Metopic Craniosynostosis Research Articles

Use of Onlay Hydroxyapatite Cement for Secondary Cranioplasty.

Children who undergo bi-fronto-orbital advancement (BFOA) frequently develop a contour deformity on the temporal and supra-orbital region, with an incidence reported as high as 55% and 75%, respectively. Up to 20% of patients may require correction. Hydroxyapatite cement (HAC) is a good alternative to autogenous tissue. The available literature on its use focusses on the reconstruction of bone defects, but little has been published on its efficacy and safety as an onlay graft over intact cranium. To describe our institution's experience with HAC in the pediatric population. Retrospective chart review from 1998 to 2018 on all patients from the Craniofacial Unit at the Sydney Children's Hospital who had either coronal or metopic craniosynostosis and underwent BFOA and later in life required cranioplasty with HAC for contour repair. We have performed 166 BFOA and nineteen secondary cranioplasties for contour repair using onlay HAC. The mean age at the time of operation was 14 years. Bi-coronal craniosynostosis was most frequently associated with secondary cranioplasty and 37% had an associated syndrome. The mean volume of HAC used was 37 mL. There was only 1 patient who had a complication (5.3%) and required partial removal of allograft. The mean length of admission was 2 days. Mean follow up time of 22.4 months. HAC represents a safe option when used correctly, with low rates of complication and satisfactory cosmetic outcomes.

School-Aged Anthropometric Outcomes After Endoscopic or Open Repair of Metopic Synostosis.

Metopic craniosynostosis can be treated by fronto-orbital advancement or endoscopic strip craniectomy with postoperative helmeting. Infants younger than 6 months of age are eligible for the endoscopic repair. One-year postoperative anthropometric outcomes have been shown to be equivalent, with significantly less morbidity after endoscopic treatment. The authors hypothesized that both repairs would yield equivalent anthropometric outcomes at 5-years postoperative. This study was a retrospective chart review of 31 consecutive nonsyndromic patients with isolated metopic craniosynostosis treated with either endoscopic or open correction. The primary anthropometric outcomes were frontal width, interfrontal divergence angle, the Whitaker classification, and the presence of lateral frontal retrusion. Peri-operative variables included estimated blood loss, rates of blood transfusion, length of stay, and operating time. There was a significantly lower rate of lateral frontal retrusion in the endoscopic group. No statistically significant differences were found in the other 3 anthropometric outcomes at 5-years postoperative. The endoscopic group was younger at the time of surgery and had improved peri-operative outcomes related to operating time, hospital stay and blood loss. Both groups had low complication and reoperation rates. In our cohort of school-aged children with isolated metopic craniosynostosis, patients who underwent endoscopic repair had superior or equivalent outcomes on all 4 primary anthropometric measures compared with those who underwent open repair. Endoscopic repair was associated with significantly faster recovery and decreased morbidity. Endoscopic repair should be considered in patients diagnosed with metopic craniosynostosis before 6 months of age.

Quantitative outcomes of endoscopic strip craniectomy for metopic craniosynostosis in children with severe trigonocephaly

To assess intermediate-term (> 3 years) outcomes of endoscopic strip craniectomy with postoperative helmet therapy (ESC + HT) for the treatment of infants with severe trigonocephaly. This retrospective study examined cranial morphology of consecutive patients with severe trigonocephaly treated with minimally invasive ESC + HT. Preoperative and follow-up clinical parameters were collected from patient charts. Interfrontal divergence angle (IFDA), a validated and accurate measure of forehead narrowing, was measured on preoperative CT scans and on preoperative and postoperative 2D photographs. Seven patients (4 male, 3 female) were included with a mean age at surgery of 2.76 months (range 1.8 to 4.1 months) and mean clinical follow-up of 3.71 years (photographic follow-up 2.73 years). The mean operative time was 91.4 min, with a mean estimated blood loss (EBL) of 57.1 ml and mean hospital length of stay of 1.14 days. IFDA improved from 118.8° to 135.9° (p < 0.01), with the mean final measurement falling within normal limits. The head circumference percentile was not significantly changed in follow-up. There was a statistically significant improvement in the inner-to-outer canthal distance ratio (p = 0.01) in follow-up, showing an improvement in hypotelorism. There were no dural tears, CSF leaks, infections, or other significant surgical morbidities, and there were no serious complications related to the use of helmet therapy. All patients achieved excellent aesthetic results judged by photographic comparison. This study demonstrated that patients treated with ESC + HT for metopic craniosynostosis showed measurable and significant improvement in forehead shape. This technique is a safe and effective alternative to more invasive surgical interventions.

A protocol of situation-dependent transfusion, erythropoietin and tranexamic acid reduces transfusion in fronto-orbital advancement for metopic and coronal craniosynostosis.

Assess the effect of a protocol of preoperative erythropoietin (EPO) and ferrous sulfate in addition to perioperative tranexamic acid (TXA) on blood transfusions in patients with coronal or metopic craniosynostosis undergoing cranial vault remodeling (CVR) with fronto-orbital advancement (FOA). Retrospective review of all coronal and metopic craniosynostosis patients undergoing CVR and FOA from March 2010 to June 2019 was performed. Before 2014 ("Control group"), all patients received blood transfusion at the start of surgery. In 2014, a protocol of preoperative EPO and ferrous sulfate with perioperative TXA and non-automatic transfusion was instituted ("Study group"). Patient demographics and anthropometrics, perioperative hemoglobin (Hb) levels, and transfusion details were collected and compared. Thirty-six patients met inclusion criteria. Twenty-one patients were in the control group, and 15 in the Study group. Nineteen patients had metopic synostosis, 11 had unicoronal synostosis, and 6 had bicoronal synostosis. There were no significant differences between groups in demographics, operative time, intraoperative crystalloid volume, craniofacial syndromes, or sutures affected. The Study group had higher preoperative Hb (13.9 ± 1.0 vs. 12.6 ± 0.8g/dL, p < 0.001), lower intraoperative Hb nadir (7.4 ± 1.8 vs. 9.2 ± 1.2g/dL) lower intraoperative transfusion rate (66.7% vs. 100%, p = 0.008), lower postoperative transfusion rate (0% vs 28.6%, p = 0.03), and exposure to fewer unique units of packed red blood cells (0.7 ± 0.6 vs. 1.5 ± 0.9units). Our protocol resulted in decreased transfusion needs. These results add valuable information to the growing body of work on transfusion reduction in craniosynostosis surgery.

MON-060 P-450 Oxidoreductase Deficiency with Antley Bixler Phenotype: A Novel Mutation

IntroductionWe present first case of 46 XY Disorder of Sex Development (DSD) from India due to P-450 Oxidoreductase Deficiency with Novel variant (p.Ala541Thr) in a heterozygous state.Case Discussion6 months old boy presented with ambiguous genitalia since birth. No history of neonatal crisis, failure to thrive and pigmentation of skin, maternal virilisation or drug ingestion during pregnancy. On examination: weight 6.2 Kg (3rd centile), height 64 cm (3rd centile), MPH-170 (25-50th centile), head circumference 38 cm (−2.7 SD), vitals stable, trigonocephaly with fused anterior and posterior fontanelle, prominent pointed forehead, midfacial hypoplasia, up slanting eyes, hypertelorism and low set ears were present. Genitalia: 1.5 cm phallus like structure with foreskin, chordee, single perineal opening in form of peno-scrotal hypospadias, bifid scrotum with poor rugosity and poor pigmentation and both gonads (1 ml) were palpable in labio-scrotal fold with external masculinization score (EMS), 6/12 and Prader stage 4.Investigations showed normal electrolytes and blood sugar, High basal ACTH, post stimulation cortisol 14mcg/dl, Basal 17-OHP was 8.6 ng/ml and post stimulation 12ng/ml, with low DHEAS 36.4 mcg/dl and androstenedione 0.42 ng/ml, LH 16.09 mIU/ml (elevated), FSH 2.97 mIU/ml (normal) and low Testosterone for his age. T/DHT 9.6 (normal<10) and Testosterone /Androstenedione ratio 0.95 (normal >0.8). Abdominal and Pelvic imaging showed normal adrenal glands and absent female internal genitalia, bilateral testis in labio-scrotal fold (right testis-6x6.5x11 mm, left testis-6.6x7x10 mm), corpora cavernosa and bifid scrotum. NCCT Head showed metopic craniosynostosis with trigonocephaly and hypotelorism. Skeletal survey showed bowing of femora. 20 cell Karyotype of peripheral blood lymphocyte was 46 XY. NGS was done of the POR gene, which revealed a heterozygous missense variation in exon 13 of the POR gene variant (p.Ala541Thr) which has not been reported yet.The patient was initiated hydrocortisone, fludrocortisone, DHT gel and corrective surgery is planned.Clinical learningAlthough in PORD classically the inheritance is generally autosomal recessive, but manifesting heterozygotes are not uncommon1. This case also shows the value of Next gen sequencing and the role it can play in DSD1. Scott RR, Gomes LG, Huang N, Van Vliet G, Miller WL. Apparent manifesting heterozygosity in P450 oxidoreductase deficiency and its effect on coexisting 21-hydroxylase deficiency. J Clin Endocrinol Metab. 2007;92:2318–2322

Quantifying the Severity of Metopic Craniosynostosis: A Pilot Study Application of Machine Learning in Craniofacial Surgery.

The standard for diagnosing metopic craniosynostosis (CS) utilizes computed tomography (CT) imaging and physical exam, but there is no standardized method for determining disease severity. Previous studies using interfrontal angles have evaluated differences in specific skull landmarks; however, these measurements are difficult to readily ascertain in clinical practice and fail to assess the complete skull contour. This pilot project employs machine learning algorithms to combine statistical shape information with expert ratings to generate a novel objective method of measuring the severity of metopic CS.Expert ratings of normal and metopic skull CT images were collected. Skull-shape analysis was conducted using ShapeWorks software. Machine-learning was used to combine the expert ratings with our shape analysis model to predict the severity of metopic CS using CT images. Our model was then compared to the gold standard using interfrontal angles.Seventeen metopic skull CT images of patients 5 to 15 months old were assigned a severity by 18 craniofacial surgeons, and 65 nonaffected controls were included with a 0 severity. Our model accurately correlated the level of skull deformity with severity (P < 0.10) and predicted the severity of metopic CS more often than models using interfrontal angles (χ = 5.46, P = 0.019).This is the first study that combines shape information with expert ratings to generate an objective measure of severity for metopic CS. This method may help clinicians easily quantify the severity and perform robust longitudinal assessments of the condition.

Discussion: Radiographic Severity of Metopic Craniosynostosis Correlates with Long-Term Neurocognitive Outcomes.

Discussion: Radiographic Severity of Metopic Craniosynostosis Correlates with Long-Term Neurocognitive Outcomes.

A genome-wide association study implicates the BMP7 locus as a risk factor for nonsyndromic metopic craniosynostosis.

Our previous genome-wide association study (GWAS) for sagittal nonsyndromic craniosynostosis (sNCS) provided important insights into the genetics of midline CS. In this study, we performed a GWAS for a second midline NCS, metopic NCS (mNCS), using 215 non-Hispanic white case-parent triads. We identified six variants with genome-wide significance (P ≤ 5 × 10-8): rs781716 (P = 4.71 × 10-9; odds ratio [OR] = 2.44) intronic to SPRY3; rs6127972 (P = 4.41 × 10-8; OR = 2.17) intronic to BMP7; rs62590971 (P = 6.22 × 10-9; OR = 0.34), located ~ 155kb upstream from TGIF2LX; and rs2522623, rs2573826, and rs2754857, all intronic to PCDH11X (P = 1.76 × 10-8, OR = 0.45; P = 3.31 × 10-8, OR = 0.45; P = 1.09 × 10-8, OR = 0.44, respectively). We performed a replication study of these variants using an independent non-Hispanic white sample of 194 unrelated mNCS cases and 333 unaffected controls; only the association for rs6127972 (P = 0.004, OR = 1.45; meta-analysis P = 1.27 × 10-8, OR = 1.74) was replicated. Our meta-analysis examining single nucleotide polymorphisms common to both our mNCS and sNCS studies showed the strongest association for rs6127972 (P = 1.16 × 10-6). Our imputation analysis identified a linkage disequilibrium block encompassing rs6127972, which contained an enhancer overlapping a CTCF transcription factor binding site (chr20:55,798,821-55,798,917) that was significantly hypomethylated in mesenchymal stem cells derived from fused metopic compared to open sutures from the same probands. This study provides additional insights into genetic factors in midline CS.

Abstract 149: Distinguishing Craniomorphometric Characteristics And Severity In 100 Metopic Synostosis Patients

Purpose: Metopic craniosynostosis is the second most common form of single suture synostosis. Controversy persists regarding the most accurate method for assessing severity in trigonocephaly. This study aimed to develop a robust diagnostic measurement system for reproducible severity assessment in trigonocephaly. In addition, it aimed to identify a severity scale to distinguish between mild, moderate, and severe metopic patients. Methods: Morphometric analysis using Materialise Mimics was performed on preoperative CT scans of infants with metopic craniosynostosis. Assessed indices of trigonocephaly were endocranial bifrontal angle, frontal angle, posterior angle of the anterior cranial fossa, brow ridge to eurion ratio, horizontal orbital cone angle, temporal depression angle, orbital rim angle, and interdacryon distance. Inter- and intra-rater reliability were established with two independent reviewers per patient. Results were analyzed using a Pearson’s correlation coefficient. Furthermore, age-based sub group analysis was performed between <6 months (group 1) and >6 months (group 2) using an unpaired T-test. Results: One hundred patients with metopic craniosynostosis were included in the analysis. The majority were male (82%) with a mean age of 6.6 months. The endocranial bifrontal angle ranged from 112.9 to 148.0 with a mean of 127.0. The frontal angle ranged from 83.2 to 109.3 with a mean of 98.3. Strong correlations existed between the frontal angle, posterior angle of anterior cranial fossa, horizontal cone angle, orbital rim angle, metopic index (bitemporal distance/biparietal distance), and upper orbital width (Pearson coefficient > 0.3 for all). Additionally, the posterior angle of anterior cranial fossa strongly correlated with zygomaticofrontal suture distance, interdacryon distance, and lateral orbital width. Changes in the endocranial bifrontal angle were associated with changes in the lateral orbital width, but there were no other correlations found between the endocranial bifrontal angle and the other measurements. Age-based subgroup analysis showed that there was no significant difference between measurements of severity between group 1 and group 2. Conclusion: In the largest radiographic series of metopic synostosis patients to date, concordance of measures was identified between the frontal angle, posterior angle of anterior cranial fossa, horizontal cone angle, orbital rim angle, metopic index, and upper orbital width. These measurements represent reliable measures for trigonocephaly assessment. Furthermore, we found that there is no significant difference in severity based on age.

Augmented reality and physical hybrid model simulation for preoperative planning of metopic craniosynostosis surgery.

The main objective of neurosurgery is to establish safe and reliable surgical techniques. Medical technology has advanced during the 21st century, enabling the development of increasingly sophisticated tools for preoperative study that can be used by surgeons before performing surgery on an actual patient. Laser-printed models are a robust tool for improving surgical performance, planning an operative approach, and developing the skills and strategy to deal with uncommon and high-risk intraoperative difficulties. Practice with these models enhances the surgeon's understanding of 3D anatomy but has some limitations with regard to tactile perception. In this study, the authors aimed to develop a preoperative planning method that combines a hybrid model with augmented reality (AR) to enhance preparation for and planning of a specific surgical procedure, correction of metopic craniosynostosis, also known as trigonocephaly. With the use of imaging data of an actual case patient who underwent surgical correction of metopic craniosynostosis, a physical hybrid model (for hands-on applications) and an AR app for a mobile device were created. The hybrid customized model was developed by using analysis of diagnostic CT imaging of a case patient with metopic craniosynostosis. Created from many different types of silicone, the physical model simulates anatomical conditions, allowing a multidisciplinary team to deal with different situations and to precisely determine the appropriate surgical approach. A real-time AR interface with the physical model was developed by using an AR app that enhances the anatomic aspects of the patient's skull. This method was used by 38 experienced surgeons (craniofacial plastic surgeons and neurosurgeons), who then responded to a questionnaire that evaluated the realism and utility of the hybrid AR simulation used in this method as a beneficial educational tool for teaching and preoperative planning in performing surgical metopic craniosynostosis correction. The authors developed a practice model for planning the surgical cranial remodeling used in the correction of metopic craniosynostosis. In the hybrid AR model, all aspects of the surgical procedure previously performed on the case patient were simulated: subcutaneous and subperiosteal dissection, skin incision, and skull remodeling with absorbable miniplates. The pre- and postoperative procedures were also carried out, which emphasizes the role of the AR app in the hybrid model. On the basis of the questionnaire, the hybrid AR tool was approved by the senior surgery team and considered adequate for educational purposes. Statistical analysis of the questionnaire responses also highlighted the potential for the use of the hybrid model in future applications. This new preoperative platform that combines physical and virtual models may represent an important method to improve multidisciplinary discussion in addition to being a powerful teaching tool. The hybrid model associated with the AR app provided an effective training environment, and it enhanced the teaching of surgical anatomy and operative strategies in a challenging neurosurgical procedure.

Assessment of Epidemiological Trends in Craniosynostosis: Limitations of the Current Classification System.

Background:Craniosynostosis affects 1 in 2,000 live births, which makes it one of the most common craniofacial abnormalities in the United States. Despite this fact, few national epidemiologic reports exist, although US and European studies have reported an increased incidence of metopic craniosynostosis. The aim of our study is to analyze the National Inpatient Sample (NIS) to support those conclusions.Methods:We identified hospitalizations from 1998 to 2012 by using the ICD-9-CM diagnosis code for congenital anomalies of skull and face bones (756.0) and procedure codes related to craniosynostosis repair (2.01, 2.03, 2.04, 2.06).Results:We analyzed data from 37,815 hospitalizations and 49,505 reconstructive procedures. There was a 61.6% increase in the number of hospitalizations related to craniosynostosis repairs. There was a 180% increase in bone graft to skull procedures, 109% increase in other cranial osteoplasty, 54% increase in formation of cranial bone flap, and a 6% decrease in opening of cranial suture.Conclusions:We observed a steady rise in the number of craniosynostosis repairs performed, but whether this is a result of a true increase in incidence, better diagnosis, or change in treatment patterns needs further research. The current classification system does not provide information about the specific suture affected (metopic, sagittal, etc.), the type of repair performed (endoscopic, fronto-orbito advancement, etc.), and whether the repair is a primary procedure or a revision. More descriptive diagnosis and procedural codes are imperative to improve the epidemiologic and outcomes data of craniosynostosis in the United States.

Cost comparison of surgical management of nonsagittal synostosis: traditional open versus endoscope-assisted techniques.

Management of craniosynostosis at an early age is important for mitigating the risk of abnormal cranial development, but treatment can result in significant expenses. Previous research has shown that endoscope-assisted craniectomy (EAC) is less costly than open cranial vault remodeling (CVR) for patients with sagittal synostosis. The aim of this study was to strengthen the existing body of healthcare cost research by elucidating the charges associated with open and endoscopic treatment for patients with nonsagittal synostosis. The authors performed a retrospective analysis of data obtained in 41 patients who underwent open CVR and 38 who underwent EAC with postoperative helmet therapy for nonsagittal, single-suture craniosynostosis (metopic, coronal, and lambdoid) between 2008 and 2018. All patients were < 1 year of age at the time of surgery and had a minimum 1 year of follow-up. Inpatient charges, physician fees, helmet charges, and outpatient clinic visits in the 1st year were analyzed. The mean ages of the children treated with EAC and open CVR were 3.5 months and 8.7 months, respectively. Patients undergoing EAC with postoperative helmet therapy required more outpatient clinic visits in the 1st year than patients undergoing CVR (4 vs 2; p < 0.001). Overall, 13% of patients in the EAC group required 1 helmet, 30% required 2 helmets, 40% required 3 helmets, and 13% required 4 or more helmets; the mean total helmeting charges were $10,072. The total charges of treatment, including inpatient charges, physician fees, outpatient clinic visit costs, and helmet charges, were significantly lower for the EAC group than they were for the open CVR group ($50,840 vs $95,588; p < 0.001). Despite the additional charges for postoperative helmet therapy and the more frequent outpatient visits, EAC is significantly less expensive than open CVR for patients with metopic, coronal, and lambdoid craniosynostosis. In conjunction with the existing literature on clinical outcomes and perioperative resource utilization, these data support EAC as a cost-minimizing treatment for eligible patients with nonsagittal synostosis.

Transfusion-Free Cranial Vault Remodeling: A Novel, Multifaceted Approach.

Approximately one in 2000 babies are born with craniosynostosis, and primary open repair is typically performed before 1 year of age. Historically, the procedure has been associated with nearly 100 percent transfusion rates. To decrease the rates of transfusion, the authors' center has developed a novel multimodal blood conservation protocol. The authors administered their standard of care to children aged 1 year or younger undergoing primary repair of craniosynostosis between 2008 and 2014. In 2014, the authors implemented the following protocol: (1) preoperative erythropoietin and ferrous sulfate, (2) local anesthetic with epinephrine infiltration of the incision, (3) PlasmaBlade incision and subgaleal dissection, (4) hypervolemic hemodilution, and (5) intravenous tranexamic acid. Procedures performed before the protocol implementation served as controls. The authors performed classic fronto-orbital advancement with anterior cranial vault remodeling for coronal and metopic craniosynostosis. For lambdoid and sagittal craniosynostosis, barrel stave osteotomies, cranial base outfracture, and interposition bone grafting were performed. A total of 279 children with a mean age of 6 months who had craniosynostosis repairs were included. One hundred forty-five underwent repair before the authors' protocol, and 134 had repairs during the authors' blood conservation protocol. Both groups were similar in demographics. Overall blood loss and operative times were significantly reduced by 73 percent and 11 percent, respectively. Blood transfusion rate decreased 92 percent (p < 0.001). These results show a strong association between the authors' blood conservation protocol and significantly reduced transfusion rates. The authors believe this is a significant step forward and can be safely applied in the great majority of children undergoing craniosynostosis repairs. Therapeutic, III.

Stress and strain propagation on infant skull from impact loads during falls: a finite element analysis

ABSTRACT Background and Objective: To simulate infant skull trauma after low height falls when variable degrees of ossification of the sutures are present. Methods: A finite elements model of a four-week-old infant skull was developed for simulating low height impact from 30 cm and 50 cm falls. Two impacts were simulated: An occipito-parietal impact on the lambdoid suture and a lateral impact on the right parietal and six cases were considered: unossified and fully ossified sutures, and sagittal, metopic, right lambdoid and right coronal craniosynostosis. Results: 26 simulations were performed. Results showed a marked increase in strain magnitudes in skulls with unossified sutures and fontanels. Higher deformations and lower Von Mises stress in the brain were found in occipital impacts. Fully ossified skulls showed less overall deformation and lower Von Mises stress in the brain. Results suggest that neonate skull impact when falling backward has a higher probability of resulting in permanent damage. Conclusion: This work shows an initial approximation to the mechanisms underlying TBI in neonates when exposed to low height falls common in household environments, and could be used as a starting point in the design and development of cranial orthoses and protective devices for preventing or mitigating TBI.

Orbito-facial dysmorphology in patients with different degrees of trigonocephaly severity: quantitative morpho-volumetric analysis in infants with non-syndromic metopic craniosynostosis

Craniofacial dysmorphology varies significantly along a wide spectrum of severity in metopic cranial synostosis (MCS). This study aimed to quantify craniofacial changes, in MCS, to investigate their relationships with the severity of trigonocephaly. By combining the metopic ridge and interfrontal angles, we identified three groups of trigonocephaly severity (mild group n.14, moderate group n.19, severe group n.18). We perform a quantitative analysis using high-resolution CT images evaluating (1) cranial fossae dimensions; (2) vault indices and ratios: interparietal/ intercoronal (IPD/ICD), interparietal/intertemporal (IPD/ITD), cephalic index, vertico-longitudinal index; (3) orbito-facial distances (midfacial depth, maxillary height, upper facial index, orbital distances, globe protrusions), maxilla and orbital volumes; (4) supratentorial (ICV) and infratentorial (PCFV) cranial volumes and supratentorial (WBV) and infratentorial (PCFBV) brain volumes. In all groups, middle skull base lengths and upper midface index were increased. In moderate and severe groups: anterior hemifossa lengths were reduced, IPD/ICD and vertico-longitudinal index were changed; midfacial depth, anterior, mild, and lateral interorbital distances were reduced; globe protrusions were increased. The comparison between moderate and severe groups showed an increase of both globe protrusions and IPD/ICD. Among all groups, ICV and WBV were reduced in the severe group. This morpho-volumetric study provides new insights in understanding the craniofacial changes occurring in infants at different severity of trigonocephaly. The increase of globe protrusions and the reduction of supratentorial volumes found in the severe group reflect the severity of trigonocephaly; these findings might have a clinical and surgical relevance.

Sustained attention and vigilance of children treated for sagittal and metopic craniosynostosis

ABSTRACTAttention problems are common in patients with craniosynostosis. Craniosynostosis is a rare condition, studies face challenges of selection bias, small sample sizes, and wide age ranges. The aim of the study was to assess the sustained attention and vigilance of children treated for sagittal and metopic craniosynostosis. To reduce selection bias, we included children that had previously undergone surgery for craniosynostosis, were between 8 and 16 years, and lived close to the craniofacial centre. The Connors Continuous Performance Test (3rd edition) was used to measure sustained attention and vigilance (n = 61; response rate: 76.3%). Attrition analysis revealed no differences between responding and non-responding groups regarding background variables. One identified difference between the SS (n = 28) and MS (n = 23) groups involved significantly better performance by the SS group in the hit-reaction time (HRT) test relative to the MS group (p < 0.05). Compared with the norms, the SS group showed significantly worse response style, detectability, omissions, commissions, perseverations, HRT response speed (HRT-SD), HRT inter-stimulus interval change (HRT-iC) (p < 0.01 for all), and variability (p < 0.05). The MS group showed significantly worse detectability, HRT-SD, variability (p < 0.01 for all), commissions, perseverations and HRT-iC (p < 0.05 for all) as compared with norms. No differences regarding attention was detected for the two different surgical techniques used for correction of sagittal synostosis. There were shortcomings in sustained attention and vigilance as compared with the norms in the SS and MS groups, although the deviations were small.

One-Piece Fronto-orbital Distraction With Midline Splitting But Without Bandeau for Metopic Craniosynostosis: Craniometric, Volumetric, and Morphologic Evaluation.

Distraction osteogenesis has gained popularity in the treatment of different types of craniosynostosis. We aimed to present the technique of 1-piece fronto-orbital distraction with midline splitting osteotomy but without bandeau for the treatment of metopic craniosynostosis, and the protocol of outcome evaluation using craniometric, volumetric, and morphologic parameters based on 3-dimensional computer simulation. This retrospective study included 9 patients with isolated metopic craniosynostosis who underwent surgical correction with distraction osteogenesis between December 2015 and February 2018. The osteotomy was designed in the form of 1-piece fronto-orbital distraction without separation of the orbital bandeau accompanied by midline splitting osteotomy. This was followed by the application of 2 pairs of cranial distractors to produce anterolateral expansion. The 3-dimensional files from preoperative and postdistraction computed tomographic data were used for the measurement of craniometric, volumetric, and morphologic parameters. The postdistraction craniometric measurement revealed a 12.52% increase in the interfrontal angle. Moreover, there were increases in the bifrontal diameter, diagonal diameters, and interorbital distance. Volumetric measurements revealed an increase in the total cranial volume by 228.1 ± 110.19 cm. The anterior compartmental volume increased by 33.24%. Morphologic evaluation in the form of curvature analysis showed shrinkage of the surface area of abnormal curvature from 29.5 ± 6.71 cm preoperatively to 3.85 ± 3.66 cm after distraction. The technique of 1-piece fronto-orbital distraction with midline splitting osteotomy but without bandeau is an effective surgical option for the treatment of metopic craniosynostosis. The postdistraction outcomes demonstrated the correction of various forms of dysmorphology in metopic craniosynostosis.

In Situ Hinge Technique for the Frontal Bandeau for the Correction of Metopic Craniosynostosis Reduces Operative Time.

Treatment of metopic craniosynostosis often involves bitemporal expansion of the anterior cranium. This report compares perioperative variables of a surgical technique in which the fronto-orbital bandeau is bent in situ to traditional fronto-orbital advancement and remodeling (FOAR). Six patients undergoing the hinge technique were compared to the senior author's 6 most recent conventional FOARs. Study and control cohorts were reasonably well matched for age and sex; only those with nonsyndromic, single-suture metopic synostosis were included. Perioperative variables such as OR time, blood loss, hardware costs, length of stay, and perioperative complications were compared between groups using unpaired t tests. Operative time was significantly decreased when the hinge technique was utilized, with a mean operative time of 159 ± 14.0 minutes for hinge patients and 193 ± 33.8 minutes for nonhinge patients (P = 0.049). Hardware was also significantly decreased from an average of 2.2 ± 1.0 plates and 35 ± 13.8 screws in nonhinge patients to 1 plate and 20 screws in each hinge patient (P < 0.02), for an average hardware saving of $2990 per hinge surgery (P = 0.019). Estimated blood loss, length of stay, and perioperative complications were not significantly different between groups. All patients in both groups had Whitaker 1 outcomes in short-term follow-up. The hinge technique for the treatment of metopic synostosis is associated with a statistically significant decrease in operative time, hardware utilization, and hardware cost. Perioperative outcomes were similar between the hinge technique and traditional FOAR in the short term, and additional follow-up is needed to determine whether the 2 have similar long-term outcomes.

S8A-06 SESSION 8A: METOPIC SYNOSTOSIS QUANTIFYING THE SEVERITY OF METOPIC CRANIOSYNOSTOSIS: A PILOT STUDY IN APPLICATION OF ADVANCED MACHINE LEARNING IN CRANIOFACIAL SURGERY

Introduction: Metopic Craniosynostosis refers to early fusion of the metopic suture. It can cause head shape anomalies and symptoms of elevated intracranial pressure. While the current standard for diagnosing the condition utilizes CT imaging and physical exam, there is no standardized method for predicting disease severity. Previous studies using interfrontal angles have looked at differences in specific skull landmarks, however these measurements are difficult to readily ascertain in clinical practice and fail to assess the complete skull contour. This pilot project employs machine learning algorithms to combine statistical shape information with expert ratings to generate a user-friendly method of measuring the severity of metopic craniosynostosis. Methods: Expert ratings of normal and metopic skull CT images were collected. Skull-shape analysis was conducted using ShapeWorks software. Advanced machine-learning was used to combine the expert ratings with our shape analysis model to predict the severity of metopic CS using CT images. Our model was then compared to the gold standard using interfrontal angles. Results: 17 metopic and 65 non-affected skull CT images of patients 5–15 months old were assigned a severity by 18 craniofacial surgeons. Our model accurately correlated the level of skull deformity with severity (p<0.10) and predicted the severity of metopic CS more often than models using interfrontal angles (χ2=5.46, p=0.019). Conclusion: This is the first study that combines shape information with expert ratings to generate an objective measure of severity for metopic craniosynostosis. This method will help clinicians easily quantify the severity and perform robust longitudinal assessments of the condition.

S8A-10 SESSION 8A: METOPIC SYNOSTOSIS COMPARISON OF HEAD SHAPE OUTCOMES IN METOPIC SYNOSTOSIS: LIMITED STRIP CRANIECTOMY VERSUS FRONTO-ORBITAL RECONSTRUCTION

Introduction: True metopic craniosynostosis (MCS), with its severely trigonocephalic head shape, is often treated with either limited incision strip craniectomy (LISC) followed by helmet orthotic treatment, or open fronto-orbital reconstructive techniques (FOR). There is controversy regarding resultant shape outcomes among craniofacial surgeons. Those adverse to LISC claim normal head shape is never attained, while proponents believe there is gradual correction to an equivalent outcome. This has become contentious, with anecdotal claims frequently the basis of the opposing arguments. No whole head quantitative 3D outcome studies, with normal controls, have been done to support these arguments. This study aims to address these gaps. Methods: 3D images of 31 patients with MCS, were analyzed retrospectively with a 1:1 cohort of age-matched normals. Head shape analyses were performed at: 1) pre-op; 2) 1 month post-op; 3) 10–14 months post-op; 4) 25–36 months post-op. 3D composite heads of MCS patients at each time point were calculated and compared to normal controls and to each other. 2D standardized cross sections of the forehead were also compared and statistically analyzed. Results: In the LISC group, improvement spread laterally across the forehead over time. Hypotelorism improved as well. By 1 month post-op the flatness of the forehead ridge extended to the medial canthus, by 10–14 months it extended to the orbitale superius, and by 25–36 months, it approached the lateral canthus. In the FOR group, after 1 month the forehead contour was nearly spherical. The height of the cranium increased at 1 year post-op. By 25–36 months, there was some widening of the interorbital distance, but no further change in forehead contour. Comparing the LISC vs. FOR groups using contour color maps, which describe protrusion or retrusion as compared to normal, the contours of the groups were similar, albeit not the same size due to age differences. In the 2D analysis, the total differences between LISC and FOR groups also decreased to a point of similarity over time. Conclusion: Both LISC and FOR techniques achieved a normal head shape, reducing the magnitude of shape differences between each intervention and normal cohorts. The pace of head shape improvement was different between the two techniques, consistent with the intuitive expectation that FOR would normalize more quickly, achieving its best approximation to normal by 1 month post-op. However, LISC achieved a similar equivalence to the normal cohort by 10–14 months post-op. This study supports the assertion that both techniques accomplish the goal of normalizing head shape.