Overcorrected Midface Advancement to Improve Airway Problems in Severe Pfeiffer Syndrome Types II and III

Distraction osteogenesis in craniosynostosis

PURPOSE OF REVIEW

Craniosynostosis, a condition of premature cranial suture fusion, can have significantly detrimental effects on development and growth due to sequelae of increased intracranial hypertension (ICP), exophthalmos, and upper airway obstruction. Evolving surgical treatments now include distraction osteogenesis (DO) due to its many benefits relative to standard cranial vault remodeling procedures. This article provides an overview and update of different surgical applications of DO for patients with craniosynostosis.

RECENT FINDINGS

DO has been utilized successfully for single and multisuture craniosynostosis with or without midface hypoplasia to increase intracranial volume, decrease ICP and improve aesthetics. It has been applied in single suture synostosis, posterior vault DO, fronto-orbital advancement, monobloc DO and Le Fort III DO. DO has been applied through modification of traditional surgical procedures with success in maintaining goals of surgery while reducing risk.

SUMMARY

DO is still a relatively new and evolving surgical technique for patients with syndromic and nonsyndromic craniosynostosis. With promising benefits, consideration for each procedure should be weighed until longer-term data is available.

Prenatal diagnosis of Pfeiffer syndrome and role of three-dimensional ultrasound: case report and review of literature

Purpose/aim of the study: We report a rare case of autosomal dominant genetic syndrome "Pfeiffer", which is part of the group of acrocephalosyndactyly, with an annual incidence <1/100,000. Three forms are known. Type I is the less common form and it is characterized by moderate-severe mediofacial hypoplasia usually with normal cognitive development. Conversely, types 2 and 3 are more common and they are associated with more severe signs and complications with a more unfavorable prognosis. The type 3 form due to the presence of a cloverleaf skull distinguishes type 2.Materials and methods: Thirty-eight-year-old primigravida was referred to our center, at 28 weeks of gestation due to borderline ventriculomegaly, macrocrania, and a short femur. First trimester screening for chromosomopathies and CF-DNA was low risk; II trimester screening ultrasound showed the presence of "short femur" and macrocrania.Result: Our ultrasound evaluation, assisted by 3D ultrasound, showed cloverleaf skull, turricephaly, moderate ventriculomegaly (13 mm), hypertelorism and exophthalmos, low ear implantation, mild rhizomelia. Ultrasound depicts Pfeiffer syndrome or other acrocephalosyndactyly syndromes (Apert syndromes, Saethre-Chotzen) or other syndromic forms of craniosynostosis like Crouzon syndrome. The NGS panel for molecular analysis of genes involved in skeletal dysplasias showed the mutation of the FGFR2 gene, de novo.Conclusions: Using three-dimensional (3D) ultrasound, it is easier to distinguish rare syndromes characterized by facial dysmorphisms such as exophthalmos, mediofacial hypoplasia, and craniosynostosis.

Morphological Basis for Airway Surgical Intervention in Apert Syndrome

OBJECTIVE

Previous studies have explored the restricted nasopharyngeal airway in Apert syndrome patients. This study aims to investigate the segmented airway volume changes with age and directly analyze their correlations with subcranial dimensions and angulations.

METHODS

Ninety-seven preoperative computed tomography scans (Apert, n = 44; control, n = 53) were included in this study, and divided into 5 age-related subgroups. Computed tomography scans were measured using Mimics and 3-matics software.

RESULTS

Before 6 months of age, the nasal cavity in Apert syndrome is reduced by 47% (P = 0.002), which gradually approximates normal thereafter; however, there remained a 30% reduction, compared with controls. It is highly correlated with the anteroposterior length of subcranial space, and the position of maxilla and palate. The pharyngeal airway volume in Apert syndrome patients, younger than 6 months, was larger than normal by 129% (P = 0.013). However, between 2 and 6 years of age, the pharyngeal airway becomes smaller than normal, with a 57% (P = 0.010) reduction in childhood and 52% (P = 0.005) in adolescence. It is closely correlated with the intercondylar and intergonial widths.

CONCLUSIONS

Airway compromise in Apert syndrome patients is attributable more to the nasal cavity in infants, but in the older child, it is the pharyngeal region. The restricted nasal airway in Apert syndrome is correlated with the subcranial space length and width, but independent of cranial base flexion. The pharyngeal airway volume in Apert syndrome is not as highly correlated with craniofacial morphology. Rather, it is impacted by the growth of mandible, which often requires surgical intervention later in childhood.

Nasopharyngeal airway and subcranial space analysis in Pfeiffer syndrome

Tracheotomy in infancy helps patients with Pfeiffer syndrome to survive by preventing respiratory crisis, but difficulty in decannulation may consequently be a challenge. This study has investigated the regional abnormalities of the nasopharyngeal airway in children with Pfeiffer syndrome to provide an anatomical basis for the surgical treatment and decannulation of the upper airway. Seventy-two preoperative computed tomograms (CT) (Pfeiffer syndrome n=30; control n=42) were included. The airway volume, cross-sectional area, and cephalometrics were measured using Materialise software. Patients with Pfeiffer syndrome developed a 50% (p<0.001) reduction of nasal airway volume, and a 44% (p=0.003) restriction in pharyngeal airway volume. In patients with Pfeiffer syndrome the cross-sectional area at the choana was only half that of the controls (p<0.001). The posterior width of the nasal airway in patients with Pfeiffer syndrome was shortened by 13% (p=0.003), and the height reduced by 21% (p<0.001). The cross-sectional areas at the condylion and gonion levels, which indicate the calibre of the pharyngeal airway at the entrance and midsection, were reduced by 67% (p<0.001) and 47% (p<0.001), respectively, when compared with the controls. The volume of the nasal airway in patients with Pfeiffer syndrome was significantly restricted in length, height, and width, and by choanal stenosis in all cases in this cohort. The reduced anteroposterior length of the nasal airway contributed to the shortened maxilla more than the anteroposterior position. The limited height and width of the nasal pathway was the result of a hypoplastic sphenoid. Restricted mediolateral and anteroposterior dimensions were evident across the entire course of the pharyngeal airway. Mediolateral maxillary expansion in addition to maxillomandibular advancement is therefore likely to benefit these patients.