Clinical Significance of Venous Anomalies in Syndromic Craniosynostosis

Changes in Ventricular Volume After Posterior Vault Distraction Osteogenesis in Patients With Syndromic and Nonsyndromic Craniosynostosis

OBJECTIVE

Little is known about the response of the ventricular system to cranial vault surgery in patients with craniosynostosis. This study aims to evaluate the changes in the cerebral ventricular system in response to posterior vault distraction osteogenesis (PVDO) in patients with syndromic and nonsyndromic craniosynostosis.

METHODS

A single-institution retrospective review of all patients with craniosynostosis undergoing PVDO from 2000 to 2022 was completed. Patients were included for analysis if they had pre and postoperative cranial computed tomography scans. Ventricular volume (VV) and intracranial volume (ICV) were calculated using segmentation software.

RESULTS

Both patients with syndromic synostosis and nonsyndromic synostosis (NSS) experienced a significant increase in ICV after PVDO, but only patients with NSS experienced a significant VV change (P = 0.004). After normalization by ICV, total, lateral, and third VV changes retained significance with percentage increases of 114%, 117%, and 89%, respectively (P < 0.05 for all).

CONCLUSION

The differing results between cohorts reinforce the concept that the intracranial milieu is different between patients with syndromic synostosis and NSS. The results of the NSS cohort suggest that these patients may exist in a compensated state in which a reduction in cerebral blood flow and VV allows for the maintenance of parenchymal health to prevent the development of intracranial hypertension. Further studies may explore VV as a surrogate marker of ICP elevation, and the utility of cranial vault remodeling on nonsynostotic pathologies with cephalocranial disproportion.

Minor Suture Fusion is Associated With Chiari Malformation in Nonsyndromic Craniosynostosis

Here, we focused on the association between minor suture fusion and Chiari malformation (CM) occurrence in nonsyndromic craniosynostosis (NSC), and evaluated how the minor suture affects the posterior cranial fossa by measuring the posterior fossa deflection angle (PFA). In this retrospective study, the clinical records of 137 patients who underwent surgery for NSC at Aichi Children's Health and Medical Center between April 2010 and May 2022 were analyzed. Clinical data from Aichi Developmental Disability Center Central Hospital was collected for 23 patients as the external validation set. Among the 137 patients, 123 were diagnosed with NSC and the remaining 14 with syndromic craniosynostosis. Of the 123 NSC patients, 23 patients presented with CM. Multivariate analysis showed that occipito-mastoid fusion was the only significant risk factor for CM ( P =0.0218). Within the NSC group, CM patients had a significantly increased PFA (6.33±8.10 deg) compared with those without CM (2.76±3.29 deg, P =0.0487). Nonsyndromic craniosynostosis patients with occipito-mastoid suture fusion had a significantly increased PFA (6.50±7.60 deg) compared with those without occipito-mastoid fusion (2.60±3.23 deg, P =0.0164). In the validation cohort, occipito-mastoid suture fusion was validated as an independent risk factor for CM in univariate analysis. Minor suture fusion may cause CM associated with NSC. Chiari malformation could develop due to an increased PFA due to minor suture fusion, which causes growth disturbance in the affected side and compensatory dilation in the contralateral side within the posterior cranial fossa.

What We Know About Intracranial Hypertension in Children With Syndromic Craniosynostosis

OBJECTIVE

A scoping review of literature about mechanisms leading to intracranial hypertension (ICH) in syndromic craniosynostosis (sCS) patients, followed by a narrative synopsis of whether cognitive and behavioral outcome in sCS is more related to genetic origins, rather than the result of ICH.

METHODS

The scoping review comprised of a search of keywords in EMBASE, MEDLINE, Web of science, Cochrane Central Register of Trials, and Google scholar databases. Abstracts were read and clinical articles were selected for full-text review and data were extracted using a structured template. A priori, the authors planned to analyze mechanistic questions about ICH in sCS by focusing on 2 key aspects, including (1) the criteria for determining ICH and (2) the role of component factors in the Monro-Kellie hypothesis/doctrine leading to ICH, that is, cerebral blood volume, cerebrospinal fluid (CSF), and the intracranial volume.

RESULTS

Of 1893 search results, 90 full-text articles met criteria for further analysis. (1) Invasive intracranial pressure measurements are the gold standard for determining ICH. Of noninvasive alternatives to determine ICH, ophthalmologic ones like fundoscopy and retinal thickness scans are the most researched. (2) The narrative review shows how the findings relate to ICH using the Monro-Kellie doctrine.

CONCLUSIONS

Development of ICH is influenced by different aspects of sCS: deflection of skull growth, obstructive sleep apnea, venous hypertension, obstruction of CSF flow, and possibly reduced CSF absorption. Problems in cognition and behavior are more likely because of genetic origin. Cortical thinning and problems in visual function are likely the result of ICH.

Craniovascular variation in four late Holocene human samples from southern South America

Craniovascular traits in the endocranium (traces of middle meningeal vessels and dural venous sinuses, emissary foramina) provide evidence of vascular anatomy in osteological samples. We investigate the craniovascular variation in four South American samples and the effect of artificial cranial modifications (ACM). CT scans of human adult crania from four archeological samples from southern South America (including skulls with ACM) are used for the analyses. The craniovascular features in the four samples are described, skulls with and without ACM are compared, and additionally, South Americans are compared to a previously analyzed sample of Europeans. Of the four South American samples, the Southern Patagonian differs the most, showing the most distinct cranial dimensions, no ACM, and larger diameters of the emissary foramina. Unlike previous studies, we did not find any major differences in craniovascular features between modified and non-modified skulls, except that the skulls with ACM present somewhat smaller foramina. South Americans significantly differed from Europeans, especially in the anteroposterior dominance of the middle meningeal artery, in the pattern of sinus confluence, in the occurrence of enlarged occipito-marginal sinuses, and in foramina frequencies and diameters. Craniovascular morphology is not affected by the cranial size, even in skulls with ACM, indicating a minor or null influence of structural topological factors. Concerning the samples from distinct geographic and climatic environments, it must be evaluated whether the craniovascular morphogenesis might be partially influenced by specific functions possibly associated with thermoregulation, intracranial pressure, and the maintenance of intracranial homeostasis.

Cranium growth, patterning and homeostasis

Craniofacial development requires precise spatiotemporal regulation of multiple signaling pathways that crosstalk to coordinate the growth and patterning of the skull with surrounding tissues. Recent insights into these signaling pathways and previously uncharacterized progenitor cell populations have refined our understanding of skull patterning, bone mineralization and tissue homeostasis. Here, we touch upon classical studies and recent advances with an emphasis on developmental and signaling mechanisms that regulate the osteoblast lineage for the calvaria, which forms the roof of the skull. We highlight studies that illustrate the roles of osteoprogenitor cells and cranial suture-derived stem cells for proper calvarial growth and homeostasis. We also discuss genes and signaling pathways that control suture patency and highlight how perturbing the molecular regulation of these pathways leads to craniosynostosis. Finally, we discuss the recently discovered tissue and signaling interactions that integrate skull and cerebrovascular development, and the potential implications for both cerebrospinal fluid hydrodynamics and brain waste clearance in craniosynostosis.

Diploic vein morphology in normal and craniosynostotic adult human skulls

Diploic veins (DV) run within the cranial diploe, where they leave channels that can be studied in osteological samples. This study investigates overall DV variability in human adults and the effects of sex, age, cranial dimensions, and dysmorphogenesis associated with craniosynostosis (CS). The morphology of macroscopic diploic channels was analyzed in a set of the qualitative and quantitative variables in computed tomography-images of crania of anatomically normal and craniosynostotic adult individuals. Macroscopic diploic channels occur most frequently in the frontal and parietal bones, often with a bilaterally symmetrical pattern. DV-features (especially DV-pattern) are characterized by high individual diversity. On average, there are 5.4 ± 3.5 large macroscopic channels (with diameters >1 mm) per individual, with a mean diameter of 1.7 ± 0.4 mm. Age and sex have minor effects on DV, and cranial proportions significantly influence DV only in CS skulls. CS is associated with changes in the DV numbers, distributions, and diameters. Craniosynostotic skulls, especially brachycephalic skulls, generally present smaller DV diameters, and dolichocephalic skulls display increased number of frontal DV. CS, associated with altered cranial dimensions, suture imbalance, increased intracranial pressure, and with changes of the endocranial craniovascular system, significantly also affects the macroscopic morphology of DV in adults, in terms of both structural (topological redistribution) and functional factors. The research on craniovascular morphology and CS may be of interest in biological anthropology, paleopathology, medicine (e.g., surgical planning), but also in zoology and paleontology.

Changes in venous drainage after posterior cranial vault distraction and foramen magnum decompression in syndromic craniosynostosis

OBJECTIVE

The authors' objective was to measure the effect of posterior cranial vault distraction (PCVD) plus foramen magnum decompression (FMD) on dural sinus volume and venous flow in patients with syndromic craniosynostosis.

METHODS

The volumes of the sagittal, straight, transverse, and sigmoid sinuses of 5 consecutive patients with syndromic craniosynostosis who underwent PCVD+FMD were calculated in cubic centimeters with T2-weighted volumetric MRI sequences before surgery, immediately after surgery, and after the end of the distraction process. Tridimensional reconstructions of phase-contrast magnetic resonance angiography (PC-MRA) images were obtained with multiplanar reconstruction (MPR).

RESULTS

The average total volume of all dural sinuses increased immediately after surgery (from 10.06 cm3 to 12.64 cm3) and continued to increase throughout the 30-day distraction period (from 12.64 cm3 to 14.71 cm3) (p = 0.04), except that the right sigmoid sinus remained stable after the initial increase. The most important increases were observed for the left transverse sinus (+113.2%), right transverse sinus (+104.3%), left sigmoid sinus (+91.3%), and sagittal sinus (+41.8%). Less important modifications were evident for the right sigmoid sinus (+33.7%) and straight sinus (+23.4%). Significant improvements in venous flow were noted on the tridimensional reconstructions of the PC-MRA images. Venous obstruction grading score improved in 4 patients (average [range] 2.4 [ 2-5]) (p = 0.023) and remained stable in 1 patient. All patients had chronic tonsillar herniation (CTH) (mean [range] 16.6 [8-26] mm), and 3 had syringomyelia. CTH showed improvement on the last follow-up MRI evaluation in 4 patients (mean [range] 10.5 [0-25] mm) and worsened from 15 mm to 19 mm in 1 patient. Syringomyelia improved in 2 patients and remained unchanged in 1.

CONCLUSIONS

This study has provided the first radiological evidence of the impact of craniofacial surgery on dural sinus anatomy and venous drainage. The venous anomalies described in patients with syndromic craniosynostosis are not static, and PCVD+FMD triggers a dynamic process that can lead to significant modifications of intracranial venous drainage. The traction exerted by the distracted bone flap onto the occipitoparietal dura mater adherent to the inner calvaria may account for the enlargement of the dural sinus throughout the distraction period. The impact of these modifications on venous pressure, intracranial pressure, CTH, and hydrocephalus remains to be determined.

Craniovascular traits and braincase morphology in craniosynostotic human skulls

Middle meningeal vessels, dural venous sinuses, and emissary veins leave imprints and canals in the endocranium, and thus provide evidence of vascular patterns in osteological samples. This paper investigates whether craniovascular morphology undergoes changes in craniosynostotic human skulls, and if specific alterations may reflect structural and functional relationships in the cranium. The analyzed osteological sample consists of adult individuals with craniosynostoses generally associated with dolichocephalic or brachycephalic proportions, and a control sample of anatomically normal adult skulls. The pattern and dominance of the middle meningeal artery, the morphology of the confluence of the sinuses, and the size and number of the emissary foramina were evaluated. Craniovascular morphology was more diverse in craniosynostotic skulls than in anatomically normal skulls. The craniosynostotic skulls often displayed enlarged occipito-marginal sinuses and more numerous emissary foramina. The craniosynostotic skulls associated with more brachycephalic morphology often presented enlarged emissary foramina, while the craniosynostotic skulls associated with dolichocephalic effects frequently displayed more developed posterior branches of the middle meningeal artery. The course and morphology of the middle meningeal vessels, dural venous sinuses, and emissary veins in craniosynostotic skulls can be related to the redistribution of growth forces, higher intracranial pressure, venous hypertension, or thermal constraints. These functional and structural changes are of interest in both anthropology and medicine, involving epigenetic traits that concern the functional and ontogenetic balance between soft and hard tissues.

Craniosynostosis and hydrocephalus: relevance and treatment modalities

INTRODUCTION

Hydrocephalus is variously associated to syndromic craniosynostosis (CS), while it is randomly encountered in monosutural CS. Pathogenesis is still debated and reliable criteria for the diagnosis of overt hydrocephalus are lacking. Additionally, optimal treatment is controversial since it should balance the need to relieve intracranial hypertension and the risk of recurrence favored by lowering intracranial pressure.

METHODS

A thorough review of the literature has been performed. Accordingly, pathogenic theories, diagnostic issues, and treatment options on hydrocephalus presenting in the context of CS are discussed.

RESULTS

The association of hydrocephalus to simple CS is considered a fortuitous event. Its treatment is usually driven by the etiology and clinical relevance of hydrocephalus, favoring treatment before surgical correction to reduce CSF-related complications. On the other side, pathogenesis of hydrocephalus in the context of syndromic CS has been mainly related to factors that are secondary to the synostostic process, such as craniocerebral disproportion and venous hypertension. Hydrocephalus complicates 12-15% of syndromic CS, though its incidence is more relevant in FGFR2-related CS and raises up to 88% in Pfeiffer syndrome. Overt hydrocephalus should be properly differentiated by non-tense ventriculomegaly that is more frequent in Apert syndrome. Since intracranial hypertension is constant in syndromic CS even in the absence of active hydrocephalus, radiological monitoring of ventricular size along with intracranial pressure monitoring is essential. Active hydrocephalus occurs more frequently in infants, though stable ventriculomegaly may evolve into overt hydrocephalus after cranial expansion. If hydrocephalus is not clinically prominent, cranial expansion should be favored as first surgical step. Although posterior cranial expansion may address posterior cranial fossa constriction and stabilize ventricular dilation, effectiveness in long-term control of hydrocephalus is not clear. ETV is an effective treatment option, though success rate is affected by the presence of brain malformations and patient age. Extrathecal CSF shunting should be used as last resource due to the increased risk of complications in this context.

CONCLUSIONS

The pathogenesis of hydrocephalus complicating syndromic CS should be further investigated. Concomitantly, the definition of reliable diagnostic criteria is advocated in order to promptly and properly identify active hydrocephalus. Finally, treatment algorithm should refine the best timing and treatment options aiming to relieve intracranial hypertension on one side and reduce the risk of restenosis on the other side.

Quantitative 3D imaging of the cranial microvascular environment at single-cell resolution

Vascularization is critical for skull development, maintenance, and healing. Yet, there remains a significant knowledge gap in the relationship of blood vessels to cranial skeletal progenitors during these processes. Here, we introduce a quantitative 3D imaging platform to enable the visualization and analysis of high-resolution data sets (>100 GB) throughout the entire murine calvarium. Using this technique, we provide single-cell resolution 3D maps of vessel phenotypes and skeletal progenitors in the frontoparietal cranial bones. Through these high-resolution data sets, we demonstrate that CD31hiEmcnhi vessels are spatially correlated with both Osterix+ and Gli1+ skeletal progenitors during postnatal growth, healing, and stimulated remodeling, and are concentrated at transcortical canals and osteogenic fronts. Interestingly, we find that this relationship is weakened in mice with a conditional knockout of PDGF-BB in TRAP+ osteoclasts, suggesting a potential role for osteoclasts in maintaining the native cranial microvascular environment. Our findings provide a foundational framework for understanding how blood vessels and skeletal progenitors spatially interact in cranial bone, and will enable more targeted studies into the mechanisms of skull disease pathologies and treatments. Additionally, our technique can be readily adapted to study numerous cell types and investigate other elusive phenomena in cranial bone biology.

Venous anomalies in hypoplastic posterior fossa: unsolved questions

INTRODUCTION

Anomalous intracranial venous anatomy is described in patients with syndromic craniosynostosis and is of significant importance when it comes to surgical morbidity. However, it is still controversial its origin, type of circulation in each syndrome, how it behaves over time, when it can be interrupted and wether it needs to be studied. The purpose of this paper is to discuss these issues by reviewing the literature.

METHODS

A literature search was performed using the PubMed database with a focus on papers including detailed descriptions of the venous outflow in complex and syndromic craniosynostosis. Search details used were the following: ("veins"[MeSH Terms] OR "veins"[All Fields] OR "venous"[All Fields]) AND ("abnormalities"[Subheading] OR "abnormalities"[All Fields] OR "anomalies"[All Fields]) AND syndromic[All Fields] AND ("craniosynostoses" [MeSH Terms] OR "craniosynostoses"[All Fields] OR "craniosynostosis"[All Fields]). Studies that exposed details of venous anomalies found in syndromic or complex craniosynostosis were selected.

RESULTS

Of a total of 211 articles found, 11 were selected for this review. Of these, 5 were case reports, 5 retrospective studies, and only 1 prospective study. From the 6 series of cases presented, 5 discussed the relationship between jugular foramen stenosis (JFS) and collateral venous drainage. The authors discuss data from the literature for each leading question presented: 1-collateral circulation: is it an intrinsic trouble, a consequence of stenosis of the cranial base foramina or related to raised intracranial pressure (ICP)?; 2-what venous anomalies should we search for, and what is the best exam to study them?; 3-collateral circulation changes with time?; 4-can neurosurgeons interrupt the collateral circulation?; 5-should we study all complex types of craniosynostosis?

CONCLUSION

The importance of the study of the venous outflow in patients with complex craniosynostosis is evident in the literature. The real relationship between intracranial hypertension, hypoplastic skull base foramen, Chiari I malformation, hydrocephalus, and venous collateral circulation remains unknown. Prospective studies focusing on molecular biology analysis will possibly solve all of these leading questions.

Fixed posterior cranial vault expansion technique

BACKGROUND

Different techniques to reshape the posterior skull vault have been developed in the last decades, all sharing the same goals of increasing the skull volume, decreasing the intracranial pressure (ICP), correcting the cranial dysmorphy, and contributing to a better growth of the skull. Though over the last years most refinements in these techniques have focused on the use of hardware as distractors or springs, the fixed posterior vault expansion remains a valuable procedure for cranial remodeling.

METHODS

We describe in details the technique used for fixed posterior vault expansion in children that is applied at the French Referral center for Craniosynostosis of Lyon, France.

DISCUSSION

The fixed posterior vault expansion increases the risk of perioperative complications due to the elevation of the posterior bone flap from the dura but allows an immediate decompression and correction of the shape, simplifying the postoperative course.

Tranexamic Acid in Craniosynostosis Surgery: A Systematic Review and Meta-Analysis

ABSTRACT

Blood loss is a potential cause of morbidity and mortality in craniosynostosis surgery. Recent reports have suggested that the use of tranexamic acid (TXA), an antifibrinolytic agent, mitigates this blood loss. A comprehensive systematic review and subsequent meta-analysis was undertaken, with the view to clarify the effectiveness of TXA in reducing blood loss and transfusion requirements in craniosynostosis surgery. Medline and PubMed databases were searched using the preferred reporting items for systematic reviews and meta-analyses technique, and 7003 articles were assessed based on predefined selection criteria. Seven trials were identified, of which 2 were randomized controlled trials and the remainder retrospective cohort studies. All trials were assessed using the Jadad and strengthening the reporting of observational studies in epidemiology scores. The meta-analysis found a clear statistical reduction in blood loss in those patients who received TXA perioperatively, with a combined blood loss reduction of 7.06 ml/kg (95% confidence interval -8.97 to -5.15, P < 0.00001). The blood loss reduction was found to extrapolate to a reduction in perioperative transfusion requirements by 8.47 ml/kg in this cohort (95% confidence interval -10.9 to -6.04, P < 00001). There were no TXA-related adverse outcomes recorded in the 258 patients who received TXA across all trials. The trials included in this meta-analysis were limited by underpowered population sizes and significant heterogeneity in blood loss recording techniques. Further, there was significant heterogeneity amongst operations performed. The current literature appears to support the use of TXA in craniosynostosis surgery, but further high quality randomized controlled trials are indicated, ideally including a subgroup analysis between the operations performed.

Late Presenting Multi-Suture Craniosynostosis

ABSTRACT

The authors provide the case of a 6-year-old male who presented late with multi-suture craniosynostosis and chronically elevated intracranial pressures (ICPs). He was surgically managed with frontal orbital advancement. This particular case illustrates the significant bleeding and unique bony pathology that can occur in patients with high ICP with concomitant venous collateralization. At 1-month follow-up, he demonstrated significant improvement with maintained expansion and no signs of elevated ICP despite delayed intervention. Frontal orbital advancement serves as an effective method for cranial vault expansion and correction of frontal deformities caused by craniosynostosis.

Craniosynostosis: Posterior Cranial Vault Remodeling

Posterior cranial vault distraction osteogenesis is a powerful, reliable, low-morbidity method to achieve intracranial expansion. It is particularly useful in treating turribrachycephaly seen in syndromic craniosynostosis, allowing for gradual expansion of the bone while stretching the soft tissues over several weeks allowing greater volumetric expansion than conventional techniques. Posterior cranial vault distraction osteogenesis constitutes a more gradual remodeling modality, with infrequent complications. As a first step in intracranial expansion, it preserves the frontal cranium for future frontofacial procedures. A drawback is the need for a second surgery to remove the device, and this must be taken into account during counseling.

Supratentorial vs infratentorial posterior calvarial distraction osteogenesis for the increase of ICV in children with syndromic or multi-suture craniosynostosis: a retrospective cohort study

PURPOSE

Craniosynostosis is the premature and pathological fusion of calvarial sutures. One modality of surgical treatment of syndromic craniosynostosis is posterior calvarial distraction (PCD). This can be either supratentorial or infratentorial. Currently, supratentorial PCD may be regarded as safer but produces a smaller increase in calvarial volume compared to infratentorial PCD. This study quantifies and compares the effectiveness of supratentorial and infratentorial PCD to help guide surgical decision-making.

METHODS

The CT and/or MRI scans of 47 cases of craniosynostosis who underwent PCD from the Birmingham Children's Hospital (BCH) were converted to sagittal series multi-planar reformatted (MPR) scans for the manual calculation of ICV. The 47 cases were classified as having undergone either supratentorial or infratentorial PCD using lateral plain film radiographs, with 28 and 32 pairs of pre- and post-operative CT/MRI scans reviewed respectively.

RESULTS

A statistically significant difference between supratentorial and infratentorial PCD was observed for the increase in supratentorial volume (STV) (P = 0.0458) and total intracranial volume (TICV) (P = 0.0437), but not for the increase in infratentorial volume (ITV) (P = 0.0697). The relationship for each volume trended towards convergence but was not achieved before the physical limit of 30 mm distraction had been reached. Intraclass correlation coefficient values for agreement of MRI and CT scans for STV, ITV and total ICV were 0.852, 0.864 and 0.854 respectively.

CONCLUSION

Our evidence suggests that supratentorial PCD is more effective for increasing ICV in a clinical setting. CT and MRI imaging modalities are acceptably clinically interchangeable for calculating ICV in craniosynostosis.

Hydrocephalus treatment in patients with craniosynostosis: an analysis from the Hydrocephalus Clinical Research Network prospective registry

OBJECTIVE

Hydrocephalus may be seen in patients with multisuture craniosynostosis and, less commonly, single-suture craniosynostosis. The optimal treatment for hydrocephalus in this population is unknown. In this study, the authors aimed to evaluate the success rate of ventriculoperitoneal shunt (VPS) treatment and endoscopic third ventriculostomy (ETV) both with and without choroid plexus cauterization (CPC) in patients with craniosynostosis.

METHODS

Utilizing the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (Registry), the authors identified all patients who underwent treatment for hydrocephalus associated with craniosynostosis. Descriptive statistics, demographics, and surgical outcomes were evaluated.

RESULTS

In total, 42 patients underwent treatment for hydrocephalus associated with craniosynostosis. The median gestational age at birth was 39.0 weeks (IQR 38.0, 40.0); 55% were female and 60% were White. The median age at first craniosynostosis surgery was 0.6 years (IQR 0.3, 1.7), and at the first permanent hydrocephalus surgery it was 1.2 years (IQR 0.5, 2.5). Thirty-three patients (79%) had multiple different sutures fused, and 9 had a single suture: 3 unicoronal (7%), 3 sagittal (7%), 2 lambdoidal (5%), and 1 unknown (2%). Syndromes were identified in 38 patients (90%), with Crouzon syndrome being the most common (n = 16, 42%). Ten patients (28%) received permanent hydrocephalus surgery before the first craniosynostosis surgery. Twenty-eight patients (67%) underwent VPS treatment, with the remaining 14 (33%) undergoing ETV with or without CPC (ETV ± CPC). Within 12 months after initial hydrocephalus intervention, 14 patients (34%) required revision (8 VPS and 6 ETV ± CPC). At the most recent follow-up, 21 patients (50%) required a revision. The revision rate decreased as age increased. The overall infection rate was 5% (VPS 7%, 0% ETV ± CPC).

CONCLUSIONS

This is the largest prospective study reported on children with craniosynostosis and hydrocephalus. Hydrocephalus in children with craniosynostosis most commonly occurs in syndromic patients and multisuture fusion. It is treated at varying ages; however, most patients undergo surgery for craniosynostosis prior to hydrocephalus treatment. While VPS treatment is performed more frequently, VPS and ETV are both reasonable options, with decreasing revision rates with increasing age, for the treatment of hydrocephalus associated with craniosynostosis.

Saethre-Chotzen syndrome: long-term outcome of a syndrome-specific management protocol

AIM

To assess the long-term outcomes of our management protocol for Saethre-Chotzen syndrome, which includes one-stage fronto-orbital advancement.

METHOD

All patients born with Saethre-Chotzen syndrome between January 1992 and March 2017 were included. Evaluated parameters included occipital frontal head circumference (OFC), fundoscopy, neuroimaging (ventricular size, tonsillar position, and the presence of collaterals/an abnormal transverse sinus), polysomnography, and ophthalmological outcomes. The relationship between papilledema and its associated risk factors was evaluated with Fisher's exact test.

RESULTS

Thirty-two patients (21 females, 11 males) were included. Median (SD) age at first surgery was 9.6 months (3.1mo) for patients who were primarily referred to our center (range: 3.6-13.0mo), the median (SD) age at last follow-up was 13 years (5y 7mo; range: 3-25y). Seven patients had papilledema preoperatively, which recurred in two. Two patients had papilledema solely after first surgery. Second cranial vault expansion was indicated in 20%. Thirteen patients had an OFC deflection, indicating restricted skull growth, one patient had ventriculomegaly, and none developed hydrocephalus. Eleven patients had emissary veins, while the transverse sinus was aberrant unilaterally in 13 (hypoplastic n=10 and absent n=3). Four patients had mild tonsillar descent, one of which was a Chiari type I malformation. Four patients had obstructive sleep apnoea (two mild, one moderate, and one severe). An aberrant transverse sinus was associated with papilledema (p=0.01).

INTERPRETATION

Single one-stage fronto-orbital advancement was sufficient to prevent intracranial hypertension for 80% of our patients with Saethre-Chotzen syndrome. Follow-up should focus on OFC deflection and venous anomalies.

Posterior vault distraction technique: how I do it

Posterior cranial vault distraction is an effective technique when a significant increase in the intracranial volume is required in patients with craniosynostoses. This technique has been proven to be safe and time saving and usually is associated with low perioperative morbidity as well as low intraoperative bleeding. Herein a technique is presented starting from the preoperative planning, describing the surgical steps of the operation and the postoperative distraction protocol used by the authors. The authors present important tips and tricks aiming to minimise complications and undesired events.

Dural sinus volume in children with syndromic craniosynostosis and intracranial hypertension

OBJECTIVE

Intracranial hypertension is a major concern in children with syndromic craniosynostosis (sCS). Cerebral venous hypertension caused by cerebral venous outflow obstruction is believed to contribute to intracranial hypertension. The authors therefore hypothesized that cerebral venous volume would be increased in those children with sCS and intracranial hypertension.

METHODS

In a case series of 105 children with sCS, of whom 32 had intracranial hypertension, cerebral MRI techniques were used to quantify the volume of the superior sagittal sinus, straight sinus (StrS), and both transverse sinuses.

RESULTS

Linear regression showed that total cerebral venous volume increased by 580.8 mm3 per cm increase in occipitofrontal head circumference (p < 0.001). No significant difference was found between the intracranial hypertension group and the nonintracranial hypertension group (p = 0.470). Multivariate ANOVA showed increased StrS volume (as a proportion of total volume) in the intracranial hypertension group (8.5% vs 5.1% in the nonintracranial hypertension group, p < 0.001). Multivariate logistic regression showed that a 100-mm3 increase in StrS volume is associated with increased odds of having intracranial hypertension by 60% (OR 1.60, 95% CI 1.24-2.08).

CONCLUSIONS

Although intracranial hypertension was not associated with total cerebral venous volume increase, it was associated with an isolated increase in StrS volume. Hence, it is unlikely that general cerebral venous outflow obstruction is the mechanism of intracranial hypertension in sCS. Rather, these findings indicate either a central cerebral vulnerability to intracranial hypertension or a mechanism involving venous blood redistribution.

Ventricular shunt complications in patients undergoing posterior vault distraction osteogenesis

PURPOSE

The primary objective of this study is to investigate post-operative morbidity and shunt revision rates of patients with shunt-dependent hydrocephalus (SDH) undergoing posterior vault distraction osteogenesis (PVDO) compared to patients undergoing conventional posterior vault reconstruction (PVR).

METHODS

A retrospective case-controlled cohort analysis of all patients with SDH undergoing PVDO and PVR for syndromic or complex craniosynostosis was performed. Demographic information, perioperative variables, distraction protocols, and shunt-related complications-infection, surgical revision of shunt, increased length of stay (LOS), and readmission within 90 days of surgery-were compared using the appropriate statistical tests.

RESULTS

Fourteen patients with ventricular shunts who underwent PVDO and eight patients with shunts who underwent PVR were identified. Shunt-related complication rates were significantly higher with PVDO (n = 5) compared to PVR (n = 0), p = 0.0093. Among the five patients who suffered complications, the most common were shunt infection (n = 4), shunt malfunction (n = 4), and wound infections (n = 3). All patients with complications required additional operations for shunt revision and/or replacement; four patients required multiple takebacks for such procedures, with an average of three additional procedures per patient.

CONCLUSIONS

In complex or syndromic craniosynostosis patients who have previously undergone ventricular shunting, PVDO is associated with higher shunt-related complications and need for additional procedures when compared to traditional PVR. While the benefits of PVDO in the treatment of syndromic craniosynostosis are well documented, the risks of PVDO in the face of a VP shunt must be considered. Further investigation into patient-specific risk factors and risk reduction strategies is warranted.

Pfeiffer Syndrome: A Therapeutic Algorithm Based on a Modified Grading Scale

BACKGROUND

Pfeiffer syndrome (PS) is a very rare condition with a wide clinical spectrum. There are only a few studies that address the classification and treatment of PS and take into account the most commonly presented clinical features. Thus, the objectives of this study are to propose an algorithm for PS management based on a modified severity scale and correlate PS severity with tracheostomy placement.

METHODS

An observational retrospective study was performed on consecutive patients with PS (n = 12), who underwent surgery between 2008 and 2018. Clinical features and findings of all included patients with PS were classified as types A, B, and C, which guided treatment workflow. The Fisher test was used to correlate the severity of patients with PS with tracheostomy placement.

RESULTS

There were 12 patients, classified as type A (n = 3), type B (n = 6), and type C (n = 3). All patients who received tracheostomies (n = 6) were stratified into the severe category (n = 9; types B and C) (P < 0.05). There were 4 minor complications, and 1 major complication according to a modified Clavien-Dindo surgical complication scale.

CONCLUSION

A treatment algorithm based on the 3 different Pfeiffer types was proposed. Severity of PS statistically correlates to tracheostomy placement.

Onset and Resolution of Chiari Malformations and Hydrocephalus in Syndromic Craniosynostosis following Posterior Vault Distraction

BACKGROUND

Patients with syndromic craniosynostosis have an increased incidence of progressive hydrocephalus and Chiari malformations, with few data on the relative benefit of various surgical interventions. The authors compare the incidence and resolution of Chiari malformations and hydrocephalus between patients undergoing posterior vault distraction osteogenesis (PVDO) and patients undergoing conventional cranial vault remodeling.

METHODS

Patients with syndromic craniosynostosis who underwent cranial vault surgery from 2004 to 2016 at a single academic hospital, with adequate radiographic assessments, were reviewed. Demographics, interventions, the presence of a Chiari malformation on radiographic studies and hydrocephalus requiring shunt placement were recorded. Mann-Whitney U and Fisher's exact tests were used as appropriate.

RESULTS

Forty-nine patients underwent PVDO, and 23 patients underwent cranial vault remodeling during the study period. Median age at surgery (p = 0.880), sex (p = 0.123), and types of syndrome (p = 0.583) were well matched. Patients who underwent PVDO had a decreased incidence of developing Chiari malformations postoperatively compared with the cranial vault remodeling cohort (2.0 percent versus 17.4 percent; p = 0.033). Not surprisingly, no significant difference was found between the groups with regard to the incidence of postoperative hydrocephalus requiring shunt placement (PVDO, 4.1 percent; cranial vault remodeling, 4.3 percent; p = 0.999).

CONCLUSIONS

As expected, PVDO did not significantly affect intracranial hydrodynamics to the extent that hydrocephalus shunting rates were different for patients with syndromic craniosynostosis. However, PVDO was associated with a reduced risk of developing a Chiari malformation; however, prospective evaluation is needed to determine causality.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Which neuroimaging techniques are really needed in Chiari I? A short guide for radiologists and clinicians

PURPOSE

To describe the most appropriate techniques and suggested protocols meant to address the various scenarios that clinicians and pediatric neurosurgeons may face in their day-to-day practice connected with Chiari I.

METHODS

Current literature related to image indications and findings in Chiari I has been reviewed. The authors focused on both standard and advanced techniques for clinical diagnosis and preoperative planning purposes.

DISCUSSION AND CONCLUSION

The complexity of providing neuroimaging guidelines for children investigated for Chiari I lies in defining the most appropriate neuroradiology tool to approach what is in fact a very heterogeneous condition with different etiopathogenetic mechanisms and associated abnormalities. Other variables that may influence the diagnostic strategy include the age of the patient, the presence of additional pathological conditions, the type of presenting symptoms, and the indication for surgical or conservative management. Although the average age at time of diagnosis is 10 years, the initial diagnosis may be done at any age, and the referral for neuroradiology workup may come from general practitioners/pediatricians, orthopedic surgeons, and endocrinologists following various baseline investigations including plain x-rays of skull and spine and/or CT head and/or MRI brain and spine.

Rapidly Progressive Multisutural Craniosynostosis in a Patient With Jackson-Weiss Syndrome and a De Novo FGFR2 Pathogenic Variant

Little is currently known about the mechanisms by which pathogenic variants of FGFR2 produce changes in the FGFR protein and influence the clinical presentation of affected individuals. We report on a patient with a de novo pathogenic variant of FGFR2 and a phenotype consistent with Jackson-Weiss syndrome who presented with delayed, rapidly progressive multisutural craniosynostosis and associated medical complications. Using 3-dimensional modeling of the FGFR protein, we provide evidence that this variant resulted in abnormal dimerization and constitutive activation of FGFR, leading to the Jackson-Weiss phenotype. Knowledge regarding the correlation between genotype and phenotype of persons with FGFR2-related craniosynostosis has the potential to allow for anticipation of medical complications, institution of early treatment, and improved clinical outcomes.

Syndromic Craniosynostosis: Complexities of Clinical Care

Patients with syndromic craniosynostosis have a molecularly identified genetic cause for the premature closure of their cranial sutures and associated facial and extra-cranial features. Their clinical complexity demands comprehensive management by an extensive multidisciplinary team. This review aims to marry genotypic and phenotypic knowledge with clinical presentation and management of the craniofacial syndromes presenting most frequently to the craniofacial unit at Great Ormond Street Hospital for Children NHS Foundation Trust.