New insights into craniosynostosis

Nervous system involvement in Pfeiffer syndrome

Pfeiffer syndrome (PS) is a rare autosomal dominant craniofacial disorder characterized by primary craniosynostosis, midface hypoplasia, and extremities' abnormalities including syndactyly. The purpose of this article was to review the current knowledge regarding how PS affects the nervous system. Methodologically, we conducted a systematic review of the existing literature concerning involvement of the nervous system in PS. Multiple-suture synostosis is common, and it is the premature fusion and abnormal growth of the facial skeleton's bones that cause the characteristic facial features of these patients. Brain abnormalities in PS can be primary or secondary. Primary anomalies are specific developmental brain defects including disorders of the white matter. Secondary anomalies are the result of skull deformity and include intracranial hypertension, hydrocephalus, and Chiari type I malformation. Spinal anomalies in PS patients include fusion of vertebrae, "butterfly" vertebra, and sacrococcygeal extension. Different features have been observed in different types of this syndrome. Cloverleaf skull deformity characterizes PS type II. The main neurological abnormalities are mental retardation, learning difficulties, and seizures. The tricky neurological examination in severely affected patients makes difficult the early diagnosis of neurological and neurosurgical complications. Prenatal diagnosis of PS is possible either molecularly or by sonography, and the differential diagnosis includes other craniosynostosis syndromes. Knowing how PS affects the nervous system is important, not only for understanding its pathogenesis and determining its prognosis but also for the guidance of decision-making in the various critical steps of its management. The latter necessitates an experienced multidisciplinary team.

Perioperative Management and Factors Associated With Transfusion in Cranial Vault Reconstruction

BACKGROUND

Bleeding is the most common adverse event in patients undergoing cranial vault reconstruction. The authors compare the transfusion rates against a national sample to determine whether the patients experience lower transfusion rates.

METHODS

The authors queried the Pediatric National Surgical Quality Improvement Program (Peds-NSQIP) for patients who underwent cranial vault reconstruction (CPT 61559) and compared them to patients who underwent cranial vault reconstruction for sagittal craniosynostosis at Children's Hospital and Medical Center (CHMC) in Omaha, Nebraska. Patients over the age of 24 months were excluded. Binary logistic regression analysis was performed using IBM-SPSS v24.0 to determine factors associated with transfusion at CHMC.

RESULTS

Patient demographics, preoperative hematocrit and platelet counts, readmission rates, and reoperation rates did not differ between CHMC (N = 54) and Peds-NSQIP (N = 1320) cohorts. Patients in the CHMC cohort had shorter preincision anesthesia times (47 versus 80 minutes, P < 0.001), shorter operative times (108 versus 175 minutes, P < 0.001), lower transfusion rates (50% versus 73%, P < 0.001), and smaller mean transfusion volumes (16 versus 33 mL/kg, P < 0.001); however mean length of stay was longer (4.1 versus 3.6 days, P < 0.001). Factors independently associated with transfusion at CHMC included preoperative hematocrit (odds ratio [OR] 0.423, P = 0.002), administration of an antifibrinolytic agent (OR 0.004, P = 0.001) and temperature at the time of incision (OR 0.020, P = 0.043).

CONCLUSION

Patients at CHMC require less transfused blood and experience low transfusion rates. Preoperative hematocrit, administration of antifibrinolytic agents, and temperature at the time of incision are all modifiable factors associated with perioperative transfusion.

Endoscopic Versus Open Repair for Craniosynostosis in Infants Using Propensity Score Matching to Compare Outcomes: A Multicenter Study from the Pediatric Craniofacial Collaborative Group

BACKGROUND

The North American Pediatric Craniofacial Collaborative Group (PCCG) established the Pediatric Craniofacial Surgery Perioperative Registry to evaluate outcomes in infants and children undergoing craniosynostosis repair. The goal of this multicenter study was to utilize this registry to assess differences in blood utilization, intensive care unit (ICU) utilization, duration of hospitalization, and perioperative complications between endoscopic-assisted (ESC) and open repair in infants with craniosynostosis. We hypothesized that advantages of ESC from single-center studies would be validated based on combined data from a large multicenter registry.

METHODS

Thirty-one institutions contributed data from June 2012 to September 2015. We analyzed 1382 infants younger than 12 months undergoing open (anterior and/or posterior cranial vault reconstruction, modified-Pi procedure, or strip craniectomy) or endoscopic craniectomy. The primary outcomes included transfusion data, ICU utilization, hospital length of stay, and perioperative complications; secondary outcomes included anesthesia and surgical duration. Comparison of unmatched groups (ESC: N = 311, open repair: N = 1071) and propensity score 2:1 matched groups (ESC: N = 311, open repair: N = 622) were performed by conditional logistic regression analysis.

RESULTS

Imbalances in baseline age and weight are inherent due to surgical selection criteria for ESC. Quality of propensity score matching in balancing age and weight between ESC and open groups was assessed by quintiles of the propensity scores. Analysis of matched groups confirmed significantly reduced utilization of blood (26% vs 81%, P < .001) and coagulation (3% vs 16%, P < .001) products in the ESC group compared to the open group. Median blood donor exposure (0 vs 1), anesthesia (168 vs 248 minutes) and surgical duration (70 vs 130 minutes), days in ICU (0 vs 2), and hospital length of stay (2 vs 4) were all significantly lower in the ESC group (all P < .001). Median volume of red blood cell administered was significantly lower in ESC (19.6 vs 26.9 mL/kg, P = .035), with a difference of approximately 7 mL/kg less for the ESC (95% confidence interval for the difference, 3-12 mL/kg), whereas the median volume of coagulation products was not significantly different between the 2 groups (21.2 vs 24.6 mL/kg, P = .73). Incidence of complications including hypotension requiring treatment with vasoactive agents (3% vs 4%), venous air embolism (1%), and hypothermia, defined as <35°C (22% vs 26%), was similar between the 2 groups, whereas postoperative intubation was significantly higher in the open group (2% vs 10%, P < .001).

CONCLUSIONS

This multicenter study of ESC versus open craniosynostosis repair represents the largest comparison to date. It demonstrates striking advantages of ESC for young infants that may result in improved clinical outcomes, as well as increased safety.

[Guide to clinical practice for the diagnosis, treatment and rehabilitation of non-syndromic craniosynostosis on 3 levels of care]

INTRODUCTION

Craniosynostosis is a congenital anomaly resulting from the premature fusion of the cranial sutures changing growth patterns of the skull.

METHODOLOGY

Focus, scope, target population and clinical questions to be solved were defined. A systematic search for evidence in different databases (Medline, Embase, KoreaMed, Cochrane Library and the website of the World Health Organization) in stages was performed: clinical practice guidelines; systematic reviews, and clinical trials and observational studies; using MeSH, Decs and corresponding free terms, unrestricted language or temporality. Risk of bias was evaluated using appropriate tools (AMSTAR, Risk of Bias or STROBE). The quality of evidence was graduated using the GRADE system. Modified Delphi Panel technique was used to assign the recommendation's strength and direction, as well as the degree of agreement with it, taking into account the quality of evidence, balance between risks and benefits of interventions, values and preferences of patients and availability of resources.

RESULTS

There were 3,712 documents obtained by search algorithms; selecting 29 documents for inclusion in the qualitative synthesis. Due to heterogeneity between studies, it was not possible to perform meta-analysis.

CONCLUSIONS

We issued 7 recommendations and 8 good practice points, which will serve as support for decision-making in the comprehensive care of patients with craniosynostosis.

Timing in neural maturation: arrest, delay, precociousness, and temporal determination of malformations

Timing is primordial in initiating and synchronizing each developmental process in tissue morphogenesis. Maturational arrest, delay, and precociousness all are conducive to neurological dysfunction and may determine different malformations depending on when in development the faulty timing occurred, regardless of the identification of a specific genetic mutation or an epigenetic teratogenic event. Delay and arrest are distinguished by whether further progressive development over time can be expected or the condition is static. In general, retardation of early developmental processes, such as neurulation, cellular proliferation, and migration, leads to maturational arrest. Retardation of late processes, such as synaptogenesis and myelination, are more likely to result in maturational delay. Faulty timing of neuronal maturation in relation to other developmental processes causes neurological dysfunction and abnormal electroencephalograph maturation in preterm neonates. Precocious synaptogenesis, including pruning to provide plasticity, may facilitate prenatal formation of epileptic circuitry leading to severe postnatal infantile epilepsies. The anterior commissure forms 3 weeks earlier than the corpus callosum; its presence or absence in callosal agenesis is a marker for the onset of the initial insult. An excessively thick corpus callosum may be due to delayed retraction of transitory collateral axons. Malformations that arise at different times can share a common pathogenesis with variations on the extent: timing of mitotic cycles in mosaic somatic mutations may distinguish hemimegalencephaly from focal cortical dysplasia type 2. Timing should always be considered in interpreting cerebral dysgeneses in both imaging and neuropathological diagnoses.

Simultaneous and differential fronto-orbital and midface distraction osteogenesis for syndromic craniosynostosis using rigid external distractor II

In syndromic craniosynostosis, the relation between the supraorbital area and the frontal bone is not good, and it is not possible to reform this area with 1-block advancement. To avoid this problem, the frontal bone is separated from the fronto-orbital bandeau, each is reshaped and remodeled separately, and then both are reattached. The retrusion of the midface, especially in syndromic craniosynostosis, is usually greater than that of cranial bones, so the technique usually separating the midface from the cranium is Le Fort III osteotomy, which allows differential distraction of each part. In this procedure, the cranial and midfacial bones are advanced simultaneously and differentially, both to the planned extent, in a single-stage operation, using rigid external distractor II, correcting exorbitism, respiratory embarrassment, and cranial structures and avoiding eye complications in the future. This procedure was used, with a follow-up, in 10 patients with syndromic craniosynostosis from 2 to 5 years.

Perioperative management of children undergoing craniofacial reconstruction surgery: a practice survey

OBJECTIVE/AIMS

  To assess current practices in the management of children undergoing craniofacial surgery and identify areas of significant practice variability with the intent to direct future research.

BACKGROUND

  The perioperative management of infants and children undergoing craniofacial reconstruction surgery can be challenging because of the routine occurrence of significant blood loss with associated morbidity. A variety of techniques have been described to improve the care for these children. It is presently unknown to what extent these practices are currently employed.

METHODS

  A web-based survey was sent to representatives from 102 institutions. One individual per institution was surveyed to prevent larger institutions from being over-represented in the results.

RESULTS

  Requests to complete the survey were sent to 102 institutions; 48 surveys were completed. The survey was composed of two parts: management of infants undergoing strip craniectomies, and management of children undergoing major craniofacial reconstruction.

CONCLUSIONS

  Significant variability exists in the management of children undergoing these procedures; further study is required to determine the optimal management strategies. Clinical trials assessing the utility of central venous pressure and other hemodynamic monitoring modalities would enable evidence-based decision-making for monitoring in these children. The development of institutional transfusion thresholds should be encouraged, as there exists a body of evidence supporting their efficacy and safety.

Endoscopic strip craniectomy in early infancy: the initial five years of anesthesia experience

BACKGROUND

Minimally invasive endoscopic strip craniectomy (ESC) is a relatively new surgical technique for treating craniosynostosis in early infancy. In this study we reviewed our anesthesia experience with ESC. The hypothesis was that infants with low body weight and syndromes would have a higher risk of perioperative blood transfusion and that those with respiratory complications are more likely to be admitted to the intensive care unit (ICU).

METHODS

We retrospectively reviewed patient charts and anesthesia records of the first 100 consecutive infants who underwent ESC between May 2004 and December 2008 and follow-up evaluations until December 2009. Outcomes included (a) perioperative blood transfusion, (b) venous air embolism (VAE), (c) ICU admission, and (d) reoperation with craniofacial reconstruction procedures. Multivariable logistic regression was used to determine significant factors of patient outcomes.

RESULTS

Infants ranging from 4 to 34 weeks of age (weight: 3.2 to 10.1 kg), presented for 87 single and 13 multiple ESC. Four infants had a craniofacial syndrome. The mean surgical time was 48 minutes (range: 26 to 86 minutes). Ninety-two infants had a median estimated blood loss of 23 mL (interquartile ranges [IQR]: 15 to 30 mL). Eight infants who required blood transfusion received a median amount of 17.2 mL/kg (IQR: 10.1 to 21.2 mL/kg). Body weight ≤5 kg (P = 0.04), sagittal ESC (P < 0.01), syndromic craniosynostosis (P < 0.01), and earlier date of surgery in the series (P < 0.01) were factors associated with blood transfusion. VAE was detected in 2 infants with no changes in clinical outcome. Eight infants were admitted to the ICU. Factors associated with ICU admission were blood transfusion (P < 0.001) and respiratory complications (P < 0.001). Eighty-two infants were discharged on postoperative day 1 (range: 1 to 3 days). Six infants underwent subsequent fronto-orbital advancement and 1 cranial vault reconstruction. Multiple-suture craniosynostosis (P < 0.01), associated syndromes (P = 0.03), and ICU admission after ESC (P = 0.04) were predictive of reoperation.

CONCLUSIONS

Twenty percent of infants undergoing ESC had 1 or more of the following: need for blood transfusion, VAE, respiratory complications, and ICU admission. Multivariable analysis confirmed that patients with lower body weight, those with earlier date of surgery in the series, those undergoing sagittal ESC, and those with syndromic craniosynostosis had a higher rate of blood transfusion. ICU admissions often occurred in infants requiring transfusion and those with respiratory complications. Infants with multiple-suture craniosynostosis were more likely to require subsequent craniofacial reconstruction procedures.

Imaging of the calvarium

The skull vault consists of a multitude of flat bones held together by the cranial sutures. Radiologists encounter a vast array of calvarial pathologies that tend to cause abnormalities in thickness, abnormalities in density, focal defects, or an excess of soft tissue or bone tissue. Further anomalies related to the cranial sutures and fontanelles occur in the dynamic pediatric skull. The imaging features of the host of conditions resulting in these commonly detected calvarial abnormalities are reviewed and illustrated.

Craniosynostosis : correlation with cranial vault shape and osseous defects

This study assessed the value of three-dimensional CT (3D CT) in the diagnosis of craniosynostosis, and correlated the cranial deformity with the presence of osseous defects in cranial vault's bones. One hundred and two children (55♀ and 47♂) with a clinical suspicion of craniosynostosis, underwent spiral computed tomography with 3D reconstruction using the shaded surface display (SSD) and volume rendering (VR) algorithms. We evaluated the presence of osseous defects in cranial bones in correlation with the type of craniosynostosis and the shape of the cranial vault. 3D CT allowed the evaluation of craniosynostosis in all patients. All patients had combined forms of craniosynostosis. Osseous defects in the bones of cranial vault were found in 56 patients of whom nine had scaphocephaly, eight plagiocephaly and one trigonocephaly. CT of the skull with three-dimensional reconstruction can safely and reliably identify craniosynostoses in children and could be used for the identification of osseous defects in the cranial vault.

Definition of topographic organization of skull profile in normal population and its implications on the role of sutures in skull morphology

The geometric configuration of the skull is complex and unique to each individual. This study provides a new technique to define the outline of skull profile and attempt to find the common factors defining the ultimate skull configuration in adult population. Ninety-three lateral skull x-ray from the computed tomographic scan films were selected and digitized. The lateral skull surface was divided into 3 regions based on the presumed location of the coronal and lambdoid sutures. Three main curvatures (frontal, parietal, occipital) were consistently identified to overlap the skull periphery. The radius, cord length, and inclination of each curvature were measured. The average values for 3 defined curvatures of the skull profile were recorded. Factor analysis of the measured values produced 3 factors explaining the skull profile. The first factor explained 32% of total variance and was related to the overall size of the head as represented by total length and the radius of the curvature in the vertex and back of the head. The second factor covered 26% of the variance representing the inverse correlation between the angle of the frontal and parietal curves. The third factor revealed the direct correlation of the occipital and parietal angle. In all of these factors, the frontal zone variation was independent or opposite of the parieto-occipital zone. A strong association between the total length of the skull, occipital curve radius, and length with the sex was shown. In conclusion, the skull profile topography has large variation and can be defined mathematically by 2 distinct territories: frontal and parieto-occipital zones. These territories hinge on the coronal suture. Therefore, the coronal suture may play a dominant role in final skull configuration.

Morphometric analysis of untreated adult skulls in syndromic and nonsyndromic craniosynostosis

The aim of this study was to perform a morphometric analysis of untreated adult skulls displaying syndromic and nonsyndromic craniosynostosis. We analyzed, in detail, 42 adult craniosynostoses (18 scaphocephaly, 11 anterior plagiocephaly, 2 trigonocephaly, 9 oxycephaly, and 2 brachycephaly) from archeological (three skulls) and pathoanatomical samples (39 skulls). The univariate and bivariate measurements from the pathological skulls were compared with 40 anatomical skulls with normal cranial vault morphology. Bony signs of chronic elevated intracranial pressure (ICP) are (1) diffuse beaten copper pattern, (2) dorsum sellae erosion, (3) suture diastasis, and (4) abnormalities of venous drainage that particularly affect the sigmoid-jugular sinus complex. The mean cranial length was significantly greater in scaphocephaly than in anatomical skulls (20.3 vs 18.0 cm), and the sagittal suture was also longer (14.3 vs 11.8 cm). There were three types of suture course in the bregma region in scaphocephaly: anterior spur (28%), normal configuration (61%), and posterior spur (11%). The plagiocephaly measurements showed nonsignificant differences, and there was no correlation between the length of the anterior and middle skull base (ipsilateral anterior-posterior shortening of the skull) and incomplete or complete suture synostosis. Bony signs of chronic elevated ICP were found in 82% of cases of oxycephaly and brachycephaly. In three such cases of oxycephaly, we found a marked (1.8-2.1 cm) elevation of bregma region. One skull (Saethre-Chotzen syndrome) yielded human DNA sufficient for polymerase chain reaction (PCR)-based amplification procedures. Mutation analyses in the FGFR3 gene revealed nucleotide alterations located in the mutational hot spot at amino acid residue 250 (g.C749). The mean cranial length in adult scaphocephaly was 12% greater than anatomical skulls. A unilateral complete or incomplete coronal synostosis can be found with or without plagiocephalic deformation. Elevation of the bregma region is a bony sign of chronic elevated ICP. These data on adult craniosynostosis could be of interest for physicians dealing with craniosynostotic children.

The Incidence of Late Cephalohematoma following Craniofacial Surgery

BACKGROUND

Cranial vault remodeling procedures are carried out for both syndromic and nonsyndromic craniosynostosis as well as to correct some acquired deformities of the cranial vault. These procedures improve not only cosmesis but also neurological symptoms. The purpose of this study was to determine the incidence of "late" cephalohematoma, an underreported complication following these complex procedures.

METHODS

A total of 113 patients underwent 127 cranial vault remodeling procedures using autogenous bone over a 6-year period. All patients who developed a late cephalohematoma 75 days or more after surgery were recorded. The time, size, and location of the cephalohematoma, the treatment performed, and the length of follow-up were also recorded. Ages at initial operation and postoperative follow-up were compared between patient groups for statistical differences.

RESULTS

Of the 113 patients, 17 developed 18 late cephalohematomas. The incidence for this complication was 15 percent. The median age at operation for all patients was 10 months, and most late cephalohematomas occurred 208 days later (range, 77 to 1416 days), at 12 to 24 months of age. Fronto-orbital advancement was the most commonly performed procedure, and 83.3 percent of late cephalohematomas occurred in the frontal region. No cephalohematomas became infected or required any operative intervention, but they were aspirated.

CONCLUSIONS

Surgeons should inform prospective parents of patients undergoing cranial vault remodeling procedures of this potential complication. This will improve parental awareness and possible avoidance strategies in future patients. Further evaluation and follow-up are required to determine the minimum length of postoperative time after which late cephalohematomas do not occur.

Basic helix-loop-helix proteins expressed during early embryonic organogenesis

The basic helix-loop-helix proteins form a special group of transcription factors unique for the eukaryotic organisms. They are crucial for the embryonic development of many fundamental organ systems such as muscle, heart, central nervous system, hematopoiteic system, and many others. They are very flexible in terms of regulating transcription in that they can either promote or repress transcription, and do so in many different ways. Basic helix-loop-helix proteins can form homo- or heterodimers with other members of the group, and are subject to post-transcriptional modifications. In this review, an overview of basic helix-loop-helix protein classification, biochemical function, and examples of past and recent advances in our understanding of embryonic development are presented, with emphasis on the vertebrate muscle, heart, brain, and eye.

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).