Craniosynostosis

Craniosynostosis surgeries at Children's Hospital of Wisconsin are performed by board-certified craniofacial plastic surgeons and board-certified pediatric neurosurgeons working together.The mildest forms of craniosynostosis do not require surgical treatment; however, most do. There are many surgical options, and they can be divided into two broad categories: minimally invasive surgery with post-operative helmet therapy, as well as traditional open surgery. Upon referral, a surgeon will review the options available with the parents to tailor the approach to the individual patient. "Before and after" photographs of children who may have had a similar type of surgery are available. There is also the option of connecting with families who have undergone the experience. Other specialists may be involved prior to surgery if necessary as children with craniosynostosis have a higher risk for other medical issues.

What is craniosynostosis?

The normal skull is actually several bones that are joined by fibrous structures called sutures. As the infant grows and develops, the sutures close after many years, forming a solid piece of bone, called the skull.

Craniosynostosis is a condition in which the sutures close too early, either in the womb or shortly after birth, that may cause problems with skull growth, and in some cases with brain growth. In these cases, premature closure of the sutures may prevent the skull from expanding sufficiently to allow normal brain growth, and cause the pressure inside of the head to increase. Usually, when this happens, the normal, unaffected sutures react by overgrowing in an attempt to preserve the volume needed for normal brain growth, and the skull grows in unusual ways resulting in abnormal shapes.

What causes craniosynostosis?

Craniosynostosis occurs in one in about 2500 live births and affects males twice as often as females. It is most often sporadic (occurs by chance with no known genetic cause), but in some families, craniosynostosis is inherited by passing on specific genes that are known to cause this condition.

Craniosynostosis is a feature of many different genetic syndromes that have a variety of inheritance patterns and chances for passing it on, depending on the specific syndrome present. It is important for the child as well as family members to be examined carefully for signs of a syndromic cause (inherited genetic disorder) of craniosynostosis such as limb defects, eye or ear abnormalities, or heart problems.

What are the different types of craniosynostosis?

There are several types of craniosynostosis. They have a typical appearance depending on which suture, or sutures, are involved, and are named both according to the head shape (words that end in –cephaly), and by which suture is abnormally fused.

skullnorm

  • Coronal synostosis is sometimes still referred to as plagiocephaly (crooked head), though that term is usually applied to the more commonly encountered condition that is related to flattening of the back of the head in newborns (deformational or positional plagiocephaly) unassociated with problems with the sutures. Coronal synostosis involves fusion of either the right, left, or both sides of the suture that runs from ear to ear over the top of the head. This condition causes the abnormal growth of the forehead and produces a flattening of the forehead and the brow on the affected side, and overgrowth, or “bossing” (bulging forward) on the opposite side when it is one-sided. The eye on the affected side may also seem to have a different shape. When both sides are involved, the forehead may appear wide and tall, but the skull is short from front to back (referred to as brachycephaly). This condition is more usual in the syndromic types. Unlike in positional plagiocephaly, the view of the top of the head is closer to a trapezoid than a parallelogram. Unilateral lambdoidal suture synostosis may also cause plagiocephaly, and is a rare form of synostosis that may be confused with positional plagiocephaly. The difference is a prominent bony ridge or spherical shape on the flattened side of the back of the skull that is apparent when there is fusion of the lambdoid suture.

skullplag

  • Metopic synostosis is fusion of the suture that runs from the top of the head down the middle of the forehead, toward the nose. It is the only one meant to close before the brain stops growing, but if it closes very early, it may result in a prominent ridge running down the forehead. In severe cases, the forehead looks quite pointed like the front of a ship, and when viewed from above looks like a triangle (hence the term trigonocephaly to describe this shape), with closely placed eyes (hypotelorism).

skulltrig 

  • Sagittal synostosis refers to early fusion of the suture that runs front to back, down the middle of the top of the head. This fusion causes a long, narrow skull. The terms used to describe this shape are scaphocephaly or dolichocephaly. This is the most common form of craniosynostosis and because the skull cannot effectively grow sideways, it overgrows front to back, sometimes with a narrow occiput (back of the skull) and overly large forehead (also referred to as frontal bossing).

skullscap

What are the signs and symptoms of craniosynostosis?

In infants with this condition, changes in the shape of the head and face are usually noticeable. The appearance of one side of the child's face may not be the same when compared to the other side. Clinical findings may include the following:

  • an absent soft spot (anterior fontanelle)
  • bony ridging corresponding to the sutures
  • apparent increasing rate of head growth when measured by circumference
  • wide or narrowly spaced eye sockets, or asymmetric eye sockets

In some cases, the pressure inside the skull may be elevated related to the fact that the skull bones cannot grow as fast as the brain. This usually only occurs if more than one suture is fusing prematurely. When this occurs, additional symptoms may include the following:

  • increased irritability, especially when laying flat
  • poor feeding
  • developmental delays

The symptoms of craniosynostosis may resemble other conditions or medical problems. Always consult your child's physician for a diagnosis.

How is craniosynostosis diagnosed?

Craniosynostosis may be congenital (present at birth), but difficult to recognize in the early weeks. It may be observed later, during a physical examination. The diagnosis often is made with a thorough physical examination, and can be confirmed with x-rays or CT scans. During the examination, your child's physician will obtain a complete prenatal and birth history of your child. He/she may ask if there is a family history of craniosynostosis or other head/face abnormalities. Your child's physician may also ask about developmental milestones. Developmental delays may require further medical investigation for underlying problems.

Treatment for craniosynostosis

Not every case of synostosis is treated surgically, and there are many surgical approaches to this problem. Specific recommendations for treatment of craniosynostosis will be determined by your child's surgeon based on a number of factors, including:

  • age of the patient
  • suture(s) involved
  • severity of the condition (complete versus partial fusion, for example)
  • expectations of what will occur without treatment
  • other medical problems that may be present

The mildest forms of craniosynostosis do not require treatment. These cases manifest as mild ridging without significant deformity. Most cases, however, do require surgical management. The goals of treatment are to a) provide adequate cranial volume for the brain to avoid deleterious effects of reduced volume and increased intracranial pressure, and b) optimize the cosmetic appearance to avoid psychosocial issues as the children get older.

Surgical options for craniosynostosis

There are many surgical options depending on the age and nature of the individual patient's craniosynostosis. These options can be divided into two broad categories: minimally invasive surgery with post-operative helmet therapy, and traditional open surgery.

Minimally invasive (endoscopic) surgery with post-operative helmet therapy

The minimally invasive approach, or endoscopically assisted strip craniectomy, is a straightforward technique involving removal of a small strip of bone incorporating the fused suture. This can be done via one or two small incisions with typically minimal blood loss and a relatively quick recovery time. Despite these advantages, there are some limitations of this technique. This procedure requires that surgery be performed at a young age (ideally less than 3.5 months of age) in order to reliably achieve an adequate cosmetic result. Patients are also required to wear a cranial-molding helmet for 7-9 months after surgery. With this technique, the helmet therapy is likely as important as the surgery in achieving the desired results. Because there is rapid head growth during the first year of life, this technique requires relatively frequent follow-up for helmet adjustments and replacements. In the minimally invasive technique, it is the growth of the brain, in concert with a series of molding helmets used for several months that gradually reshapes the head.

Traditional surgery

Traditional open surgery refers to a variety of techniques involving a more direct repair of the cranial abnormality. These techniques require bigger incisions, longer operative time, greater blood loss (and often blood transfusion), and longer hospital stays. These disadvantages are balanced by numerous advantages. Open surgery can typically be done on children up to the age of 10-11 months without compromising the cosmetic outcome. There is immediate improvement in cranial volume and appearance without a requirement for post-operative helmet use. The child wakes up with a different head shape that is easily recognized right after surgery.

There is no definitive "best" option. Although open surgical techniques have a longer track record, it is generally felt that both minimally invasive and open surgery yield similar outcomes both in terms of normalizing brain volume, intracranial pressure, cosmesis, and complications. Fortunately, major complications (stroke or death) are rare in craniosynostosis surgery. Minor complications are more frequent and include infection, hematoma, and healing problems requiring additional surgery.

Patients are admitted to the hospital on the day of the operation. After surgery, it is common for the child to have a turban-like dressing around his/her head. The face and eyelids may be swollen after this type of surgery. Patients are ready to go home when they are comfortable with only oral medication, have an adequate oral intake, and demonstrate baseline behavior. Patients undergoing minimally invasive surgery are often ready to go home the day after surgery. Patients undergoing open surgery often require 3-4 days in the hospital. Patients are followed closely after surgery and less frequently over time. Children are typically monitored until at least the age of 6 years.