|Fast facts for craniosynostosis|
- When a growth plate (skull growth suture) in the skull gets stuck or frozen (craniosynostosis), skull growth is slowed and the skull volume cannot grow fast enough to accommodate the rapid increase in the size of the brain. The stuck suture also can lead to abnormal head shape. In fact, the abnormality of the head shape is often the key diagnostic feature as to which growth plate has closed prematurely.
- High brain pressure (intracranial hypertension) can accompany craniosynostosis, with clinical presentation notable for irritability, feeding difficulties, failure to thrive, headache, developmental delays, visual changes, calvarial towering, supraorbital recession, or lack of circumferential skull growth.
- The optimal timing of craniosynostosis surgery remains controversial even today, although the majority of craniofacial surgeons operate between 3 and 12 months of age.
- Posterior deformational plagiocephaly, secondary to a supine sleeping position, will generally resolve with positional changes, physiotherapy, or helmet therapy and is only rarely a surgical condition.
Introduction to craniosynostosis
Craniosynostosis is defined as the premature closure of a cranial suture which causes abnormal calvarial growth. Preoperative assessment for craniosynostosis includes a detailed medical history, physical examination, and radiographic imaging. Radiological investigation may be necessary to corroborate the diagnosis and/or rule out any associated intracranial abnormalities.
Surgical intervention is indicated in craniosynostosis both for the correction of calvarial contour deformities and the prevention of psychosocial dysfunction, intracranial hypertension, and/or mental retardation. Sutural release in simple craniosynostosis has been advised due to the concerns regarding raised intracranial pressure as well as the mild but significant developmental delay in the aging child. Patients with complex synostoses present with increased severity in physical and neurological symptoms; therefore, surgical intervention is even more imperative.
The Importance of a Team Approach
Children born with craniosynostosis need the skills of several medical professionals to correct the problems associated with the anomaly. In addition to needing neurosurgery and plastic surgery to repair the fused growth suture, these children may have problems requiring the skills of an ophthalmologist, a geneticist, a behavioral psychologist, and others.
For that reason, parents should seek the help of a Craniofacial Team as early as possible. Medical professionals with special experience in the problems of craniofacial anomalies have formed these teams all over the country to help parents plan for their child's care from birth, or even before. A cleft/craniofacial team includes plastic surgeons, neurosurgeons, pediatric dentists, orthodontists, otolaryngologists, oral and maxillofacial surgeons, speech and language specialists, behavioral psychologists, hearing specialists, a nurse, and a genetic counselor.
Preparing for your child's surgery
Preoperative considerations include the optimal type and timing of surgical correction for craniosynostosis. A broad range of surgical options exist in the armamentarium of contemporary craniofacial surgical reconstruction, all with the primary objective of releasing the affected suture to permit normalization of skull growth in the setting of accelerated cerebral growth. An open craniofacial approach remains the mainstay of therapy, relying upon wide scalp dissection, extensive calvarial osteotomies, and variable skull reconfiguration.
Metopic synostosis (trigonocephaly)
Metopic synostosis is marked by a variable degree of phenotypic severity, ranging from mild ridging to the formation of a triangular shaped head (trigonocephaly) or prominent "keel" forehead with or without hypotelorism. In general, the goals of surgery are the normalization of the forehead with reconstitution of a normal supraorbital rim if necessary. Individuals presenting solely with a prominent midline keel may be best served by simple contouring of the frontal bone or by removal of the frontal bone flap followed by reconfiguration. Conversely, patients with significant trigonocephaly and hypotelorism will require a fronto-orbital reconstruction, recontouring the frontal bone and laterally expanding the orbits at the same time.
Sagittal synostosis (scaphocephaly, dolichocephaly)
Children with sagittal synostosis will present with a narrow, elongated skull (dolichocephaly – long-headedness, scaphocephaly – boat-shaped). Depending upon the region of greatest premature fusion of the sagittal suture, the child may manifest frontal or occipital bossing, or a combination of both. Some children will also demonstrate a "towering" skull, also known as turricephaly.
The treatment for sagittal synostosis remains controversial, with surgical approaches ranging from minimal removal of involved suture and bone to extensive total calvarectomy and reconfiguration. Simple synostectomy, or simple strip craniectomy, is safe and well-tolerated, providing adequate cosmetic results in select patients with mild deformities. It, however, has several disadvantages stemming from the fact that it strictly addresses the fused suture and not the compensatory changes in skull shape. It also leaves a large unprotected area over the vertex of the skull, an area with a high rate of restenosis and renewed growth restriction.
Coronal synostosis (anterior plagiocephaly/brachycephaly)
Patients with unicoronal synostosis present with anterior, or frontal, plagiocephaly whereas those with bilateral coronal involvement display brachycephaly. Features of anterior plagiocephaly include forehead flattening and orbital recession coupled with contralateral compensatory frontal protrusion.
Lambdoid synostosis and Posterior Deformational Plagiocephaly
Posterior plagiocephaly due to lambdoid suture synostosis is a rare event today, with the majority of observed posterior plagiocephaly secondary to positional molding. Understanding the differences between lambdoid synostosis and posterior deformational plagiocephaly is critical towards making the appropriate diagnosis and designing the proper course of treatment. Children with lambdoid synostosis characteristically have a trapezoid-shaped head in association with posterior displacement of the ipsilateral ear, contralateral occipital bossing, and frequent ridging of the affected lambdoid suture. In contrast, posterior deformational plagiocephaly is marked by a parallelogram-shaped head, anterior displacement of the ipsilateral ear, and ipsilateral frontal bossing in the absence of palpable ridging along the lambdoid sutures. Infants with true lambdoid synostosis may benefit from a variety of surgical approaches, aiming to release the affected suture(s) and normalize the posterior calvarial vault contour.
Risks and complications
Perioperative complications may include wound infection, superficial brain injury, cerebrospinal fluid leak, hematoma, and ocular injury. Intraoperative blood loss requiring transfusion is expected. It is imperative to accurately gauge the extent of blood loss and match accordingly with packed red blood cells. Other serious perioperative complications consist of ischemic brain injury, epidural and subdural hemorrhage, and severe transfusion reactions. Long-term postoperative concerns include recurrent skull deformities, cranial bone defects that fail to fill in over time, and hardware-related problems. Depending on the extent of morphologic asymmetry, intracranial hypertension, and developmental delay, recurrent calvarial deformities may require a minor or major reoperation. Postoperative mortality rates are low and continue to decline with technological advancements and experience.