Craniosynostosis

Optimizing Blood Loss and Management in Craniosynostosis Surgery: A Systematic Review of Outcomes Over the Last 40 Years

Surgical correction of craniosynostosis can involve significant blood loss. Rates of allogenic blood transfusion have been reported to approach 100%. Multiple interventions have been described to reduce blood loss and transfusion requirements. The aim of this study was to analyze various approaches over the last 4 decades to optimize blood loss and management during craniosynostosis surgery.

PRISMA guidelines for systematic reviews were followed. PubMed and Cochrane database searches identified studies analyzing approaches to minimizing blood loss or transfusion rate in craniosynostosis surgery.

Primary outcomes included rate or amount of allogenic or autologous blood transfusion, estimated blood loss (EBL), postoperative hemoglobin (Hg), or hematocrit (Hct) levels. Secondary outcomes were examined when reported.

Fifty-two studies met inclusion criteria. There was marked heterogeneity regarding design, inclusion criteria, surgical intervention, and endpoints. The majority of the studies were nonrandomized and noncomparative. Four studies analyzed erythropoietin (EPO), 6 analyzed various cell-saver (CS) technologies, 18 analyzed antifibrinolytics (tranexamic acid [TXA], aminocaproic acid [ACA], and aprotinin [APO]), 8 analyzed various alternatives, and 16 analyzed multimodal pathways & protocols. Some studies analyzed multiple approaches.

Although the majority of studies reviewed represent level III/IV evidence, several high-quality level I studies were identified and included. Level I evidence supported an improvement in blood outcomes by utilizing EPO, CS, and TXA, individually or in concert with one another. Thus, this review suggests that a multi-prong approach may be the most effective means to optimize blood loss and transfusion outcomes in craniosynostosis surgery.

Joint Cranial Bone Labeling and Landmark Detection in Pediatric CT Images Using Context Encoding

Image segmentation, labeling, and landmark detection are essential tasks for pediatric craniofacial evaluation. Although deep neural networks have been recently adopted to segment cranial bones and locate cranial landmarks from computed tomography (CT) or magnetic resonance (MR) images, they may be hard to train and provide suboptimal results in some applications. First, they seldom leverage global contextual information that can improve object detection performance. Second, most methods rely on multi-stage algorithm designs that are inefficient and prone to error accumulation. Third, existing methods often target simple segmentation tasks and have shown low reliability in more challenging scenarios such as multiple cranial bone labeling in highly variable pediatric datasets. In this paper, we present a novel end-to-end neural network architecture based on DenseNet that incorporates context regularization to jointly label cranial bone plates and detect cranial base landmarks from CT images. Specifically, we designed a context-encoding module that encodes global context information as landmark displacement vector maps and uses it to guide feature learning for both bone labeling and landmark identification. We evaluated our model on a highly diverse pediatric CT image dataset of 274 normative subjects and 239 patients with craniosynostosis (age 0.63 ± 0.54 years, range 0-2 years). Our experiments demonstrate improved performance compared to state-of-the-art approaches.

Data-driven Normative Reference of Pediatric Cranial Bone Development

Available normative references of cranial bone development and suture fusion are incomplete or based on simplified assumptions due to the lack of large datasets. We present a fully data-driven normative model that represents the age- and sex-specific variability of bone shape, thickness, and density between birth and 10 years of age at every location of the calvaria.

Crouzon syndrome in a fraternal twin: A case report and review of the literature

BACKGROUND

Crouzon syndrome (CS; OMIM 123500) is an autosomal dominant inherited craniofacial disorder caused by mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. CS is characterized by craniofacial dysostosis, exophthalmos, and facial anomalies with hypoplastic maxilla and relative mandibular prognathism.

CASE SUMMARY

Our report involves a 6-year-old fraternal twin boy with many caries in the oral cavity who presented with characteristic features of CS based on clinical and radiographic examinations along with Sanger sequencing. The fraternal girl did not show any abnormalities indicating CS. Carious teeth and poor oral hygiene were managed promptly through administering appropriate behavior guidance, orthodontic treatment was planned, and preventive procedures were described.

CONCLUSION

CS could occur in a fraternal twin caused by a de novo mutation of the FGFR2 gene. Oral hygiene instruction, preventive programs on oral hygiene, orthodontic treatment, and maxillary osteotomy were required for treatment.

Is computer-assisted design and manufacturing technology useful in the surgical management of trigonocephaly?

The aim of this study is to assess the usefulness of CAD/CAM technology in the surgical treatment of trigonocephaly compared to conventional surgical treatment. Children operated from trigonocephaly between 2017 and 2019 at the French Referral Center for craniosynostosis of Femme-Mère-Enfant Hospital of Lyon, France, were included and separated in two groups. Group 1 included children operated on trigonocephaly using CAD-CAM technology; Group 2 included children operated on trigonocephaly without CAD-CAM technology. Age, gender, duration of surgery, complications, blood transfusion and esthetic results were analyzed. The experience of the craniofacial surgeon was also evaluated and quantified in order to weigh the results. Twenty children were included in the study: 10 in the Group 1 and 10 in the Group 2. No statistical difference was observed between these 2 groups concerning the duration of the surgery (137 min ± 39,17 versus 137,2 min ± 64,50; p = 0,85), complications (20% in group 1 versus 10% in group 2; p = 1), the realization of blood transfusion (80% in group 1 versus 70% in group 2) and the esthetic results (5/5 in group 1 versus 4,6/5 in group 2; p = 0,21). However, the use of CAD-CAM technology significantly accelerates the duration of surgery by 25.8 min on average for the surgeon starting in craniofacial surgery (from 197,8 ± 10,21 min without CAD-CAM to 172 ± 18,76 min with CAD-CAM; p = 0.05) but significantly slows the experienced surgeon by 25.4 min on average (from 76,6 ± 8,65 min without CAD-CAM to 102 ± 6,2 min with CAD-CAM; p = 0.01). In the management of trigonocephaly, CAD/CAM technology seems to present a modest interest for the experienced surgeon but presents a real interest for the young surgeon. Within the limitations of the study, it seems that CAD/CAM technology is a relevant addition to the armamentarium of doctors who are in training because surgical time is reduced.

Partial Suture Fusion in Nonsyndromic Single-Suture Craniosynostosis

INTRODUCTION

Partial synostosis of cranial sutures has been shown to have clinical and diagnostic significance. However, there is limited published information about how suture fusion progresses over time. In this study, we evaluate patients with nonsyndromic single-suture synostosis. We aim to define the incidence of partial versus complete suture fusion and whether a correlation exists between the degree of suture fusion and age.

METHODS

Two hundred fifty-four patients with nonsyndromic single-suture synostosis were evaluated. Preoperative computed tomography (CT) scans were rendered in 3-dimensions, all sutures were visualized and assessed for patency or fusion, and length of fusion was measured. Findings were grouped according to suture type (sagittal, coronal, metopic, or lambdoid), the degree of fusion (full, >50%, or <50%), and patient age at time of CT scan (0-90, 91-180, 181-360, or >360 days). Data were analyzed to correlate patient age versus the degree of suture fusion.

RESULTS

For all patients, 72% had complete and 28% had partial synostosis. Ratios of full to partial fusion for each suture type were as follows: sagittal 97:36, coronal 35:22, metopic 46:4, and lambdoid 4:10. The sagittal, coronal, and metopic groups demonstrated greater probabilities of complete suture fusion as patient age increases (P = .021, P < .001, P = .001, respectively). This trend was also noted when all sutures were considered together by age-group (P < .001).

CONCLUSION

We note a partial suture fusion rate of 28.3%. Our analysis shows a correlation between the extent of suture synostosis and patient age. Finally, we demonstrate that different sutures display different patterns of partial and complete fusion.

Custom-Made Three-Dimensional Models for Craniosynostosis

The use of computer-aided design and computer-aided manufacturing in oral and maxillofacial surgery is an ever-growing field.The availability of 3D models, cutting guides, and customised surgical instruments gives surgeons the opportunity to modify and improve their surgical procedures.Here, we discuss the use of computer-aided design-computer-aided manufacturing to improve the management of a case of nonsyndromic metopic synostosis through the construction of: A cutting guide for the cranium, custom-made orbital protectors, a 3D model of the predicted postoperative meninges to allow off the table bone recontouring, and a template frontal bar to allow more specific recontouring of the frontal bar.

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.

Recent Advances in Craniosynostosis

Craniosynostosis is a pathologic craniofacial disorder and is defined as the premature fusion of one or more cranial (calvarial) sutures. Cranial sutures are fibrous joints consisting of nonossified mesenchymal cells that play an important role in the development of healthy craniofacial skeletons. Early fusion of these sutures results in incomplete brain development that may lead to complications of several severe medical conditions including seizures, brain damage, mental delay, complex deformities, strabismus, and visual and breathing problems. As a congenital disease, craniosynostosis has a heterogeneous origin that can be affected by genetic and epigenetic alterations, teratogens, and environmental factors and make the syndrome highly complex. To date, approximately 200 syndromes have been linked to craniosynostosis. In addition to being part of a syndrome, craniosynostosis can be nonsyndromic, formed without any additional anomalies. More than 50 nuclear genes that relate to craniosynostosis have been identified. Besides genetic factors, epigenetic factors like microRNAs and mechanical forces also play important roles in suture fusion. As craniosynostosis is a multifactorial disorder, evaluating the craniosynostosis syndrome requires and depends on all the information obtained from clinical findings, genetic analysis, epigenetic or environmental factors, or gene modulators. In this review, we will focus on embryologic and genetic studies, as well as epigenetic and environmental studies. We will discuss published studies and correlate the findings with unknown aspects of craniofacial disorders.

Coronal craniosynostosis due to TCF12 mutations in patients from Turkey

Craniosynostosis consists of premature fusion of one or more cranial sutures and can be seen as part of a syndrome or diagnosed as nonsyndromic (isolated). Although more than 180 craniosynostosis syndromes have been identified, 70% of the cases are diagnosed as nonsyndromic. On the other hand, genetic causes of the cases are mostly unknown and the overall frequency of the genetic diagnosis is around 25%. In this study, we used targeted Next Generation Sequencing (NGS) analysis to identify the genetic variations of two craniosynostosis cases. We have identified two different truncating mutations, a known NM_207036.1:c.778_779delAT;p.(Met260Valfs*5) and a novel NM_207036.1:c.1102_1108delTCACCTC;p.(Pro369Glnfs*26) TCF12 variants. Additionally, upon physical examination of these two cases, we have observed some shared clinical similarities as well as differences such as bilateral simian crease and hidden cleft palate. This is the first study that reports the TCF12 mutations in Turkish patients with coronal suture synostosis.

Tranexamic Acid Decreases Blood Transfusion Burden in Open Craniosynostosis Surgery Without Operative Compromise

In the surgical management of craniosynostosis, there is a high red blood cell (RBC) transfusion burden due to the small blood volume of the patients combined with significant blood loss that can occur with open surgery (OS). Tranexamic acid (TXA) is an antifibrinolytic which has been shown to decrease such a burden in particular surgeries. The aim of this study was to compare the operative outcomes of craniosynostosis OS which did and did not utilize TXA. Searches of 7 electronic databases from inception to February 2018 were conducted following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. There were 206 articles screened against selection criteria for inclusion. Relevant data were extracted and analyzed using meta-analysis of proportions. A total of 9 comparative studies were included for meta-analysis. Compared with the control cohort, craniosynostosis OS utilizing TXA demonstrated significantly lower intraoperative RBC transfusion volumes (mean difference, -8.25 mL/kg; P < 0.001), blood loss (mean difference, -10.96 mL/kg; P < 0.001) and postoperative RBC transfusion incidence (odds ratio, OR, 0.12; P = 0.005). Fresh frozen plasma and crystalloid transfusion, operation time, length of stay, and complications were not significantly different with TXA use. Based on the comparative evidence currently available, TXA significantly decreased RBC transfusion burden during craniosynostosis OS without operative compromise. There is significant heterogeneity in reported TXA regimes in the literature. Future studies that are larger, randomized, and account for these factors will further enhance the authors' understanding.

How does nonsyndromic craniosynostosis affect on bone width of nasal cavity in children? - Computed tomography study

Craniosynostosis is caused by premature fusion of one or more cranial sutures, restricting skull, brain and face growth. Nonsyndromic craniosynostosis could disturb the proportions of face. Although morphometric diameters of nasal cavity in healthy children are already known, they have not been established yet in children with nonsyndromic craniosynostosis. The aim our study was to check whether diameters of bone structures of nasal cavity in children with nonsyndromic craniosynostosis measured in CT are within normal range. 249 children aged 0–36 months (96 with clinical diagnosis of nonsyndromic craniosynostosis and 153 in control group) were included into the study. The following diameters were measured on head CT scans: anterior bony width (ABW), bony choanal aperture width (BCAW), right and left posterior bony width (between bone sidewall and nasal cavity septum—RPBW and LPBW). The study group has been divided into 4 categories, depending on child’s age. The dimensions measured between bone structures of nasal cavity were statistically significantly lower in comparison to the control group. They did not depend on the sex for ABW, nor on age in groups 7–12 months and < 2 years for BCAW, RPBW and LPBW. The measured dimensions increased with age. In children with nonsyndromic craniosynostosis the diameter of pyriform aperture and bony choanal aperture were lower than in controls, what may be described as fronto-orbital anomalies. Morphometric measurements of anthropometric indicators on CT scans could be used as standards in the clinical identification of craniosynostosis type and may help in planning surgical procedures, particularly in the facial skeleton in children.

Reduced Intercarotid Artery Distance in Syndromic and Isolated Brachycephaly

INTRODUCTION

The morphology of the skull base can be altered in craniosynostoses. The objective of this study is to evaluate the reduced intercarotid artery distance in the lacerum segment in patients with syndromic and isolated brachycephaly.

MATERIALS AND METHODS

The distances between the inner walls of the carotid canal at the lacerum segment were measured on high-resolution CT scans in children with Crouzon (25), Pfeiffer (21), Apert (26), Saethre-Chotzen (7) syndromes, isolated bicoronal synostosis (9), and compared to an age-matched control group (30).

RESULTS

A significantly smaller mean distance between carotid canal walls was observed in Crouzon (11.1 ± 4.9 mm), Pfeiffer (9.6 ± 5.1 mm), Apert (12.3 ± 4.3 mm), Saethre-Chotzen (14.8 ± 3.0 mm) syndromes, and isolated bicoronal synostosis (14.9 ± 3.7 mm) as compared to the control group (19.7 ± 2.4 mm, P < 0.001, P < 0.001, P < 0.001, P = 0.005, and P = 0.002, respectively). There was no statistically significant difference in intercarotid canal distance among the Apert, Saethre-Chotzen and isolated bicoronal synostosis groups. Overall, the brachycephalic group showed reduced intercarotid canal distance comparing to controls (P < 0.001).

DISCUSSION AND CONCLUSIONS

There is significant reduction of the distance between carotid canals in brachycephalic patients. This distance is more significantly altered in FGFR-related brachycephaly syndromes (especially Crouzon and Pfeiffer syndromes), than Saethre-Chotzen syndrome (TWIST1 mutation) and isolated non-syndromic bicoronal synostosis. This study highlights the importance of FGFRs in shaping the skull base. Altered vascular course of the internal carotid arteries can have important implications in planning skull base surgery in brachycephalic patients.

Diagnosis of infant synostotic and nonsynostotic cranial deformities: a review for pediatricians

Objective:

To review the current comprehensive care for nonsyndromic craniosynostosis and nonsynostotic cranial deformity and to offer an overall view of these craniofacial conditions.

Data source:

The review was conducted in the PubMed, SciELO, and LILACS databases without time or language restrictions. Relevant articles were selected for the review.

Data synthesis:

We included the anatomy and physiology of normal skull development of children, discussing nuances related to nomenclature, epidemiology, etiology, and treatment of the most common forms of nonsyndromic craniosynostosis. The clinical criteria for the differential diagnosis between positional deformities and nonsyndromic craniosynostosis were also discussed, giving to the pediatrician subsidies for a quick and safe clinical diagnosis. If positional deformity is accurately diagnosed, it can be treated successfully with behavior modification. Diagnostic doubts and craniosynostosis patients should be referred straightaway to a multidisciplinary craniofacial center.

Conclusions:

Pediatricians are in the forefront of the diagnosis of patients with cranial deformities. Thus, it is of paramount importance that they recognize subtle cranial deformities as it may be related to premature fusion of cranial sutures.

Diagnosis of infant synostotic and nonsynostotic cranial deformities: a review for pediatricians

OBJECTIVE

To review the current comprehensive care for nonsyndromic craniosynostosis and nonsynostotic cranial deformity and to offer an overall view of these craniofacial conditions.

DATA SOURCE

The review was conducted in the PubMed, SciELO, and LILACS databases without time or language restrictions. Relevant articles were selected for the review.

DATA SYNTHESIS

We included the anatomy and physiology of normal skull development of children, discussing nuances related to nomenclature, epidemiology, etiology, and treatment of the most common forms of nonsyndromic craniosynostosis. The clinical criteria for the differential diagnosis between positional deformities and nonsyndromic craniosynostosis were also discussed, giving to the pediatrician subsidies for a quick and safe clinical diagnosis. If positional deformity is accurately diagnosed, it can be treated successfully with behavior modification. Diagnostic doubts and craniosynostosis patients should be referred straightaway to a multidisciplinary craniofacial center.

CONCLUSIONS

Pediatricians are in the forefront of the diagnosis of patients with cranial deformities. Thus, it is of paramount importance that they recognize subtle cranial deformities as it may be related to premature fusion of cranial sutures.

Diagnostic features of prematurely fused cranial sutures on plain skull X-rays

PURPOSE

The characteristic features of prematurely fused craniosynostosis in plain radiographs have already been described in literature, but there is no clinical trial investigating the individual features of every single form of craniosynostosis. We described suture-specific characteristics as well as its frequency of appearance in plain radiographs in every different form of craniosynostosis. Intraoperative findings served as control to confirm the diagnosis.

METHODS

One hundred twenty-seven children with prematurely fused cranial sutures who underwent a skull X-ray from 2008 to 2012 were investigated in the present study. In detail, 34 children with frontal, 60 with sagittal, 13 with unilateral and 14 with bilateral coronal synostosis and 3 with unilateral lambdoid craniosynostosis as well as 3 children with a bilateral lambdoid synostosis were included.

RESULTS

Typical radiological characteristics in craniosynostosis exist. These features as well as its frequency in craniosynostosis in plain skull radiographs are presented. In all cases, these typical features enabled a correct diagnosis, which was confirmed by intraoperative findings.

CONCLUSION

The frequency of the appearance of typical features is listed and may serve as a "mental internal check list" in the radiological approach to craniosynostosis. The study points out the value of plain skull X-rays as it enabled proper diagnosis in all investigated 127 cases.

Custom made orthotic device for maintaining skull architecture during the postoperative period in infants undergoing craniosynostosis surgery

AIM

To fabricate a cost effective, indigenous and simple orthotics helmet for post-operative cranial molding in patients with craniosynostosis surgery.

METHODS

We present a case of 15 month old infant with secondary cranial vault deformity. Cranial vault remodeling surgery involving the posterior skull was planned and executed to increase the posterior gap, so that brain growth would be facilitated towards this empty space. Materials such as thermoplastic sponge, thermoplastic ionomer resin sheet, soft sponge and Velcro straps are used to fabricate a cranial orthotics helmet.

RESULTS

We have successfully used the above materials to fabricate the orthotics helmet for post-operative cranial molding.

CONCLUSION

The technique described in this article is simple and cost effective. It can be custom made according to the demands of the surgical technique and the type of synostosis. It favors an individualistic prognosis, and proves worthwhile as every synostosis requires a unique treatment plan. It is an excellent adjuvant to craniosynostosis remodeling surgery.

Metabolic changes and factors influencing base deficit in infants undergoing craniosynostosis surgery: a retrospective study

BACKGROUND

Corrective craniosynostosis surgery is often associated with a large amount of blood loss and metabolic disturbances. In the present study, we investigated the severity, duration of metabolic disturbances, and causal risk factors in infants.

METHODS

A retrospective analysis was performed of 36 infants who underwent craniosynostosis surgery. We analyzed the following: demographics, duration of surgery, intraoperative blood loss, RBC, FFP and fluids transfused, urine output, hemodynamic parameters, and electrolyte and base deficit (BD) values. The lowest intraoperative BD value and time required (period I: <6 h; period II: 6-12 h; period III: >12 h) for BD values to return to normal (-4 to +2) in the postoperative period were determined. In addition, we recorded the postoperative length of stay in the ICU and hospital, postoperative blood loss, and early complications.

RESULTS

We detected that 88% of the patients had subnormal BD levels and 22% had metabolic acidosis. The lowest average BD measured during the operation was -8.4 ± 2.6 mmol/l. We carried out a multiple regression analysis, which revealed that lower BD values were associated with a longer duration of hypotension (p = 0.002, R(2) = 0.453) and greater intraoperative blood loss (p = 0.002, R(2) = 0.674). We examined the amount of intraoperative blood loss and found that that there were fewer blood product transfusions in period I patients and longer hypotensive episodes in period III patients. Also, a negative correlation was detected between the lowest intraoperative BD value with ICU duration (p = 0.004, r = -0.466) and hospital stay (p < 0.001, r = -0.764).

CONCLUSION

Almost all patients developed intraoperative negative BD, which was prolonged in the postoperative period. The most important risk factors for developing negative BD are the amount of blood loss and duration of hypotension.

Morphology of the foramen magnum in syndromic and non-syndromic brachycephaly

PURPOSE

The shape and size of the foramen magnum (FM) can be altered in craniosynostoses. However, few studies have investigated these changes. In this paper, we investigate the morphology of the foramen magnum in syndromic and non-syndromic brachycephaly.

METHODS

Surface area, anteroposterior (AP) diameter, and transverse diameters of the FM were measured on high-resolution CT scans in children with Crouzon (25), Pfeiffer (21), Apert (26), Saethre-Chotzen (7) syndromes, and isolated bicoronal synostosis (9) and compared to an age-matched control group (30).

RESULTS

A significantly smaller FM surface area was observed in Crouzon (6.3 ± 1.7 cm(2)) and Pfeiffer (6.4 ± 2.3 cm(2)) syndromes as compared to the control group (7.4 ± 1.3 cm(2), p = 0.006 and p = .017, respectively). In comparison to the control group, no statistically significant alteration in FM surface area was noted in patients with Apert, Saethre-Chotzen, or isolated bicoronal synostosis (p = 0.37, p = 0.71, p = 0.40 respectively). The transverse diameter of FM was significantly smaller in Crouzon, Pfeiffer, and Apert syndromes compared to the control group (p = 0.005, p = 0.002, p = 0.03 respectively). In Saethre-Chotzen and isolated bicoronal synostosis, no difference in transverse diameter was demonstrated. Among all groups, only Crouzon syndrome showed reduced anteroposterior diameter as compared to controls (p = 0.005). In Pfeiffer and Apert syndromes, there was elongation of the shape of the FM with a relatively narrowed width as demonstrated in a significantly increased AP to transverse diameter ratio (p = 0.002 and p = 0.019, respectively).

DISCUSSION AND CONCLUSIONS

The FM shape and area is significantly altered in fibroblast growth factor receptor (FGFR)-related brachycephaly syndromes (Crouzon, Pfeiffer, and Apert), whereas in patients with Saethre-Chotzen syndrome (TWIST-1 mutation) and isolated non-syndromic bicoronal synostosis, the shape and mean FM area was not statistically different from that of normals. This study brings to light the important role of FGFRs on FM growth and shape. TWIST-1 mutation (Saethre-Chotzen syndrome) does not appear to have an important effect in shaping the FM.

Secondary bicoronal synostosis after metopic craniosynostosis surgical reconstruction

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

Tranexamic Acid reducing blood transfusion in children undergoing craniosynostosis surgery

BACKGROUND

Surgical correction of craniosynostosis in children is associated with substantial intraoperative bleeding. Intraoperatively administered tranexamic acid (TXA) can lessen blood loss during orthopedic and cardiovascular surgery, but its efficacy in craniosynostosis surgery is uncertain. Therefore, a meta-analysis performed with published comparative studies was to determine whether TXA could reduce packed red blood cells (or erythrocytes) (PRBCs) transfused and blood loss during pediatric craniosynostosis surgery.

METHODS

Two PubMed and EMBASE electronic databases were searched until June 2012. Eligible studies were restricted in comparative controlled trials.

RESULTS

Four studies in 3 articles with 138 patients were included. The results showed that intraoperative administration of TXA can significantly reduce transfusion of PRBCs (weighed mean difference [WMD] = -10.81, 95% confidence interval [CI] = -16.84 to -4.78, P < 0.00001). In the level of blood loss, the meta-analysis on 4 studies showed that the difference was statistically significant (WMD = -20.53, 95% CI = -32.26 to -8.80, P = 0.0006) between the TXA groups and the control groups. However, the subgroup analysis on randomized controlled trials showed that TXA did not significantly reduce blood loss during surgery compared with the placebo group (WMD = -30.79, 95% CIs = -71.72 to 10.14, P = 0.14).

CONCLUSIONS

Tranexamic acid can significantly reduce the transfusion of PRBCs in children undergoing craniosynostosis surgery. However, there is a controversy on the efficacy of TXA in reducing blood loss. Therefore, new randomized controlled trials to assess the effects of TXA in children with craniosynostosis surgery should be conducted.

Rapid re-synostosis following suturectomy in pediatric mice is age and location dependent

Craniosynostosis is the premature fusion of the cranial sutures early in development. If left untreated, craniosynostosis can lead to complications resulting from cranial deformities or increased intracranial pressure. The standard treatment involves calvarial reconstruction, which in many cases undergoes rapid re-synostosis. This requires additional surgical intervention that is associated with a high incidence of life threatening complications. To better understand this rapid healing, a pediatric mouse model of re-synostosis was developed and characterized. Defects (1.5mm by 2.5mm) over the posterior frontal suture were created surgically in weanling (21 days post-natal) and adolescent (50 days post-natal) C57Bl/6J mice. In addition, defects were created in the frontal bone lateral to the posterior frontal suture. The regeneration of bone in the defect was assessed using advanced image processing algorithms on micro-computed tomography scans. The genes associated with defect healing were assessed by real-time PCR of mRNA isolated from the tissue present in the defect. The results showed that the weanling mouse healed in a biphasic process with bone bridging the defect by post-operative (post-op) day 3 followed by an increase in the bone volume on day 14. In adolescent mice, there was a delay in bone bridging across the defect, and no subsequent increase in bone volume. No bridging of the defect by 14 days post-op was seen in identically sized defects placed lateral to the suture in both weanling and adolescent animals. This study demonstrates that bone regeneration in the cranium is both age and location dependent. Rapid and robust bone regeneration only occurred when the defect was created over the posterior frontal suture in immature weanling mice.

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.

Crouzon syndrome with primary optic nerve atrophy and normal brain functions: A case report

BACKGROUND

This report and review of literature aimed to assess an unusual case of Crouzon syndrome characterized by distinctive disfigurement of craniofacial skeletal and soft tissue structures with primary optic nerve atropy.

METHODS

We present a case of a 12-year-old girl with Crouzon syndrome displaying classic facial abnormalities with reduced vision and hearing loss.

CONCLUSION

Crouzon syndrome should be managed as early as possible as it results in airway obstruction, decreased vision, mental retardation and poor cosmetic appearance.

Craniosynostosis and 3-dimensional computed tomography

Craniosynostosis is when cranial sutures fuse prematurely. It causes cosmetic deformity and may limit brain growth with more serious consequences, such as hydrocephalus. It may involve one or more sutures, may be syndromic, and is thought most likely to result from genetic causes. Specific sutural closures result in reproducible cranial appearances and head shapes. Three-dimensional computed tomography has become the standard for preoperative diagnosis to allow surgical planning as well as postsurgical assessment. Early diagnosis allows early surgical management, which improves outcome. Nonsyndromic and syndromic craniosynostoses are illustrated in this pictorial review.

Evaluation and management of nonsyndromic craniosynostosis

Craniosynostosis (craniostenosis) is premature fusion of the sutures of the cranial vault. Several factors can affect the growth of the cranial vault during embryonic life and after birth, leading to different types of craniosynostosis; these can be classified on the basis of the specific sutures that are fused. Prognosis is improved by early diagnosis, and it is important to establish the correct approach to these patients on the basis of clinical and neuroradiological investigation. The first priority is to identify the type of craniosynostosis and to distinguish between the types that require surgical intervention and those that do not. We report on the different forms of nonsyndromic craniosynostosis, their clinical and neuroradiological diagnoses, and surgical strategies.

CONCLUSION

The aim of this review is to provide to paediatricians a correct diagnostic approach and management of children affected from nonsyndromic craniosynostosis, for which a careful physical, ophthalmological and neurological examination is fundamental, whereas brain Computed tomography and magnetic resonance imaging are necessary for patients in which the diagnosis is uncertain or for cases of syndromic craniosynostosis.

Molecular analysis of coronal perisutural tissues in a craniosynostotic rabbit model using polymerase chain reaction suppression subtractive hybridization

BACKGROUND

In the United States, the incidence of craniosynostosis (premature fusion of the sutures of the cranial vault) is one in 2000 to 3000 live births. The condition can cause increased intracranial pressure, severely altered head shape, and mental retardation. The authors have previously described a colony of rabbits with heritable coronal suture synostosis. This model has been instrumental in describing the postsurgical craniofacial growth associated with craniosynostosis. The molecular analysis of this model has been limited by the lack of molecular tools for use in rabbits. To understand the pathogenesis of craniosynostosis, the authors compared gene expression in perisutural tissues between wild-type and craniosynostotic rabbits using polymerase chain reaction suppression subtractive hybridization.

METHODS

Suppression subtractive hybridization polymerase chain reaction was performed on RNA derived from pooled samples of calvariae from 10-day-old wild-type (n = 3) and craniosynostotic (n = 3) rabbits to obtain cDNA clones enriched in either wild-type tissues (underexpressed in craniosynostotic tissue) or craniosynostotic tissues (overexpressed in craniosynostotic compared with wild-type).

RESULTS

Differential expression was identified for approximately 140 recovered cDNA clones up-regulated in craniosynostotic tissues and 130 recovered clones for wild-type tissues. Of these, four genes were confirmed by quantitative reverse-transcriptase polymerase chain reaction as being overexpressed in craniosynostotic sutural tissue: β-globin (HBB), osteopontin (SPP1), osteonectin (SPARC), and cathepsin K (CTSK). Two genes were confirmed to be underexpressed in the craniosynostotic samples: collagen 3, alpha 1 (COL3A1) and ring finger protein 12 (RNF12).

CONCLUSION

The differential expression of these gene products in our naturally occurring craniosynostotic model appears to be the result of differences in the normal bone formation/resorption pathway.

Pictorial essay: The many faces of craniosynostosis

Craniosynostosis is a common condition in the pediatric age group, which may either be isolated or may present as part of a craniofacial syndrome. This pictorial review illustrates the underlying mechanisms and pathophysiology of craniosynostosis, the various types of craniosynostoses, common craniofacial syndromes and the role of imaging in their diagnosis and management.

Blocking bone morphogenetic protein function using in vivo noggin therapy does not rescue premature suture fusion in rabbits with delayed-onset craniosynostosis

BACKGROUND

Craniosynostosis is defined as the premature fusion of one or more cranial sutures. Bone morphogenetic proteins (BMPs), regulators of ossification, have been implicated in premature suture fusion. Noggin, an extracellular BMP inhibitor, has been shown experimentally to inhibit resynostosis following surgery. The present study was designed to test the hypothesis that BMP inhibition using noggin therapy may rescue sutures destined to fuse by inhibiting initial ossification.

METHODS

Twenty-six, 10-day old rabbits with familial, delayed-onset, coronal suture synostosis were randomly divided into three groups: (1) the sham surgical control group, (2) the bovine serum albumin-treated group [10 μg/suture (protein/vehicle controls)], and (3) the noggin therapy group (10 μg/suture; experimental group). Sutural growth was monitored by radiopaque markers implanted at 10 days of age. At 25 days, the bovine serum albumin or noggin was combined with a slow-resorbing collagen vehicle and injected subperiosteally above the coronal suture. Somatic and sutural growth data were collected at 10, 25, 42, and 84 days of age. Coronal sutures were harvested at 84 days to histologically assess fusion.

RESULTS

Results showed no significant (p > 0.05) differences in suture separation at any age. Suture fusion assessed by histomorphology did not differ among the three groups. Although previous data showed noggin to inhibit postoperative resynostosis in this craniosynostotic rabbit model, here there was no effect on initial suture fusion.

CONCLUSION

These results suggest that in this rabbit model of craniosynostosis, BMPs do not play a role in the pathogenesis of craniosynostosis and only play a role in postoperative bony wound healing.

Craniosynostosis: a radiological and surgical perspective

Craniosynostosis is the premature fusion of the cranial sutures. It is identified early in life either due to cosmetic deformity or due to more serious functional complications. Isolated forms of craniosynostosis are much more common and less challenging in their management than their syndromic counterpart. Modern multislice computed tomography and 3D reconstructions have revolutionized surgical planning and follow-up. We review the radiological features of the craniosynostoses, complications, and associated conditions that may alter patient management. Common surgical techniques and postoperative appearances are illustrated in the article.

Visual function in nonsyndromic craniosynostosis: past, present, and future

BACKGROUND

Previous studies on visual function in craniosynostosis have mainly focused on ocular movements and ophthalmologic findings. More recently, some studies also included the assessment of more functional and electrophysiological aspects of vision, such as acuity and visual evoked potentials.

METHODS

We reviewed all the relevant publications on visual findings in infants and children with both syndromic and nonsyndromic craniosynostosis and reported our own recent experience on the presurgical assessment of visual function in infants with single suture nonsyndromic craniosynostosis.

RESULTS

Most studies report abnormal ophthalmologic findings, mainly strabismus and refractive deficits. Only few recent studies, including ours, have reported the impairment of more functional aspects of vision, such as visual acuity and visual evoked potentials in relation to the various forms of craniosynostoses.

DISCUSSION

We suggest a few guidelines for further studies, which may help to better elucidate the mechanisms underlying possible visual impairment in the various types of craniosynostosis.

Visual function in infants with non-syndromic craniosynostosis

The aim of this study was to assess various aspects of visual function in children with single-suture, non-syndromic craniosynostosis. Thirty-eight infants (28 males, 10 females; age range 3.5-13mo, mean age 7mo, 11 with plagiocephaly, 12 with trigonocephaly, and 15 with scaphocephaly), were assessed with a battery of tests specifically designed to assess various aspects of visual function in infancy. Thirty-two of the 38 infants had at least one abnormality on one of the aspects of visual function assessed. Abnormal eye movements were found in eight infants of the whole cohort and were mainly found in infants with plagiocephaly (6/11), who also had frequent visual field abnormalities (5/11). In contrast, fixation shift, an aspect of visual function related to the integrity of parietal lobes, was more frequently abnormal in patients with scaphocephaly. Our results suggest that the presence and severity of visual impairment is related to the type of craniosynostosis. Follow-up studies after surgical correction are needed to evaluate the possible beneficial effects of reconstructive surgery on visual function.

Diagnostic imaging in the management of craniosynostoses

Craniosynostoses are the most frequent craniofacial malformations. However, with a prevalence of 3-6 cases per 10,000 live births they are amongst the rarely seen diseases and their definite diagnosis thus poses a challenge to the physician. When an abnormal calvarial configuration is detected, a radiological evaluation is necessary to characterize the deformity and to guide the corrective surgical procedure. The demand for clear diagnostic criteria is justified by the severity of the disease and the possible consequences of delayed diagnosis. In addition to the clinical signs (deformation of the head), conventional skull X-rays show typical radiological alterations and are used for basic diagnostics. Diagnostic tests that may be performed to confirm the diagnosis and assess the extent of the problem, include computed tomography (CT), 3D-CT, magnetic resonance imaging (MRI) scans, and ultrasonography. In the present review we will describe the most important clinical and radiological characteristics of craniosynostosis by means of clinical, radiological and operative situs examples.

Pitfalls for the pediatrician: positional molding or craniosynostosis?

Abnormal head morphology is common among infants and often leads parents to ask their pediatricians for guidance. While the vast majority of such children development and prevent adverse neurobehavioral sequelae secondary to increased intracranial pressure or impaired cerebral growth. The coordination of a multidisciplinary team in the setting of a center experienced in the management of craniosynostosis will assure the best possible results for each patient.

Early surgical treatment of nonsyndromic craniosynostosis

BACKGROUND

Craniosynostosis, a premature fusion of cranial sutures, can happen as an isolated defect (nonsyndromic) or as part of a syndrome. It may lead to raised intracranial pressure and deformity of both the cranial and facial skeletons. Early surgery is usually the best treatment choice. The aim of this study was to review the experience of a multidisciplinary staff with the surgical treatment of nonsyndromic craniosynostosis.

METHODS

All the nonsyndromic craniosynostosis cases treated surgically from 1991 to 2005 at 2 neurosurgical centers were reviewed. The variables analyzed were sex, age, weight, type of deformity, estimated volemia, surgical technique, surgical time, blood loss, PO hospitalization time, and complications. All data were stored in a database and analyzed with Microsoft Access (Microsoft Corp, Seattle, WA) and SPSS V11.0 (SPSS, Inc, Chicago, IL).

RESULTS

The sample consisted of 120 patients (70 males, 50 females). Six patients were excluded because of their atypical timing of treatment (average age, 72 months). The final average age was 7.08 months (variation, 1-18), and the average weight was 7.8 kg. The types of deformities found were scaphocephaly (n = 54, 45%), plagiocephaly (n = 27, 22%), trigonocephaly (n = 19, 16%), brachycephaly (n = 16, 13%), and oxycephaly (n = 4, 3%). The mean surgical time was 186 minutes and the mean PO hospitalization time was 6.8 days. The mortality on this series was 2.6% (3 patients). In the last operated cases, a significant improvement in morbid-mortality was observed.

CONCLUSION

A multidisciplinary approach, including neurosurgeons, neurologists, and pediatricians, and appropriate training of the clinical surgical staff can minimize the risks and decrease the complications in the treatment of craniosynostosis, leading to a satisfactory outcome.

The infant skull: a vault of information

The art of interpreting skull radiographs is slowly being lost as trainees in radiology see fewer plain radiographs and depend more heavily on computed tomography and magnetic resonance imaging. Nevertheless, skull radiographs still provide significant information that is helpful in finding pathologic conditions and appreciating their extents. Abnormalities in the skull may be reflected as variations in the density, size, and shape of the skull, as well as skull defects. Skeletal dysplasias may manifest as a generalized decrease in calvarial density (hypophosphatasia, osteogenesis imperfecta), a generalized increase in calvarial density (osteopetrosis), or a focal increase in density (frontometaphyseal dysplasia). Diffusely decreased or increased calvarial density is usually associated with a process that affects the entire skeleton. Therefore, correct differentiation among these dysplasias depends on other concurrent features. Decreased size of the cranial vault at birth generally implies an underlying insult to the brain, including fetal alcohol syndrome and the so-called TORCH infections (toxoplasmosis, rubella, cytomegalovirus infection, herpes simplex). Macrocephaly may result from skeletal dysplasia or an increase in the intracranial volume (eg, due to underlying anomalies of the brain such as hydrocephalus).

New insights into craniosynostosis

Craniosynostosis is a congenital developmental disorder involving premature fusion of cranial sutures, often associated with multiple neurological manifestations. The perspective of this group of disorders has changed dramatically in the new era of molecular genetics. In the last decade a large literature with new concepts in craniosynostosis has appeared. More than 100 syndromes associated with craniosynostosis have been described, and in about a dozen, the molecular defect has been identified. Pediatric neurologists are less aware than geneticists, neurosurgeons, and craniofacial surgeons of these changes. General concepts about craniosynostosis are here presented with updates of clinical and genetic aspects of well-defined syndromes such as Apert, Crouzon, Pfeiffer, Saethre-Chotzen. Evidence of their relationship with fibroblast growth factor receptors (FGFRs) 1, 2, and 3, and with causative genes such as TWIST has been documented. New and other less common syndromes also are discussed. The differences between positional and synostotic plagiocephaly are important, as well as the cause of nonsyndromic craniosynostosis. The prognosis and neurological outcome of patients, including "benign" forms of craniosynostosis, are other important aspects. Major advances have occurred in understanding pathogenesis, diagnosis, and treatment of craniosynostosis. The role of local dura mater and apoptosis; modalities of imaging such as prenatal ultrasound and three-dimensional and spiral CT have improved the accuracy in diagnosis, and the new approaches in surgical treatment involving efficient and less invasive methods, are evidence of these advances.