Alterations in Sphenoid Anatomy in Craniosynostosis: Implications for Fronto-Orbital Advancement

OBJECTIVE

Fronto-orbital advancement involves removal of the fronto-orbital bandeau. Visualization of the saw blade is lost as it passes through the fronto-orbital-sphenoid junction (FOSJ), placing the temporal lobe at risk of injury. We aim to provide a 3D analysis of the space surrounding this osteotomy to differentiate various types of craniosynostoses.

DESIGN

Retrospective cohort.

SETTING

Institutional.

PATIENTS

Thirty patients with isolated unicoronal synostosis, nonsyndromic bicoronal synostosis, metopic synostosis, Apert syndrome, Crouzon syndrome, and Muenke syndrome.

INTERVENTIONS

CT scans conducted between 2 months to 2 years of age were 3D reconstructed to compare craniometrics against normal controls.

MAIN OUTCOME MEASURE(S)

Craniometrics.

RESULTS

The mean bone thickness of the FOSJ at the level of the supraorbital rim was significantly small for the Apert, unicoronal and bicoronal groups. The mean vertical height of the middle cranial fossa from the lesser sphenoid wing was significantly greater in the unicoronal group. The mean vertical height of the tip of the temporal lobe from the lateral sphenoid ridge was greater in the unicoronal, isolated bicoronal, and Apert groups. The mean corneal protrusion beyond the lateral orbital rim was significantly greater in the Apert and unicoronal groups. The mean horizontal depth of the orbit was smallest in the Apert group. The mean vertical distance between the dacryon and the foramen cecum, and the mean volume of temporal lobe beneath the sphenoid shelf were the largest in the Apert group.

CONCLUSIONS

Patients with Apert syndrome have the most unfavorable morphology of the anterior and middle cranial fossae.

What can a morphometric study of unoperated children teach us about the natural history of metopic synostosis?

OBJECTIVE

Outcomes of surgical repair of trigonocephaly are well reported in the literature, but there is a paucity of information on the natural history of unoperated children. The authors evaluated a group of unoperated children with metopic synostosis to describe the natural change in head shape over time.

METHODS

A database was screened for scans of children with unoperated trigonocephaly (2010-2021). Multisuture cases and those with a metopic ridge were excluded. Three-dimensional surface scans (3D stereophotogrammetry/CT) were used for morphological analysis. Nine previously published parameters were used: frontal angle (FA30°), anteroposterior (AP) volume ratio (APVR), AP area ratio (APAR), AP width ratios 1 and 2 (APWR1 and APWR2), and 4 AP diagonal ratios (30° right APDR [rAPDR30], 30° left APDR [lAPDR30], 60° right APDR [rAPDR60], and 60° left APDR [lAPDR60]).

RESULTS

Ninety-seven scans were identified from a cohort of 316 patients with a single metopic suture, in which the male-to-female ratio was 2.7:1. Ages at the time of the scan ranged from 9 days to 11 years and were stratified into 4 groups: group 1, < 6 months; group 2, 6-12 months; group 3, 1-3 years; and group 4, > 3 years. Significant improvements were detected in 5 parameters (APVR, APAR, APWR1, rAPDR30, and lAPDR30) over time, whereas no significant differences were found in FA30, APWR2, rAPDR60, and lAPDR60 between age groups.

CONCLUSIONS

Forehead shape (surface area and volume), as well as narrowing and anterolateral contour at the frontal points, differed significantly over time without surgery. However, forehead angulation, narrowing, and anterolateral contour at temporal points did not show significant differences. This knowledge will aid in surgical and parental decision-making.

Health-related quality of life of children treated for non-syndromic craniosynostosis

Health-related quality of life (HRQoL) allows the acquisition of the subjective perspective of patients regarding their health and function; yet a very few studies have been evaluated HRQoL of patients treated for craniosynostosis (CS). In this retrospective, descriptive cohort study, school-aged children (7-16 years) treated for non-syndromic CS were assessed using the Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales. Seventy-three patients and their parents responded to the PedsQL (response rate: 80.2%). Patients generally estimated average HRQoL with no difference compared to the normal population sample. Further, no difference in HRQoL was found between treated sagittal (SS) or metopic synostosis. In the SS group, surgical methods involving spring-assisted surgery and pi-plasty were unrelated to HRQoL outcomes. Additionally, HRQoL was highly correlated with intelligence quotient (IQ, r = 0.42; p = 0.0004) and adaptive behavior skills (ABAS, r = 0.57; p = 0.0001). Furthermore, differences were observed in estimated physical function (p = 0.002) and school function (p = 0.012) between self- and proxy reports (i.e. parents estimated child HRQoL as higher than did the children). Children treated for CS have a generally average HRQoL, and neither CS type nor surgical method influenced HRQoL outcomes. Moreover, children and parents estimated HRQoL differently, suggesting the importance of using both self- and proxy reporting in patient-reported measures. HRQoL was strongly related to IQ and ABAS, indicating that the PedsQL can be used as a screening instrument to identify craniofacial patients in need of further psychological assessment.

Targeted Sequencing of Candidate Regions Associated with Sagittal and Metopic Nonsyndromic Craniosynostosis

Craniosynostosis (CS) is a major birth defect in which one or more skull sutures fuse prematurely. We previously performed a genome-wide association study (GWAS) for sagittal non-syndromic CS (sNCS), identifying associations downstream from BMP2 on 20p12.3 and intronic to BBS9 on 7p14.3; analyses of imputed variants in DLG1 on 3q29 were also genome-wide significant. We followed this work with a GWAS for metopic non-syndromic NCS (mNCS), discovering a significant association intronic to BMP7 on 20q13.31. In the current study, we sequenced the associated regions on 3q29, 7p14.3, and 20p12.3, including two candidate genes (BMP2 and BMPER) near some of these regions in 83 sNCS child-parent trios, and sequenced regions on 7p14.3 and 20q13.2-q13.32 in 80 mNCS child-parent trios. These child-parent trios were selected from the original GWAS cohorts if the probands carried at least one copy of the top associated GWAS variant (rs1884302 C allele for sNCS; rs6127972 T allele for mNCS). Many of the variants sequenced in these targeted regions are strongly predicted to be within binding sites for transcription factors involved in craniofacial development or bone morphogenesis. Variants enriched in more than one trio and predicted to be damaging to gene function are prioritized for functional studies.

Elevated intracranial pressure with craniosynostosis: a multivariate model of age, syndromic status, and number of involved cranial sutures

OBJECTIVE

Children with multiple prematurely fused cranial sutures and those undergoing surgical correction later in life appear to experience worse neurocognitive outcomes, but it is unclear whether higher intracranial pressure (ICP) is implicated in this process. The purpose of this study was to elucidate the effect of age at intervention and number of involved cranial sutures on ICP, as well as to assess which cranial suture closure may be more associated with elevated ICP.

METHODS

The prospective craniofacial database at the authors' institution was queried for patients undergoing initial corrective surgery for craniosynostosis in whom intraoperative measurement of ICP was obtained prior to craniectomy. Age, involved sutures, and syndromic status were analyzed in the context of measured ICP by using multiple linear regression.

RESULTS

Fifty patients met the inclusion criteria. Age at procedure (p = 0.028, β = +0.060 mm Hg/month) and multiple-suture involvement (p = 0.010, β = +4.175 mm Hg if multisuture) were both significantly implicated in elevated ICP. The actual number of major sutures involved was significantly correlated to ICP (p = 0.001; β = +1.687 mm Hg/suture). Among patients with single-suture involvement, there was an overall significant difference of median ICP across the suture types (p = 0.008), with metopic having the lowest (12.5 mm Hg) and sagittal having the highest (16.0 mm Hg). Patients with multiple-suture involvement had significantly higher ICP (p = 0.003; 18.5 mm Hg). Patients with craniofacial syndromes were 79.3 times more likely to have multiple-suture involvement (p < 0.001). Corrective surgery for craniosynostosis demonstrated significant intraoperative reduction of elevated ICP (all p < 0.050).

CONCLUSIONS

Syndromic status, older age at intervention for craniosynostosis, and multiple premature fusion of cranial sutures were associated with significantly higher ICP.

Increased Incidence of Ophthalmologic Findings in Children With Concurrent Isolated Nonsyndromic Metopic Suture Abnormalities and Deformational Cranial Vault Asymmetry

OBJECTIVE

The purpose of this project was to study the incidence of ophthalmologic findings which are known to be risk factors for amblyopia in children who have coexisting metopic suture abnormalities and deformational plagiocephaly (DP) and brachycephaly (DB).

DESIGN

Institutional Review Board-approved retrospective study reviewing records of a consecutive cohort of children under 2 years of age with metopic suture abnormalities and cranial vault asymmetries seen in both the plastic surgery and ophthalmology clinics from 2007 to 2017.

SETTING

Institutional tertiary care center with all care in plastic surgery under the senior author and the standard of care accepted in pediatric ophthalmology under one of two ophthalmologists.

PATIENTS

After application of exclusion criteria, 76 children diagnosed with metopic suture abnormalities and DP/DB were included in the study. Patients with severe trigonocephaly, other suture involvement, syndromic diagnoses, and primary ocular disorders were excluded.

MAIN OUTCOME MEASURES

Describe the incidences of refractive errors (astigmatism, hyperopia, and myopia), anisometropia, strabismus, and amblyopia within the study population.

RESULTS

In our patient population, the rates of amblyopia (17.1%) and strabismus (15.8%) are higher than the general pediatric population rates of 1.5% to 1.8% and 2.4% to 3.6%, respectively. Overall, 47.4% had significant refractive error: 28.9% with astigmatism, 15.8% with hyperopia, 5.3% with myopia, and 10.5% with anisometropia.

CONCLUSIONS

In our patient population, children with coexisting metopic suture abnormalities and DP or DB had significant risk for amblyopia, strabismus, and refractive errors.

The Use of Eye Tracking to Discern the Threshold at Which Metopic Orbitofrontal Deformity Attracts Attention

INTRODUCTION AND OBJECTIVES

Surgical treatment for trigonocephaly aims to eliminate a stigmatizing deformity, yet the severity that captures unwanted attention is unknown. Surgeons intervene at different points of severity, eliciting controversy. This study used eye tracking to investigate when deformity is perceived.

MATERIAL AND METHODS

Three-dimensional photogrammetric images of a normal child and a child with trigonocephaly were mathematically deformed, in 10% increments, to create a spectrum of 11 images. These images were shown to participants using an eye tracker. Participants' gaze patterns were analyzed, and participants were asked if each image looked "normal" or "abnormal."

RESULTS

Sixty-six graduate students were recruited. Average dwell time toward pathologic areas of interest (AOIs) increased proportionally, from 0.77 ± 0.33 seconds at 0% deformity to 1.08 ± 0.75 seconds at 100% deformity (P < .0001). A majority of participants did not agree an image looked "abnormal" until 90% deformity from any angle.

CONCLUSION

Eye tracking can be used as a proxy for attention threshold toward orbitofrontal deformity. The amount of attention toward orbitofrontal AOIs increased proportionally with severity. Participants did not generally agree there was "abnormality" until deformity was severe. This study supports the assertion that surgical intervention may be best reserved for more severe deformity.

Endoscopic surgery for nonsyndromic craniosynostosis: a 16-year single-center experience

OBJECTIVE

In this paper the authors review their 16-year single-institution consecutive patient experience in the endoscopic treatment of nonsyndromic craniosynostosis with an emphasis on careful review of any associated treatment-related complications and methods of complication avoidance, including preoperative planning, intraoperative management, and postoperative care and follow-up.

METHODS

A retrospective chart review was conducted on all patients undergoing endoscopic, minimally invasive surgery for nonsyndromic craniosynostosis at Rady Children's Hospital from 2000 to 2015. All patients were operated on by a single neurosurgeon in collaboration with two plastic and reconstructive surgeons as part of the institution's craniofacial team.

RESULTS

Two hundred thirty-five patients underwent minimally invasive endoscopic surgery for nonsyndromic craniosynostosis from 2000 to 2015. The median age at surgery was 3.8 months. The median operative and anesthesia times were 55 and 105 minutes, respectively. The median estimated blood loss (EBL) was 25 ml (median percentage EBL 4.2%). There were no identified episodes of air embolism or operative deaths. One patient suffered an intraoperative sagittal sinus injury, 2 patients underwent intraoperative conversion of planned endoscopic to open procedures, 1 patient experienced a dural tear, and 1 patient had an immediate reexploration for a developing subgaleal hematoma. Two hundred twenty-five patients (96%) were admitted directly to the standard surgical ward where the median length of stay was 1 day. Eight patients were admitted to the intensive care unit (ICU) postoperatively, 7 of whom had preexisting medical conditions that the team had identified preoperatively as necessitating a planned ICU admission. The 30-day readmission rate was 1.7% (4 patients), only 1 of whom had a diagnosis (surgical site infection) related to their initial admission. Average length of follow-up was 2.8 years (range < 1 year to 13.4 years). Six children (< 3%) had subsequent open procedures for perceived suboptimal aesthetic results, 4 of whom (> 66%) had either coronal or metopic craniosynostosis. No patient in this series either presented with or subsequently developed signs or symptoms of intracranial hypertension.

CONCLUSIONS

In this large single-center consecutive patient series in the endoscopic treatment of nonsyndromic craniosynostosis, significant complications were avoided, allowing for postoperative care for the vast majority of infants on a standard surgical ward. No deaths, catastrophic postoperative morbidity, or evidence of the development of symptomatic intracranial hypertension was observed.

Endoscopy-assisted early correction of single-suture metopic craniosynostosis: a 19-year experience

In BriefThe long-term results of treating infants with metopic craniosynostosis by using endoscopic, minimally invasive techniques are reported. The impetus arose from the lack of consistent and favorable outcomes associated with calvarial vault remodeling techniques and from the very traumatic and invasive nature of these procedures. The results presented show excellent and consistent long-term outcomes that are superior to traditional methods and are associated with minimal trauma, blood loss, and anesthetic exposure, and with short surgical times.

Bicoronal and metopic craniosynostosis in association with a de novo unbalanced t(2;7) chromosomal translocation

We report the case of a developmentally appropriate infant male with a de novo unbalanced chromosome translocation involving bands 2q32.1 and 7p21.3. The child was noted to have metopic and bicoronal craniosynostosis with closely spaced eyes, turricephaly, and flattening of the forehead. © 2016 Wiley Periodicals, Inc.

Evaluating Children With Metopic Craniosynostosis: The Cephalic Width-Intercoronal Distance Ratio

OBJECTIVE

To identify an additional objective measure to aid in the evaluation of children with isolated metopic craniosynostosis.

DESIGN

This is a retrospective study comparing specific computed tomography scan measurements between surgical and nonsurgical cohorts of children with isolated metopic craniosynostosis. Children were included if they were diagnosed with isolated metopic craniosynostosis and ultimately underwent computed tomography scan imaging as part of their evaluation. The subjects were placed in the surgical or nonsurgical cohorts on the basis of the final treatment recommendation after they completed a full multidisciplinary, multimodality evaluation. Comparisons were made with a control group of unaffected patients from our institutional trauma registry.

SETTING

Tertiary academic institution.

PATIENTS, PARTICIPANTS

The subjects are patients who had been previously evaluated in our clinic for isolated metopic craniosynostosis and received a computed tomography scan as part of their workup.

RESULTS

The average intercoronal distances were significantly different among all three groups (P < .002). The average cephalic width-intercoronal distance ratio for children who received a recommendation for surgery differed significantly from that of both the observation cohort and the control group (P < .001). However, the cephalic width-intercoronal distance ratio did not differ between the observation cohort and the control group (P = .927).

CONCLUSIONS

The cephalic width-intercoronal distance ratio may be an additional objective measurement to aid in the clinical evaluation of children with metopic craniosynostosis.

Secondary bicoronal synostosis after metopic craniosynostosis surgical reconstruction

Re-synostosis after standard surgical procedures for nonsyndromic craniosynostosis is a rare event, which can occur at the same suture or rarely in adjacent sutures. Here, we report 2 patients with primary metopic craniosynostosis who developed bicoronal synostosis in previously opened sutures several months after surgery.

Correction of metopic synostosis utilizing an in situ bandeau approach

Metopic craniosynostosis is a common growth disturbance in the infant cranium, second only to sagittal synostosis. Presenting symptoms are usually of a clinical nature and are defined by an angular forehead, retruded lateral brow, bitemporal narrowing, and a broad-based occiput. These changes create the pathognomonic trigonocephalic cranial shape. Aesthetic in nature, these morphological changes do not constitute the only developmental issues faced by children who present with this malady. Recent studies and anecdotal evidence have also demonstrated that children who present with metopic synostosis may face issues with respect to intellectual and/or psychological development. The authors present an elegant approach to the surgical reconstruction of the trigonocephalic cranium using an in situ bandeau approach.