent stage of treatment.

Complications of Mandibular Distraction Osteogenesis in Infants with Isolated Robin Sequence

Mandibular Distraction Osteogenesis (MDO) is now the preferred procedure to alleviate airway obstruction in infants with severe Robin Sequence (RS). However, there have been very few studies investigating complications related to MDO surgery performed on patients affected by isolated RS. In this study, age at distraction, weight at distraction, preoperative intubation, repeat MDO and complications associated with MDO were included as variables. Minor, moderate and major problems were evaluated and recorded as surgical site infections (SSI), injuries to the facial nerve, self-extinction hypertrophic scars, temporomandibular joint ankylosis, device failures, early ossification and fibrous non-union. One hundred and fifty one patients with isolated RS were included. At distraction, the mean age was 72 days (12-540 days) and the mean weight was 4.05 kg (2.4-12.2 kg). Only one patient needed tracheostomy after MDO, and none required further distraction. Ultimately, the complication rate was 15.23%, and there was a total of 7.95% minor, 9.27% moderate and 0% major complications. Minor incidents included surgical site infection (SSI) managed with antibiotics taken orally (n = 8), neuropraxia in the VII cranial nerve (CN) (n = 1), and hypertrophic scarring (n = 3). Incidents reported as moderate were SSIs managed with intravenous antibiotics (n = 9), incision and drainage (n = 3) and self-extubation (n = 2). There was no case of TMJ ankylosis. There were no cases of early or premature ossification, fibrous non-union and device fracture. In conclusion, MDO is an effective and appropriate management technique for infants with isolated RS and severe airway obstruction. Infections at the surgery site accounted for the vast majority of the complications. Further investigations may be needed to determine the long-term consequences of MDO.

The management of upper airway obstruction in Pierre Robin Sequence

Pierre Robin Sequence (PRS) is defined by a constellation of characteristics including micrognathia, glossoptosis and airway obstruction. PRS can occur in isolation or can be associated with syndromes and another anomalies. Airway obstruction and feeding difficulties are the major presenting issues, and the severity of the condition ranges from mild, with minimal to no symptoms, to severe, with overt obstruction resulting in apnoeas, severe respiratory distress and cyanosis. The presence of airway obstruction can result in obstructive sleep apnoea and abnormalities in gas exchange, as well as exacerbation of already present feeding difficulties and failure to thrive, secondary to mismatch of caloric intake to energy usage associated with increased effort of breathing. Management of airway obstruction for infants with PRS varies between centres. This paper explores the surgical and non-surgical management options available, their effectiveness and pitfalls in children with PRS. Despite the pros and cons of each management option, it is evident that resource availability and multidisciplinary clinical support are key factors to successful management.

Effects of Mandibular Distraction Osteogenesis on Three-Dimensional Upper Airway Anatomy in Newborns Affected by Isolated Pierre Robin Sequence

Background

Effective airway management is critical to Pierre Robin Sequence treatment. The goal of this study is to assess the three-dimensional changes in airway size and shape in 117 newborns with isolated Pierre Robin sequence who underwent mandibular distraction osteogenesis.

Methods

During the study period (11/29/2016 to 11/26/2019), 117 newborns affected by isolated Pierre Robin sequence met the inclusion criteria for the present study. All 117 included patients underwent linear distraction. Demographic variables were recorded and analyzed. Cone-beam computed tomography were performed before and after mandibular distraction osteogenesis. A systemic quantitative three-dimensional analysis of size and shape of upper airway was performed.

Results

The mean age was 71 day (range 12 to 213). The mean weight was 3.9 kg (range 2.3-6.8). A total of 53 patients are female and 64 are male. When the distraction device was removed, the upper and lower jaws were symmetrically aligned. Pre- and post-distraction comparison clearly showed osteogenesis. For the size of the upper airway, airway volume, anteroposterior dimension of the retroglossal airway, lateral dimension of retroglossal airway, minimum retropalatal area, minimum retroglossal area, average cross-sectional area and minimum cross-sectional area increased significantly after mandibular distraction osteogenesis (P < 0.001). However, the airway length did not change significantly (P > 0.05). For the shape of the upper airway, the lateral/anteroposterior ratio in the retroglossal region and the ratio of the retropalatal airway diameter to the retroglossal airway diameter significantly decreased after mandibular distraction osteogenesis (P < 0.001). The airway uniformity significantly increased after mandibular distraction osteogenesis (P < 0.001).

Conclusion

Mandibular distraction osteogenesis for isolated Pierre Robin sequence improved size and shape of the upper airway, further confirming mandibular osteogenesis distraction as an effective surgical modality to address the airway obstruction in newborns affected by isolated Pierre Robin sequence. Cone-beam computed tomography scanning and analysis can serve as a safe and effective examination modality for upper airway applications of PRS newborns.

Imaging characteristics of the mandible and upper airway in children with Robin sequence and relationship to the treatment strategy

Some patients with Robin sequence (RS) may respond to conservative therapy, while others require surgery; however, there are currently no objective anatomical criteria to gauge surgical indication. The purpose of this study was to explore the imaging characteristics of the mandible and upper respiratory tract in children with RS and examine how individual morphometric parameters influence the treatment strategy. Cone beam computed tomography (CBCT) images were obtained from 57 children with RS. Twenty parameters were measured as potential surgical indicators. The children were divided into two groups according to surgical requirement: a non-surgical group (26 children) and a surgical group (31 children who underwent mandibular osteodistraction). Differences in the imaging parameters were compared between the groups. The mandibular ramus was shorter bilaterally (left, P = 0.047; right, P = 0.027) and the mandibular body was longer bilaterally (left, P = 0.030; right, P = 0.025) in the surgical group when compared to the non-surgical group. In addition, the mandibular angle bilaterally (left, P = 0.023; right, P = 0.003) and the cross-sectional area at the epiglottis tip (P = 0.010) were smaller in the surgical group. Compared to RS patients receiving conservative treatment, children requiring surgery have specific anatomical features of the mandible and upper airway that can be used as surgical indications.

A clinical prediction rule to identify difficult intubation in children with Robin sequence requiring mandibular distraction osteogenesis based on craniofacial CT measures

BACKGROUND

Airway management is challenging in children with Robin sequence (RS) requiring mandibular distraction osteogenesis (MDO). We derived and validated a prediction rule to identify difficult intubation before MDO for children with RS based on craniofacial computed tomography (CT) images.

METHOD

This was a retrospective study of 69 children with RS requiring MDO from November 2016 to June 2018. Multiple CT imaging parameters and baseline characteristic (sex, age, gestational age, body mass index [BMI]) were compared between children with normal and difficult intubation according to Cormack-Lehane classification. A clinical prediction rule was established to identify difficult intubation using group differences in CT parameters (eleven distances, six angles, one section cross-sectional area, and three segment volumes) and clinicodemographic characteristics. Predictive accuracy was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

The overall incidence of difficult intubation was 56.52%, and there was no significant difference in sex ratio, age, weight, height, BMI, or gestational age between groups. The distance between the root of the tongue and posterior pharyngeal wall was significantly shorter, the bilateral mandibular angle shallower, and the cross-sectional area at the epiglottis tip smaller in the difficult intubation group. A clinical prediction rule based on airway cross-sectional area at the tip of the epiglottis was established. Area > 36.97 mm² predicted difficult intubation while area < 36.97 mm² predicted normal intubation with 100% sensitivity, 62.5% specificity, 78.6% positive predictive value, and 100% negative predictive value (area under the ROC curve = 0.8125).

CONCLUSION

Computed tomography measures can objectively evaluate upper airway morphology in patients with RS for prediction of difficult intubation. If validated in a larger series, the measures identified could be incorporated into airway assessment tools to guide treatment decisions. This was a retrospective study and was granted permission to access and use these medical records by the ethics committee of Guangzhou Women and Children's Medical Center.

TRIALS REGISTRATION

Registration No. ChiCTR1800018252, NaZhang, Sept 7 2018.