First Vault Expansion in Apert and Crouzon-Pfeiffer Syndromes: Front or Back?

Free-floating bone flap posterior cranial vault release in syndromic craniosynostosis

The aim of this study was to investigate the efficacy of non-detachable free-floating bone flap posterior cranial vault release (FFBF-PCVR) in syndromic craniosynostosis. A retrospective review was completed of subjects who underwent FFBF-PCVR at 4 time-points: within 3 months preoperatively, 7 days postoperatively, 3 months postoperatively and at the last follow-up postoperatively. Volumetric and craniometric data, the ratio of ventricular diameter, and the cerebellar tonsillar descent were measured after FFBF-PCVR by using computed tomographic and magnetic resonance imaging. A total of 19 patients underwent FFBF-PCVR. The mean age was 11.7 months (range 4-36 months). The mid cranial height, posterior cranial height, and anterior posterior diameter length significantly increased from preoperative to postoperative 7 days, from postoperative 7 days to postoperative3 months, and from postoperative 3 months to the last follow-up. There was a significant increase in pre- to 7 days postoperative intracranial volume (1195.21 ± 246.56 cm³, p < 0.001; respectively), 3 months postoperative intracranial volume (1228.03 ± 249.61 cm³, p < 0.001; respectively), and intracranial volume at last follow-up (1390.25 ± 219.99 cm³, p < 0.001; respectively). There was a significant increase in 7 days' postoperative to 3 months' postoperative intracranial volume (p < 0.001; respectively), and intracranial volume at last follow-up (p < 0.001; respectively). There was a significant increase in 3 months postoperative to intracranial volume at last follow-up (p < 0.001). The mean intracranial volume increased by an average of 36.6 percent (range, 18.1 to 79.2 percent) at last follow-up. The degree of hydrocephalus in the preoperative child was (45.77% ± 9.17%), and at the last follow-up after surgery, the degree of hydrocephalus was (35.02 ± 9.50%), p < 0.01). Preoperatively, 14 patients (73.7 percent) had radiographic evidence of Chiari malformation type I. The cerebellar tonsillar descent, measured using pre- and postoperative MRI, decreased in all patients after FFBF-PCVR (preoperative: 7.5 ± 1.4 mm, postoperative: 5.3 ± 1.7 mm; p = 0.001). FFBF-PCVR can efficiently expand the posterior cranial vault with only one surgical procedure. Moreover, it helps to relieve hydrocephalus and cerebellar tonsillar herniation.

Craniosynostosis: Current Evaluation and Management

ABSTRACT

Craniosynostosis is characterized by the premature fusion of one or more cranial sutures, which can lead to abnormal skull shape and restricted skull growth. Although most cases are present in isolation, some are associated with genetic syndromes, such as Pfeiffer, Muenke, Couzon, Apert, and others, which increases the complexity of care. Today, a spectrum of surgical options to treat craniosynostosis are available and range from traditional open cranial vault remodeling to newer and less invasive suturectomy-based techniques. Which procedure is offered to a patient depends on not only the specific synostosis pattern but also factors such as patient age, the need for additional procedures or interventions, and evidence of elevated intracranial pressure. Thorough consultations with families to discuss achievable goals for cosmesis and function are essential in providing optimal care to each impacted child.

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.

Posterior Cranial Distraction in Craniosynostosis: A Systematic Review of the Literature

OBJECTIVE

Posterior cranial distraction (PCD) is a surgical technique to address craniosynostosis, especially in syndromic patients. The technique has the ability to significantly expand the cranium, while requiring minimal dural dissection, compared to cranial remodeling. Our goals were to determine the patient characteristics and surgical outcomes of PCD. The two questions that we sought to answer were: 1) What is the average published complication rate and the most common complications of PCD? and 2) How much intracranial volume expansion can one expect with PCD?

DESIGN

A PubMed database search of articles on PCD was performed. Case reports and articles with overlapping patients were excluded. A systematic review was performed using the remaining articles.

MAIN OUTCOME MEASURES

Patient data were extracted in order to determine the total number of patients, patients with a syndrome, types of syndromes, mean age at surgery, mean distraction distance, mean increase in intracranial volume, and complications.

RESULTS

18 articles representing 325 patients were analyzed. A syndrome was present in 68.6% of patients. The mean age at time of surgery was 22.1 months. Mean distraction amount was 24.7 mm. Mean increase in intracranial volume was 253.2 cm3. The overall complication rate was 32.2%, with the most common complications being surgical-site infection, hardware-related complications and delayed wound healing.

CONCLUSIONS

PCD is a powerful technique in the management of syndromic craniosynostosis, although complication rates are significantly higher than traditional remodeling techniques. Future studies should compare the effects of supratorcular and infratorcular osteotomies on intracranial volume, cosmesis and complications.

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.

Influence of Nonsyndromic Bicoronal Synostosis and Syndromic Influences on Orbit and Periorbital Malformation

BACKGROUND

Oculoorbital disproportion in patients with craniosynostosis has similarities and dissimilarities between syndromic and nonsyndromic cases. The authors hypothesized that these two conditions have specific individual influences as they relate to development of the orbital and periorbital skeletons.

METHODS

A total of 133 preoperative computed tomography scans (nonsyndromic bicoronal synostosis, n = 38; Apert syndrome bicoronal synostosis subtype, n = 33; Crouzon syndrome bicoronal synostosis subtype, n = 10; controls, n = 52) were included. Craniometric and volumetric analyses related to the orbit and periorbital anatomy were performed.

RESULTS

Orbital cavity volume was mildly restricted in nonsyndromic bicoronal synostosis (7 percent, p = 0.147), but more so in Apert and Crouzon syndromes [17 percent (p = 0.002) and 21 percent (p = 0.005), respectively]. The sphenoid side angle in Apert syndrome was wider than when compared to Crouzon syndrome (p = 0.043). The ethmoid side angle in Apert patients, however, was narrower (p = 0.066) than that in Crouzon patients. Maxilla anteroposterior length was more restricted in Apert syndrome than Crouzon syndrome (21 percent, p = 0.003) and nonsyndromic cases (26 percent, p < 0.001). The posterior nasal spine position was retruded in Crouzon syndrome (39 percent, p < 0.001), yet the anterior nasal spine position was similar in Apert and Crouzon syndromes.

CONCLUSIONS

Orbit and periorbital malformation in syndromic craniosynostosis is likely the combined influence of syndromic influences and premature suture fusion. Apert syndrome expanded the anteriorly contoured lateral orbital wall associated with bicoronal synostosis, whereas Crouzon syndrome had more infraorbital rim retrusion, resulting in more severe exorbitism. Apert syndrome developed maxillary hypoplasia, in addition to the maxillary retrusion, observed in Crouzon syndrome and nonsyndromic bicoronal synostosis patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Prevalence of Ocular Anomalies in Craniosynostosis: A Systematic Review and Meta-Analysis

Background: The aim of this study was to describe the ophthalmic abnormalities and their prevalence in craniosynostosis prior to craniofacial surgery. Methods: A systematic search was conducted on Medline OVID, Embase, Cochrane, Google Scholar, Web of Science Core Collection. Inclusion criteria were English papers, children aged <18 years with non-syndromic and syndromic craniosynostosis, case reports, case series, and case-control studies. A system of domains was established consisting of an anatomic and functional ophthalmic domain. A meta-analysis of single proportions was carried out using random effects model and pooled mean proportions with 95% confidence intervals (CI) were calculated. Results: Thirty-two papers analyzing 2027 patients were included. Strabismus was the most common anomaly in non-syndromic craniosynostosis: Horizontal strabismus was highest prevalent in unicoronal craniosynostosis (UCS) 19% (95% CI 9–32), followed by vertical strabismus 17% (95% CI 5–33). In syndromic craniosynostosis, horizontal strabismus was most prevalent in Crouzon syndrome 52% (95 CI 26–76), followed by Apert syndrome 50% (95% CI 42–58). Vertical strabismus was most prevalent in Saethre-Chotzen 60% followed by Muenke’s syndrome 36%. Furthermore, astigmatism was the second most reported outcome in non-syndromic craniosynostosis and highest prevalent in UCS 35% (95% CI 21–51). In syndromic craniosynostosis, astigmatism was most frequently seen in Crouzon syndrome 43% (95% CI 22–65), followed by Apert syndrome 34% (95% CI 14–58). Moreover, in syndromic craniosynostosis, 5–40% had a decrease in visual acuity (VA) ≤ 0.3 LogMAR in the better eye and 11–65% had a VA ≤ 0.3 LogMAR in at least one eye. Discussion: This review demonstrates the high prevalence of ocular anomalies in non-syndromic and syndromic craniosynostosis. A multidisciplinary and systematic approach is needed for the screening and optimal treatment of these conditions in a timely manner.

Cerebral cortex maldevelopment in syndromic craniosynostosis

AIM

To assess the relationship of surface area of the cerebral cortex to intracranial volume (ICV) in syndromic craniosynostosis.

METHOD

Records of 140 patients (64 males, 76 females; mean age 8y 6mo [SD 5y 6mo], range 1y 2mo-24y 2mo) with syndromic craniosynostosis were reviewed to include clinical and imaging data. Two hundred and three total magnetic resonance imaging (MRI) scans were evaluated in this study (148 patients with fibroblast growth factor receptor [FGFR], 19 patients with TWIST1, and 36 controls). MRIs were processed via FreeSurfer pipeline to determine total ICV and cortical surface area (CSA). Scaling coefficients were calculated from log-transformed data via mixed regression to account for multiple measurements, sex, syndrome, and age. Educational outcomes were reported by syndrome.

RESULTS

Mean ICV was greater in patients with FGFR (1519cm³ , SD 269cm³ , p=0.016) than in patients with TWIST1 (1304cm³ , SD 145cm³ ) or controls (1405cm³ , SD 158cm³ ). CSA was related to ICV by a scaling law with an exponent of 0.68 (95% confidence interval [CI] 0.61-0.76) in patients with FGFR compared to 0.81 (95% CI 0.50-1.12) in patients with TWIST1 and 0.77 (95% CI 0.61-0.93) in controls. Lobar analysis revealed reduced scaling in the parietal (0.50, 95% CI 0.42-0.59) and occipital (0.67, 95% CI 0.54-0.80) lobes of patients with FGFR compared with controls. Modified learning environments were needed more often in patients with FGFR.

INTERPRETATION

Despite adequate ICV in FGFR-mediated craniosynostosis, CSA development is reduced, indicating maldevelopment, particularly in parietal and occipital lobes. Modified education is also more common in patients with FGFR.

Morbidity Associated With Anterior Versus Posterior Cranial Vault Expansion for Early Treatment of Syndromic Craniosynostosis: A Systematic Review and Meta-Analysis

PURPOSE

The purpose of this systematic review and meta-analysis was to estimate and compare rates of unplanned reoperation and complications after undergoing either fronto-orbital advancement (anterior cranial vault expansion) or posterior cranial vault expansion as an early surgery in the management of syndromic craniosynostosis.

MATERIALS AND METHODS

A literature search was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant articles were identified in 2 electronic databases (PubMed and EMBASE) from the time of electronic publication to November 2020. Quality assessment and risk of bias were appraised using the Grading of Recommendations Assessment, Development and Evaluation system. A meta-analysis was performed comparing rates of reoperation and complications between participants who underwent anterior or posterior cranial vault expansion as an early surgery.

RESULTS

Of 1,373 screened records, 7 met inclusion criteria. Six were included in the meta-analysis. The studies that met inclusion criteria reported on 103 patients treated with anterior techniques and 72 patients treated with a posterior approach. Anterior cranial vault expansion was associated with significantly higher rates of reoperation (Peto odds ratio = 2.83; 95% confidence interval = 1.19, 6.74, P = .02) and complications (Peto odds ratio = 2.61; 95% confidence interval = 1.12, 6.12, P = .03) than posterior cranial vault expansion.

CONCLUSIONS

Both anterior and posterior approaches are suitable options in the treatment of syndromic craniosynostosis depending on patient-specific factors. Anterior cranial vault expansion was associated with higher rates of unplanned reoperation and complications than posterior techniques in this analysis. Because of the paucity of literature which met inclusion criteria, this study was not able to assess critical outcome variables such as distance distracted/volumetric expansion, estimated blood loss, and cost. Larger studies evaluating both techniques under multiple institutions with long-term follow-up are indicated.

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).

Posterior Cranial Vault Distraction Osteogenesis Utilizing a Posterior-Superior Distraction Vector in the Treatment of Mercedes Benz Pattern Craniosynostosis

ABSTRACT

Bilateral lambdoid and sagittal synostosis, or Mercedes Benz Syndrome, is a rare complex craniosynostosis resulting in frontal bossing, a tapered posterior fossa, and an anteriorly displaced cranial vertex. Its ideal surgical correction must result in posterior expansion, skull elongation, and caudal repositioning of the vertex. We present a craniometric analysis of skull changes with posterior-superior distraction and introduce a novel craniometric measure: vertex position. In this study, a retrospective review was performed to analyze outcomes of posterior cranial vault distraction osteogenesis (PVDO) using a posterior-superior distraction vector from 2016 to 2019. Cranial vertex position was measured as a fraction of the occipitofrontal diameter from rostral to caudal (0-1.0). Four patients underwent PVDO at mean age 10.61 ± 3.16 months utilizing a posterior-superior distraction vector. Linear distraction distance averaged 30.30 ± 0.90 mm with a mean consolidation period of 3.98 ± 0.72 months. Mean corrected change in intra-cranial volume was 236.30 ± 3.71 mL, at an average rate of 7.81 ± 2.00 mL/mm of distraction. Increases in anterior cranial height (7.83 ± 2.51 mm), middle cranial height (8.43 ± 4.21 mm), posterior cranial height (13.15 ± 7.45 mm), and posterior cranial fossa height (21.99 ± 8.55 mm) were observed. Cranial vertex demonstrated a mean posterior movement of 0.18 ± 0.13. PVDO utilizing a posterior-superior distraction vector for management of nonsyndromic bilateral lambdoid and sagittal synostosis effectively increases intracranial volume and height and provides an esthetic outcome with posterior movement of the cranial vertex.

Prenatal diagnosis of Pfeiffer syndrome and role of three-dimensional ultrasound: case report and review of literature

Purpose/aim of the study: We report a rare case of autosomal dominant genetic syndrome "Pfeiffer", which is part of the group of acrocephalosyndactyly, with an annual incidence <1/100,000. Three forms are known. Type I is the less common form and it is characterized by moderate-severe mediofacial hypoplasia usually with normal cognitive development. Conversely, types 2 and 3 are more common and they are associated with more severe signs and complications with a more unfavorable prognosis. The type 3 form due to the presence of a cloverleaf skull distinguishes type 2.Materials and methods: Thirty-eight-year-old primigravida was referred to our center, at 28 weeks of gestation due to borderline ventriculomegaly, macrocrania, and a short femur. First trimester screening for chromosomopathies and CF-DNA was low risk; II trimester screening ultrasound showed the presence of "short femur" and macrocrania.Result: Our ultrasound evaluation, assisted by 3D ultrasound, showed cloverleaf skull, turricephaly, moderate ventriculomegaly (13 mm), hypertelorism and exophthalmos, low ear implantation, mild rhizomelia. Ultrasound depicts Pfeiffer syndrome or other acrocephalosyndactyly syndromes (Apert syndromes, Saethre-Chotzen) or other syndromic forms of craniosynostosis like Crouzon syndrome. The NGS panel for molecular analysis of genes involved in skeletal dysplasias showed the mutation of the FGFR2 gene, de novo.Conclusions: Using three-dimensional (3D) ultrasound, it is easier to distinguish rare syndromes characterized by facial dysmorphisms such as exophthalmos, mediofacial hypoplasia, and craniosynostosis.

Cephalocranial Disproportionate Fossa Volume and Normal Skull Base Angle in Pfeiffer Syndrome

BACKGROUND

Pfeiffer syndrome is a rare syndromic craniosynostosis disorder, with a wide range of clinical manifestations. This study aims to investigate the structural abnormalities of cranial fossa and skull base development in Pfeiffer patients, to provide an anatomic basis for surgical interventions.

METHOD

Thirty preoperative CT scans of Pfeiffer syndrome patients were compared to 35 normal controls. Subgroup comparisons, related to differing suture synostosis, were performed.

RESULTS

Overall, the volume of anterior and middle cranial fossae in Pfeiffer patients were increased by 31% (P < 0.001) and 19% (P = 0.004), versus controls. Volume of the posterior fossa in Pfeiffer patients was reduced by 14% (P = 0.026). When only associated with bicoronal synostosis, Pfeiffer syndrome patients developed enlarged anterior (68%, P = 0.001) and middle (40%, P = 0.031) fossae. However, sagittal synostosis cases only developed an enlarged anterior fossa (47%, P < 0.001). The patients with solely bilateral squamosal synostosis, developed simultaneous reduced anterior, middle and posterior cranial fossae volume (all P ≤ 0.002). The overall skull base angulation, measured on both intracranial and subcranial surfaces, grew normally.

CONCLUSION

Enlarged anterior cranial fossae in Pfeiffer syndrome children is evident, except for the squamosal synostosis cases which developed reduced volume in all fossae. Volume of the middle cranial fossa is influenced by associated cranial vault suture synostosis, specifically, sagittal synostosis cases develop normal middle fossa volume, while the bicoronal cases develop increased middle fossa volume. Posterior cranial fossa development is restricted by shortened posterior cranial base length. Surgical intervention in Pfeiffer syndrome patients optimally should be indexed to different suture synostosis.

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.

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 "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.

Apert syndrome: Cranial procedures and brain malformations in a series of patients

Background:

Apert syndrome is one of the most severe craniofacial disorders. This study aims to describe the craniofacial surgeries and central nervous system malformations of a cohort of children with Apert syndrome treated in the past 20 years and to compare these data with previously published data.

Methods:

Retrospective analysis of a series of patients with Apert syndrome treated between 1999 and 2019 in our hospital. Information was analyzed regarding craniofacial procedures, hydrocephalus and presence of shunts, Chiari malformation Type 1, and other brain malformations such as corpus callosum and septum pellucidum anomalies.

Results:

Thirty-seven patients were studied. Ventriculoperitoneal shunt prevalence was 24.3%, and 8.1% of patients required decompressive surgery for Chiari malformation. All of them needed at least one cranial vault remodeling procedure. The median age for this procedure was 8 months. In 69.7% of patients, the first cranial vault intervention was performed in the fronto-orbital region. In 36.4% of patients, a midface advancement had been performed at the time of this review, although this proportion was very dependent on the follow-up period and the age of the patients. The median age for the midface advancement procedure was 5.25 years. Anomalies of the corpus callosum and the septum pellucidum were reported in 43.2% and 59.5% of patients, respectively.

Conclusion:

Apert syndrome is a type of syndromic craniosynostosis, and patients usually require one or more cranial and facial surgeries. In comparison with other syndromic craniosynostosis types, Apert syndrome less frequently requires a VP shunt or treatment for a Chiari malformation.

Neurological deficits are present in syndromic craniosynostosis patients with and without tonsillar herniation

BACKGROUND

Children with syndromic craniosynostosis (sCS) have a higher incidence of cerebellar tonsillar herniation (TH) than the general population. In the general population, TH ≥ 5 mm below the foramen magnum is associated with typical neurological deficits but, in sCS, we do not know whether this degree of TH is required before such deficits occur.

OBJECTIVE

This prospective cohort study aimed to determine the association between findings on neurological assessment and cerebellar tonsillar position.

METHODS

Magnetic resonance imaging (MRI) was used to determine TH ≥ 5 mm and the presence of syringomyelia. In regard to the outcome of neurological deficits, these were categorized according to: A, cerebellar function; B, cranial nerve abnormalities; and C, sensory or motor dysfunction.

RESULTS

Twenty of 63 patients with sCS (32% [95% confidence interval 21-45%]) had TH ≥ 5 mm and/or syringomyelia. There was no significant difference in proportion between individual forms of sCS: 16/34 Crouzon, 2/11 Muenke, 2/12 Apert, and 0/7 Saethre-Chotzen patients. Neurological deficits were prevalent (73% [95% confidence interval 60-83%]), and as frequent in patients with TH ≥ 5 mm and/or syringomyelia as those without. Surgery occurred in 3 patients overall, and only in Crouzon patients.

CONCLUSION

Determining the effect of TH ≥ 5 mm on neurologic functioning in sCS patients is used to better determine when surgical intervention is warranted. However, we have found that neurological deficits are prevalent in sCS patients, irrespective of cerebellar tonsillar position, suggesting that such findings are developmental and, in part, syndrome-specific central nervous system features.

Cranial Fossa Volume and Morphology Development in Apert Syndrome

BACKGROUND

Apert syndrome causes normal or enlarged intracranial volume overall as patients grow. This study aimed to trace the segmental anterior, middle, and posterior cranial fossae volume and structural morphology in these patients, to help discern a more focused and individualized surgical treatment plan for patients with Apert syndrome.

METHODS

This study included 82 preoperative computed tomographic scans (Apert, n = 32; control, n = 50) divided into five age-related subgroups. The scans were measured using image processing and three-dimensional modeling software.

RESULTS

The middle cranial fossa volume was increased and was the earliest change noted. It was increased by 45 percent (p = 0.023) compared with controls before 6 months of age and remained increased into adulthood (161 percent, p = 0.016), with gradually increasing severity. The anterior and posterior cranial fossae volumes also increased, by 35 percent (p = 0.032) and 39 percent (p = 0.007), respectively. Increased depth of cranial fossae contributed most to the increase in volumes of patients with Apert syndrome, with correlation coefficients of 0.799, 0.908, and 0.888 for anterior, middle, and posterior cranial fossa, respectively. The intracranial volume was increased 12 percent (p = 0.098) across the entire test age range (0 to 26 years old), but only had statistical significance during the age range of 6 to 18 years (22 percent, p = 0.001).

CONCLUSIONS

Malformation of the middle cranial fossa is an early, perhaps the initial, pivotal cranial morphologic change in Apert syndrome. Increased cranial fossae depth is an inherent characteristic of the maldevelopment. Normalization of cranial volume and circumference overall may not achieve a normal skull structure, as it does not correct regional craniocerebral disproportion.

Analysis of Airway and Midface in Crouzon Syndromes

BACKGROUND

Crouzon syndrome is associated with severe respiratory impairment of the upper airway due in part to midfacial dysmorphology. We calculated the distinctive nasal diameter and pharyngeal airway volume in patients with Crouzon syndrome and compared them with age-matched control subjects.

METHODS

Children with computed tomography scans in the absence of surgical intervention were included. Computed tomography scans were digitized and manipulated using Surgicase CMF (Materialise). Craniometric data relating to the midface and airway were collected. For all linear measurements, mean percent increases or decreases were calculated relative to the size of control subjects, and volumetric assessment of the airway was tabulated. Statistical analysis was performed using t test.

RESULTS

Twenty-six computed tomography scans were included (control n = 17, Crouzon n = 9). All children were in early mixed dentition. Pharyngeal airway volume was decreased in patients with Crouzon syndrome relative to control subjects by 46% (P = 0.003). The distance from the posterior tongue to the posterior pharyngeal wall decreased 31% when comparing the Crouzon group versus the control (P = 0.04).

CONCLUSIONS

Three-dimensional analysis revealed notably decreased pharyngeal and nasal airway volumes in patients with Crouzon syndrome, but nasal bone tissue and soft tissue measurements showed very little change between patients and control subjects.

Cortical Thickness in Crouzon-Pfeiffer Syndrome: Findings in Relation to Primary Cranial Vault Expansion

Background

Episodes of intracranial hypertension are associated with reductions in cerebral cortical thickness (CT) in syndromic craniosynostosis. Here we focus on Crouzon-Pfeiffer syndrome patients to measure CT and evaluate associations with type of primary cranial vault expansion and synostosis pattern.

Methods

Records from 34 Crouzon-Pfeiffer patients were reviewed along with MRI data on CT and intracranial volume to examine associations. Patients were grouped according to initial cranial vault expansion (frontal/occipital). Data were analyzed by multiple linear regression controlled for age and brain volume to determine an association between global/lobar CT and vault expansion type. Synostosis pattern effect sizes on global/lobar CT were calculated as secondary outcomes.

Results

Occipital expansion patients demonstrated 0.02 mm thicker cortex globally (P = 0.81) with regional findings, including: thicker cortex in frontal (0.02 mm, P = 0.77), parietal (0.06 mm, P = 0.44) and occipital (0.04 mm, P = 0.54) regions; and thinner cortex in temporal (-0.03 mm, P = 0.69), cingulate (-0.04 mm, P = 0.785), and, insula (-0.09 mm, P = 0.51) regions. Greatest effect sizes were observed between left lambdoid synostosis and the right cingulate (d = -1.00) and right lambdoid synostosis and the left cingulate (d = -1.23). Left and right coronal synostosis yielded effect sizes of d = -0.56 and d = -0.42 on respective frontal lobes.

Conclusions

Both frontal and occipital primary cranial vault expansions correlate to similar regional CT in Crouzon-Pfeiffer patients. Lambdoid synostosis appears to be associated with cortical thinning, particularly in the cingulate gyri.

Muenke syndrome: long-term outcome of a syndrome-specific treatment protocol

OBJECTIVE

The authors evaluated the long-term outcome of their treatment protocol for Muenke syndrome, which includes a single craniofacial procedure.

METHODS

This was a prospective observational cohort study of Muenke syndrome patients who underwent surgery for craniosynostosis within the first year of life. Symptoms and determinants of intracranial hypertension were evaluated by longitudinal monitoring of the presence of papilledema (fundoscopy), obstructive sleep apnea (OSA; with polysomnography), cerebellar tonsillar herniation (MRI studies), ventricular size (MRI and CT studies), and skull growth (occipital frontal head circumference [OFC]). Other evaluated factors included hearing, speech, and ophthalmological outcomes.

RESULTS

The study included 38 patients; 36 patients underwent fronto-supraorbital advancement. The median age at last follow-up was 13.2 years (range 1.3-24.4 years). Three patients had papilledema, which was related to ophthalmological disorders in 2 patients. Three patients had mild OSA. Three patients had a Chiari I malformation, and tonsillar descent < 5 mm was present in 6 patients. Tonsillar position was unrelated to papilledema, ventricular size, or restricted skull growth. Ten patients had ventriculomegaly, and the OFC growth curve deflected in 3 patients. Twenty-two patients had hearing loss. Refraction anomalies were diagnosed in 14/15 patients measured at ≥ 8 years of age.

CONCLUSIONS

Patients with Muenke syndrome treated with a single fronto-supraorbital advancement in their first year of life rarely develop signs of intracranial hypertension, in accordance with the very low prevalence of its causative factors (OSA, hydrocephalus, and restricted skull growth). This illustrates that there is no need for a routine second craniofacial procedure. Patient follow-up should focus on visual assessment and speech and hearing 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.

Use of Multidirectional Cranial Distraction Osteogenesis for Cranial Expansion in Syndromic Craniosynostosis

Patients with syndromic craniosynostosis often require a large amount of cranial expansion to avoid intracranial hypertension, but the surgical procedure remains controversial. A patient of severe syndromic craniosynostosis with multiple bony defects and anomalous venous drainage at the occipital region was treated by multidirectional cranial distraction osteogenesis (MCDO) at the age of 8 months. Distraction started 5 days after surgery and ceased on postoperative day 16. The distraction devices were removed 27 days after completing distraction. After device removal, the increase of intracranial volume was 155 ml and the cephalic index was improved from 115.5 to 100.5. The resultant cranial shape was well maintained with minimal relapse at postoperative 9 months. In cases of syndromic craniosynostosis with multiple bony defects and/or anomalous venous drainage at the occipital region, expansion of the anterior cranium by MCDO is a viable alternative to conventional methods.

What's New in Syndromic Craniosynostosis Surgery?

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the role of prenatal screening and counseling of parents of unborn children with syndromic craniosynostosis. 2. Recognize the genetic abnormalities, craniofacial phenotype, associated anomalies, and challenges associated with each of the five major forms of syndromic craniosynostosis. 3. Identify the pros and cons associated with timing and types of cranial vault remodeling techniques in this patient population. 4. Understand the risks and benefits associated with midface advancement with Le Fort III, Le Fort II plus zygomatic repositioning, monobloc, and facial bipartition. 5. Understand the important role of psychological counseling throughout childhood in this at-risk group.

SUMMARY

Crouzon, Apert, Pfeiffer, Muenke, and Saethre-Chotzen syndromes are the five most common forms of syndromic craniosynostosis. Although each has different genetic underpinnings and associated anomalies, their hallmark finding is turribrachycephaly most often associated with bicoronal craniosynostosis. The role of prenatal screening and counseling is growing, with caregivers becoming involved before birth. Multidisciplinary care from birth onward involves craniofacial plastic surgeons, neurosurgeons, otolaryngologists, ophthalmologists, orthodontists, anesthesiologists, psychologists, speech therapists, and geneticists. Early partial, or regional, craniectomy may be urgently indicated in multisuture cases with signs of increased intracranial pressure. Others may be managed successfully with posterior cranial vault distraction, middle vault expansion, or fronto-orbital advancement. Some authors have advocated early monobloc advancement for those patients who require acute airway intervention and globe protection, although the risks of these procedures are high. Many patients will require midfacial advancement with a Le Fort III, Le Fort II plus zygomatic repositioning, monobloc, or facial bipartition. The indications, risks, and benefits for each midfacial procedure must be considered, as this step in the treatment algorithm may carry the greatest functional and aesthetic benefits but also the potential for the greatest morbidity. At the culmination of facial growth, it is not uncommon for patients to require conventional orthognathic surgery and other bony contouring and soft-tissue procedures. Finally, an understanding of the psychological aspects of craniofacial difference, both in affected individuals and in their families, is essential to a successful, holistic approach.

Apert syndrome: Surgical outcomes and perspectives

PURPOSE

Apert syndrome is a rare congenital malformation with severe craniofacial anomalies. The aim of this study was to review the outcomes of craniofacial and neurosurgical interventions in Apert syndrome patients treated at a single institution.

MATERIALS AND METHODS

A retrospective review of all patient records with a diagnosis of Apert syndrome assessed and managed in the Australian Craniofacial Unit (ACFU) from 1985 to 2013 was conducted.

RESULTS

A total of 94 patients were identified, and 130 transcranial procedures were performed. Of the patients, 83 underwent a fronto-orbital advancement (FOA) as their primary procedure, and 18 patients also underwent a posterior vault procedure. Twenty patients underwent a fronto-facial monobloc advancement. Overall, 70% of patients underwent at least 2 transcranial procedures. Shunts were inserted in 2 patients preoperatively and in 5 patients postoperatively for cerebrospinal fluid (CSF) leaks or acute hydrocephalus. Re-do FOAs were performed in 8 patients. Patients who underwent an FOA at the age of more than 18 months had no recurrence of raised intracranial pressure (ICP). Of 18 patients who also underwent a posterior vault procedure, 1 patient had recurrence of raised ICP. Midfacial surgery was performed early if there was evidence of obstructive sleep apnoea (OSA), but delayed midfacial surgery was preferred. Complications were reported in 18% of procedures. The most common complications were CSF leaks and acute hydrocephalus.

CONCLUSION

Shunting is rarely required in Apert syndrome patients, confirming a predominantly nonprogressive ventriculomegaly. FOA appears to be a more stable procedure when performed at an age of more than 18 months. Undergoing a posterior vault procedure may reduce the risk of recurrent raised ICP and lead to fewer transcranial procedures needed in childhood. Midfacial surgery should be delayed until adolescence where there is no evidence of OSA, psychological disturbance, or complications of exorbitism. Complications are rare when these patients are treated by an experienced craniofacial team.