Normative ranges of anthropometric cranial indices and metopic suture closure during infancy

Multimodal Outcomes of Early Open Extended Midline Strip Craniectomy With Bilateral Microbarrel Staving for Correction of Isolated Nonsyndromic Sagittal Synostosis

AIM

Sagittal synostosis is the most common craniosynostosis. The aim of surgery is to preserve cognitive function and to correct the morphologic changes. In our unit, the authors offer strip craniectomy and microbarrel staving (SMB) performed at 16 to 22 weeks. This study aims to ascertain the 7-year outcome of scaphocephaly correction by SMB. The authors investigate whether the improvement in cranial index (CI) is sustained over time, and report speech and language and neurodevelopmental outcomes.

METHODS

All nonsyndromic patients with sagittal synostosis who underwent SMB between 2009 and 2012 were identified from a prospectively created database that recorded anthropometric measurements, quality metrics, and neurodevelopmental outcomes.

RESULTS

A total of 27 patients were analyzed. The mean CI preoperatively was 67.5% (±3.5), and at 7 years 78% (±4.8). Regarding neurodevelopmental outcomes at 7 years, SDQ responses did not highlight any concerns for social, emotional, or behavioral outcomes. The vast majority of those who completed a WASI-II assessment performed within the average ranges in terms of cognitive ability. In terms of speech and language 70% of subjects demonstrated receptive language within normal level (WNL). Seventy-seven percent of subjects demonstrated expressive language WNL.

CONCLUSIONS

In conclusion, after 7 years of follow-up, early open extended SMB is a safe and effective method for correction of isolated nonsyndromic isolated sagittal synostosis. Across the neurodevelopmental measures and assessments, the children in the current study appeared to perform within expected ranges. Speech and language problems are more prevalent than in the general population.

Persistent Depression of the Lambda Site with Progressive Skull Deformity May Be a Sign of Suture Closure: Case Series and Pathologic Consideration

BACKGROUND

Flat head syndrome (FHS) sometimes occurs when a baby maintains the same head position during the first several months of life, causing a skull deformity. FHS usually improves with time and natural growth, although some show aggravation against conservative treatment. We reviewed pathologically proved early closure of skull suture that may be seen secondary to FHS.

METHODS

The clinical and radiologic findings of the patients who showed progressive skull deformity resembling FHS were retrospectively reviewed. All the patients underwent surgical treatment and pathologic specimens were obtained.

RESULTS

The detected patients included two 5-month-old infants and one 1-year-old child. The former were conservatively treated without any obvious premature suture closure on computed tomography (CT), and later developed progressive tower-like skull deformities. The infants were diagnosed with possible premature fusion of lambda site and underwent removal around lambda depression (LD). The latter showed evident sagittal suture closure on CT with digital markings, and was diagnosed with increased intracranial pressure and underwent cranioplasty of posterior expansion. Histopathologic specimens obtained from the patients' resected sutures showed irregularly narrowed suture structure with ossification and fibrous tissue proliferation within them, supporting the diagnosis of premature closure of the sagittal sutures. Their postoperative courses were uneventful, and their skull deformities subsequently improved.

CONCLUSIONS

Conservative therapy-resistant progressive occipital skull deformity with LD may be a sign of early suture closure, even if CT does not show obvious suture closure. The findings are helpful for early diagnosis and might lead to minimal invasive surgery if needed.

Comparison of molding helmet therapy versus natural course in twins with nonsynostotic head deformation

This observational study aims to compare the effectiveness of helmet therapy versus natural course in twin siblings suffering from nonsynostotic head deformations. A retrospective analysis of all twin couples treated with helmet therapy between March 2009 and May 2017 at an orthopedic hospital was conducted. Inclusion criteria were me if only one twin received helmet therapy. The other twin acted as control. A classification for different head shapes was used. A total of 61 twin couples was included. Change in outcome parameters of helmet therapy and natural course differed significantly: cranial vault asymmetry (CVA) -0.66 cm vs. -0.04 cm, cranial vault asymmetry index (CVAI) -5.35% vs. -0.51% (both p < 0.001), cephalic index (CI) -3.10% vs. -1.91% (p = 0.006). Helmet therapy showed a success rate (CI < 90% and CVAI ≤7% or better) of 63.6% vs. 21.1% in children with natural course (p = 0.002). Within the limitations of the study it seems that the results of this retrospective, single-center study confirm that helmet therapy to be a reliable treatment for mild to severe positional head deformation.

"Validation of Artificial Intelligence Severity Assessment in Metopic Craniosynostosis"

OBJECTIVE

Several severity metrics have been developed for metopic craniosynostosis, including a recent machine learning-derived algorithm. This study assessed the diagnostic concordance between machine learning and previously published severity indices.

DESIGN

Preoperative computed tomography (CT) scans of patients who underwent surgical correction of metopic craniosynostosis were quantitatively analyzed for severity. Each scan was manually measured to derive manual severity scores and also received a scaled metopic severity score (MSS) assigned by the machine learning algorithm. Regression analysis was used to correlate manually captured measurements to MSS. ROC analysis was performed for each severity metric and were compared to how accurately they distinguished cases of metopic synostosis from controls.

RESULTS

In total, 194 CT scans were analyzed, 167 with metopic synostosis and 27 controls. The mean scaled MSS for the patients with metopic was 6.18 ± 2.53 compared to 0.60 ± 1.25 for controls. Multivariable regression analyses yielded an R-square of 0.66, with significant manual measurements of endocranial bifrontal angle (EBA) (P = 0.023), posterior angle of the anterior cranial fossa (p < 0.001), temporal depression angle (P = 0.042), age (P < 0.001), biparietal distance (P < 0.001), interdacryon distance (P = 0.033), and orbital width (P < 0.001). ROC analysis demonstrated a high diagnostic value of the MSS (AUC = 0.96, P < 0.001), which was comparable to other validated indices including the adjusted EBA (AUC = 0.98), EBA (AUC = 0.97), and biparietal/bitemporal ratio (AUC = 0.95).

CONCLUSIONS

The machine learning algorithm offers an objective assessment of morphologic severity that provides a reliable composite impression of severity. The generated score is comparable to other severity indices in ability to distinguish cases of metopic synostosis from controls.

Management of Unicoronal and Metopic Synostoses: Minimally Invasive Approaches

Early endoscopic-assisted correction of unicoronal and metopic synostosis is an excellent, safe, cost-effective, and highly effective option for affected patients. Although open calvarial remodeling has a place in the armamentarium of the craniofacial team, the skull base changes seen in endoscopic-assisted techniques are unparalleled. The procedures are associated with low morbidity and no mortality. There is minimal blood loss, decreased operating time, significantly reduced blood transfusion rates, decreased hospitalization length, decreased cost, and less pain and swelling. Early diagnosis and referral for surgical evaluation are critical to obtaining these results.

Imaging of Pfeiffer Syndrome: A Case Report

BACKGROUND: Pfeiffer syndrome (PS) is a rare case in the Asian population, and only a few have been reported in Indonesia. This case report aims to spotlight the identification of PS with its correlated radiological imaging and distinguish it from other syndromes. CASE REPORTS: The authors report a case of a 5-year-old girl with PS, manifested by brachyturricephally, broad thumbs and big toes, and medially deviated big toes. The patient also had proptosis, midface hypoplasia, and bilateral Syndactyly of the fingers and toes. This report confirms the thorough examination procedures and indexes to identify PS as a literature reference for the research of reported PS in Southeast Asian race patients and as one comprehensive source for identification using index figures. CONCLUSION: This report provides a detailed radiology interpretation of PS on Southeast Asian race patients. Radiological findings can help in diagnosing and determining adequate treatment as needed.

Predictive Statistical Model of Early Cranial Development

OBJECTIVE

We present a data-driven method to build a spatiotemporal statistical shape model predictive of normal cranial growth from birth to the age of 2 years.

METHODS

The model was constructed using a normative cross-sectional computed tomography image dataset of 278 subjects. First, we propose a new standard representation of the calvaria using spherical maps to establish anatomical correspondences between subjects at the cranial sutures - the main areas of cranial bone expansion. Then, we model the cranial bone shape as a bilinear function of two factors: inter-subject anatomical variability and temporal growth. We estimate these factors using principal component analysis on the spatial and temporal dimensions, using a novel coarse-to-fine temporal multi-resolution approach to mitigate the lack of longitudinal images of the same patient.

RESULTS

Our model achieved an accuracy of 1.54 ± 1.05 mm predicting development on an independent longitudinal dataset. We also used the model to calculate the cranial volume, cephalic index and cranial bone surface changes during the first two years of age, which were in agreement with clinical observations.

SIGNIFICANCE

To our knowledge, this is the first data-driven and personalized predictive model of cranial bone shape development during infancy and it can serve as a baseline to study abnormal growth patterns in the population.

Spherical harmonics to quantify cranial asymmetry in deformational plagiocephaly

Cranial deformation and deformational plagiocephaly (DP) in particular affect an important percentage of infants. The assessment and diagnosis of the deformation are commonly carried by manual measurements that provide low interuser accuracy. Another approach is the use of three-dimensional (3D) models. Nevertheless, in most cases, deformation measurements are carried out manually on the 3D model. It is necessary to develop methodologies for the detection of DP that are automatic, accurate and take profit on the high quantity of information of the 3D models. Spherical harmonics are proposed as a new methodology to identify DP from head 3D models. The ideal fitted ellipsoid for each head is computed and the orthogonal distances between head and ellipsoid are obtained. Finally, the distances are modelled using spherical harmonics. Spherical harmonic coefficients of degree 2 and order − 2 are identified as the correct ones to represent the asymmetry characteristic of DP. The obtained coefficient is compared to other anthropometric deformation indexes, such as Asymmetry Index, Oblique Cranial Length Ratio, Posterior Asymmetry Index and Anterior Asymmetry Index. The coefficient of degree 2 and order − 2 with a maximum degree of 4 is found to provide better results than the commonly computed anthropometric indexes in the detection of DP.

Quantifying Orthotic Correction of Trigonocephaly Using Optical Surface Scanning

ABSTRACT

Numerous publications describe techniques to measure trigonocephaly caused by metopic synostosis, but they are potentially hazardous for use in acquiring longitudinal data. Optical surface scanning technology can safely yield craniometrics but has not established a practical means for measuring objective morphological changes to trigonocephaly during the practical time constraints of a clinical visit. The purpose of this preliminary study was to evaluate a method for safely and repeatedly measuring frontal angle (FA) using technology available at multiple centers providing treatment with cranial remolding orthoses.Optical scans of infants who underwent endoscopic-assisted minimally-invasive craniectomy for repair of metopic synostosis with cranial remolding were retrospectively analyzed. A novel FA measurement technique "FA30" was developed based on repeatable, geometrically-related surface landmarks approximating the glabella and frontotemporali. Results were compared to a control group and categories of non-synostotic deformity. Inter-rater reliability was assessed for pre- and post-treatment scan measurements among separate clinicians.All trigonocephalic subjects (n = 5) had initial FA30 significantly lower than the control group and other cohorts (P < 0.001). During the course of orthotic cranial remolding following surgical release mean FA30 increased from 121.5° to 138.5° (P < 0.001), approaching the control group mean of 144.4°. Intraclass coefficient calculation showed high reliability (intraclass correlation coefficient: 0.993, 95% confidence interval: 0.957-0.998, P < 0.001), which was supported with Bland-Altman analyses of agreement.Optical surface scanning may provide a safe, accurate, and repeatable means to measure FA. Increase in FA30 demonstrates correction of trigonocephaly. The method presented enables expeditious reporting of treatment progress to the infant's surgeon and parents, and has potential for use in optimizing treatment outcomes at multiple centers.

Image processing and machine learning for telehealth craniosynostosis screening in newborns

OBJECTIVE

The authors sought to evaluate the accuracy of a novel telehealth-compatible diagnostic software system for identifying craniosynostosis within a newborn (< 1 year old) population. Agreement with gold standard craniometric diagnostics was also assessed.

METHODS

Cranial shape classification software accuracy was compared to that of blinded craniofacial specialists using a data set of open-source (n = 40) and retrospectively collected newborn orthogonal top-down cranial images, with or without additional facial views (n = 339), culled between April 1, 2008, and February 29, 2020. Based on image quality, midface visibility, and visibility of the cranial equator, 351 image sets were deemed acceptable. Accuracy, sensitivity, and specificity were calculated for the software versus specialist classification. Software agreement with optical craniometrics was assessed with intraclass correlation coefficients.

RESULTS

The cranial shape classification software had an accuracy of 93.3% (95% CI 86.8-98.8; p < 0.001), with a sensitivity of 92.0% and specificity of 94.3%. Intraclass correlation coefficients for measurements of the cephalic index and cranial vault asymmetry index compared to optical measurements were 0.95 (95% CI 0.84-0.98; p < 0.001) and 0.67 (95% CI 0.24-0.88; p = 0.003), respectively.

CONCLUSIONS

These results support the use of image processing-based neonatal cranial deformity classification software for remote screening of nonsyndromic craniosynostosis in a newborn population and as a substitute for optical scanner- or CT-based craniometrics. This work has implications that suggest the potential for the development of software for a mobile platform that would allow for screening by telemedicine or in a primary care setting.

Statistical shape modelling for the analysis of head shape variations

The aim of this study is, firstly, to create a population-based 3D head shape model for the 0 to 2-year-old subjects to describe head shape variability within a normal population and, secondly, to test a combined normal and sagittal craniosynostosis (SAG) population model, able to provide surgical outcome assessment. 3D head shapes of patients affected by non-cranial related pathologies and of SAG patients (pre- and post-op) were extracted either from head CTs or 3D stereophotography scans, and processed. Statistical shape modelling (SSM) was used to describe shape variability using two models - a normal population model (MODEL1) and a combined normal and SAG population model (MODEL2). Head shape variability was described via principal components analysis (PCA) which calculates shape modes describing specific shape features. MODEL1 (n = 65) mode 1 showed statistical correlation (p < 0.001) with width (125.8 ± 13.6 mm), length (151.3 ± 17.4 mm) and height (112.5 ± 11.1 mm) whilst mode 2 showed correlation with cranial index (83.5 mm ± 6.3 mm, p < 0.001). The remaining 9 modes showed more subtle head shape variability. MODEL2 (n = 159) revealed that post-operative head shape still did not achieve full shape normalization with either spring cranioplasty or total calvarial remodelling. This study proves that SSM has the potential to describe detailed anatomical variations in a paediatric population.

A Comparison of Intracranial Volumes and Metopic Index in Patients With Isolated Metopic Ridge, Metopic Craniosynostosis, and Normal Healthy Children

BACKGROUND

Previous research has shown that patients with metopic craniosynostosis have significantly reduced intracranial volumes (ICVs) compared to normal healthy children. Furthermore, the metopic index (ratio of midfrontozygomatic diameter to maximal cranial width) has been described as an anthropometric cranial index for patients with metopic craniosynostosis. We aimed to determine whether patients with isolated metopic ridge have significantly different ICVs or metopic indices than normal children and patients with metopic craniosynostosis.

METHODS

A retrospective chart review of all patients with a diagnosis of a metopic ridge or metopic craniosynostosis was performed from 2000 to 2015 at Rady Children's Hospital. Patients were grouped based on computed tomographic scans consistent with metopic craniosynostosis versus metopic ridge.

RESULTS

Data were available for 15 metopic ridge patients, 74 metopic craniosynostosis patients, and 213 normal patients. Mean metopic ridge ICV was greater than mean metopic craniosynostosis ICV at 4 to 6 months and 7 to 12 months. Controlling for age and sex, the difference in ICV associated with metopic ridging was 197.484 cm3 and 137.770 cm3 at 4 to 6 and 7 to 12 months, respectively. Similarly, mean metopic index was significantly greater in metopic ridge patients compared to mean metopic craniosynostosis at 4 to 6 months and at 7 to 12 months.

CONCLUSIONS

Our study provides volumetric and anthropometric data to support the hypothesis that isolated metopic ridge is an intermediate phenotype between metopic craniosynostosis and normal cranial anatomy. We hope that characterizing the spectrum of disease involving premature closure of the metopic suture with regard to ICV and metopic index will aid physicians in their management of patients with isolated metopic ridge.

Fusion patterns of major calvarial sutures on volume-rendered CT reconstructions

OBJECTIVE

Recently, the authors investigated the normal course of fusion of minor lateral calvarial sutures on "3D" volume-rendered head CT reconstructions in pediatric trauma patients. While evaluating these reconstructions, they found many more fused sagittal sutures than expected given the currently accepted prevalence of sagittal craniosynostosis. In the present study, using the same set of head CT reconstructions, they investigated the course of fusion of the sagittal as well as the lambdoid, coronal, and metopic sutures.

METHODS

They reviewed all volume-rendered head CT reconstructions performed in the period from 2010 through mid-2012 at Children's Hospital Colorado for trauma patients aged 0-21 years. Each sagittal, lambdoid, coronal, or metopic suture was graded as open, partially fused, or fused. The cephalic index (CI) was calculated for subjects with fused and partially fused sagittal sutures.

RESULTS

After exclusions, 331 scans were reviewed. Twenty-one subjects (6%) had fusion or partial fusion of the sagittal suture. Four of the 21 also had fusion of the medial lambdoid and/or coronal sutures. In the 17 subjects (5%) with sagittal suture fusion and no medial fusion of adjacent sutures, the mean CI was 77.6. None of the 21 subjects had been previously diagnosed with craniosynostosis. Other than in the 21 subjects already mentioned, no other sagittal or lambdoid sutures were fused at all. Nor were other coronal sutures fused medially. Coronal sutures were commonly fused inferiorly early during the 2nd decade of life, and fusion progressed superiorly and medially as subjects became older; none were completely fused by 18 years of age. Fusion of the metopic suture was first seen at 3 months of life; fusion was often not complete until after 2 years.

CONCLUSIONS

The sagittal and lambdoid sutures do not usually begin to fuse before 18 years of age. However, more sagittal sutures are fused before age 18 than expected given the currently accepted prevalence of craniosynostosis. This finding is of unknown significance, but likely many of them do not need surgery. The coronal suture often begins to fuse inferiorly early in the 2nd decade of life but does not usually complete fusion before 18 years of age. The metopic suture often starts to fuse by 3 months of age, but it may not completely fuse until after 2 years of age.

Minimally Invasive Endoscopic Surgery for Infantile Craniosynostosis: A Longitudinal Cohort Study

OBJECTIVE

To evaluate patient outcomes of minimally invasive endoscopic strip craniectomy (ESC) for craniosynostosis.

STUDY DESIGN

This is a retrospective cohort analysis (2004-2018) of 500 consecutive infants with craniosynostosis treated by ESC with orthotic therapy at a single center. Operative outcomes included transfusions, complications, and reoperations as well as head circumference change based on World Health Organization percentiles. Multivariable logistic regression was used to identify risk factors associated with blood transfusion. Paired t tests were used for within-patient comparisons and Fisher exact test to compare syndromic and nonsyndromic subgroups.

RESULTS

ESC was associated with low rates of blood transfusion (6.6%), complications (1.4%), and reoperations (3.0%). Risk factors for transfusion included syndromic craniosynostosis (P = .01) and multiple fused sutures (P = .02). Median surgical time was 47 minutes, and hospital length of stay 1 day. Transfusion and reoperation rates were higher among syndromic patients (both P < .001). Head circumference normalized by 12 months of age relative to World Health Organization criteria in infants with sagittal, coronal, and multisuture craniosynostosis (all P < .001).

CONCLUSIONS

ESC is a safe, effective, and durable correction of infantile craniosynostosis. ESC can achieve head growth normalization with low risks of blood transfusion, complications, or reoperation. Early identification of craniosynostosis in the newborn period and prompt referral by pediatricians allows families the option of ESC vs larger and riskier open reconstruction procedures.

Optimal duration of postoperative helmet therapy following endoscopic strip craniectomy for sagittal craniosynostosis

OBJECTIVEMany infants with sagittal craniosynostosis undergo effective surgical correction with endoscopic strip craniectomy (ESC) and postoperative helmet therapy (PHT). While PHT is essential to achieving optimal cosmesis following ESC, there has been little comprehensive analysis of the ideal PHT duration needed to attain this goal.METHODSThe authors retrospectively reviewed the charts of infants undergoing ESC and PHT for sagittal synostosis at our institution between 2008 and 2015. Data collected included age at surgery, follow-up duration, and PHT duration. Cephalic index (CI) was evaluated preoperatively (CIpre), at its peak level (CImax), at termination of helmet therapy (CIoff), and at last follow-up (CIfinal). A multivariate regression analysis was performed to determine factors influencing CIfinal.RESULTSThirty-one patients (27 male, 4 female) were treated in the studied time period. The median age at surgery was 2.7 months (range 1.6 to 3.2) and the median duration of PHT was 10.4 months (range 8.4 to 14.4). The mean CImax was 0.83 (SD 0.01), which was attained an average of 8.4 months (SD 1.2) following PHT initiation. At last follow-up, there was an average retraction of CIfinal among all patients to 0.78 (SD 0.01). Longer helmet duration after achieving CImax did not correlate with higher CIfinal values. While CImax was a significant predictor of CIfinal, neither age at surgery nor CIpre were found to be predictive of final outcome.CONCLUSIONSPatients undergoing ESC and PHT for sagittal synostosis reach a peak CI around 7 to 9 months after surgery. PHT beyond CImax does not improve final anthropometric outcomes. CIfinal is significantly dependent on CImax, but not on age, nor CIpre. These results imply that helmet removal at CImax may be appropriate for ESC patients, while helmeting beyond the peak does not change final outcome.

Analysis of Cranial Morphology of Healthy Infants Using Homologous Modeling

OBJECTIVE

Data on cranial morphology of healthy individuals can be used as the guide in the treatment of cranial deformity. There are many reports analyzing the cranial morphology of healthy children in the past. But most of them focus on 2-dimensional values, and there are only a few reports, which analyzed the cranial morphology of Japanese healthy infants. We report a novel method that enables the comprehensive analysis of cranial morphology of Japanese healthy infants in 3D.

METHODS

Craniofacial CT data of 20 healthy infants (9 males, 11 females) ranging in age from 1 to 11 months were collected. Based on the CT data, we created 20 homologous models of cranium using software specifically designed to support homologous modeling. We averaged vertex coordinates of the homologous models to create average model. We further performed principal component analysis, and created virtual models based on each principal component. The contribution rate was calculated, and the features described by each principal component were interpreted.

RESULTS

We created the average cranial model of Japanese healthy infants. Seven principal components (cumulative contribution rate: 89.218%) were interpreted as to which part of the cranial shape each component was related to. The elements were extracted that may characterize the cranial morphology of some of the clinical conditions such as dolico/brachycephaly and deformational plagiocephaly. Some of these elements have not been mentioned in the past literature.

CONCLUSION

Homologous modeling was considered to be valid and strong tool for comprehensive analysis of cranial morphology.

Determination of reference values for normal cranial morphology by using mid-sagittal vector analysis in Japanese children

Mid-Sagittal Vector Analysis (MSVA) is a method of measuring the distance from a defined central point on the skull surface in the entire mid-sagittal plane and provides a clear description of the lateral view of the skull. We used a series of images of normal skulls of Japanese children to determine normal MSVA values. For this cross-sectional study, we first constructed a database of head CT and MRI images of children aged 0-6 years (41.5 ± 24.9 month (mean ± SD)) who showed no abnormality of cranial development and growth at the time of imaging. Measurement errors due to lateral shifting of the sagittal plane during MSVA were examined, CT and MRI images taken in the same patients at the same time were compared, and measurement differences were examined. Finally, MSVA was carried out, and the mean of the measured values was calculated according to age group. Two hundred ninety-five images were included in the database. When the lateral shifting of the sagittal plane was within 4 mm from the true mid-sagittal plane, the mean errors were less than 1 mm at all measurement points. Between the CT and MRI images from the same patients, most differences in MSVA values were within ±1 mm. These differences were thus acceptable for use in clinical settings. After the above verifications, 220 images were extracted for determination of normal MSVA values. We established a normal dataset of MSVA for Japanese children that can be used effectively for preoperative diagnosis, surgery planning, and postoperative assessment of cranial deformities.

Endoscopic surgery for patients with syndromic craniosynostosis and the requirement for additional open surgery

OBJECTIVE Recent reports have described early endoscopic suturectomy as a treatment option for patients with syndromic craniosynostosis, but such patients often require subsequent calvarial remodeling. The authors describe their experience with this patient population and seek to identify predictors of sufficiency of endoscopic surgery alone. METHODS The medical records of patients with syndromic craniosynostosis who underwent endoscopic repair were retrospectively reviewed. Demographic data, operative details, and follow-up data were collected. RESULTS A total of 6 patients with syndromic craniosynostosis underwent endoscopic surgery followed by helmet therapy during the study period. Of these, 3 patients were male. The involved syndromes included Crouzon, Pfeiffer, Jackson-Weiss, Muenke, Saethre-Chotzen, and craniosynostosis-3 (n = 1 each). The patients underwent endoscopic surgery at a median age of 2.1 months (range 0.9-4.1 months). The median estimated blood loss was 30 ml (range 20-100 ml), with 2 patients requiring a transfusion. The median length of stay in the hospital was 1.5 days (range 1-4 days), and the median follow-up was 29.0 months (range 16.8-81.7 months), with 1 patient (16.7%) requiring an open revision. Three patients (50%) were classified as Whitaker Category I at the last follow-up. The patients for whom additional open surgery was performed or recommended (Whitaker Category IV) were the oldest patients in the cohort, ranging from 2.6 to 4.1 months at the time of surgery. CONCLUSIONS This series demonstrates that endoscopic surgery can be sufficient to treat syndromic craniosynostosis without subsequent open calvarial remodeling over a median follow-up period of at least 2 years. The findings suggest that younger age at the time of endoscopic surgery may be an important factor in determining the sufficiency of this procedure. Even among patients who require subsequent open calvarial remodeling, early endoscopic surgery may allow for growth and development of the brain and skull while delaying the need for open remodeling until the patient is older and can better tolerate the procedure.