Focus session on the changing "epidemiology" of craniosynostosis (comparing two quinquennia: 1985-1989 and 2003-2007) and its impact on the daily clinical practice: a review from Necker Enfants Malades

Geometric Morphometric Study on Distinguishing Metopic Craniosynostosis from Metopic Ridging

Background

Craniosynostosis, a common congenital anomaly, results from premature fusion of the cranial sutures. One of the forms of craniosynostosis is premature fusion of the metopic suture, referred to as trigonocephaly, but the diagnosis of metopic suture synostosis remains controversial. The purpose of this study was to clarify, using geometric morphometric analysis, if a metopic ridge alone observed in cases of mild trigonocephaly represents a pathological phenomenon.

Methods

Three different cranial morphologies were compared among patients up to 2 years old who were categorized into the true group, the mild group, and the normal group, based on the presence or absence of specific symptoms, history of cranioplasty for trigonocephaly, or lack of any abnormality on computed tomography. Using the obtained computed tomography images, 235 anatomical landmarks and semi-landmarks were plotted on the entire cranial surface for analysis of neurocranial morphology, and the cranial shapes represented by landmarks were analyzed using geometric morphometrics. Principal components of shape variations among specimens were then computed, based on the variance-covariance matrix of the Procrustes residuals of all specimens, and statistically analyzed.

Results

The principal component analyses of the variations in endocranial shape, frontal bone shape, and occipital bone shape did not show any significant differences in cranial morphology between mild trigonocephaly and normal skulls; however, true trigonocephaly was found to differ significantly from mild trigonocephaly and normal skulls.

Conclusions

These findings suggest that in assessments of cranial morphology, the presence of a ridge alone cannot be diagnosed as fundamentally pathological, and may represent normal morphology.

Endoscopic surgery for craniosynostosis: A systematic review and single-arm meta analysis

BACKGROUND

Craniosynostosis, a developmental craniofacial anomaly, can impair brain development and cause abnormal skull shape due to premature closure of one or more cranial sutures. Traditional surgical treatments have evolved from open operations to minimally invasive endoscopic techniques. This systematic review and meta-analysis aim to evaluate the effectiveness and safety of the endoscopic approach in craniosynostosis correction.

METHODS

Adhering to Cochrane Group standards and the PRISMA framework, this review utilized databases like PubMed, Embase, and Web of Science, focusing on clinical and surgical outcomes of endoscopic craniosynostosis operations up to December 2023. Inclusion criteria emphasized studies with at least five patients undergoing endoscopic procedures, while exclusion criteria involved non-English papers, incomplete texts, and overlapping data. Statistical analysis used R software with various packages, and methodological bias was assessed using the ROBINS-I framework.

RESULTS

The review included 30 studies (4 prospective, 26 retrospective) with 2561 patients. The median age at operation was 3.20 months. Findings showed a mean operative time of 68.06 min, median hospital stay of 1.28 days, and mean blood loss of 29.89 ml. Blood transfusion was required in 9.97% of cases. Helmet therapy post-operation was common, with a median duration of 9 months. The rate of postoperative complications was 1.86%, and the reoperation rate was 3.07%. No procedure-related mortality was observed. The study noted substantial variations in the handling of craniosynostosis and a lack of consensus on the optimal timing and surgical approach.

CONCLUSION

Endoscopic techniques for craniosynostosis repair demonstrate safety and effectiveness, characterized by low complication risks and favorable surgical outcomes. However, due to the limitations of observational studies and inherent heterogeneity, further comprehensive and controlled trials are needed to validate these findings and understand the long-term outcomes of the endoscopic approach.

Systematic Review of Nonsyndromic Craniosynostosis: Genomic Alterations and Impacted Signaling Pathways

BACKGROUND

Genetic research in nonsyndromic craniosynostosis remains limited compared with syndromic craniosynostosis. This systematic review aimed to comprehensively summarize the genetic literature of nonsyndromic craniosynostosis and highlight key signaling pathways.

METHODS

The authors performed a systematic literature search of PubMed, Ovid, and Google Scholar databases from inception until December of 2021 using search terms related to nonsyndromic craniosynostosis and genetics. Two reviewers screened titles and abstract for relevance, and three reviewers independently extracted study characteristics and genetic data. Gene networks were constructed using Search Tool for Retrieval of Interacting Genes/Proteins (version 11) analysis.

RESULTS

Thirty-three articles published between 2001 and 2020 met inclusion criteria. Studies were further classified into candidate gene screening and variant identification studies ( n = 16), genetic expression studies ( n = 13), and common and rare variant association studies ( n = 4). Most studies were good quality. Using our curated list of 116 genes extracted from the studies, two main networks were constructed.

CONCLUSIONS

This systematic review concerns the genetics of nonsyndromic craniosynostosis, with network construction revealing TGF-β/BMP, Wnt, and NF-κB/RANKL as important signaling pathways. Future studies should focus on rare rather than common variants to examine the missing heritability in this defect and, going forward, adopt a standard definition.

Clomiphene Citrate and Enclomiphene Hydrochloride Exposure Is Associated With Interfrontal Suture Fusion in Zebrafish

Background: The last several decades have witnessed an increase in metopic craniosynostosis incidence. Population-based studies suggest that pharmacological exposure in utero may be responsible. This study examined effects of the fertility drug clomiphene citrate (CC) on calvarial development in an established model for craniofacial development, the zebrafish Danio rerio. Results: Zebrafish larvae were exposed to clomiphene citrate or its isomer enclomiphene for five days at key points during calvarial development. Larvae were then raised to adulthood in normal rearing water. Zebrafish were analyzed using whole-mount skeletal staining. We observed differential effects on survivability, growth and suture formation depending on the treatment. Treatments with CC or enclomiphene at 5.5 mm SL led to increased fusion of the interfrontal suture (p < .01) compared to controls. Conclusions: Exposure to fertility drugs appears to affect development of the cranial vault, specifically the interfrontal suture, in zebrafish. Further research is required to identify the signaling mechanisms at play. This work suggests that fertility drug treatment may contribute to the increased incidence of metopic craniosynostosis observed globally.

Aesthetic results in children with single suture craniosynostosis: proposal for a modified Whitaker classification

OBJECTIVE

Aesthetic assessment after surgery for non-syndromic single suture craniosynostosis (SSC) is crucial. Surgeons' evaluation is generally based on Whitaker classification, while parental impression is generally neglected. The aim of this paper is to compare aesthetic perceptions of parents and surgeons after surgery for SSC, expressed by a 10-item questionnaire that complement Whitaker's classification.

METHODS

The authors submitted a 10-item questionnaire integrating Whitaker's classification in order to evaluate the degree of satisfaction, the detailed aesthetics results and the need for surgical revision, to surgeons and parents of a consecutive series of patients operated for SSC between January 2007 and December 2018. The results were collected blindly.

RESULTS

A total of 70 patients were included in the study. Scaphocephaly and trigonocephaly were the two most frequent craniosynostosis. Parents and surgeons general aesthetics evaluation and average rating for Whitaker's classification were 1.86 vs 1.67 (p = 0.69) and 1.19 vs 1.1 (p = 0.45) respectively. Parents' evaluation for scar perception and alopecia (p < 0.00001), the presence of bony crest (0.002), bony bump (p < 0.00001), or other bone irregularities (p = 0.02) are significantly worse when compared to surgeons' perception.

CONCLUSIONS

Parents seem to be more sensitive to the detection of some aesthetic anomalies and their opinion should not be neglected. The authors propose a modified Whitaker classification based on their results to better stratify the aesthetic outcome after surgery for SSC.

Ciliary Signalling and Mechanotransduction in the Pathophysiology of Craniosynostosis

Craniosynostosis (CS) is the second most prevalent inborn craniofacial malformation; it results from the premature fusion of cranial sutures and leads to dimorphisms of variable severity. CS is clinically heterogeneous, as it can be either a sporadic isolated defect, more frequently, or part of a syndromic phenotype with mendelian inheritance. The genetic basis of CS is also extremely heterogeneous, with nearly a hundred genes associated so far, mostly mutated in syndromic forms. Several genes can be categorised within partially overlapping pathways, including those causing defects of the primary cilium. The primary cilium is a cellular antenna serving as a signalling hub implicated in mechanotransduction, housing key molecular signals expressed on the ciliary membrane and in the cilioplasm. This mechanical property mediated by the primary cilium may also represent a cue to understand the pathophysiology of non-syndromic CS. In this review, we aimed to highlight the implication of the primary cilium components and active signalling in CS pathophysiology, dissecting their biological functions in craniofacial development and in suture biomechanics. Through an in-depth revision of the literature and computational annotation of disease-associated genes we categorised 18 ciliary genes involved in CS aetiology. Interestingly, a prevalent implication of midline sutures is observed in CS ciliopathies, possibly explained by the specific neural crest origin of the frontal bone.

Benefits of clinical criteria and high-throughput sequencing for diagnosing children with syndromic craniosynostosis

An accurate diagnosis of syndromic craniosynostosis (CS) is important for personalized treatment, surveillance, and genetic counselling. We describe detailed clinical criteria for syndromic CS and the distribution of genetic diagnoses within the cohort. The prospective registry of the Norwegian National Unit for Craniofacial Surgery was used to retrieve individuals with syndromic CS born between 1 January 2002 and 30 June 2019. All individuals were assessed by a clinical geneticist and classified using defined clinical criteria. A stepwise approach consisting of single-gene analysis, comparative genomic hybridization (aCGH), and exome-based high-throughput sequencing, first filtering for 72 genes associated with syndromic CS, followed by an extended trio-based panel of 1570 genes were offered to all syndromic CS cases. A total of 381 individuals were registered with CS, of whom 104 (27%) were clinically classified as syndromic CS. Using the single-gene analysis, aCGH, and custom-designed panel, a genetic diagnosis was confirmed in 73% of the individuals (n = 94). The diagnostic yield increased to 84% after adding the results from the extended trio-based panel. Common causes of syndromic CS were found in 53 individuals (56%), whereas 26 (28%) had other genetic syndromes, including 17 individuals with syndromes not commonly associated with CS. Only 15 individuals (16%) had negative genetic analyses. Using the defined combination of clinical criteria, we detected among the highest numbers of syndromic CS cases reported, confirmed by a high genetic diagnostic yield of 84%. The observed genetic heterogeneity encourages a broad genetic approach in diagnosing syndromic CS.

A new approach of crenellated fronto-orbital advancement for the management of trigonocephaly: Technical note

Trigonocephaly is a craniosynostosis characterized by a premature fusion of the metopic suture associating a characteristic triangular head shape, with a frontal medial crest and hypotelorism. Various techniques have been described for its surgical treatment which is usually performed during the first year of life. However, there might be cases with a late referral, after the age of one year. One of the technical issues with a fronto-orbital advancement surgery in a child over one year of age is that there is a significant risk of persistent residual bone defects. This article describes a surgical technique of crenellated fronto-orbital advancement for correcting trigonocephaly in children over one year of age, allowing to reduce residual bone defects.

Emissary veins and pericerebral cerebrospinal fluid in trigonocephaly: do they define a specific subtype?

INTRODUCTION

The premature fusion of the metopic suture may be associated with the presence of emissary veins (EV) and abnormally large pericerebral cerebrospinal fluid (CSF) spaces which suggest an associated focal disturbance in CSF dynamics. The incidence of such findings and their potential significance in terms of management of the disease have not been fully elucidated. The aim of this study is to investigate whether these phenomena identify specific subtypes of trigonocephaly. In such a direction, we evaluated the volume of the pericerebral CSF spaces and their relationship to the morphology ("Ω," "V," or flat type) of the prematurely fused metopic suture and to the value of the interfrontal angle value on the grounds of computed tomographic (CT) scan examinations.

METHOD

The preoperative brain CT scans of 74 children (52 boys, 22 girls) with trigonocephaly who had undergone fronto-orbital remodeling were evaluated. The volume of the pericerebral CSF spaces and the value of the interfrontal angle were calculated. The type of intracranial notch was studied and classified according to its shape on the preoperative CT scan: a groove "Ω," a ridge/"V" ridge or absent when flat and evidence of emissary veins related to the abnormally fused suture.

RESULTS

Preoperatively, an endocranial metopic groove or ridge was seen in 70% of the children. Emissary veins were identified in 34 of 74 patients (45%), at a mean distance of 2.04 cm (1.18-2.94 cm) from the nasion. The presence of large pericerebral CSF spaces significantly correlated with the presence of EV (p < 0.05), with the "Ω" type (p < 0.05) and with interfrontal angles under 134° (p < 0.005).

CONCLUSIONS

Metopic suture early fusion shows an association between EV, pericerebral CSF spaces, and the "Ω" groove appearance of the suture. This association identifies a specific subgroup in which the presence of emissary veins and large pericerebral CSF spaces is an indicator of local venous hypertension due to the sagittal sinus constriction within an osseous groove created by the abnormal suture fusion process. The implications for the surgical management and long-term results as compared to trigonocephalic children with small or absent normal peripheral spaces and EV are still to be determined.

New method for quantification of severity of isolated scaphocephaly linked to intracranial volume

PURPOSE

The aim is to implement Utrecht Cranial Shape Quantificator (UCSQ) for quantification of severity of scaphocephaly and compare UCSQ with the most used quantification method, cranial index (CI). Additionally, severity is linked to intracranial volume (ICV).

METHODS

Sinusoid curves of 21 pre-operative children (age < 2 years) with isolated scaphocephaly were created. Variables of UCSQ (width of skull and maximum occiput and forehead) were combined to determine severity. CI was calculated. Three raters performed visual scoring for clinical severity (rating of 6 items; total score of 12 represents most severe form). Pearson's correlation test was used for correlation between UCSQ and visual score and between both CIs. ICV was calculated using OsiriX. ICV was compared to normative values and correlated to severity.

RESULTS

Mean UCSQ was 22.00 (2.00-42.00). Mean traditional CI was 66.01 (57.36-78.58), and mean visual score was 9.1 (7-12). Correlations between both traditional CI and CI of UCSQ and overall visual scores were moderate and high (r = - 0.59; p = 0.005 vs. r = - 0.81; p < 0.000). Mean ICV was 910 mL (671-1303), and ICV varied from decreased to increased compared to normative values. Negligible correlation was found between ICV and UCSQ (r = 0.26; p > 0.05) and between ICV and CI and visual score (r = - 0.30; p > 0.05 and r = 0.17; p > 0.05, respectively).

CONCLUSION

Our current advice is to use traditional CI in clinical practice; it is easy to use and minimally invasive. However, UCSQ is more precise and objective and captures whole skull shape. Therefore, UCSQ is preferable for research. Additionally, more severe scaphocephaly does not result in more deviant skull volumes.

Clinical and aesthetic outcome analysis of a case series of trigonocephaly patients after early fronto-orbital advancement

The timing of operation for trigonocephaly is recommended before the age of 1 year. To evaluate the outcome of a consecutive series operated in a single centre, the current study was performed. The study cohort comprised a retrospective single-centre series of 20 patients with trigonocephaly operated before the age of 12 months. Intra- and postoperative clinical data, as well as aesthetic outcome measured by two-dimensional asymmetry index (2D AI) and correction of the curvature on lateral and pictures from above were evaluated. Furthermore, to evaluate postoperative aesthetic outcome, a new classification (Grades I-IV) was proposed. The mean age of the cohort was 7.9 months. 2D AI changed from 0.049 pre- to 0.03 postoperatively (P=0.165). The correction of the curvature in lateral pictures yielded a significant change on postoperative pictures (P=0.002) as well as on pictures from above. Using the proposed classification, 16/20 (80%) patients had a postoperative outcome of Grade I, 4/20 (20%) Grade II. In patients operated before the age of 12 months an excellent (Grade I, AI <0.03) or good aesthetic (Grade II, adequate parents' or surgeon's opinion) result could be reached in all patients.

NGS targeted screening of 100 Scandinavian patients with coronal synostosis

Craniosynostosis (CS), the premature closure of one or more cranial sutures, occurs both as part of a syndrome or in isolation (nonsyndromic form). Here, we have studied the prevalence and spectrum of genetic alterations associated with coronal suture closure in 100 Scandinavian patients treated at a single craniofacial unit. All patients were phenotypically assessed and analyzed with a custom-designed 63 gene NGS-panel. Most cases (78%) were syndromic forms of CS. Pathogenic and likely pathogenic variants explaining the phenotype were found in 80% of the families with syndromic CS and in 14% of those with nonsyndromic CS. Sixty-five percent of the families had mutations in the CS core genes FGFR2, TWIST1, FGFR3, TCF12, EFNB1, FGFR1, and POR. Five novel pathogenic/likely pathogenic variants in TWIST1, TCF12, and EFNB1 were identified. We also found novel variants in SPECC1L, IGF1R, and CYP26B1 with a possible modulator phenotypic effect. Our findings demonstrate that NGS targeted sequencing is a powerful tool to detect pathogenic mutations in patients with coronal CS and further emphasize the importance of thorough assessment of the patient's phenotype for reliable interpretation of the molecular findings. This is particularly important in patients with complex phenotypes and rare forms of CS.

A review of the management of single-suture craniosynostosis, past, present, and future

BACKGROUND

Craniosynostosis is a condition in which 2 or more of the skull bones fuse prematurely. The spectrum of the disorder most commonly involves the closure of a single suture in the skull, but it can also involve syndromic diagnoses in which multiple skull bones and/or bones outside of the cranium are affected. Craniosynostosis can result in cosmetic deformity as well as potential limitations in brain growth and development, and the neurocognitive impact of the condition is just starting to be studied more thoroughly. Our knowledge regarding the genetics of this condition has also evolved substantially. In this review, the authors explore the medical and surgical advancements in understanding and treating this condition over the past century, with a focus on how the diagnosis and treatment have evolved.

METHODS

In this review article, the authors, who are the leaders of a craniofacial team at a major academic pediatric hospital, focus on single-suture craniosynostosis (SSC) affecting the 6 major cranial sutures and discuss the evolution of the treatment of SSC from its early history in modern medicine through the current state of the art and future trends. This discussion is based on the authors' broad experience and a comprehensive review of the literature.

SUMMARY

The management of SSC has evolved substantially over the past 100 years. There have been major advances in technology and medical knowledge that have allowed for safer treatment of this condition through the use of newer techniques and technologies in the fields of surgery, anesthesia, and critical care. The use of less invasive surgical techniques along with other innovations has led to improved outcomes in SSC patients. The future of SSC treatment will likely be guided by elucidation of the causes of neurocognitive delay in these children and assessment of how the timing and type of surgery can mitigate adverse outcomes.

Imaging in craniosynostosis: when and what?

PURPOSE

Currently, the interest on craniosynostosis in the clinical practice is raised by their increased frequency and their genetic implications other than by the still existing search of less invasive surgical techniques. These reasons, together with the problem of legal issues, make the need of a definite diagnosis for a crucial problem, even in single-suture craniosynostosis (SSC). Although the diagnosis of craniosynostosis is primarily the result of physical examination, craniometrics measuring, and observation of the skull deformity, the radiological assessment currently plays an important role in the confirmation of the diagnosis, the surgical planning, and even the postoperative follow-up. On the other hand, in infants, the use of radiation or the need of sedation/anesthesia raises the problem to reduce them to minimum to preserve such a delicate category of patient from their adverse effects.

METHODS, RESULTS AND CONCLUSIONS

This review aims at summarizing the state of the art of the role of radiology in craniosynostosis, mainly focusing on indications and techniques, to provide an update not only to pediatric neurosurgeons or maxillofacial surgeons but also to all the other specialists involved in their management, like neonatologists, pediatricians, clinical geneticists, and pediatric neurologists.

Evaluation of Direct Surgical Remodeling of Frontal Bossing in Patients With Sagittal Synostosis

BACKGROUND

The need for surgical correction of frontal bossing in patients with sagittal synostosis is currently debated. The authors retrospectively analyzed frontal bossing in patients with isolated, nonsyndromic sagittal synostosis who underwent calvarial remodeling with and without frontal craniotomy and compared with control subjects.

METHODS

The authors analyzed computed tomography (CT) scans of patients with sagittal synostosis <9 months of age (6.2 ± 1.6 months) who underwent modified-pi procedure either with frontal craniotomy (FC, n = 15) or without frontal craniotomy (NFC, n = 10). Only patients treated with both pre-operative and 1-year post-operative CT scans were included. Non-synostotic age-matched control scans were also analyzed. Cephalic index (CI), 3 previously validated measures of frontal bossing (bossing angle, horizontal bossing ratio, and vertical bossing ratio), and pre-nasion volume ratio were obtained. Additionally, three-dimensional photographs of 10 FC patients were evaluated for frontal bossing between 1 and 8 years post-operatively.

RESULTS

Pre-operatively, no significant differences were found between the 2 groups (.064<P < 0.940). Both groups showed greater scaphocephaly and frontal bossing compared to controls (P < 0.001). One-year post-operatively, all measures improved but remained significantly different than normal values except: CI of NFC patients (P = 0.296); bossing angle (P = 0.068) and horizontal bossing ratio (P = 0.129) of FC patients. Compared to NFC patients, horizontal bossing ratio was significantly improved in FC patients (P = 0.017, mean difference of 0.047). No other statistically significant differences were found between the 2 techniques (0.127<P < 0.637).In our long-term study of FC patients up to 9 years of age (n = 10), the authors analyzed forehead inclination as our measure of frontal bossing in three-dimensional photographs. A linear regression analysis showed a significant reduction in forehead inclination with age, decreasing 1.3 ± 0.4 degrees per year (P = 0.021). Forehead inclination for controls did not change significantly with age (P = 0.558).

CONCLUSIONS

At 1-year following modified-pi procedure, FC patients approached normalization of their forehead morphology to a greater extent than NFC patients. However, neither group completely normalized during this time period. Frontal bossing in FC patients continued to decrease with age, which reveals the post-operative dynamic nature of frontal bone morphology during childhood for these patients.

Is There an Advantage to Minimizing Surgery in Scaphocephaly? A Study on Extended Strip Craniectomy Versus Extensive Cranial Vault Remodeling

BACKGROUND

Different techniques have been described to correct scaphocephaly. In authors' institution, total cranial vault remodeling (TCVR) was the standard of care. To limit the extent of surgery and the need for transfusion, the technique was minimized to extended strip craniectomy (ESC) without helmet therapy. This retrospective study compares outcome and morbidity between ESC and TCVR.

METHODS

Twenty-seven scaphocephalic patients were included. The ESC was performed in 9 patients between 2012 and 2014, and TCVR in 17 patients between 2008 and 2016. Data on blood loss and transfusion rate, duration of surgery, length of hospital stay (LOS), head circumference, and cephalic index (CI) were collected retrospectively. A cosmetic outcome score (COS) was developed to rate esthetic outcome since CI is a limited and crude measurement of cosmetic outcome.

RESULTS

The LOS was identical in both groups, but duration of surgery was significantly shorter in ESC (P < 0.0001). Transfusion rate appeared higher in the TCVR group, but differences were not significant (P = 0.11). Cosmetic outcome appeared slightly worse in the ESC group, but results were not significantly different (P = 0.66). There was, however, a significant improvement in postoperative CI in the TCVR group (P < 0.0001).

CONCLUSION

The only advantage of ESC was the reduced duration of surgery, but this could not prevent the need for transfusion in this group of patients. The improvement of the CI was significantly less pronounced after ESC, but the COS was not significantly worse in the ESC group. The scar and LOS were similar in both groups. Therefore, our findings indicate that minimizing TCVR to ESC without helmet therapy does not provide significant advantages.

An update of ophthalmic management in craniosynostosis

Craniosynostosis has a varied clinical spectrum, ranging from isolated single suture involvement to multisutural fusions. Syndromic and nonsyndromic patients require orchestrated and multidisciplinary care from birth to adulthood. Advances in our understanding of craniosynostosis over the last quarter-century have resulted in more systematic management of the problems associated with the syndromic and nonsyndromic forms of this condition. This review provides an update on the genetic basis of, management of strabismus and oculoplastic manifestations in, and visual surveillance of patients with craniosynostosis.

Practical Computed Tomography Scan Findings for Distinguishing Metopic Craniosynostosis from Metopic Ridging

Background:

Premature fusion of the metopic suture (ie, metopic craniosynostosis) can be difficult to discriminate from physiological closure of the metopic suture with ridging (MR). Yet, MCS is treated surgically, whereas MR is treated nonsurgically. Often, the diagnosis can be made by physical examination alone, but in difficult cases, a computed tomography (CT) scan can add additional diagnostic information.

Methods:

We de-identified, randomized, and analyzed the CT scans of patients with MCS (n = 52), MR (n = 20) and age-matched normative controls (n = 52) to identify specific findings helpful in distinguishing between MCS and MR. Four expert clinicians were blinded to the clinical diagnosis and assessed each CT for features of the orbits, frontal bones, and inner table of calvaria.

Results:

Although no single feature was diagnostic of MCS, we identified several signs that were correlated with MCS, MR, or controls. Features such as “posteriorly displaced frontal bone” and “frontal bone tangent to mid-orbit or medial” demonstrated higher correlation with MCS than MR and the addition of other features improves the accuracy of diagnosis as did inclusion of the interfrontal divergence angle.

Conclusion:

The presence of a closed metopic suture in addition to other CT scan findings may improve the accuracy of diagnosing MCS, MR, and normocephaly.

Impact of extra-axial cerebrospinal fluid collection in frontal morphology after surgical treatment of scaphocephaly

Background

Infants with sagittal suture synostosis often present a pathologic dilatation of subarachnoid spaces. The impact of such subarachnoid spaces' enlargement in the morphology of the skull, especially on the forehead and on the surgical outcome, was analyzed.

Methods

Children less than 6 months of age undergoing a surgical correction of the scaphocephaly with Renier's H technique between 2003 and 2008 were included in the study. In these patients, preoperative and postoperative fronto-occipital diameter (FOD), biparietal diameter (BPD), temporal width (TW), and naso-frontal angle (NFA) were measured. Cranial index (CI) and the difference between preoperative and postoperative CI (ΔCI) were calculated. Preoperative cranio-cortical width (CCW) was measured to analyze the subarachnoid spaces' volumes. The children here considered were then divided into two groups: Group 1 with CCW within normal estimated value corrected for age and Group 2 with CCW larger than estimated normal value.

Results

About 159 children were enrolled (72.3% male). CCW was larger than expected in 95 children (59.8%). A positive correlation between CCW and BPD (P ≤ 0.001) and a negative correlation between CCW and NFA (P ≤ 0.001) were found. When comparing the two groups, the mean age at preoperative computed tomography (CT) scan was 121 days in Group 1 and 110 days in Group 2. The mean age at operation was 130 days in Group 1 and 123 in Group 2. The mean age at postoperative examination (RX or CT scan) was 53.4 months in Group 1 and 51.8 months in Group 2. Preoperatively, the mean BPD, TW, and CI were significantly larger in Group 2 (P ≤ 0.01), whereas the NFA was significantly narrower (P = 0.03). Postoperative analysis showed that ΔCI was statistically different between the two groups (Group 1: 10%, Group 2: 7%; P < 0.04). The duration of follow-up period ranged between 19 and 129 months.

Conclusion

Two main subtypes of forehead of infants with scaphocephaly may be distinguished. Indeed, the morphology of the forehead differs when a pathologic subarachnoid spaces' enlargement is present preoperatively and it also affects the postoperative evolution. Such observation highlights the importance of evaluating whether subarachnoid spaces are enlarged when planning a surgical correction in isolated sagittal suture synostosis.

Control of metopic emissary veins in trigonocephaly surgery. Technical note

INTRODUCTION

Trigonocephaly with its premature fusion of the metopic synostosis is associated with a risk of cerebral compression and several craniofacial morphological deformations. Numerous surgical techniques have been proposed to enlarge and reshape the forehead. They all carry a risk of bleeding during osteotomies, especially in the region of the superior sagittal sinus (SSS) encased in the early fused suture and of the paired metopic transosseous emissary veins superior to the glabella, which is typical of this type of synostosis. In fact, these paired metopic transosseous veins are often, if not always, the source of major bleeding when torn during the elevation of the frontal flap.

TECHNICAL NOTE

A simple technical variant may prevent or at least easily control bleeding in this region during the early phases of the surgical repair. The technical variant to the standard surgical techniques utilized to correct trigonocephaly consists in preserving a triangle of bone above the glabella (about 4 cm at the base and 4 cm in height). The triangle of bone contains the initial segment of the SSS and the emissary metopic veins draining the frontal poles. After removing the frontal flap in a conventional manner, this technical variant allows to detach the veins as well as the SSS from the surrounding bone structures under direct visualization, also in case of vessels running partially encased in the bone. Once the venous structure is detached and hemostasis controlled, this last piece of frontal bone may be removed without unnecessary "iatrogenic" bleeding.

CONCLUSION

The propounded procedure does not prolong the surgical time significantly and does not require additional surgical skills or equipment.

Bilambdoid and sagittal synostosis: Report of 39 cases

Background:

Bilambdoid and sagittal synostosis (BLSS), also called “Mercedes Benz synostosis,” is a multisutural craniosynostosis that has been described as a specific entity. However, this synostotic pattern can also be found in syndromic craniostenosis. To better define this entity we reviewed our experience with bilambdoid and sagittal synostosis.

Methods:

We searched our prospective database for cases of bilambdoid and sagittal synostosis among all types of craniosynostosis. Two groups were distinguished – patients with isolated BLSS and the group of syndromic craniostenosis for whom BLSS was observed at initial presentation. We reviewed the clinical findings, associated diseases, and their management specifically for isolated BLSS patients.

Results:

Thirty-nine patients were diagnosed with bilambdoid and sagittal synostosis among 4250 cases of craniosynostosis treated in our department over a period of 42 years. Among them, 8 were finally diagnosed as Crouzon syndrome. Of the 31 patients identified with isolated bilambdoid and sagittal synostosis, 25 (81%) were males and 6 (19%) were females. The average age at diagnosis was 17 months. At diagnosis, 16% of the population presented with papillary edema and 58% posterior digitate impressions. Two types of craniofacial dysmorphy were observed – a pattern with narrow occiput (71% of cases) and a pattern with dolichocephaly (29% of cases). Cerebellar tonsillar herniation was the most frequently associated malformation (61% of the isolated BLSS). Surgical management evolved during the years, and several surgical techniques were used to treat patients with BLSS, including isolated biparietal vault remodeling, posterior vault remodelling, and posterior vault expansion with internal or external distraction. In some cases, a craniocervical junction decompression was also performed. The mean follow-up was 82 months (7 years). The overall mental development was within normal limits in most children, but a mental delay was found in 25%.

Conclusion:

Bilambdoid and sagittal synostosis constitute an isolated entity in almost 80% of the cases, whereas in the remaining 20% it is part of a faciocraniosynostosis syndrome. Two phenotypes may be found. Early surgical management is indicated, and several techniques can be used in this heterogeneous population. A cerebellar tonsillar prolapse is present in a majority of cases.

Is Postoperative Intensive Care Unit Care Necessary following Cranial Vault Remodeling for Sagittal Synostosis?

BACKGROUND

Of U.S. craniofacial and neurosurgeons, 94 percent routinely admit patients to the intensive care unit following cranial vault remodeling for correction of sagittal synostosis. This study aims to examine the outcomes and cost of direct ward admission following primary cranial vault remodeling for sagittal synostosis.

METHODS

An institutional review board-approved retrospective review was undertaken of the records of all patients who underwent primary cranial vault remodeling for isolated sagittal craniosynostosis from 2009 to 2015 at a single pediatric hospital. Patient demographics, perioperative course, and outcomes were recorded.

RESULTS

One hundred ten patients met inclusion criteria with absence of other major medical problems. Average age at operation was 6.7 months, with a mean follow-up of 19.8 months. Ninety-eight patients (89 percent) were admitted to a general ward for postoperative care, whereas the remaining 12 (11 percent) were admitted to the intensive care unit for preoperative or perioperative concerns. Among ward-admitted patients, there were four (3.6 percent) minor complications; however, there were no major adverse events, with none necessitating intensive care unit transfers from the ward and no mortalities. Average hospital stay was 3.7 days. The institution's financial difference in cost of intensive care unit stay versus ward bed was $5520 on average per bed per day. Omitting just one intensive care unit postoperative day stay for this patient cohort would reduce projected health care costs by a total of $540,960 for the study period.

CONCLUSION

Despite the common practice of postoperative admission to the intensive care unit following cranial vault remodeling for sagittal craniosynostosis, the authors suggest that postoperative care be considered on an individual basis, with only a small percentage requiring a higher level of care.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Genetic advances in craniosynostosis

Craniosynostosis, the premature ossification of one or more skull sutures, is a clinically and genetically heterogeneous congenital anomaly affecting approximately one in 2,500 live births. In most cases, it occurs as an isolated congenital anomaly, that is, nonsyndromic craniosynostosis (NCS), the genetic, and environmental causes of which remain largely unknown. Recent data suggest that, at least some of the midline NCS cases may be explained by two loci inheritance. In approximately 25-30% of patients, craniosynostosis presents as a feature of a genetic syndrome due to chromosomal defects or mutations in genes within interconnected signaling pathways. The aim of this review is to provide a detailed and comprehensive update on the genetic and environmental factors associated with NCS, integrating the scientific findings achieved during the last decade. Focus on the neurodevelopmental, imaging, and treatment aspects of NCS is also provided.

In vitro evaluation of poly (lactic-co-glycolic acid)/polyisoprene fibers for soft tissue engineering

The polymeric blend of poly (lactic-co-glycolic acid) (PLGA) and polyisoprene (PI) has recently been explored for application as stents for tracheal stenosis and spring for the treatment of craniosynostosis. From the positive results presented in other biomedical applications comes the possibility of investigating the application of this material as scaffold for tissue engineering (TE), acquiring a deeper knowledge about the polymeric blend by exploring a new processing technique while attending to the most fundamental demands of TE scaffolds. PLGA/PI was processed into randomly oriented microfibers through the dripping technique and submitted to physical-chemical and in vitro characterization. The production process of fibers did not show an effect over the polymer's chemical composition, despite the fact that PLGA and PI were observed to be immiscible. Mechanical assays reinforce the suitability of these scaffolds for soft tissue applications. Skeletal muscle cells demonstrated increases in metabolic activity and proliferation to the same levels of the control group. Human dermal fibroblasts didn't show the same behaviour, but presented cell growth with the same development profile as presented in the control group. It is plausible to believe that PLGA/PI fibrous three-dimensional scaffolds are suitable for applications in soft tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2581-2591, 2017.

Photometric evaluation of cranial and facial symmetry in hemicoronal single suture synostosis treated with surgical fronto-orbital remodeling

OBJECTIVE

Evaluation of frontal vault symmetry and progressive facial symmetrization in a cohort of patients with hemicoronal single suture synostosis treated with a standardized cranioplasty and rigid fixation.

PATIENTS AND METHODS

Fifty-four patients with hemicoronal synostosis operated between 1999 and 2014 were reviewed retrospectively. Pre, immediately postoperative and yearly photographs from the top of the skull and frontal views of the face were taken with the same head position and projection. A photogrammetric method was applied to quantify the pre and postoperative contour changes. The anterior skull hemispheres were traced, divided into two equal parts and the areas were compared. Angular measurements obtained by the intersection of the interpupillary line and the glabella perpendicular vertical line were calculated. The average photographic follow-up was 6.8 years. Range 1-14 years.

RESULTS

The average advancement on the affected side was 18 mm (range: 16-23 mm). The pre-surgical cranial area on the affected side was increased on average 14.6 + 2.4% (range: 10-18%). The angular measurements documented the frontal symmetry obtained and the progressive improvement of facial symmetry.

CONCLUSION

Cranioplasty with rigid fixation achieved a stable correction of anterior plagiocephaly leading to subsequent symmetrical facial growth. Photogrammetry allowed fora quantitative long-term validation.

Unilateral coronal synostosis: can we trust the sagittal suture as a landmark for the underlying superior sagittal sinus?

OBJECTIVE The sagittal suture is usually considered an external anatomical landmark, indicating the location of the superior sagittal sinus (SSS) for surgical approaches. Children with unilateral coronal synostosis (UCS) often present with an important deviation of the sagittal suture. Because these patients usually undergo frontal reconstruction or even endoscope-assisted minimally invasive procedures, it is imperative to know the location of the SSS. The aim of this investigation was to study the anatomical relationship between the SSS and the sagittal suture in children with anterior plagiocephaly. METHODS The authors retrospectively studied the relationship between the sagittal sinus and the sagittal suture at 5 points: nasion, midpoint nasion-bregma, bregma, midpoint bregma-lambda, and lambda. The study analyzed CT scans of 50 children with UCS admitted to the craniofacial unit of Necker Enfants Malades Hospital between March 2006 and March 2013 and compared them with 50 control children with no evidence of craniosynostosis, bone disease, or genetic syndromes. The authors also analyzed the presence of extracerebral fluid collection and ventricular asymmetry in children with UCS. RESULTS Fifty-six percent of patients had anterior right UCS and 44% had left-sided UCS. Type I UCS was seen in 1 patient, Type IIA in 20 patients, Type IIB in 20 patients, and Type III in 9 patients. The authors found that the nasion is usually deviated to the ipsilateral side of the synostosis, the bregma contralaterally, and the lambda ipsilaterally. The gap distances between the reference point and the SSS were 0-7.3 mm (mean 1.4 mm) at the nasion; 0-16.7 mm (mean 3.8 mm) at the midpoint nasion-bregma; 0-12 mm (mean 5.8 mm) at the bregma; 0-9.5 mm (mean 3 mm) at the midpoint bregma-lambda; and 0-11.6 mm (mean 5.5 mm) at the lambda. Conversely, a discrepancy of more than 1 mm between the SSS and the position of the suture was found only in 7 control cases (14%). Of patients with UCS, 38% presented with an extracerebral fluid collection contralateral to the fused coronal suture. Fifty-two percent had a ventricular asymmetry, which was characterized by reduced ventricular volume ipsilateral to the synostosis in all but 1 patient. CONCLUSIONS In this study, the SSS was usually deviated contralaterally to the closed coronal suture. It tended to be in the midline of the cranial vault and could be projected virtually along an imaginary line passing through the midline of the cranial base. The authors recommend a distance of 37 mm from the sagittal suture as a safety margin during surgery.

Cerebrospinal fluid collections in sagittal suture synostosis

PURPOSE

The premature fusion of the sagittal suture (scaphocephaly) may be associated with intracranial cerebrospinal fluid (CSF) dynamics alterations resulting in pericerebral effusion (PE) and/or ventriculomegaly. However, the etiology and development of such collections are not fully elucidated. The aims of this study are to clarify the characteristics of intracranial CSF collection in scaphocephaly, consider the role of surgery, and analyze the prognostic factor on CSF dynamics.

METHOD

The pre- and postoperative cerebral imaging of 63 children (48 boys, 15 girls) with scaphocephaly who underwent craniotomy with decompression of the superior sagittal sinus (SSS) before 6 months of age between 2008 and 2015 were retrospectively studied. The PE was compared to the estimated value corrected for age (normal control). Evans' index (EI) was calculated. Correlations among these values and indices were analyzed.

RESULT

Preoperatively, 36 of 63 patients (57 %) had larger PE than expected, and 36 of 63 patients (57 %) had pathological EI (EI > 0.3), and among them, 26 (46 %) had both. Patients with large PE tended to have pathological EI (p = 0.005). The PE and the EI were significantly decreased postoperatively (p < 0.001). The PE decreased faster than the expected natural course in 59 of 63 patients (92 %) postoperatively.

CONCLUSION

The precise comparison with estimated PE prevalence corrected for age showed that PE can be found in more than half of the children with scaphocephaly, associated with ventriculomegaly. Surgery has a significant efficacious role in decreasing those CSF collections. The long-term significance of such CSF collections in scaphocephaly is still to be elucidated.

Neurodevelopmental and esthetic results in children after surgical correction of metopic suture synostosis: a single institutional experience

INTRODUCTION

Metopic suture synostosis leading to trigonocephaly is considered the second most frequent type of craniosynostosis. Besides esthetic results, we present 25 consecutive pediatric cases operated upon metopic suture synostosis with a focus on the child's motor, speech, and neurocognitive development.

METHODS

Twenty-five children (aged 6 to 33 months; median 9.2 months) with trigonocephaly were operated upon between 2002 and 2012 with fronto-orbital advancement including frontal bone cranioplasty and fronto-orbital bandeau remodeling. Neurodevelopmental deficits were evaluated by a standardized questionnaire including gross motor function, manual coordination, speech, and cognitive function performed by independent pediatric/developmental neurologists before surgery and at 6 and 12 months of time interval postoperatively.

RESULTS

Twenty-one (84 %) boys and four (16 %) girls were included in this study. Mean follow-up period was 33 ± 28 months. Outcome analysis for esthetic results showed a high degree of satisfaction by the parents and treating physicians in 23 cases (92 %). Preoperative evaluation revealed neurodevelopmental deficits in 10 children (40 %; six mild, four moderate degree). Twelve children (48 %) were proven to have a normal preoperative neuropediatric development. Mild or moderate developmental restraints were no longer apparent in 6/13, improved but still apparent in 3/13, and stable in 4/13, 6 months after cranial vault reconstruction. At 12 months of follow-up, deficits were no longer present in 9/13 and improved in 4/13. Apart from this cohort, two children were diagnosed with a syndromic form, and one child had a fetal valproate syndrome. In these three children, neurodevelopmental deficits were more pronounced. Neurocognitive progress was obvious, but was comparably slower, and major deficits were still apparent at last follow-up. All children with proven mild/moderate/severe deficits received intensive physiotherapy, logopedic, or neurobehavioral support.

CONCLUSIONS

As shown in a single-center observation, surgical correction of metopic suture synostosis not only refines esthetic appearance but also might improve neurodevelopmental outcome if deficits are apparent, even in syndromic forms of the deformity under additional physiotherapy, logopedic, or neurobehavioral support.

Endoscope-assisted repair of metopic synostosis

PURPOSE

Endoscopic treatment of nonsyndromic craniosynostosis has been used in recent decades. The aim of this study is to present the results of endoscope-assisted surgery of the patients with metopic synostosis.

METHODS

Nineteen patients with metopic synostosis underwent endoscope-assisted surgery between 2005 and 2012. The frontal angle was measured on CT scans pre- and postoperatively. A midline strip craniectomy was made, making sure that the removal extended inferiorly to the nasofrontal suture. Postoperatively, all patients wear a custom molding helmet. The helmet was then worn for 23 h daily and worn for the next 10-12 months.

RESULTS

There were 15 boys and 4 girls, ranging in age from 4 to 24 weeks. Mean operative time and transfused blood volume were 43.42 min and 76.31 ml, respectively. Mean follow-up was 59.3 weeks. Good esthetic results, judged by radiological examination and photograph comparison, were obtained in all patients.

CONCLUSIONS

Endoscope-assisted repair of metopic synostosis is safe and offers promising results in infants before the age of 6 months. Molding helmet therapy following surgery is very important in obtaining the good results. Early diagnosis and referral for surgery are crucial.

Scaphocephaly and cranial vault reconstruction: Renier's 'H' technique

BACKGROUND

Resulting from an early fusion of the sagittal suture, scaphocephaly (SC) is the most frequent form of all craniosynostosis and represents 40-60% of all cases. The scope of this study is to describe the first series of Renier's 'H' technique to be applied in children with SC outside of France.

METHODS

A consecutive review is made of the medical records of children hospitalized in the last 6 years (between March 2007 and March 2013) with isolated SC in whom Renier's 'H' technique was performed.

RESULTS

Thirteen children met the criteria for inclusion in the study. Considering medical evaluation and parental satisfaction, the evaluation of postsurgical cranial reconstruction was classified as satisfactory in all cases.

CONCLUSIONS

We consider the Renier's H technique to be effective in the cranial reshaping of children with isolated SC, with satisfactory esthetic postsurgical results.

Scaphocephaly correction with retrocoronal and prelambdoid craniotomies (Renier's "H" technique)

The aim of this paper is to describe the surgical technique, originally devised by Dr. Renier which is currently used to treat children with scaphocephaly under 6 months of age at the Craniofacial Unit of Hopital Necker Enfants Malades (French National Referral Center for Faciocraniosynostosis), focusing on its advantages and limitations.

Anterior fronto-orbital remodeling for trigonocephay

INTRODUCTION

Trigonocephaly secondary to the premature fusion of the metopic synostosis is associated to a risk of cerebral compression and several craniofacial morphological alterations. Numerous surgical techniques have been proposed. They all carry a risk of secondary temporal hollowing

PURPOSE

The aim of this paper is to describe the surgical technique used for trigonocephaly at the craniofacial unit of Hopital Necker Enfants Malades (French National Referral Center for Faciocraniosynostosis) focusing on its advantages and limitations. Resorbable osteosynthesis should be part of the current techniques.

Spring-assisted posterior skull expansion without osteotomies

INTRODUCTION

A posterior flatness of the skull vault can be observed in infants with brachycephaly. Such posterior deformation favours the development of turricephaly which is difficult to correct. To reduce the risk of such deformation, an early posterior skull remodelling has been suggested. Translambdoid springs can be used to allow for a distraction through the patent lambdoid sutures and obtain a progressive increase of the posterior skull volume.

SURGICAL TECHNIQUE

The procedure consists in a posterior scalp elevation, the patient being on a prone position. Springs made of stainless steel wire (1.5 mm in diameter) are bent in a U-type fashion, and strategically positioned across both lambdoid sutures. No drilling is usually necessary, as the lambdoid suture can be gently forced with a subperiosteal elevator in its middle and an indentation can be created with a bony rongeur on each side of the open suture to allow for a self-retention of bayonet-shaped extremity of the spring. Careful attention is addressed to the favoured prone position during the post-operative period. After a delay of 3-6 months, the springs can be removed during a second uneventful procedure, with limited incisions, usually as a preliminary step of the subsequent frontal remodelling.

CONCLUSION

The concept of spring-assisted expansion across patent sutures under 6 months of age was confirmed in our experience (19 cases). Insertion of the springs allowed for immediate distraction across the suture. A posterior remodelling of the skull could be achieved with minimal morbidity allowing to delay safely a radical anterior surgery.

Isolated sagittal craniosynostosis: definition, classification, and surgical indications

Sagittal craniosynostosis (SC) remains the most common type of synostosis, accounting for about a half of all forms. It would result from a mesenchymal disorder involving the intramembranous ossification of the sagittal suture and leading to its early fusion. No specific data on the etiologic factors are currently available. The premature ossification of the sagittal suture can result in three main types of SC, according to the different segment prevalently involved: anterior, posterior, and complete SC. The diagnosis is easily obtained by clinical examination. However, a radiological work up (3D CT scan) may be necessary to rule out hidden venous or cranial anomalies possibly associated with most severe cases, or for the surgical planning. The most common indication for surgery is the improvement of the cosmetic appearance of the skull, since a cranial deformation may have a significant psychological impact on affected subjects. To relieve from raised intracranial pressure is a further indication to surgery. Although an increased intracranial pressure can be demonstrated in a minority of affected children at diagnosis, indeed, it can present later (usually after the second/third year of life) with chronic symptoms. The role of surgery in the preservation of cognitive functions in scaphocephalic patients does not seem to be relevant, since minor anomalies of the cerebral development associated with SC would occur independently from the cranial shape. On the other hand, the surgical correction may show a protective effect on some visual skills, like the ability to fix and follow, and the fixation shift.

Metopic synostosis

Premature closure of the metopic suture results in a growth restriction of the frontal bones, which leads to a skull malformation known as trigonocephaly. Over the course of recent decades, its incidence has been rising, currently making it the second most common type of craniosynostosis. Treatment consists of a cranioplasty, usually preformed before the age of 1 year. Metopic synostosis is linked with an increased level of neurodevelopmental delays. Theories on the etiology of these delays range from a reduced volume of the anterior cranial fossa to intrinsic malformations of the brain. This paper aims to provide an overview of this entity by giving an update on the epidemiology, etiology, evolution of treatment, follow-up, and neurodevelopment of metopic synostosis.