Risk factors for first weaning failure following mandibular distraction osteogenesis in pediatric patients with Pierre Robin sequence: a nested case-control study / 中华麻醉学杂志

Objective:To identify the risk factors for the first weaning failure following mandibular distraction osteogenesis in pediatric patients with Pierre Robin sequence (PRS).Methods:Clinical data of pediatric patients with PRS who underwent mandibular distraction osteogenesis from January 2018 to February 2023 were collected, including sex, age, premature birth, birth weight, surgical weight, cleft palate, syndrome type PRS, laryngeal/tracheobronchial malacia, simple congenital heart disease, complex congenital heart disease, preoperative mechanical ventilation, preoperative pulmonary infection, blood albumin concentration, difficulty in tracheal intubation under a visual laryngoscope, surgical duration, postoperative ventilator-associated pneumonia, duration of mechanical ventilation at first weaning, and traction length at first weaning. Children in whom the first postoperative machine withdrawal failed were included in observation group and matched to control cases(control group) in a 1∶4 ratio. The risk factors of which P values were less than 0.05 would enter the logistic regression analysis to stratify the risk factors for postoperative weaning failure. Results:There were significant differences in birth weight, cleft palate, duration of mechanical ventilation and traction length at first weaning, rate of combined cleft palate, preoperative pulmonary infection rate, rate of preoperative mechanical ventilation, and rate of postoperative ventilator-associated pneumonia between the two groups ( P<0.05). Binary logistic stepwise regression analysis showed that the preoperative mechanical ventilation ( OR=18.154, 95% CI 3.971-82.990, P<0.001) and postoperative ventilator-associated pneumonia ( OR=36.942, 95% CI 1.307-1043.985, P=0.034) were independent risk factors for first weaning failure after mandibular distraction osteogenesis, while birth weight gain ( OR=0.225, 95% CI 0.076-0.668, P=0.007) was a protective factor for first weaning failure ( P<0.05). Conclusions:Preoperative mechanical ventilation and postoperative ventilator-associated pneumonia are independent risk factors and birth weight gain is a protective factor for first weaning failure following mandibular distraction osteogenesis in pediatric patients with PRS.

The airway management and treatment of newborns with micrognathia and laryngomalacia / 临床耳鼻咽喉头颈外科杂志

Objective:To explore the perioperative airway management and treatment of newborns with micrognathia and laryngomalacia. Methods:From January to December 2022, a total of 6 newborns with micrognathia and laryngomalacia were included. Preoperative laryngoscopy revealed concomitant laryngomalacia. These micrognathia were diagnosed as Pierre Robin sequences. All patients had grade Ⅱ or higher symptoms of laryngeal obstruction and required oxygen therapy or non-invasive ventilatory support. All patients underwent simultaneous laryngomalacia surgery and mandibular distraction osteogenesis. The shortened aryepiglottic folds were ablated using a low-temperature plasma radiofrequency during the operation. Tracheal intubation was maintained for 3-5 days postoperatively. Polysomnography（PSG） and airway CT examination were performed before and 3 months after the surgery. Results:Among the 6 patients, 4 required oxygen therapy preoperatively and 2 required non-invasiveventilatory support. The mean age of patients was 40 days at surgery. The inferior alveolar nerve bundle was not damaged during the operation, and there were no signs of mandibular branch injury such as facial asymmetry after the surgery. Laryngomalacia presented as mixed type: type Ⅱ+ type Ⅲ. The maximum mandibular distraction distance was 20 mm, the minimum was 12 mm, and the mean was 16 mm. The posterior airway space increased from a preoperative average of 3.5 mm to a postoperative average of 9.5 mm. The AHI decreased from a mean of 5.65 to 0.85, and the lowest oxygen saturation increased from a mean of 78% to 95%. All patients were successfully extubated after the surgery, and symptoms of laryngeal obstruction such as hypoxia and feeding difficulties disappeared. Conclusion:Newborns with micrognathia and laryngomalacia have multi-planar airway obstruction. Simultaneous laryngomalacia surgery and mandibular distraction osteogenesis are safe and feasible, and can effectively alleviate symptoms of laryngeal obstruction such as hypoxia and feeding difficulties, while significantly improving the appearance of micrognathia.

Perioperative evaluation and management of neonates with Pierre-Robin sequence / 中华实用儿科临床杂志

Objective:To summarize the clinical characteristics of neonates with Pierre-Robin sequence (PRS) who received mandibular distraction osteogenesis (MDO), in order to provide a basis for perioperative evaluation and management.Methods:Data of neonates diagnosed with PRS and receiving MDO in the Department of Neonatology, Guangzhou Women and Children′s Medical Center between December 2016 and December 2019 were collected for a retrospective study.According to the types of respiratory support needed before surgery, they can be categorized into 3 groups: the invasive ventilation group, the noninvasive ventilation group, the oxygen therapy/positioning therapy group.According to the usage of sedative and analgesic drugs after surgery, they were categorized into 2 groups: the sedative-analgesic group(Fentanyl Citrate and Midazolam) and the single sedative group(Midazolam alone).Results:A total of 31 children were admitted, 22 cases of whom received MDO at an age of (22.09±8.42) d, including 11 cases in the invasive ventilation group, 5 cases in the non-invasive ventilation group, and 6 cases in the therapy/positioning therapy group before surgery; there was statistical significance in severe respiratory distress (81.8% vs.60.0% vs.0) and feeding difficulties (100.0% vs.80.0% vs.50.0%) among the 3 groups (all P<0.05), while there was no difference in laryngomalacia rate(63.6% vs.20.0% vs.33.3%), non-gain in weight before surgery(81.8% vs.80.0% vs.66.7%), postoperative ventilation duration[(7.5±3.4) d vs.(7.2±5.3) d vs.(6.9±4.1) d]and hospital stay[(36.3±9.3) d vs.(34.1±0.3) d vs.(33.8±7.5) d] (all P>0.05). Among these 22 patients, there were 9 cases in the sedative-analgesic group, and 13 cases in the single sedative group.Compared with the single sedative group, cases in the sedative-analgesic group had significantly lower extubation rate (0 vs.15.4%) and shorter hospital stay[(32.3±5.2) d vs.(39.8±7.3) d], and the difference were statistically significant (all P<0.05). Besides, there were no differences in postoperative ventilation duration[(7.4 ± 3.9) d vs.(7.6 ± 4.2) d]between both groups ( P>0.05). The postoperative remission rate of airway obstruction was 100%. Conclusions:MDO in children in their neonatal period could achieve favorable efficacy.The duration of postoperative ventilator support and hospital stay in children with severe airway obstruction could not be prolonged compared with children with mild obstruction, and postoperative sedation and analgesic management can reduce the extubation rate.

Numerical simulation of unilateral mandibular distraction osteogenesis / 医用生物力学

Objective To study the law of shape changes of mandiblular distraction osteogenesis in the patient with hemifacial microsomia(HFM) and compare the results with the real effect on the patient by establishing the models of mandibular and masticatory muscles, and to put forward some good suggestions on procedures of treating patients diagnosed as HFM and related cases. Methods Based on the original data of the patient with HFM, combined with the MIMICS software (medical image control system software), the model of the patient’s mandibular and masticatory muscles was constructed by applying the technique of three dimensional (3D) reconstruction, and then put the entity structure into the ANSYS software to simulate the effect of the surgery. Results The established preoperative and postoperative finite element analytic model could present the characteristics such as digitalization and individuation. Conclusions Compared with the effects of the real surgery for the same patient, the result of numerical simulation showed to be good matching and could provide personalized guidance for different patients before their operation.

Histological changes and expression of nerve growth factor in the inferior alveolar nerve after distraction osteogenesis

Early Relapse of Mandibular Asymmetry During Consolidation Period in Distraction Osteogenesis

Mandibular distraction osteogenesis has gained popularity as a surgical technique for hemifacial microsomia. Although there was the general acceptance of mandibular distraction osteogenesis by surgeons, the standardization of techniques among surgeons has been limited due to short period of its history. So, many surgeons having make an effort for suggesting standard protocol, based on various clinical experiences. We found that corrected mandibular asymmetry of hemifacial microsomia by rapid distraction osteogensis has a tendency to relapse, in spite of external fixator during consolidation period. On this, we studied that which factors have influences on relapse of mandibular asymmetry during consolidation period. As a result, there were significant differences of the relapse during consolidation period in proportion to mandibular hypoplasia and the vertical distraction distance. But there was no significant difference of the relapse among the duration of the consolidation period groups. And there was significant difference of the vertical distraction distance in proportion to mandibular hypoplasia. The amount of the relapse during consolidation period has correlation with the severity of the mandibular hypoplasia. In conclusion, the severity of the mandibular hypoplasia is the important forecast index of relapse during consolidation period.