Posterior cranial vault expansion in the treatment of craniosynostosis. Comparison of current techniques

Early posterior vault distraction osteogenesis changes the syndromic craniosynostosis treatment paradigm: long-term outcomes of a 23-year cohort study

BACKGROUND

Early surgical management of syndromic craniosynostosis varies widely between centers, with patients typically undergoing multiple intracranial procedures through childhood. This study evaluates the long-term impact of early posterior vault distraction osteogenesis (PVDO) versus conventional treatment paradigms on the number and timing of subsequent craniofacial procedures.

METHODS

We retrospectively analyzed the longitudinal operative patterns of patients with syndromic craniosynostosis treated from 2000 to 2023 with greater than five years of follow-up. Outcomes of patients who underwent early PVDO and conventional vault reconstruction were compared.

RESULTS

Fifty-five patients met the inclusion criteria (30 PVDO and 25 conventional). Age at initial vault surgery was similar between the PVDO and conventional cohorts (7.6 vs. 8.8 months), as were baseline craniometrics (p > 0.05). Multiple fronto-orbital advancement (FOA) procedures were performed in only 1/30 (3%) PVDO-treated patient versus 12/25 (48%) conventionally-treated patients (p < 0.001). Twelve (40%) PVDO-treated patients did not undergo FOA at all. Among patients with Apert and Crouzon syndromes, fewer PVDO-treated patients required FOA prior to midface surgery (33% vs. 92%, p = 0.004) or repeat FOA (6% vs. 50%, p = 0.005) compared to conventionally-treated patients. Among patients with Muenke and Saethre-Chotzen syndromes, a similar proportion of patients required FOA in the PVDO and conventional cohorts (91% vs. 100%, p = 0.353), though no PVDO-treated patients required repeat FOA (0% vs. 44%, p = 0.018).

CONCLUSIONS

Early PVDO is associated with a reduction in the high burden of both FOA and, critically, revisionary frontal procedures which are commonly seen in conventionally-treated patients with syndromic craniosynostosis.

Secondary metopic craniosynostosis after posterior cranial decompression in cloverleaf skull deformity

Cloverleaf skull deformity or Kleeblattschadel syndrome is a severe condition where multiple cranial sutures are absent and prematurely fused, leading to a trilobate head shape. The remaining open sutures or fontanelles compensate for rapid brain expansion, while the constricted fused calvarium restricts brain growth and results in increased intracranial pressure. Recent data show that early posterior cranial and foramen magnum decompression positively affects infants with cloverleaf skulls. However, long-term sequelae are still rarely discussed. We hereby report a child who developed secondary metopic craniosynostosis after posterior cranial decompression, which required a front-orbital advancement and cranial remodelling as a definitive procedure.

Towards a radiation free numerical modelling framework to predict spring assisted correction of scaphocephaly

Sagittal Craniosynostosis (SC) is a congenital craniofacial malformation, involving premature sagittal suture ossification; spring-assisted cranioplasty (SAC) - insertion of metallic distractors for skull reshaping - is an established method for treating SC. Surgical outcomes are predictable using numerical modelling, however published methods rely on computed tomography (CT) scans availability, which are not routinely performed. We investigated a simplified method, based on radiation-free 3D stereophotogrammetry scans.Eight SAC patients (age 5.1 ± 0.4 months) with preoperative CT and 3D stereophotogrammetry scans were included. Information on osteotomies, spring model and post-operative spring opening were recorded. For each patient, two preoperative models (PREOP) were created: i) CT model and ii) S model, created by processing patient specific 3D surface scans using population averaged skin and skull thickness and suture locations. Each model was imported into ANSYS Mechanical (Analysis System Inc., Canonsburg, PA) to simulate spring expansion. Spring expansion and cranial index (CI - skull width over length) at times equivalent to immediate postop (POSTOP) and follow up (FU) were extracted and compared with in-vivo measurements.Overall expansion patterns were very similar for the 2 models at both POSTOP and FU. Both models had comparable outcomes when predicting spring expansion. Spring induced CI increase was similar, with a difference of 1.2%±0.8% for POSTOP and 1.6%±0.6% for FU.This work shows that a simplified model created from the head surface shape yields acceptable results in terms of spring expansion prediction. Further modelling refinements will allow the use of this predictive tool during preoperative planning.

Spring-assisted posterior vault expansion: a parametric study to improve the intracranial volume increase prediction

Spring-assisted posterior vault expansion has been adopted at the London Great Ormond Street Hospital for Children to treat raised intracranial pressure in patients affected by syndromic craniosynostosis, a congenital calvarial anomaly causing the premature fusion of skull sutures. This procedure involves elastic distractors used to dynamically reshape the skull and increase the intracranial volume (ICV). In this study, we developed and validated a patient-specific model able to predict the ICV increase and carried out a parametric study to investigate the effect of surgical parameters on that final volume. Pre- and post-operative computed tomography data relative to 18 patients were processed to extract simplified patient-specific skull shape, replicate surgical cuts, and simulate spring expansion. A parametric study was performed to quantify each parameter's impact on the surgical outcome: for each patient, the osteotomy location was varied in a pre-defined range; local sensitivity of the predicted ICV to each parameter was analysed and compared. Results showed that the finite element model performed well in terms of post-operative ICV prediction and allowed for parametric optimization of surgical cuts. The study indicates how to optimize the ICV increase according to the type of procedure and provides indication on the most robust surgical strategy.

Re-imagining early cloverleaf skull deformity management from front to back approach-30 years on

The cloverleaf skull deformity remains among the most complicated craniofacial conditions to successfully manage. Many cases achieve largely unsatisfactory outcomes due to the requirement for frequent reoperation on the cranial vault and failure to deal with all the elements of the craniofaciostenosis in a timely fashion. Early cranial vault surgery without addressing the cranial base deformity and its attendant cerebrospinal fluid flow changes is invariably challenging and disappointing. A recent focus on the expansion of the posterior cranial vault as a primary procedure with the greater volume change allows a delay in fronto-orbital advancement and reduced need for repeat surgery. We herein describe three cases of complex multisuture craniosynostosis with cloverleaf skull deformity who underwent neonatal posterior cranial vault decompression along with foramen magnum decompression. Our report examines the safety and rationale for this pre-emptive surgical approach to simultaneously deal with the cranial vault and craniocervical junction abnormalities and thus change the early trajectory of these complex cases.

Morphometric analysis and outcomes following posterior cranial vault distraction in syndromic and multisuture craniosynostosis

BACKGROUND

Turribrachycephaly is a common feature in many syndromic and multisuture craniosynostoses and is traditionally treated with total cranial vault reshaping and fronto-orbital advancement. A staged approach with posterior cranial vault distraction as a primary procedure followed by anterior cranial vault reshaping has the advantage of reducing the vertical dimension of the skull in a controlled and gradual manner while expanding the cranial volume. The purpose of this study was to evaluate outcomes following posterior cranial vault expansion using distraction osteogenesis at a single tertiary pediatric center.

METHODS

This retrospective review included all cases of posterior cranial vault distraction at a single institution from 2008 to 2022 performed by one surgeon. Morphometric outcomes such as Turricephaly Index (TI) and posterior cranial volume (PCV) were assessed from pre- and postoperative computerized tomography scans for patients who underwent posterior cranial vault distraction as a primary first-stage operation. Clinical outcomes and complications were collated.

RESULTS

A total of 41 patients (25 females, 16 males; mean age 11 months) with syndromic craniosynostosis (n = 32) and nonsyndromic craniosynostosis (n = 9) were included. The main indication for posterior cranial vault distraction in this cohort was turricephaly (63%). The mean distraction distance was 25.9 mm and the mean decrease in TI was 18%. The estimated increase in PCV from distraction in this cohort was 19.7%. In this cohort of patients, 13 patients (32%) experienced complications but there were no mortalities.

CONCLUSION

Posterior cranial vault distraction osteogenesis is an effective surgical procedure to increase intracranial volume and correct turricephaly in children with syndromic and nonsyndromic craniosynostosis. This procedure is considered a safe and effective first-stage cranial operation in children with syndromic craniosynostosis with increased intracranial pressure and or turricephaly.

Craniofacial Distraction Osteogenesis

Distraction osteogenesis (DO) of the craniofacial skeleton has become an effective technique for the treatment of both nonsyndromic and syndromic conditions. The advent of craniofacial DO has allowed for earlier intervention in pediatric patients with less complication risk and morbidity compared to traditional techniques. In this review, we will discuss current application and technique for craniofacial DO by anatomical region and explore future applications in craniofacial surgery.

Spring-Assisted Cranial Expansion for Multisuture Craniosynostosis: First Case Report from the Indian Subcontinent

We present a first use case report from the Indian subcontinent of a 5-month-old child with multisuture craniosynostosis with raised intracranial pressure managed by spring-assisted cranial expansion followed by traditional fronto-orbital advancement and cranial vault remodeling. We emphasize the advantages of spring-assisted cranial expansion in extremely young infants with raised intracranial pressure over posterior vault distraction osteogenesis and open posterior vault remodeling.

Two-Center Review of Posterior Vault Expansion following a Staged or Expectant Treatment of Crouzon and Apert Craniosynostosis

BACKGROUND

The timing of posterior cranial expansion for the management of intracranial pressure can be "staged" by age and dysmorphology or "expectant" by pressure monitoring. The authors report shared outcome measures from one center performing posterior vault remodeling (PCVR) or distraction (PVDO) following a staged approach and another performing spring-assisted expansion (SAPVE) following an expectant protocol.

METHODS

Apert or Crouzon syndrome patients who underwent posterior expansion younger than 2 years were included. Perioperative outcomes and subsequent cranial operations were recorded up to last follow-up and intracranial volume changes measured and adjusted using growth curves.

RESULTS

Thirty-eight patients were included. Following the expectant protocol, Apert patients underwent SAPVE at a younger age (8 months) than Crouzon patients (16 months). The initial surgery time was shorter but total operative time, including device removal, was longer for PVDO (3 hours 52 minutes) and SAPVE (4 hours 34 minutes) than for PCVR (3 hours 24 minutes). Growth-adjusted volume increase was significant and comparable. Fourteen percent of PCVR, 33% of PVDO, and 11% of SAPVE cases had complications, but without long-term deficits. Following the staged approach, 5% underwent only PVDO, 85% had a staged posterior followed by anterior surgery, and 10% required a third expansion. Following the expectant approach, 42% of patients had only posterior expansion at last follow-up, 32% had a secondary cranial surgery, and 26% had a third cranial expansion.

CONCLUSION

Two approaches involving posterior vault expansion in young syndromic patients using three techniques resulted in comparable early volume expansion and complication profiles.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Syndromic Craniosynostosis: Cranial Vault Expansion in Infancy

Syndromic craniosynostosis (CS) represents a relatively uncommon disease process that poses significant reconstructive challenges for the craniofacial surgeon. Although there is considerable overlap in clinical features associated with various forms of syndromic CS, key extracranial features and close examination of the extremities help to distinguish the subtypes. While Virchow's law can easily guide the diagnosis of single suture, nonsyndromic CS, syndromic CS traditionally results in atypical presentations inherent to multiple suture fusion. Coronal ring involvement in isolation or associated with additional suture fusion is the most common pattern in syndromic CS often resulting in turribrachycephaly.

Accelerated cranial distraction protocol for one-piece fronto-orbital distraction osteogenesis without bandeau in patients with craniosynostosis

This study aimed to compare the bony relapse ratios of standard and accelerated distraction protocols (ADP) in one-piece fronto-orbital distraction osteogenesis (DO). Patients with unilateral or bilateral coronal synostoses who underwent one-piece fronto-orbital DO were included. The accelerated cranial distraction protocol included a 3-day latency period and a distraction rate of 1-2 mm/day, followed by a 4-week consolidation period. Intracranial volume was measured using computed tomography (CT) before the surgery, at the end of the consolidation period, and 1 year after the removal of distractors. The intracranial volume changes and relapse ratios were calculated. This study included 32 patients; of these, 16 were included in each of the ADP and standard protocol (SP) groups. The mean ages were 1.4 years and 1.6 years in the ADP and SP groups, respectively (p = 0.895). In the ADP and SP groups, the expanded volumes were 270.9 ± 90.3 cm³ and 284.6 ± 149.7 cm³ (p = 0.91) and the growth-corrected expanded volumes were 162.1 ± 67.5 cm³ and 177.1 ± 105.2 cm³, respectively (p = 0.867). The relapse and growth-corrected relapse ratios showed no significant differences between the two groups, suggesting similar stability between the two protocols. The relapse ratios were 7.1 ± 4.8% and 7.3 ± 5.0% (p = 0.91) and the growth-corrected relapse ratios were -3.0 ± 3.3% and -2.4 ± 2.7%, respectively (p = 0.498). Within the limitations of the study, it seems that the ADP can shorten the distraction period without compromising stability. This may contribute to resolving the disadvantages and highlighting the advantages of DO.

Early cranial vault distraction for a more balanced and enhanced expansion: a 3D craniometric analysis of anterior versus posterior distraction osteogenesis in patients with craniosynostosis

OBJECTIVE

Posterior distraction osteogenesis (DO) is widely accepted for the treatment of craniosynostosis. The aim of this study was to quantitatively compare the effect of DO on the cranial vault according to the age of the patient and direction of distraction.

METHODS

This was a retrospective study of patients with craniosynostosis who underwent DO in the anteroposterior direction. Postdistraction changes in intracranial volume (ICV), anteroposterior distance, biparietal distance, cranial height, and frontal bossing angle were measured using Mimics software on CT scans. Craniometric data were analyzed using a multivariate regression model.

RESULTS

Thirty-two patients (16 anterior and 16 posterior DOs) were included in the study. The mean ICV increase in the anterior and posterior DO group was 211 cm3 (range 142-281 cm3) and 214 cm3 (range 150-279 cm3), respectively. Patients who were aged 1 year or younger showed a greater percentage increase in ICV than patients older than 1 year. In the anterior DO group, a more balanced increase in both anterior and posterior anteroposterior distance was observed in patients aged 1 year or younger when compared to patients older than 1 year. In the posterior DO group, a bigger expansion and smoother contour in the posterior cranial fossa was observed in patients aged 1 year or younger.

CONCLUSIONS

Both anterior and posterior DO are effective surgical options for expanding the cranial vault in patients with craniosynostosis. Early distraction appeared to show greater morphological changes in the growing cranial vault than those predicted with the vector of distraction.

"Ten Years of Posterior Cranial Vault Expansion via Distraction Osteogenesis: An Update and Critical Evaluation"

PURPOSE

The goal of this study was to describe the 10-year evolution of our surgical technique and institutional perioperative outcomes using posterior vault distraction osteogenesis (PVDO) in patients with syndromic and multi-suture craniosynostosis.

METHODS

We performed a retrospective cohort study of patients who underwent PVDO for treatment of syndromic and multi-suture craniosynostosis at a single institution over a 10-year period. Demographic data, perioperative outcomes, distraction patterns, and complications were analyzed. Outcomes for patients in the first 5 years ("early cohort") were compared to those of the latter 5 years ("late cohort").

RESULTS

110 patients underwent a total of 118 PVDO procedures. Syndromic patients represented 83.6% of the cohort (n=92) and were significantly younger than non-syndromic patients at the time of first PVDO (median 14.1 [6.6, 40.1] vs 42.7 [15.2, 59.6] months, p=0.014). Mean distraction distance in the anterior-posterior direction was 30.8 mm (SD=7.4). Compared to the early cohort, PVDO in the late cohort had faster median operative times (144.0min [123.0, 189.0] vs 161.0min [138.0, 199.0], p=0.038), lower estimated blood loss as a percent of blood volume (28.5 [20.6, 45.3] vs 50.0 [31.1, 95.8], p<0.001), and lower blood replacement as percent of blood volume (39.5 [23.8, 59.1] vs 56.3 [37.8, 110.1], p=0.009).

CONCLUSIONS

Our 10-year experience with PVDO demonstrates continued overall safety and efficacy with improved perioperative outcomes over time. While it has become our first line of expansion in syndromic craniosynostosis, shortcomings such as need for device removal, infectious concerns, and potential for CSF leak merit attention by the craniofacial community.

Update in Management of Craniosynostosis

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the craniofacial dysmorphology of craniosynostosis, and the variation of each type. 2. Identify the functional concerns and learn the rationale behind timing of operative intervention. 3. Approach each dysmorphology critically and identify the operative intervention needed to improve form and function 4. Understand and address the specific issues related to syndromic craniosynostosis and be able to delineate management plan.

SUMMARY

Craniosynostosis is a condition in which premature fusion of one or more cranial sutures lead to abnormal head shape and growth restriction of the brain. Nonsyndromic craniosynostosis occurs in isolation, and usually involves a single suture, whereas syndromic craniosynostosis may involve multiple sutures and is associated with extracraniofacial findings. Although surgical management can be similar, the treatment plan must take into consideration issues specific to the syndromes. This article aims to provide a concise overview of the authors' current understanding regarding the presentation, treatment principle, surgical option, and debates in craniosynostosis.

Transverse Distraction Osteogenesis for Posterior Narrowing of the Cranial Vault

SUMMARY

Although conventional posterior vault distraction osteogenesis is known to achieve the greatest improvement in intracranial volume, anteroposterior expansion of the cranial vault is not always ideal in certain head shapes. Transverse posterior vault distraction osteogenesis is an alternative reconstructive strategy in patients presenting with recalcitrant multisuture craniosynostosis resulting in scaphocephaly with posterior narrowing. The authors present a multimedia demonstration of placing the cranial hinge points at the superior anterior aspect of the bone segments in order to achieve increased intracranial volume and significant improvement in posterior head shape, while preserving normal anterior skull dimensions.

Management of Chiari 1 malformation and hydrocephalus in syndromic craniosynostosis: A review

Chiari 1 malformation and hydrocephalus are frequent findings in multi-suture and syndromic craniosynostosis patients. In this article, we review the pathogenesis, clinical significance, and management options for these conditions with comments from our own experience. The role of premature fusion of skull base sutures leading to a crowded posterior fossa and venous outflow obstruction resulting in impaired cerebrospinal fluid (CSF) absorption is highlighted. Management options are unique in this group and we advocate early (prior to 6 months of age) posterior vault expansion by distraction osteogenesis (DO) in the management of Chiari 1 malformation. Foramen magnum decompression is recommended for a select few either as part of posterior vault expansion or at a later date. Treatment of hydrocephalus, utilizing a ventriculoperitoneal (VP) shunt with preferably a programmable high-pressure valve and anti-siphon device, is required in a small percentage of cases despite successful posterior vault expansion. Patients need to be carefully selected and managed as hydrocephalus often serves as an important cranial vault growth stimulus. Further, they require careful monitoring and thought to ensure the management of these conditions and the timing of any intervention provides the optimal long-term outcome for the patient.

Management of ventriculomegaly in pediatric patients with syndromic craniosynostosis: a single center experience

INTRODUCTION

Management of ventriculomegaly in pediatric patients with syndromic craniosynostosis (SC) requires understanding the underlying mechanisms that cause increased intracranial pressure (ICP) and the role of cerebrospinal fluid (CSF) in cranial vault expansion in order to select the best treatment option for each individual patient.

METHODS

A total of 33 pediatric patients with SC requiring craniofacial surgery were retrospectively evaluated. Cases of nonsyndromic craniosynostosis and shunt-induced craniosynostosis were excluded. Six syndrome-based categories were distinguished: Crouzon syndrome, Pfeiffer syndrome, Apert syndrome, cloverleaf skull syndrome, and others (Muenke syndrome, Sensenbrenner syndrome, unclassified). All of the patients were treated surgically for their cranial deformity between 2010 and 2016. The presence of ventriculomegaly and ventriculoperitoneal (VP) shunt requirement with its impact in cranial vault expansion were analyzed. Clinical and neuroimaging studies covering the time from presentation through the follow-up period were revised. The mean postoperative follow-up was 6 years and 3 months. A systematic review of the literature was conducted through a PubMed search.

RESULTS

Of the total of 33 patients with SC, 18 (54.5%) developed ventriculomegaly and 13 (39.4%) required ventriculoperitoneal (VP) shunt placement. Six patients (18.2%) required shunt placement previous to craniofacial surgery. Seven patients (21.2%) required a shunt after craniofacial surgery. Seven fixed pressure ventriculoperitoneal shunts and six programmable valves were placed as first choice. All patients improved their clinical symptoms after shunt placement. Aesthetic results seemed to be better in patients with programmable shunts.

CONCLUSIONS

Unless clear criteria for overt hydrocephalus are present, it is recommended to perform craniofacial surgery as a first step in the management of patients with SC in order to preserve the expansive effect of CSF for cranial vault expansion. In our experience, the use of externally programmable valves allows for the treatment of hydrocephalus while maintaining the expansive effect of CSF for the remodeling of the cranial vault. Prospective evaluations are needed to determine causality.

Posterior vault distraction osteogenesis: indications and expectations

Cranial vault remodeling (CVR) in patients with craniosynostosis serves to correct abnormal skull morphology and increase intracranial volume to prevent or treat pathologic increases in intracranial pressure (Taylor and Bartlett, Plast Reconstr Surg 140: 82e-93e, 2017). Distraction osteogenesis is a well-established technique for bony repositioning and growth stimulation in the facial and long bones, in which the gradual separation of bony segments at an osteotomy site results in generation of new bone and subsequent bone lengthening (Greene, 2018). While initially described in the orthopedic literature, the relevance and applicability of distraction osteogenesis to craniofacial surgery has been well-studied and is now well-established (Steinbacher et al., Plast Reconstr Surg 127: 792-801, 2011). Posterior cranial vault distraction osteogenesis (PVDO) was introduced as a treatment option for cranial vault expansion in patients with craniosynostosis in 2009 by White et al., based upon the premise that posterior vault distraction could provide greater intracranial volume expansion than fronto-orbital advancement and remodeling (FOAR), but that acute posterior cranial vault expansions were limited by the soft tissue envelope of the infant scalp and prone to relapse related to the supine positioning typical of infants (White et al., Childs Nerv Syst 25: 231-236, 2009). Since this introduction, significant evidence has accrued regarding the safety of, and outcomes after, PVDO. PVDO is now known to provide larger increases in intracranial volume in comparison to anterior cranial vault remodeling procedures (Derderian et al., Plast Reconstr Surg 135:1665-1672, 2015) and to provide morphologic improvements in both the posterior and anterior cranial vaults (Goldstein et al., Plast Reconstr Surg 131:1367-1375, 2013). Perioperative major morbidity is comparable to conventional vault remodeling (Taylor et al., Plast Reconstr Surg 129:674e-680e, 2012) and the procedure has been safely applied to patients of various ages with syndromic and non-syndromic craniosynostosis (Zhang et al., J Craniofac Surg 29:566-571, 2018; Li et al., J Craniofac Surg 27:1165-1169, 2016). Many high-volume craniofacial centers now consider PVDO the preferred first operation in infants with syndromic craniosynostosis, and indications for this procedure continue to expand as evidence accrues regarding its utility and safety (Steinbacher et al., Plast Reconstr Surg 127: 792-801, 2011; Swanson et al., Plast Reconstr Surg 137:829e-841e, 2016).

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.

The Expanding Role of Posterior Vault Distraction Osteogenesis in Idiopathic Intracranial Hypertension and Slit Ventricle Syndrome

ABSTRACT

The purpose of this study was to compare perioperative safety and efficacy of posterior vault distraction osteogenesis (PVDO) in patients with primary nonsynostotic cephalo-cranial disproportion, namely slit ventricle syndrome and idiopathic intracranial hypertension (IIH), to a cohort of patients with craniosynostosis (CS). A retrospective review of patients undergoing PVDO from 2009 to 2019 at our institution was performed. Craniosynostosis patients were matched by sex and age at PVDO to the nonsynostotic cohort. Operative details, perioperative outcomes, and distraction patterns were analyzed with appropriate statistics. Nine patients met inclusion criteria for the non-CS cohort. Six patients (67%) underwent PVDO for slit ventricle and the remaining 3 patients (33%) underwent PVDO for IIH. The majority of CS patients were syndromic (n = 6, 67%) and had multisuture synostosis (n = 7, 78%). The non-CS cohort underwent PVDO at a median 56.1 months old [Q1 41.1, Q3 86.6] versus the CS cohort at 55.7 months [Q1 39.6, Q3 76.0] (P = 0.931). Total hospital length of stay was longer in the non-CS patients (median days 5 [Q1 4, Q3 6] versus 3 [Q1 3, Q3 4], P = 0.021). Non-CS patients with ventriculoperitoneal shunts had significantly less shunt operations for ICP concerns post-PVDO (median rate: 1.74/year [Q1 1.30, Q3 3.00] versus median: 0.18/year [Q1 0.0, Q3 0.7]; P = 0.046). In this pilot study using PVDO to treat slit ventricle syndrome and IIH, safety appears similar to PVDO in the synostotic setting. The cohort lacks adequate follow-up to assess long term efficacy, although short-midterm follow-up demonstrates promising results with less need for shunt revision and symptomatic relief. Future studies are warranted to identify the preferred surgical approach in these complex patients.

Surgical Result and Identification of FGFR2 Variants Using Whole-Exome Sequencing in a Chinese Family With Crouzon Syndrome

ABSTRACT

Crouzon syndrome is considered as one of the most common craniosynostosis syndromes with a prevalence of 1 in 65,000 individuals, and has a close relationship with variants in fibroblast growth factor receptor 2. Here the authors described a Crouzon syndrome case, which was asked for surgery treatment for the symptom of multisuture craniosynostosis. Mild midfacial retrusion, larger head circumference, proptosis, pseudo-prognathism, and dental malposition could also be found obviously. Then fronto-orbital advancement and cranial cavity expansion were performed to the child. After whole-exome sequencing (WES) and Sanger sequencing, gene variants in the exons 2 and 3 of FGFR2 were detected. And protein tyrosine 105 replaced by cysteine in the extracellular region of FGFR2 was also detected. After operation, she presented a satisfactory anterior plagiocephaly and scaphocephaly correction, and the result was satisfied by surgeons and her parents. Variants detected using WES have further research prospect.

Cranial Vault Distraction in Nonsyndromic Sagittal Synostosis

ABSTRACT

A multitude of operations exists for the treatment of patients with sagittal craniosynostosis presenting after 6 months of age, of which total cranial vault remodeling now provides the most reliable aesthetic outcome. As our national craniofacial center evolved and began to develop a comprehensive multi-disciplinary team to manage complex surgical cases, we offered cranial vault distraction as an alternative to more invasive surgery for late presentation nonsyndromic scaphocephaly. The authors conducted a retrospective review of all patients undergoing this procedure.An average distraction distance of 39.4 mm was achieved in 15 patients aged 1 to 9 years. As a result, the cephalic index changed an average of 4%. The mean transfusion volume in the perioperative period was 32.47% of estimated blood volume. There were 2 complications requiring further operative intervention and distraction was stopped early in 1 patient.The authors propose that internal calvarial distraction is a viable alternative to total cranial vault remodeling for the management of late presentations of sagittal craniosynostosis.

Distraction osteogenesis in craniosynostosis

PURPOSE OF REVIEW

Craniosynostosis, a condition of premature cranial suture fusion, can have significantly detrimental effects on development and growth due to sequelae of increased intracranial hypertension (ICP), exophthalmos, and upper airway obstruction. Evolving surgical treatments now include distraction osteogenesis (DO) due to its many benefits relative to standard cranial vault remodeling procedures. This article provides an overview and update of different surgical applications of DO for patients with craniosynostosis.

RECENT FINDINGS

DO has been utilized successfully for single and multisuture craniosynostosis with or without midface hypoplasia to increase intracranial volume, decrease ICP and improve aesthetics. It has been applied in single suture synostosis, posterior vault DO, fronto-orbital advancement, monobloc DO and Le Fort III DO. DO has been applied through modification of traditional surgical procedures with success in maintaining goals of surgery while reducing risk.

SUMMARY

DO is still a relatively new and evolving surgical technique for patients with syndromic and nonsyndromic craniosynostosis. With promising benefits, consideration for each procedure should be weighed until longer-term data is available.

Risk Factors for Occipital Step-Off Deformities in Posterior Vault Distraction Osteogenesis

PURPOSE

The goal of this study was to investigate patient specific factors and surgical techniques that affect occipital step-off deformity in children undergoing posterior vault distraction osteogenesis (PVDO).

METHODS

Patients who underwent PVDO were retrospectively reviewed and included if a high resolution three-dimensional computed tomography scan was available 1-year post-distractor removal. Two craniofacial surgeons were blinded to individual subjects and presented with 3 still images of three-dimensional bone reconstructions and asked to rate the degree of step off: none, mild, moderate, or severe. The data were analyzed with multinomial logistic regressions and other appropriate statistics.

RESULTS

Forty-one patients met inclusion criteria. All patients had multisuture or bicoronal craniosynostosis. Multinomial logistic regression identified age at PVDO (Cox and Snell = 0.487, P < 0.001) as a predisposing factor and one potentially protective factor, height of osteotomy (Cox and Snell = 0.394, P = 0.004) in univariate models. Post-hoc pairwise Mann-Whitney U test revealed there was decreased step-off rating when comparing osteotomy below torcula (median 0, [IQR 0, 3]) and above torcula (median 3 [IQR 1, 4]; P = 0.036) as well as a decreased step-off when below inion (median 0 [IQR 0, 1]; P = 0.001) was compared to above the torcula.

CONCLUSIONS

Older age at PVDO predict increased risk of developing an occipital step-off deformity after PVDO, while design of the occipital osteotomy below the inion is protective. Barrel staves with greenstick outfracture did not lower the risk of occipital step-off in this sample, the reasons for which are unclear.

Posterior cranial vault distraction osteogenesis in the immunocompromised patient

PURPOSE

The treatment of patients with multisuture craniosynostosis is complex and patient-dependent. Cranial distraction osteogenesis is a relatively new procedure for treatment of these patients, with its use increasing in many centers. With this increased use comes an expanding range of indications. Surgical management of multisuture craniosynostosis in therapeutically immunosuppressed patients following a solid organ transplant presents unique challenges. We describe our experience with posterior cranial vault distraction in two patients with multisuture craniosynostosis that had previously undergone organ transplantation.

METHODS

Two solid-organ transplant recipient patients with multisuture craniosynostosis were identified. A detailed examination of their medical/transplant history and perioperative details were recorded.

RESULTS

The first patient was a 3-year-old girl who received a kidney transplantation in infancy and subsequently presented with a symptomatic Chiari malformation and papilledema. Imaging revealed pansynostosis. She underwent posterior cranial vault distraction extending into a Chiari decompression. Her postoperative course was complicated by distractor site infection at the beginning of consolidation, necessitating early removal of distractors. The second patient was a 2-year-old boy who received a heart transplantation at the age of 3 months and subsequently presented with head shape concerns. Imaging revealed bicoronal and sagittal craniosynostosis. He underwent a posterior cranial vault distraction without complication. Following removal of the distractors, he developed an infection at one of the distractor sites with associated fever and leukocytosis, necessitating washout and drain placement. Both patients achieved successful cranial vault expansion with distraction osteogenesis and at a 2-year follow-up do not have evidence of elevated intracranial pressure.

CONCLUSIONS

Immunosuppressive therapy has the potential to inhibit wound healing and place patients at risk for wound infection. Although we have demonstrated successful cranial vault expansion with distraction in two immunosuppressed children, extra care must be taken with these patients when placing semi-buried hardware. Specifically, prompt identification and proactive management of potential infectious complications is critical to applying this technique safely in these patients.

Craniometric and Volumetric Analysis of Posterior Vault Distraction Osteogenesis: 10 Year Update

PURPOSE

The purpose of this study is to quantitatively establish the volumetric changes observed with posterior vault distraction osteogenesis in the anterior, middle, and posterior thirds of the cranial vault; characterize change in cranial length, width, and height, correlating these changes to demographic variables that may help identify why younger kids gain more volume; and describe the short-term position of the transport segment.

METHODS

Multisuture craniosynostosis patients who underwent posterior vault distraction osteogenesis were retrospectively reviewed. Pediatric, dose-reduced, thin cut helically acquired head computed tomography scans were analyzed on Materialise Mimics v22 (Materialise, Ghent, Belgium). Pre and post-PVDO and "old" and "young" cohort were compared.

RESULTS

Twenty-one patients met inclusion criteria. The change in cranial length was significantly less at a median of 14.9 mm [Interquartile range (IQR) 11.8, 31.6] compared to the X-ray measured AP distraction distance (30 mm [IQR 24, 33]; P < 0.001) and significantly less than the theoretically calculated distance (23 mm [IQR 19, 31]; P = 0.012). Median anterior cranial height was shorter post PVDO (82.9 mm, [IQR 64.8, 92.6] versus 78.7 mm [IQR 57.0, 88.7]; P = 0.030). The younger cohort saw a greater increase in total intracranial volume (median 335.1 mL [IQR 163.2, 452.3, median 37.1%] versus 144.6 mL [IQR 119.0, 184.8, median 12.0%]; P = 0.011).

CONCLUSIONS

This is the first study to quantify volumetric changes to the anterior, middle, and posterior cranial vaults and demonstrates benefits of preforming PVDO at a younger age to help control turricephaly and produce greater percentage volumetric increases.

A Review on Variability in Treatment Protocols With Posterior Cranial Vault Distraction

BACKGROUND

Prior studies have confirmed the ability of posterior cranial vault distraction osteogenesis (PVDO) to expand the intracranial volume in patients with craniosynostosis. To date, there is scant literature on the optimal distraction protocol for PVDO. The authors sought to review the literature and define a common protocol for posterior cranial vault distraction.

METHODS

The authors performed a systematic review for published PVDO protocols. The data collected from these studies included age at the time of PVDO, number of distraction devices placed, time for latency, rate and rhythm of distraction, distraction length, time for consolidation, and surgical outcomes.

RESULTS

A total of 286 patients were identified within 24 studies from 2011 to 2019. The mean age of patients identified was 25.34 months. After application of distractors, latency period ranged between 1 and 7 days, with most patients undergoing 5 to 7 days of latency. Once distraction was begun, the majority of patients (77.4%) underwent 1 mm of distraction daily. Total lengths of distraction ranged between 13 and 35 mm, with the largest cohort of patients undergoing 26 to 30 mm of total distraction. A total of 60 complications were reported for a total of 212 patients, yielding an overall complication rate of 28.3%.

CONCLUSIONS

Although there is variability in reported PVDO protocols, the majority are similar to distraction osteogenesis protocols described for long bone sites. Increased patient age correlates with selection of a greater latency period and total distraction length, while frequency of complications is also increased.

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.

Craniosynostosis: Monobloc Distraction with Internal Device and Its Variant for Infants with Severe Syndromic Craniosynostosis

The introduction of distraction osteogenesis to frontofacial monobloc advancement has increased the safety of the procedure. One hundred forty-seven patients with syndromic craniosynostosis underwent frontofacial monobloc advancement using 4 internal distractors. Twenty-five were aged 18 months or less. Ten patients presented with a tracheostomy, 5 (50%) were decannulated after surgery, and 3 others (30%) required an additional intervention before decannulation. Six patients required the addition of a transfacial pin and external traction. Very early frontofacial monobloc with 4 internal distractors is a safe and effective treatment to protect the ophthalmic, neurologic, and respiratory functions in infants with severe syndromic craniosynostosis.

Analysis of Actual Versus Predicated Intracranial Volume Changes for Distraction Osteogenesis Using Virtual Surgical Planning in Patients With Craniosynostosis

INTRODUCTION

The primary outcome metric in patients with craniosynostosis are changes in intracranial volumes (ICVs). In patients who undergo distraction osteogenesis (DO) to treat craniosynostosis, changes are also dependent on the length of distraction. Virtual surgical planning (VSP) has been used to predict anticipated changes in ICV during cranial vault reconstruction. The purpose of this study is to analyze the actual versus predicted ICV changes using VSP in patients who undergo DO for craniosynostosis management.

METHODS

All patients with craniosynostosis treated with DO at a single institution, Rady Children's Hospital, between December 2013 and May 2019 were identified. Inclusion criteria are as follows: VSP planning with predicted postoperative ICV values and preoperative and postdistraction CT scans to quantify ICV. Postoperative ICV and VSP-estimated ICV were adjusted for age-related ICV growth. The primary outcome measure calculated was age-adjusted percent volume change per millimeter distraction (PVCPD), and results were analyzed using paired Wilcoxon signed rank tests.

RESULTS

Twenty-seven patients underwent DO for cranial vault remodeling. Nineteen patients were nonsyndromic, and 8 patients were syndromic. The median postoperative PVCPD was 0.30%/mm, and the median VSP-estimated PVCPD was 0.36% per millimeter (P < 0.001). A subanalysis of nonsyndromic patients showed a median postoperative PVCPD of 0.29%/mm in nonsyndromic patients that differed significantly from the VSP estimate of 0.34%/mm (P = 0.003). There was also a significant difference in syndromic patients' observed PVCPD of 0.41%/mm versus VSP estimate of 0.79%/mm (P = 0.012).

CONCLUSIONS

Virtual surgical planning overestimates the change in ICV attributable to DO in both syndromic and nonsyndromic patients.

Automated Lateral Ventricular and Cranial Vault Volume Measurements in 13,851 Patients Using Deep Learning Algorithms

BACKGROUND

No large dataset-derived standard has been established for normal or pathologic human cerebral ventricular and cranial vault volumes. Automated volumetric measurements could be used to assist in diagnosis and follow-up of hydrocephalus or craniofacial syndromes. In this work, we use deep learning algorithms to measure ventricular and cranial vault volumes in a large dataset of head computed tomography (CT) scans.

METHODS

A cross-sectional dataset comprising 13,851 CT scans was used to deploy U-Net deep learning networks to segment and quantify lateral cerebral ventricular and cranial vault volumes in relation to age and sex. The models were validated against manual segmentations. Corresponding radiologic reports were annotated using a rule-based natural language processing framework to identify normal scans, cerebral atrophy, or hydrocephalus.

RESULTS

U-Net models had high fidelity to manual segmentations for lateral ventricular and cranial vault volume measurements (Dice index, 0.878 and 0.983, respectively). The natural language processing identified 6239 (44.7%) normal radiologic reports, 1827 (13.1%) with cerebral atrophy, and 1185 (8.5%) with hydrocephalus. Age-based and sex-based reference tables with medians, 25th and 75th percentiles for scans classified as normal, atrophy, and hydrocephalus were constructed. The median lateral ventricular volume in normal scans was significantly smaller compared with hydrocephalus (15.7 vs. 82.0 mL; P < 0.001).

CONCLUSIONS

This is the first study to measure lateral ventricular and cranial vault volumes in a large dataset, made possible with artificial intelligence. We provide a robust method to establish normal values for these volumes and a tool to report these on CT scans when evaluating for hydrocephalus.

Chiari Malformation Type 1 and Syringomyelia in a Patient With Prior Surgically-Treated Sagittal Synostosis Effectively Treated With Posterior Cranial Vault Distraction Osteogenesis

ABSTRACT

The presenting report describes the use of a posterior cranial vault distraction procedure in resolving a Chiari malformation with associated syringomyelia following a surgically-treated nonsyndromic craniosynostosis. Chiari malformations are typically treated with posterior fossa decompression with or without expansion duraplasty. The objective of this report is to describe the effectiveness in resolving both Chiari malformation and secondary syringomyelia with posterior cranial vault distraction osteogenesis. A 5-year-old male, with a history of surgery for sagittal synostosis during infancy, presented with daily severe headaches and dysesthesias in the hands and feet. Imaging demonstrated a copper-beaten calvarium and a Chiari 1 malformation with a 7 mm diameter C4-T1 syrinx. He underwent posterior cranial vault distraction osteogenesis over 3 months to increase his intracranial volume. The patients' headaches improved significantly, and his dysesthesias resolved postoperatively. A magnetic resonance imaging performed 7 months after completion of distraction demonstrated resolution of the Chiari malformation and decompression of his syrinx. A computed tomography scan at 9 months postdistraction showed resolution of the copper-beaten calvarium. Patients with a history of craniosynostosis can develop inadequate cranial volume over time due to abnormal skull growth, leading to secondary Chiari malformation with or without syringomyelia. Posterior vault distraction is an effective strategy to address these conditions and can be employed later in childhood to treat the underlying pathology. The mechanism potentially expands both calvarium and dura, which in turn addresses both the Chiari malformation and secondary syringomyelia.

Spring-assisted posterior vault expansion-a single-centre experience of 200 cases

PURPOSE

Children affected by premature fusion of the cranial sutures due to craniosynostosis can present with raised intracranial pressure and (turri)brachycephalic head shapes that require surgical treatment. Spring-assisted posterior vault expansion (SA-PVE) is the surgical technique of choice at Great Ormond Street Hospital for Children (GOSH), London, UK. This study aims to report the SA-PVE clinical experience of GOSH to date.

METHODS

A retrospective review was carried out including all SA-PVE cases performed at GOSH between 2008 and 2020. Demographic and clinical data were recorded including genetic diagnosis, craniofacial surgical history, surgical indication and assessment, age at time of surgery (spring insertion and removal), operative time, in-patient stay, blood transfusion requirements, additional/secondary (cranio)facial procedures, and complications.

RESULTS

Between 2008 and 2020, 200 SA-PVEs were undertaken in 184 patients (61% male). The study population consisted of patients affected by syndromic (65%) and non-syndromic disorders. Concerns regarding raised intracranial pressure were the surgical driver in 75% of the cases, with the remainder operated for shape correction. Median age for SA-PVE was 19 months (range, 2-131). Average operative time for first SA-PVE was 150 min and 87 for spring removal. Median in-patient stay was 3 nights, and 88 patients received a mean of 204.4 ml of blood transfusion at time of spring insertion. A single SA-PVE sufficed in 156 patients (85%) to date (26 springs still in situ at time of this analysis); 16 patients underwent repeat SA-PVE, whilst 12 underwent rigid redo. A second SA-PVE was needed in significantly more cases when the first SA-PVE was performed before age 1 year. Complications occurred in 26 patients with a total of 32 events, including one death. Forty-one patients underwent fronto-orbital remodelling at spring removal and 22 required additional cranio(maxillo)facial procedures.

CONCLUSIONS

Spring-assisted posterior vault expansion is a safe, efficient, and effective procedure based on our 12-year experience. Those that are treated early in life might require a repeat SA-PVE. Long-term follow-up is recommended as some would require additional craniomaxillofacial correction later in life.

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.

Posterior vault "free-floating" bone flap: indications, technique, advantages, and drawbacks

BACKGROUND

The enlargement of the posterior cranial fossa volume is considered one of the main steps of the surgical management of children with multiple sutures craniosynostosis. Different management options have been proposed including fixed expansive craniotomy, free bone flap craniotomy, and distraction osteogenesis.

OBJECTIVES

To review indications to "free bone flap" craniotomy for the posterior fossa expansion, detailing advantages, disadvantages, and complications related to the technique.

RESULTS AND CONCLUSIONS

A review of the literature shows that "free bone flap" posterior expansion cranioplasty still has a role, particularly in infants with thin and "honeycomb" structure of the bone, allowing to gain adequate intracranial volume increases and to postpone to a more adequate time surgery aimed at anterior cranial fossa expansion.

Extended experience in parieto-occipital expansion surgery by meander technique-clinical and radiological evaluation

INTRODUCTION

Brachycephaly and anterior and posterior plagiocephaly appear as an isolated entity or manifest in syndromic conditions. In severe cases, possible treatment options currently comprise either cranioplasty or osteogenetic distraction. The aim of this paper is to retrospectively review the perioperative course of a series of children treated by posterior meander expansion technique at our institution with focus on the course of postoperative intracranial volume and eventual tonsillar descent evolution.

METHODS

Forty-two children received a posterior cranial vault remodeling by means of a posterior meander technique during a 7-year period. Hospital records were reviewed, and pre- and postoperative MRIs were analyzed for intracranial volume, cephalic and asymmetry index, and tonsillar position over time.

RESULTS

Median age at surgery was 11.5 months (range 17 days-10 years). Nineteen children had a symmetrical cranial deformity, twenty-three an asymmetrical synostosis. Half of the cohort showed a syndromic condition. Transfusions were administered in the majority (92.2%) of the cases. A significant postoperative increase of intracranial volume was present from 1188.9 ± 370.4 cm³ to 1324.8 ± 352.9 cm³ (p < 0.001). The asymmetry index showed a significant improvement postoperatively: 0.86 ± 0.06 versus 0.91 ± 0.05 (p < 0.001), while the cephalic index showed a non-statistical change (0.91 ± 0.11 versus 0.88 ± 0.08). Tonsillar herniation, bilateral or homolateral, showed no significant changes at early control, while a nonsignificant amelioration of tonsillar descent was seen among children older than 12 months at late imaging follow-up.

CONCLUSION

Among the osteoplastic techniques, the posterior meander technique offers several advantages, such as early mobilization of the child, less bony defects, absence of implants, and a small complication rate. However, further comparative studies among different surgical techniques are needed.

Upward vectors for osteogenic distraction treatment in secondary chronic intracranial hypertension in children undergoing scaphocephaly surgery: 2 cases reported

The occurrence of secondary synostosis of coronal sutures at distance from H-craniectomy surgery for scaphocephaly concerns about 10% of children. Intracranial hypertension in these children remains exceptional but generally requires a surgical reoperation. Two children aged 3 and 5- months- old had been operated for scaphocephaly by H-craniectomy in two different hospital centers. Their clinical follow-up described a partial persistence of dolichocephalic deformity and an impression of parietal stenosis. During their growth, chronic headaches appeared with a complaint expressed at the ages of 4 and 5 years. In both cases, ophthalmic examination revealed significant bilateral papillary edema without loss of visual acuity. The imaging assessment (CT-scan and MRI) showed the absence of Chiari malformation and venous abnormality. For both, there was a compression image of the parietal lobes in relation to the persistence of a temporoparietal synostosis. An osteogenic parietal distraction permitted a volumetric brain expansion consecutive to the skull and meninges remodeling in only 6 months, associated with a leap forward acquisition, a normalization of the ophthalmic examination, and a complete loss of headaches. In conclusion, this new approach could be used in the case of chronic intracranial hypertension consecutive to a secondary parietal synostosis after a scaphocephaly surgery.

Hydrocephalus and Chiari malformation pathophysiology in FGFR2-related faciocraniosynostosis: A review

BACKGROUND

Patients with syndromic faciocraniosynostosis due to the mutation of the fibroblast growth factor receptor (FGFR) 2 gene present premature fusion of the coronal sutures and of the cranial base synchondrosis. Cerebrospinal fluid (CSF) circulation disorders and cerebellar tonsil prolapse are frequent findings in faciocraniosynostosis.

OBJECTIVE

We reviewed the medical literature on the pathophysiological mechanisms of CSF disorders such as hydrocephalus and of cerebellar tonsil prolapse in FGFR2-related faciocraniosynostosis.

DISCUSSION

Different pathophysiological theories have been proposed, but none elucidated all the symptoms present in Apert, Crouzon and Pfeiffer syndromes. The first theory that addressed CSF circulation disruption was the constrictive theory (cephalocranial disproportion): cerebellum and brain stem are constricted by the small volume of the posterior fossa. The second theory proposed venous hyperpressure due to jugular foramens stenosis. The most recent theory proposed a pressure differential between CSF in the posterior fossa and in the vertebral canal, due to foramen magnum stenosis.

National 30-Day Outcomes for Posterior Cranial Vault Distraction

BACKGROUND

Posterior vault distraction (PVD) can rapidly expand calvarial volume in infancy. Limited data exist regarding its perioperative and postoperative safety profile. This study sought to investigate the patient profile, outcomes, and safety of PVD using a national pediatric database.

METHODS

Posterior vault distraction patients between 2012 and 2016 were isolated from the National Surgical Quality Improvement Program Pediatric database. Patient background, perioperative outcomes, and risk factors were analyzed using chi-squared, t test analysis, and multivariate regression.

RESULTS

Ninety-four patients who underwent PVD were isolated with 67 ultimately meeting inclusion criteria for the study. The majority of patients undergoing PVD had limited other documented comorbidities. No patients required reoperation or 30-day readmission. There were no incidences of stroke, surgical site infection, or death. Subdividing outcomes by specialty, plastic surgeons performed PVD on significantly older patients than neurosurgeons (188 days vs 138 days, P = 0.008). Increasing age was associated with increasing operative time (P < 0.001). Furthermore, increasing age is associated with greater absolute transfusion requirements (P = 0.018) and higher, but not significant, risk of requiring any volume of blood transfusion (P = 0.105).

CONCLUSIONS

Posterior vault distraction is a safe procedure to rapidly expand calvarial volume in the setting of craniosynostosis. Increasing patient age is the strongest predictor for prolonged operative time and higher blood transfusion volumes.

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.

Dynamic Chess-Table Cranial Expansion for Treatment of Craniocerebral Disproportion: Technical Note and Volumetric Results

OBJECTIVE

Craniocerebral disproportion (CCD) is a challenging disease, and several expansile procedures have been used for its treatment. This report describes the dynamic chess-table cranial expansion technique and reports on 9 patients with primary and secondary CCD treated with this procedure.

METHODS

Nine patients affected by CCD were treated with chess-table cranial expansion and reviewed. Symptoms of increased intracranial pressure (ICP) and radiologic findings were analyzed. ICP was monitored using epidural or telemetric sensors. Intracranial volume was measured using computed tomography image processing tools before the surgery, 24 hours after the surgery, and 1 month later. A mathematical model was developed to explain the clinical and surgical results.

RESULTS

Five patients had secondary CCD and 4 had primary CCD. The mean age for cranial expansion was 16.78 years. The most frequent symptoms were headaches, nausea/vomiting, and decreased consciousness. Slit ventricles and sutural sclerosis were observed in 33.3% and 55.6% of patients. The mean ICP before the procedure was 48.67 mm Hg. Progressive cranial expansion was seen in all patients after surgery. The mean ICP decreased to 11 mm Hg and mean intracranial volume expansion was 85.8 cm³ at 1 month after surgery. There were no serious complications after surgery. All patients improved their symptoms, and no patient needed additional cranial expansion procedures.

CONCLUSIONS

Chess-table cranial expansion is a safe and effective procedure and may be used as an alternative treatment for CCD. Progressive expansion of the intracranial volume is related to a decrease in ICP recordings and an improvement of symptoms.

Results and limits of posterior cranial vault expansion by osteotomy and internal distractors

Background:

Expanding the posterior cranial vault has become a common procedure in the treatment of complex craniosynostosis. Several techniques are available to remodel the posterior vault. Aim of this study was to analyze the posterior vault distraction osteogenesis.

Methods:

Between 2011 and 2014, 21 children (12 boys) were operated on for a posterior distraction of the cranial vault. The mean age was 8.6 months (minimum, 3 months; maximum, 15 years). Thirteen patients presented a craniofacial syndrome. Five had already been operated on (two anterior cranial surgery, two suboccipital decompression, and one craniotomy for sagittal synostosis). Raised intracranial pressure (ICP) was present in 6 patients. Seven patients had symptomatic cerebellar tonsils herniation (TH).

Results:

In 17 children, 2 lateral distractors were placed, in 3 a 3^rd medial distractor was placed, and in 1 child 4 distractors were implanted. Volumetric analysis based on computed tomography showed a mean increase of volume of 13.9% 117 days later. After the distraction, symptoms related to raised ICP or TH were improved in all patients, however, radiologically TH was improved at the last follow-up in 54% of the cases.

Conclusion:

Posterior cranial vault distraction is an efficacious technique to enlarge the posterior skull vault and treat increased ICP. Moreover, it appears to be efficacious in treating TH-related symptoms.

Morphometric Analysis of the Posterior Cranial Fossa in Syndromic and Nonsyndromic Craniosynostosis

Posterior cranial fossa (PCF) anatomy can be abnormal in craniosynostosis, and hindbrain herniation may occur. This study analyzed PCF anatomy in single suture and complex craniosynostosis.Children with craniosynostosis and age-matched controls were identified. Cephalic index (CI) for cranial vault and PCF as well as tentorial (TA) and occipital angles (OA) were measured on preoperative imaging.Children with syndromic (N = 6), bicoronal (N = 4), sagittal (N = 12), and metopic synostosis (N = 4) as well as controls (N = 10) were enrolled. Mean CI for cranial vault was 0.89, 0.93, 0.65, 0.74, and 0.78, respectively. Corresponding CI for PCF was 0.81, 0.93, 0.62, 0.74, and 0.78. Mean TA and OA were 45.4° and 96.6° in syndromic, 39.7° and 87.0° in bicoronal, 34.0 and 75.0° in sagittal, 39.7° and 87.0° in metopic synostosis, and 42.9° and 88.3° in controls.While CI, TA, and OA in metopic synostosis were similar to controls, abnormalities were found in syndromic, bicoronal, and sagittal synostosis. Syndromic and bicoronal craniosynostosis patients had a higher CI for both cranial vault and PFC as well as larger TA and OA, indicating a brachycephalic skull with steep tentorium and narrow PCF. In sagittal synostosis, CI for cranial vault and PCF were lower and TA and OA smaller, reflecting scaphocephalic deformity also at PCF, with a flat tentorium. This study provides basic PCF morphometry in craniofacial conditions.