Secondary Suture Fusion after Primary Correction of Nonsyndromic Craniosynostosis: Recognition of the Problem and Identification of Risk Factors

Secondary metopic craniosynostosis after posterior cranial decompression in cloverleaf skull deformity

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

A Systematic Review of Idiopathic Secondary Stenosis Following Index Surgery for Craniosynostosis

BACKGROUND

Primary craniosynostosis is a congenital craniofacial disorder in which cranial sutures prematurely close. Iatrogenic secondary stenosis is abnormal cranial suture closure caused by surgical manipulation of the suture. In contrast, idiopathic secondary stenosis develops in a suture that did not undergo surgical manipulation. The objective of this systematic review was to consolidate and characterize the incidence, classification, and management of idiopathic secondary stenosis in the literature.

METHODS

Literature from PubMed, Web Of Science, and EMBASE from 1970 to March 2022 was reviewed. The following information was extracted for individual patients: incidence of idiopathic secondary stenosis, index primary craniosynostosis, primary surgical correction, presenting signs of secondary stenosis, management, and further complications.

RESULTS

Seventeen articles detailing 1181 patients were included. Ninety-one developed idiopathic secondary stenosis (7.7%). Only 3 of these patients were syndromic. The most common index craniosynostosis was sagittal synostosis (83.5%). The most common suture undergoing idiopathic secondary stenosis was the coronal suture (91.2%). Patients presented at a median age of 24 months. The most common presenting sign was a radiologic finding (85.7%), although some patients presented with headache or head deformity. Only 2 patients, both syndromic, had complications following surgical correction of secondary stenosis.

CONCLUSIONS

Idiopathic secondary stenosis is a rare, long-term complication following index surgical repair of craniosynostosis. It can occur following any surgical technique. It most commonly affects the coronal suture but can affect any of the sutures, including pansynostosis. Surgical correction is curative in nonsyndromic patients.

Elevated Intracranial Pressure After Primary Surgical Correction of Sagittal Suture Craniosynostosis

Study Design: A Case Report. Objective: Craniosynostosis is a craniofacial condition defined by premature fusion of at least one cranial suture. Resynostosis or secondary craniosynostosis of a previously patent adjacent suture following primary repair is a relatively common complication. While studies have assessed the rates of secondary craniosynostosis and subsequent reoperation, extremely limited data regarding reoperation techniques is available. Methods: We present a unique case of a pediatric patient with sagittal craniosynostosis who previously underwent a modified pi procedure and later developed resynostosis of the sagittal suture and secondary synostosis of the bicoronal sutures. We subsequently performed total cranial vault reconstruction with virtual surgical planning (VSP). Results: At his 31-month postoperative follow-up, he displayed normal head shape and denied any clinical signs of elevated intracranial pressures with a normal ophthalmological exam. Conclusions: The reoperation was successful with no significant postoperative complications noted. Performing geometric expansion with VSP to manage fusion of a previously open suture following primary treatment of sagittal synostosis should be considered within the armamentarium of operative options.

Does Coronal Suturectomies and Occipital Barrel Staves Make a Difference in Early Reconstruction for Sagittal Craniosynostosis?

BACKGROUND

Various surgical methods are used for early treatment of nonsyndromic sagittal craniosynostosis. The craniofacial centers in Uppsala and Helsinki fundamentally both use the H-Craniectomy: Renier's technique. However, the Helsinki group systematically adds coronal suturectomies to prevent secondary coronal synostosis and posterior barrel staves to address posterior bulleting. The effects of these additions in early treatment of sagittal craniosynostosis are currently unknown.

METHODS

Thirty-six patients from Uppsala and 27 patients from Helsinki were included in the study. Clinical data and computed tomography scans were retrieved for all patients.

RESULTS

The Helsinki patients had a smaller preoperative Cranial index (CI) (65 vs 72) and a smaller preoperative width (10.1 vs 11.2). There was no difference in postoperative CI, corresponding to a difference in change in CI. Regression analysis indicated that the larger change in CI in the Helsinki group was mainly due to a lower preoperative CI allowing for a larger normalization. The Helsinki patients had less growth in length (1.5 vs 2.1 cm) and more growth in width (2.3 vs 1.9 cm). There were no differences in head circumference or surgical complications. Secondary coronal synostosis was present in 43% of the Uppsala group at 3 years of age, while calvarial defects located at sites of previous coronal suturectomies and posterior barrel staving were seen in the Helsinki group 1 year postoperatively.

CONCLUSIONS

Lower preoperative CI appears to be the main factor in determining the amount of normalization in CI. Prophylactic coronal suturectomies do not seem to benefit preservation of coronal growth function since the modification correlates to less sagittal growth and more growth in width.

Secondary Raised Intracranial Pressure After Cranial Vault Remodeling for Isolated Sagittal Craniosynostosis

ABSTRACT

The management of sagittal craniosynostosis has evolved over the decades as teams seek to refine their surgical approaches to idealize head shape with the least possible morbidity. Here, the authors identify the incidence of raised intracranial pressure (ICP) and its risk factors, requiring secondary surgical intervention after cranial vault remodeling (CVR) procedure at a single tertiary referral craniofacial unit. A retrospective case-control study was performed on the patients with isolated non-syndromic sagittal craniosynostosis. All patients who underwent CVR in our unit and had a minimum of 1.5 years follow-up were included. One hundred and eighty-four patients (134 male and 50 female) who underwent primary CVR surgery for isolated sagittal craniosynostosis were included. Thirteen patients (7.07%) had clinical evidence of late raised ICP resulting in repeat CVR procedures. Higher incidence of raised ICP in patients who had primary surgery before 6 months than after or at 6 months of age (P = 0.001). There were 23.5%, 5.6%, 3.2%, and 1.9% of secondary raised ICP patients who underwent the primary surgery between 1999-2004, 2005-2010, 2011-2015 and 2016-2018, respectively (P = 0.024). The risk of secondary raised ICP was higher in patients with isolated sagittal craniosynostosis whose primary surgery occurred before the age of 6 months (two times more likely). More extensive CVR can be performed safely in sagittal synostosis with promising outcomes. The late presentation with raised ICP reinforces the importance of long-term multidisciplinary protocol-based follow-up.

Coronal and lambdoid suture evolution following total vault remodeling for scaphocephaly

OBJECTIVE

Different types of surgical procedures are utilized to treat craniosynostosis. In most procedures, the fused suture is removed. There are only a few reports on the evolution of sutures after surgical correction of craniosynostosis. To date, no published study describes neosuture formation after total cranial vault remodeling. The objective of this study was to understand the evolution of the cranial bones in the area of coronal and lambdoid sutures that were removed for complete vault remodeling in patients with sagittal craniosynostosis. In particular, the investigation aimed to confirm the possibility of neosuture formation.

METHODS

CT images of the skulls of children who underwent operations for scaphocephaly at the Hôpital Femme Mère Enfant, Lyon University Hospital, Lyon, France, from 2004 to 2014 were retrospectively reviewed. Inclusion criteria were diagnosis of isolated sagittal synostosis, age between 4 and 18 months at surgery, and availability of reliable postoperative CT images obtained at a minimum of 1 year after surgical correction. Twenty-six boys and 11 girls were included, with a mean age at surgery of 231.6 days (range 126-449 days). The mean interval between total vault reconstruction and CT scanning was 5.3 years (range 1.1-12.2 years).

RESULTS

Despite the removal of both the coronal and lambdoid sutures, neosutures were detected on the 3D reconstructions. All combinations of neosuture formation were seen: visible lambdoid and coronal neosutures (n = 20); visible lambdoid neosutures with frontoparietal bony fusion (n = 12); frontoparietal and parietooccipital bony fusion (n = 3); and visible coronal neosutures with parietooccipital bony fusion (n = 2).

CONCLUSIONS

This is the first study to report the postoperative skull response after the removal of normal patent sutures following total vault remodeling in patients with isolated sagittal synostosis. The reappearance of a neosuture is rather common, but its incidence depends on the type of suture. The outcome of the suture differs with the incidence of neosuture formation between these transverse sutures. This might imply genetic and functional differences among cranial sutures, which still have to be elucidated.

Clinical Features of Bilambdoid and Sagittal Synostosis (BLSS): A Retrospective Multicenter Study in Japan

ABSTRACT

Bilambdoid and sagittal synostosis (BLSS), a rare form of multisutural craniosynostosis, is sometimes known as the Mercedes-Benz syndrome due to the appearance of the fused sagittal and bilateral lambdoid sutures. Although previous studies have described some of its clinical features, the pathology of this disease is not yet fully understood. Moreover, it has been pointed out that BLSS is more common among individuals of Hispanic ethnicity, but its incidence in Asia remains unclear. In the present study, BLSS cases in Japan were analyzed to determine the characteristics of the condition in Japan. Three hospitals in Tokyo participated in the present study. Patients with BLSS who underwent cranial remodeling were included. Data on patient demographics, clinical symptoms, status of the cranial sutures, morphological subclassification, surgical procedures, developmental status, and genetic mutations were analyzed. In total, 22 patients met the enrollment criteria and were included, indicating a higher incidence of BLSS in Japan than in other nations reported in previous studies. In terms of morphological subclassification, there were 15 brachycephalic, 4 dolichocephalic, and 3 normocephalic. For the initial cranial procedure, 7 patients underwent a single-stage cranioplasty, 13 underwent a posterior distraction, and 2 underwent lateral expansion. Patients with a normocephalic cranial morphology tended to undergo surgery at an older age than patients with the other two types. Appropriate timing for surgery is important for healthy development; hence, surgeons should remember that BLSS can lead to "balanced dysmorphism" that may have led to a delay in diagnosis due to its normal-looking morphology.

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.

Secondary Coronal Synostosis After Early Surgery for Sagittal Craniosynostosis: Implications for Cranial Growth

ABSTRACT

Secondary Coronal Synostosis (SCS) in patients operated for non-syndromic Sagittal Craniosynostosis is a postoperative phenomenon with unclear implications. The aim of this study was to investigate whether SCS is a negative or a benign occurrence in the postoperative course. The authors hypothesized that SCS is related to reduced cranial growth and intracranial hypertension. Thirty-one patients operated for SC at an early age with the H-craniectomy technique were included in the study. Associations between SCS and cranial shape, growth, and signs of intracranial hypertension were analyzed. Intracranial volume distribution was assessed by measuring partial intracranial volumes defined by skull base landmarks. A total of 12/31 patients developed SCS during the postoperative course. The presence of SCS was associated with a higher prevalence of gyral impressions and a larger normalization of Cranial Index due to less growth in the anteroposterior plane. The SCS group had a smaller postoperative intracranial volume due to less posterior intracranial volume as well as less growth in head circumference. Whether this is a growth restriction caused by the SCS or a secondary effect of less primary brain growth remains to be determined. However, the correlation between SCS, less cranial growth and gyral impressions does imply that SCS should be taken into consideration during clinical follow-up as a potentially adverse event.

Revisiting the Resolution of Chiari Malformation in Nonsyndromic Craniosynostosis: A Case of Posterior Cranial Vault Reconstruction in Secondary Pan-Suture Synostosis

BACKGROUND

While commonly seen in syndromic craniosynostosis, the incidence of Chiari malformation (CM) in nonsyndromic craniosynostosis has been reported at 5% and there is a lack of understanding of the pathophysiology and management of CM in this patient population.

CASE DESCRIPTION

We present a 5-year-old male patient who underwent a sagittal craniosynostosis repair at the age of 5 months and returned at the age of 5 years with daily headaches associated with behavioral changes. He was found to have pan-synostoses and radiographic evidence of increased intracranial pressure, including a Chiari malformation. Neurologic and genetic workup was unremarkable. A cranial vault reconstruction was performed, and subsequent imaging demonstrated resolution of previously noted Chiari malformation.

CONCLUSIONS

In our case, we provided a unique window into the underlying pathophysiology for CM in patients with concurrent nonsyndromic craniosynostosis that we hope will add to the current foundation of literature supporting the intricate relation between cranial vault compliance and Chiari malformation or hindbrain herniation. Furthermore, we provide insight into the management of acquired CM and support isolated cranial vault reconstruction in those who do not appear to have symptomatic suboccipital compression.