Craniosynostosis of the lambdoid suture

Long-term outcomes of nonsyndromic isolated unilateral lambdoid craniosynostosis

This study combined qualitative and quantitative approaches to evaluate outcomes of isolated nonsyndromic unilateral lambdoid synostosis at the Children's Hospital of Philadelphia. Volumetric, linear, and angular analyses were performed on long-term postoperative and normal control scans. Preoperative and postoperative clinical photographs were evaluated for the presence of dysmorphic frontofacial features. Among 26 included patients, median age of surgery was 10 months and mean postoperative follow-up was 5.9 ± 5.7 years. Two (7.7%) patients underwent secondary cranial vault procedures. At most recent follow-up, 2 (7.7%) subjects reported intermittent headaches. Twenty (90.9%) of 22 patients were assigned Whitaker grade I. Among 9 subjects with long-term imaging at age 11.5 ± 5.3, posterior vault asymmetry, posterior fossa deflection angle, cranial base angle, and ear position asymmetry all remained greater than in the control group. Of subjects included in the frontofacial feature analysis (n = 10), 50% had resolution of all dysmorphic frontofacial features present preoperatively. Overall, most subjects who underwent PVR did not require revisional surgery and had good outcomes both aesthetically and functionally. Despite residual abnormalities in the cranial base and posterior vault, most had resolution of parietal bossing and facial scoliosis. Ear position asymmetry was the most common dysmorphic feature at long-term follow-up.

Calvarial Vault Remodeling Technique for Lambdoid Craniosynostosis

SUMMARY

Premature fusion of the lambdoid suture is the most uncommon single-suture synostosis. It presents with a classic "windswept" appearance, a trapezoid-shaped head, and significant skull asymmetry notable for an ipsilateral mastoid bulge and contralateral frontal bossing. Because of the rarity of lambdoid synostosis, little is known about optimal techniques for its treatment. In particular, the proximity of the lambdoid suture to critical intracranial structures such as the superior sagittal and transverse sinuses represents a potential for significant intraoperative bleeding. Prior work has shown that parietal asymmetry persists after repair in these cases. In this article, the authors present a technique for the treatment of unilateral lambdoid craniosynostosis along with two representative cases. This calvarial vault remodeling technique requires the removal of both ipsilateral and contralateral parietal bones. These are moved across hemispheres and reinset on opposite sides to help correct the parietal asymmetry. Obliquely orientated barrel stave osteotomies are performed to provide a safe mechanism for correction of occipital flattening. The authors' early results show improvement in correction of volume asymmetry 1 year postoperatively relative to patients treated with prior calvarial vault remodeling techniques. The authors believe the technique presented here corrects the windswept appearance in patients with lambdoid craniosynostosis and also reduces the potential for complications. Further work will be necessary to confirm this technique's long-term efficacy in a larger cohort.

Exploring Different Management Modalities of Nonsyndromic Craniosynostosis

Craniosynostosis is an atypical skull shape characterized by the premature fusion of cranial sutures. It is one of the most common congenital anomalies encountered by craniofacial surgeons, with a prevalence of one in every 2000-2500 births. It is classified into two main types: syndromic and nonsyndromic. In syndromic, the patient presents with other abnormalities involving the trunk, face, or extremities. While in nonsyndromic the only anomy is the premature fusion, which usually involves one suture; the most common subtypes are unicoronal, sagittal, bicoronal, metopic, and lambdoid. As a consequence, premature fusion before its natural time restricts the space for the brain to grow, increases intracranial pressure, causes damage to the brain tissue, and affects the development of the child. This review comprehensively provides a detailed overview of nonsyndromic craniosynostosis and aims to highlight the importance of early and accurate diagnosis, and determining the most suitable intervention, whether surgical or conservative modalities. The optimal treatment approach produces the most favorable aesthetic and functional outcomes.

Cognitive Development in Lambdoid Craniosynostosis: A Systematic Review and Meta-Analysis

OBJECTIVE

Lambdoid craniosynostosis affects approximately 1 in 33 000 live births per year, and surgical correction is often sought in order to achieve normocephaly and allow for adequate brain growth. However, the effects of lambdoid synostosis and its treatment on cognitive development are unknown.

DESIGN

Systematic review and meta-analysis.

PATIENTS, PARTICIPANTS

A systematic review of Ovid Medline, Embase, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov was conducted in January 2022. Included studies assessed cognitive development of patients with nonsyndromic unilateral lambdoid craniosynostosis.

MAIN OUTCOME MEASURES

Results of developmental tests were compared to normative data or controls to generate Hedges' g for meta-analysis.

RESULTS

Nine studies met the inclusion criteria. Meta-analysis of 3 studies describing general cognition showed that cases scored significantly lower than their peers, but within 1 standard deviation (g = 0.37, 95% CI [-0.64, -0.10], P = .01). Meta-analysis of verbal and psychomotor development showed no significant differences in children with lambdoid synostosis. Studies were of fair quality and had moderate-to-high heterogeneity.

CONCLUSIONS

Patients with lambdoid craniosynostosis may score slightly below average on tests of general cognition in comparison to normal controls, but results in other domains are variable. Analyses were limited by small sample sizes. Multidisciplinary care and involvement of a child psychologist may be helpful in identifying areas of concern and providing adequate scholastic support. Further research recruiting larger cohorts will be necessary to confirm these findings and extend them to other developmental domains such as attention and executive function.

Spring-Assisted Surgery of Unilambdoid Craniosynostosis

Craniosynostosis is traditionally treated with extensive cranial vault reconstructions (CVRs). Although less invasive techniques, such as endoscopic strip craniectomy with postoperative helmet therapy, have been successful, they also present difficulties. An alternative method is distraction osteogenesis using either manually controlled devices or specially designed springs. In this study, the authors provide the first comparison of spring-assisted surgery (SAS) with CVR for the treatment of unilambdoid synostosis (ULS). Fourteen consecutive patients (8 CVR and 6 SAS) treated for ULS at Sahlgrenska University Hospital between 2005 and 2018 were included. Skull shape and deviations were evaluated using previously defined measurement points on 3-dimensional computed tomography scans preoperatively, at spring removal, and at 3 years of age. Posterior and middle cranial fossa (PCF and MCF, respectively), skull-base cant, facial twist, and mastoid bulge (MB) were measured, and clinical data were obtained from chart reviews. The results indicated that at the 3-year follow-up, PCF, MCF, and MB improved in both groups, with no significant difference in outcome observed between methods. In the SAS group, duration of operation [61±27 min (mean±SD)] and perioperative bleeding (3.5±2.8 mL/kg body weight) were both significantly lower relative to the CVR group (P<0.05). These findings showed that both SAS and CVR resulted in similar improvements in treating ULS, although neither produced complete normalization of skull shape. The results suggest that early diagnosis and operation allow less extensive SAS to be performed without adversely affecting the results.

Atypical sagittal suture craniosynostosis: pathological considerations for early closure of the anterior part of the sagittal suture

Sagittal suture synostosis is one of the most common craniosynostoses and is often diagnosed by characteristic narrow and long skull shape, scaphocephaly. However, some patients with sagittal suture synostosis do not present with typical scaphocephaly, making early diagnosis difficult. In this study, five cases of characteristic skull deformity showing a narrowing of the cranium posterior to the coronal suture on computed tomography (CT) are presented. The three older children presented with papilledema and intellectual disability and a closed sagittal suture on CT. The two infant cases were diagnosed with the characteristic cranial deformities with aggravation of the deformity over time, but sagittal suture closure was not evident on CT. All patients underwent cranial remodeling surgery. In the two infant cases, the histopathological findings showed that the anterior part of the sagittal suture was firmly fused with fibrous tissue without bony fusion. These findings suggested that narrowing of the cranium posterior to the coronal suture might be due to functional fusion of the anterior portion of the sagittal suture prior to bony fusion. In an infant presenting with such a deformity that shows aggravation of the deformity over time, surgical treatment should be considered.

Data-driven cranial suture growth model enables predicting phenotypes of craniosynostosis

We present the first data-driven pediatric model that explains cranial sutural growth in the pediatric population. We segmented the cranial bones in the neurocranium from the cross-sectional CT images of 2068 normative subjects (age 0-10 years), and we used a 2D manifold-based cranial representation to establish local anatomical correspondences between subjects guided by the location of the cranial sutures. We designed a diffeomorphic spatiotemporal model of cranial bone development as a function of local sutural growth rates, and we inferred its parameters statistically from our cross-sectional dataset. We used the constructed model to predict growth for 51 independent normative patients who had longitudinal images. Moreover, we used our model to simulate the phenotypes of single suture craniosynostosis, which we compared to the observations from 212 patients. We also evaluated the accuracy predicting personalized cranial growth for 10 patients with craniosynostosis who had pre-surgical longitudinal images. Unlike existing statistical and simulation methods, our model was inferred from real image observations, explains cranial bone expansion and displacement as a consequence of sutural growth and it can simulate craniosynostosis. This pediatric cranial suture growth model constitutes a necessary tool to study abnormal development in the presence of cranial suture pathology.

Perioperative Comparison Between Open Cranial Vault Remodeling and Distraction Osteogenesis for Unilateral Lambdoid Craniosynostosis

There are multiple treatment options for unilateral lambdoid craniosynostosis (ULS) including open posterior cranial vault remodeling (OCVR) and distraction osteogenesis (DO). There is a paucity of data comparing these techniques in the treatment of ULS. This study compared the perioperative characteristics of these interventions for patients with ULS. An IRB-approved chart review was performed from January 1999 to November 2018 at a single institution. Inclusion criteria included the diagnosis of ULS, treatment with either OCVR or DO using a posterior rotational flap technique, and a minimum 1-year follow-up. Seventeen patients met the inclusion criteria (12 OCVR and 5 DO). Patients in each cohort were found to have a similar distribution in sex, age at the time of surgery, synostosis laterality, weight, and length of follow-up. There was no significant difference in mean estimated blood loss/kg, surgical time, or transfusion requirements between cohorts. Distraction osteogenesis patients had a longer mean hospital length of stay (3.4 +/- 0.6 d versus 2.0 +/- 0.6 d, P = 0.0004). All patients were admitted to the surgical ward postoperatively. In the OCVR cohort, complications included 1 dural tear, 1 surgical site infection, and 2 reoperations. In the DO cohort, 1 patient had a distraction site infection, treated with antibiotics. There was no significant difference in estimated blood loss, volume of blood transfusion, or surgical time between OCVR and DO. Patients who underwent OCVR had a higher incidence of postoperative complications and the need for reoperation. This data provides insight into the perioperative differences between OCVR and DO in patients with ULS.

Utilizing Computer-Assisted Design and Virtual Surgical Planning for Correction of Unilateral Lambdoid Synostosis

Unilateral lambdoid synostosis is the rarest form of single-suture craniosynostosis. Although various surgical approaches have been described, cranial vault remodeling remains the predominant approach. To aid in surgical planning, preoperative virtual surgical modeling using a patient's presenting computed tomography scan can be used to increase reconstructive precision and to reduce operative time. Presented is a 7-month-old male with unilateral lambdoid synostosis who underwent medically modeled cranial vault reconstruction.

Premature Fusion of the Posterior Intraoccipital Synchondrosis, A Minor Suture Mimic of Lambdoid Craniosynostosis

ABSTRACT

The posterior intraoccipital synchondrosis (PIOS) is a cartilaginous division separating the exoccipital and supraoccipital bones, allowing for flexibility of the cranial base at birth and which later ossifies in adolescence. The authors report a case of right PIOS synostosis that resembled right lambdoid synostosis, with left occipital bossing in a healthy, six-month-old female with an unremarkable birth history and no antecedent trauma. An initial referral was made from the pediatrician to oncology because of a concern over the presence and growth of a possible mass at the left occiput. Over 8 months, this mass grew and became more firm, accompanied by left occipital bossing and right occipital flattening. A computed tomography was obtained, which demonstrated the fusion of the PIOS, prompting a referral to plastic surgery. Cranial vault remodeling with switch cranioplasty was performed at age 14 months, complicated only by a superficial infection along the suture line. There are exceedingly few reports of PIOS synostosis, with occipital osteodiastasis related to birth trauma as the only prior explanation for this condition. With no birth trauma and delayed onset, our case likely represents idiopathic PIOS synostosis. With the many similarities in presentation, the surgical approaches commonly used for lambdoid synostosis, particularly switch cranioplasty, are suitable solutions to PIO synchondrosis with optimal functional and aesthetic outcomes.

The clinical manifestations, molecular mechanisms and treatment of craniosynostosis

Craniosynostosis is a major congenital craniofacial disorder characterized by the premature fusion of cranial suture(s). Patients with severe craniosynostosis often have impairments in hearing, vision, intracranial pressure and/or neurocognitive functions. Craniosynostosis can result from mutations, chromosomal abnormalities or adverse environmental effects, and can occur in isolation or in association with numerous syndromes. To date, surgical correction remains the primary treatment for craniosynostosis, but it is associated with complications and with the potential for re-synostosis. There is, therefore, a strong unmet need for new therapies. Here, we provide a comprehensive review of our current understanding of craniosynostosis, including typical craniosynostosis types, their clinical manifestations, cranial suture development, and genetic and environmental causes. Based on studies from animal models, we present a framework for understanding the pathogenesis of craniosynostosis, with an emphasis on the loss of postnatal suture mesenchymal stem cells as an emerging disease-driving mechanism. We evaluate emerging treatment options and highlight the potential of mesenchymal stem cell-based suture regeneration as a therapeutic approach for craniosynostosis.

Management of Lambdoid Craniosynostosis: A Comprehensive and Systematic Review

BACKGROUND

Craniosynostosis is a condition characterized by the premature fusion of 2 or more skull bones. Craniosynostosis of the lambdoid suture is one of the rarest forms, accounting for 1-4% of all craniosynostoses. Documented cases are separated into simple (single suture), complex (bilateral), and associated with adjacent synostoses ("Mercedes Benz" Pattern) or syndromes (i.e., Crouzon, Sathre-Chotzen, Antley-Bixler). This condition can manifest phenotypic deformities and neurological sequelae that can lead to impaired cognitive function if improperly treated or left undiagnosed. Preferred surgical techniques have varied over time but all maintain the common goals of establishing proper head shape and preventing of complications that could contribute to aforementioned sequelae.

SUMMARY

This comprehensive review highlights demographic distributions, embryological development, pathogenesis, clinical presentation, neurological sequelae, radiologic findings, surgical techniques, surgical outcomes, and postoperative considerations of patients with lambdoid craniosynostosis presentation. In addition, a systematic review was conducted to explore the operative management of lambdoid craniosynostosis using PubMed, Embase, and Scopus databases, with 38 articles included after screening. Key Messages: Due to a low volume of published cases, diagnosis and treatment can vary. Large overlap in presentation can occur in patients that display lambdoid craniosynostosis and posterior plagiocephaly, furthering the need for comprehensive analysis. Possessing the knowledge and tools to properly assess patients with lambdoid craniosynostosis will allow for more precise care and improved outcomes.

Conventional posterior cranial vault expansion: indications and results-review of the literature

In the late 1980s, craniofacial surgery units reported suboptimal cosmetic results, cranial volume restriction, and intracranial hypertension after anterior cranial vault remodeling in bilateral coronal synostosis associated with severe brachyturricephaly. A possible explanation was a severe associated growth restriction of the posterior calvaria with radiological synostosis at the lambda sutures. "Conventional" or "fixed" posterior cranial vault expansion techniques were developed to address these limitations, sometimes as the first surgical step in a two-staged protocol of total calvarial reconstruction, combined with suboccipital decompression in cases of symptomatic cerebellar tonsillar herniation or, more easily, to resolve the characteristic occipital flattening of lambdoid synostosis. Various surgical approaches have been described; however, the indications for and timing of surgical treatment and postoperative evaluation of results still remain controversial. Although more invasive, conventional posterior cranial vault expansion has proven to be safe and offers a remodeled and protective bony vault immediately after surgery, but the underlying cranial base malformation remained untreated, with implications in the postoperative growth of the facial skeleton. Overcorrection, rigid stabilization, and grafting are also concerns to be addressed.

Clinical Features and the Use of Three-Dimensional Imaging for Unilateral Lambdoid Synostosis

INTRODUCTION

True isolated lambdoid craniosynostosis is rare. It requires corrective surgery to prevent intracranial pressure and aesthetic stigma by significant dyscrania. We summarize our case series for lambdoid craniosynostosis outlining the pathophysiology, clinical findings and surgical approaches and outcomes.

METHODOLOGY

A retrospective analysis of our data from 2010 to 2020 summarized our cases of true lambdoid synostosis. We have used the medical notes and the radiological findings from computed tomography scans to summarize a case series of isolated lambdoid synostosis.

RESULTS

Our case series demonstrated 7 patients with true isolated lambdoid craniosynostosis. In most cases surgical intervention in the form of posterior cranial vault remodeling utilizing a bandeau, based on occipital advancement techniques, has demonstrated the most consistently favorable aesthetic outcome.

CONCLUSIONS

Surgical referral to a craniofacial center should be sought early in difficult to diagnose cases. Although rare, surgical intervention is indicated to correct potentially increased intracranial pressure and to ameliorate cranial dyscrania.

Planning and Osteotomy Designs in the Correction of Single-Suture Craniosynostosis

BACKGROUND

Craniosynostosis is among the abnormalities that are more commonly encountered by craniofacial surgeons. Although the overall concepts for cranial vault remodeling are relatively simple, osteotomy designs and methods for calvarial rearrangement are highly varied. In this work, we present a summary of the known designs for correction of single-suture craniosynostosis.

METHODS

A review of the literature was performed of the more frequently used osteotomy designs for single-suture craniosynostosis, as well as their reported results and outcomes. Also reviewed are some of the current available approaches for the diagnosis and surgical planning for single-suture craniosynostosis.

RESULTS

There remains a diversity of techniques available for the reconstruction of each fused cranial suture. Certain osteotomy designs are reported in the literature and are used by craniofacial surgeons more frequently. Each has its own benefits and disadvantages, and there is a growing body of outcome data available to guide surgical decision-making. Regarding diagnosis and surgical planning, computed tomography with 3-dimensional reconstruction remains the diagnostic standard of care, and efforts are ongoing to develop and implement new diagnostic modalities like Black Bone MRI to reduce radiation exposure.

CONCLUSIONS

There has been ongoing evolution of the surgical techniques available to reconstruct single-suture craniosynostosis, leading to ever-improving patient outcomes.

Management of Pre-existing Ventriculoperitoneal Shunt in Posterior Vault Distraction for Lambdoid Craniosynostosis: A Case Report and Technical Note

Posterior vault distraction osteogenesis (DO) is an emerging treatment option for craniosynostosis. Operative nuances detailing surgical management are being described with increasing use and experience. In this article, we discuss the surgical management of an 8-month-old male with a ventriculoperitoneal shunt (VPS) diagnosed with bilateral lambdoid craniosynostosis and Chiari I malformation. The patient underwent successful bilateral posterior fossa DO without surgical re-implantation of the shunt. Pre- and post-operative imaging confirmed no migration of the VPS. Intracranial volume increased by 20.1% and posterior fossa volume increased by 39.9%. Our experience illustrates that posterior vault DO can be done safely in the setting of a parieto-occipital VPS, in a single operative setting, without the need of additional procedures.

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.

Distinguishing Between Lambdoid Craniosynostosis and Deformational Plagiocephaly: A Review of This Paradigm Shift in Clinical Decision-Making and Lesson for the Future

The cause of occipital asymmtery can be either extrinsic or intrinsic. Intrinsic causes include lambdoid craniosynsotosis. This condition is generally treated with cranial vault expansion surgery. Extrinsic causes include deformational plagiocephaly, which became commonplace after the "Back to Sleep Campaign" instituted in the 1980s by the American Academy of Pediatrics. The treatment of this condition is non surgical. Dr. Joseph Gruss was instumental in differentiating between these conditions and reducing the number of unnecessary surgeries that were previously being performed.

Computational modelling of patient specific spring assisted lambdoid craniosynostosis correction

Lambdoid craniosynostosis (LC) is a rare non-syndromic craniosynostosis characterised by fusion of the lambdoid sutures at the back of the head. Surgical correction including the spring assisted cranioplasty is the only option to correct the asymmetry at the skull in LC. However, the aesthetic outcome from spring assisted cranioplasty may remain suboptimal. The aim of this study is to develop a parametric finite element (FE) model of the LC skulls that could be used in the future to optimise spring surgery. The skull geometries from three different LC patients who underwent spring correction were reconstructed from the pre-operative computed tomography (CT) in Simpleware ScanIP. Initially, the skull growth between the pre-operative CT imaging and surgical intervention was simulated using MSC Marc. The osteotomies and spring implantation were performed to simulate the skull expansion due to the spring forces and skull growth between surgery and post-operative CT imaging in MSC Marc. Surface deviation between the FE models and post-operative skull models reconstructed from CT images changed between ± 5 mm over the skull geometries. Replicating spring assisted cranioplasty in LC patients allow to tune the parameters for surgical planning, which may help to improve outcomes in LC surgeries in the future.

A Novel Sand Dollar and Staves Technique for Unilateral Lambdoid Craniosynostosis

BACKGROUND

Unilateral lambdoid synostosis (ULS) is the rarest form of craniosynostosis. Due to the associated cranio-caudal shift seen in ULS, surgical correction is technically challenging from a morphological standpoint. Herein, the authors present a novel "Sand-Dollar and Staves" technique for the repair of ULS.

METHODS

A zigzag coronal incision is performed, and an anteriorly-based pericranial flaps are elevated. Prefabricated cutting guides are placed and the calvarium is marked. To treat the flattening on the ipsilateral side, a wedged suturectomy is performed with additional barrel staves. A large circle centered over the bulging on the contralateral side is cut out above the open lambdoid suture. This piece is barrel staved in a radial fashion, leaving the center intact and creating a Sand-Dollar appearance. This disk is then flattened and trimmed. The modified Sand-Dollar is fixed using an absorbable plating system. While gentle pressure is applied to the Sand-Dollar piece as it is being secured, the ipsilateral side demonstrates compensatory filling. Results are evaluated using the Whitaker Classification.

RESULTS

Four patients underwent surgical correction with this technique. The procedure was performed at mean age of 11.7 months. The mean operative time was 2.5 hours. Intraoperative blood loss was 50 to 100 ml. Total hospitalization time was 2 to 3 days. No post-operative complications were encountered. Whitaker scores ranged from 1 to 1.5. The mean follow-up was 10 months.

CONCLUSION

The Sand-Dollar and Staves procedure is a novel, single-stage approach for the management of ULS with decreased operative time, blood loss, and hospital stay with satisfactory aesthetic outcomes.

Comparative analysis of cranial vault remodeling versus endoscopic suturectomy in the treatment of unilateral lambdoid craniosynostosis

OBJECTIVE

Unilateral lambdoid synostosis is the premature fusion of a lambdoid suture or sutures and represents the least common form of craniosynostosis, occurring in 1 in 40,000 births. Cranial vault remodeling (CVR) and endoscopic suturectomy with helmet therapy (ES) are surgical approaches that are used to allow for normal brain growth and improved craniofacial symmetry. The authors conducted a comparative outcomes analysis of patients with lambdoid synostosis undergoing either CVR or ES.

METHODS

The authors conducted a retrospective consecutive cohort study of patients with nonsyndromic lambdoid synostosis who underwent surgical correction identified from a single-institution database of patients with craniosynostosis seen between 2000 and 2018. Cranial growth was measured in head circumference percentile and z score.

RESULTS

Nineteen patients (8 female and 11 male) with isolated unilateral lambdoid synostosis were identified (8 right and 11 left). Six underwent CVR and 13 underwent ES. No statistically significant differences were noted between surgical groups with respect to suture laterality, the patient's sex, and length of follow-up. Patients treated with ES presented and underwent surgery at a younger age than those treated with CVR (p = 0.0002 and p = 0.0001, respectively). Operating and anesthesia time, estimated blood loss, and ICU and total hospital days were significantly lower in ES (all p < 0.05). No significant differences were observed in pre- and postoperative head circumference percentiles or z scores between groups up to 36 months postoperatively. No patients required reoperation as of last follow-up.

CONCLUSIONS

Endoscopic management of lambdoid synostosis is safe, efficient, and efficacious in terms of intraoperative and long-term cranial growth outcomes when compared to CVR. The authors recommend this minimally invasive approach as an option for correction of lambdoid synostosis in patients presenting early in their course.

Diagnosis, Management, and Outcome in 9 Children with Unilateral Posterior Synostotic Plagiocephaly

BACKGROUND

Posterior synostotic plagiocephaly represents a rare challenging type of craniosynostosis, often misdiagnosed as a simple posterior positional plagiocephaly. Underdiagnosed forms may result in delayed diagnosis and neurosurgical management, with potential ophthalmologic, cognitive, and aesthetic sequelae in children.

METHODS

Here we retrospectively analyzed data of 9 posterior synostotic plagiocephaly infants treated in our center over a 10-year period (January 2000-December 2009).

RESULTS

Patients averaged 10 months of age, and there was a clear male predominance (8 males/1 female). Cerebral computed tomography scan was performed in all patients, and the abnormal suture was located at the right side in 7 cases (77.77%). Ipsilateral occipitomastoid bulge and occipital flattening were found in all cases (100%). Posterior ear displacement was found in 7 cases (77.77%), and there was minimal facial asymmetry in 4 cases (44.44%). The ophthalmoscopic examination found a papillary edema grade 1 in 2 cases and grade 2 in 4 cases. There were no deaths or reoperation in our series. All of our patients underwent a neurosurgical correction, with total ophthalmic recovery in all patients with preoperative papillae edema. Eight patients had an early satisfactory aesthetic aspect. Long-term follow-up in treated children found a normal childhood, with no major school dysfunctions and normal social integration.

CONCLUSIONS

Interesting findings in our series were male gender predominance and predilection of the right-side synostotic lambdoid suture. We think that early correct diagnosis and appropriate neurosurgical treatment may prevent potential complications such as neurocognitive and aesthetic sequelae in children with posterior synostotic plagiocephaly.

A review of the management of single-suture craniosynostosis, past, present, and future

BACKGROUND

Craniosynostosis is a condition in which 2 or more of the skull bones fuse prematurely. The spectrum of the disorder most commonly involves the closure of a single suture in the skull, but it can also involve syndromic diagnoses in which multiple skull bones and/or bones outside of the cranium are affected. Craniosynostosis can result in cosmetic deformity as well as potential limitations in brain growth and development, and the neurocognitive impact of the condition is just starting to be studied more thoroughly. Our knowledge regarding the genetics of this condition has also evolved substantially. In this review, the authors explore the medical and surgical advancements in understanding and treating this condition over the past century, with a focus on how the diagnosis and treatment have evolved.

METHODS

In this review article, the authors, who are the leaders of a craniofacial team at a major academic pediatric hospital, focus on single-suture craniosynostosis (SSC) affecting the 6 major cranial sutures and discuss the evolution of the treatment of SSC from its early history in modern medicine through the current state of the art and future trends. This discussion is based on the authors' broad experience and a comprehensive review of the literature.

SUMMARY

The management of SSC has evolved substantially over the past 100 years. There have been major advances in technology and medical knowledge that have allowed for safer treatment of this condition through the use of newer techniques and technologies in the fields of surgery, anesthesia, and critical care. The use of less invasive surgical techniques along with other innovations has led to improved outcomes in SSC patients. The future of SSC treatment will likely be guided by elucidation of the causes of neurocognitive delay in these children and assessment of how the timing and type of surgery can mitigate adverse outcomes.

Imaging in craniosynostosis: when and what?

PURPOSE

Currently, the interest on craniosynostosis in the clinical practice is raised by their increased frequency and their genetic implications other than by the still existing search of less invasive surgical techniques. These reasons, together with the problem of legal issues, make the need of a definite diagnosis for a crucial problem, even in single-suture craniosynostosis (SSC). Although the diagnosis of craniosynostosis is primarily the result of physical examination, craniometrics measuring, and observation of the skull deformity, the radiological assessment currently plays an important role in the confirmation of the diagnosis, the surgical planning, and even the postoperative follow-up. On the other hand, in infants, the use of radiation or the need of sedation/anesthesia raises the problem to reduce them to minimum to preserve such a delicate category of patient from their adverse effects.

METHODS, RESULTS AND CONCLUSIONS

This review aims at summarizing the state of the art of the role of radiology in craniosynostosis, mainly focusing on indications and techniques, to provide an update not only to pediatric neurosurgeons or maxillofacial surgeons but also to all the other specialists involved in their management, like neonatologists, pediatricians, clinical geneticists, and pediatric neurologists.

Use of black-bone MRI in the diagnosis of the patients with posterior plagiocephaly

PURPOSE

Ionising radiation exposure is especially harmful to brain development. The purpose of this study was to evaluate whether black-bone (BB) magnetic resonance imaging (MRI), a non-ionising imaging method, offers an alternative to ionising imaging methods such as computed tomography (CT) in the examination of cranial deformities.

METHODS

From 2012 to 2014, a total of 408 children were referred to the Craniofacial Centre at the Helsinki University Hospital for further examination due to flatness of the posterior skull. Fifteen of these patients required further diagnostic imaging. To avoid ionising radiation, we used an MRI protocol that included sequences for evaluation of both brain anatomy and skull bone and sutures by BB-MRI. A semi-automatic skull segmentation algorithm was developed to facilitate the visualisation. Two patients with scaphocephaly were included in the study to confirm the ability to differentiate synostosis with BB-MRI.

RESULTS

We obtained informative 3D images using BB-MRI. Seven patients (7/15, 46.7%) had plagiocephaly on the right side and seven on the left side (7/15, 46.7%). One patient (1/15, 6.7%) had symmetric posterior flatness affecting both sides. Neither structural nor signal-intensity alterations of the brain were detected in visual analysis.

CONCLUSION

BB-MRI provides an alternative to CT when imaging craniofacial deformities. BB-MRI provides not only high-quality 3D-reconstructed imaging of the bony structures and sutures but also information on brain structure in one imaging session. With further development, this method could replace ionising radiation-based methods in analysing deformities of the skull.

Twenty-Year Review of a Single Surgeon's Experience Using a Unique Surgical Technique to Correct Lambdoidal Synostosis

BACKGROUND

Numerous techniques for the surgical management of lambdoidal synostosis have been previously described; however, no best practice technique currently exists. Surgical procedures range from complete posterior calvarial reconstruction to distraction osteogenesis techniques. Our primary purpose is to describe a novel approach to correct unilateral or bilateral lambdoidal synostosis.

METHODS

A retrospective review was performed on a single surgeon's experience with craniosynostosis (1994-2014). Specifically, craniosynostosis cases involving the lambdoidal suture, which were repaired using a novel 'tongue and groove' technique, were identified.

RESULTS

A total of 664 craniosynostosis cases were retrieved, with 21 primarily involving the lambdoidal suture (3.2%). Of these, 18 were unilateral and 3 were bilateral lambdoidal synostosis. Male-to-female ratio was 3:1. Average age of first encounter with a craniofacial physician was 33 weeks (8 months). Average age at time of surgery was 43 weeks (10.75 months). Complications of this technique included 1 patient who experienced refusion of his lambdoidal suture and fusion of his sagittal suture, and 4 who returned for bone graft coverage of full-thickness calvarial defects owing to a lack of complete reossification.

CONCLUSION

The "tongue and groove" technique represents a novel method for the management of lambdoidal synostosis with good esthetic outcomes, allowing immediate cranial stabilization with increased skull volume. This technique, used by the senior author for >20 years, provides a reproducible and reliable method of correcting lambdoidal synostosis.

Nonsyndromic Craniosynostosis and Deformational Head Shape Disorders

This article provides an overview of etiology, epidemiology, pathology, diagnosis, and treatment of nonsyndromic craniosynostosis, including sagittal, metopic, coronal, lambdoid, and complex synostosis. Detailed discussion is presented regarding indications for surgical intervention and management options, including frontoorbital advancement, cranial vault reconstruction, endoscopic strip craniectomy, spring-assisted strip craniectomy, and cranial vault distraction osteogenesis. Deformational plagiocephaly is also presented with treatment options including repositioning, physical therapy, and helmet therapy.

Genetic advances in craniosynostosis

Craniosynostosis, the premature ossification of one or more skull sutures, is a clinically and genetically heterogeneous congenital anomaly affecting approximately one in 2,500 live births. In most cases, it occurs as an isolated congenital anomaly, that is, nonsyndromic craniosynostosis (NCS), the genetic, and environmental causes of which remain largely unknown. Recent data suggest that, at least some of the midline NCS cases may be explained by two loci inheritance. In approximately 25-30% of patients, craniosynostosis presents as a feature of a genetic syndrome due to chromosomal defects or mutations in genes within interconnected signaling pathways. The aim of this review is to provide a detailed and comprehensive update on the genetic and environmental factors associated with NCS, integrating the scientific findings achieved during the last decade. Focus on the neurodevelopmental, imaging, and treatment aspects of NCS is also provided.

Physiological Changes and Clinical Implications of Syndromic Craniosynostosis

Syndromic craniosynostosis has severe cranial stenosis and deformity, combined with hypoplastic maxillary bone and other developmental skeletal lesions. Among these various lesions, upper air way obstruction by hypoplastic maxillary bone could be the first life-threatening condition after birth. Aggressive cranial vault expansion for severely deformed cranial vaults due to multiple synostoses is necessary even in infancy, to normalize the intracranial pressure. Fronto-orbital advancement (FOA) is recommended for patients with hypoplastic anterior part of cranium induced by bicoronal and/or metopic synostoses, and posterior cranial vault expansion is recommended for those with flattening of the posterior part of the cranium by lambdoid synostosis. Although sufficient spontaneous reshaping of the cranium can be expected by expansive cranioplasty, keeping the cranial bone flap expanded sufficiently is often difficult when the initial expansion is performed during infancy. So far distraction osteogenesis (DO) is the only method to make it possible and to provide low rates of re-expansion of the cranial vault. DO is quite beneficial for both FOA and posterior cranial vault expansion, compared with the conventional methods. Associated hydrocephalus and chronic tonsillar herniation due to lambdoid synostosis can be surgically treatable. Abnormal venous drainages from the intracranial space and air way obstruction should be always considered at any surgical procedures. Neurosurgeons have to know well about the managements not only of the deformed cranial vault and the associated brain lesions but also of other multiple skeletal lesions associated with syndromic craniosynostosis, to improve treatment outcome.

Skull base development and craniosynostosis

Abnormal skull shape resulting in craniofacial deformity is a relatively common clinical finding, with deformity either positional (positional plagiocephaly) or related to premature ossification and fusion of the skull sutures (craniosynostosis). Growth restriction occurring at a stenosed suture is associated with exaggerated growth at the open sutures, resulting in fairly predictable craniofacial phenotypes in single-suture non-syndromic pathologies. Multi-suture syndromic subtypes are not so easy to understand without imaging. Imaging is performed to define the site and extent of craniosynostosis, to determine the presence or absence of underlying brain anomalies, and to evaluate both pre- and postoperative complications of craniosynostosis. Evidence for intracranial hypertension may be seen both pre- and postoperatively, associated with jugular foraminal stenosis, sinovenous occlusion, hydrocephalus and Chiari 1 malformations. Following clinical assessment, imaging evaluation may include radiographs, high-frequency US of the involved sutures, low-dose (20-30 mAs) CT with three-dimensional reformatted images, MRI and nuclear medicine brain imaging. Anomalous or vigorous collateral venous drainage may be mapped preoperatively with CT or MR venography or catheter angiography.