Single Suture Craniosynostoses

  1. Overview
  2. Skull Growth
  3. Fusion of the Suture
  4. Diagnosis Craniosynostosis
  5. Problems Caused by Sutural Fusions
  6. Does Craniosynostosis Need Treatment
  7. Four Types
  8. Treatement
  9. Best Time to Operate
  10. Final Thoughts

 

Overview

There are four different types of major single suture synostoses (synostosis is a general term meaning “fused bones”), with each type being caused by a different skull suture fusing shut. Following the general overview below, each type of synostosis (sagittal, coronal, metopic and lambdoid) is discussed individually. Finally, the surgical treatments for the single sutural craniosynostoses are reviewed. To begin with, it is important to determine if a child actually has craniosynostosis. This is because the most common cause for an abnormal skull shape is not craniosynostosis, but instead is the result of deforming forces acting on the skull resulting causing what is called “positional plagiocephaly.” Positional plagiocephaly is discussed elsewhere on this site (see Deformations).It is also important for parents to realize that just because there is ridging on their child’s head, it does not necessarily mean that this suture is fused and that surgery is required.Return to Menu

 

 

 

 

 

Skull Growth

In order to understand craniosynostosis, it is helpful to know a little bit about the normal growth of the skull. The skull is not made up of one single bone, but instead is made up of different bones. The junctions where these bones meet are called sutures. We know that sutures are very important in growing children. The skull does not grow on its own; instead, it only gets larger because the brain is growing and putting pressure on the skull to get larger. So, when the brain is not growing, the skull does not get larger. In the first few years of life, the brain grows very quickly. As the brain grows, it stretches the skull bones apart, with the sutures acting like expansion joints. It is believed that this stretching of the sutures sends a signals to the skull bones (and to the covering of the brain, or “dura”) indicating the need for the skull to grow bigger (actually, the growth of the skull is slightly more complicated than this, and a simplified version is being presented here). If one of these sutures has fused shut, the skull cannot expand in this area of the skull sufficient to accommodate the growing brain, so the brain must push the other non-fused sutures further apart, in order to get enough room for the brain. This combination of factors (poor growth by the fused suture, and compensatory growth by the remaining open sutures) produces an abnormal skull shape, which then begins to become obvious to parents and pediatricians.Return to Menu

 

 

 

 

 

Fusion of the Suture

What causes sutures to abnormally fuse shut? The two most common reasons for premature closure of a skull suture are either a change in one of the child’s genes, or the result of outside pressure on the skull that induces the suture to close. When only a single suture is fused shut, the most common cause is usually “environmental,” or the result of outside pressure on the skull occurring sometime before birth. We know that it is possible to cause craniosynostosis in animals by restricting skull growth while the animal is still in the womb, and it is very likely that this is the primary cause for the majority of the single sutural synostoses in babies. The uterus, or womb, is a relatively small space. We know that sometimes babies can end up in certain positions in the uterus where they cannot move around freely (for example, the breech position). We suspect that children born with a single sutural synostosis may have been positioned in the uterus in such a way that there is continuous pressure on a certain area of the skull. This pressure can restrict the ability of the skull bones to be stretched apart by the growing brain. If the suture cannot stretch apart, it “thinks” its job is done and it fuses shut. Abnormal skull shapes, and single sutural synostoses, are more commonly seen in twins than in single births, further supporting this theory of in utero constraint. Craniosynostosis is also more common in boys than girls leading some researchers to speculate that testosterone might make suture closure more likely to occur when there is pressure on the skull inside the womb. Mothers who have delivered babies with single sutural synostosis should not feel guilty that they did anything wrong during their pregnancy to cause this condition. Craniosynostosis occurs in spite of the mother doing everything right.

In most instances, when children born with a single sutural craniosynostosis grow up, they will not pass this trait on to their own children. However, it has been reported (and we have seen cases of this, as well) of single sutural synostoses being passed from generation to generation. When this does occur, this hereditary pattern suggests that this sutural fusion is more likely caused by a specific gene. It is possible to test for some of these genes to see if they are present in children with craniosynostosis (something that we are currently doing in Dallas). However, it should be remembered that the overwhelming majority of single sutural synostoses appear to be the product of two parents with normal genes, and a mother who has normal prenatal care. Should children born with a single sutural synostosis decide to have children of their own in adulthood, the chance of passing on the condition is estimated to be less than 2%. The chance of a couple having a second child with a single sutural synostosis is also thought to be about 2%.

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Diagnosing Craniosynostosis

 

The diagnosis of craniosynostosis is usually made by a doctor ordering x-rays; the simplest type is called a “plain x-ray.” On a plain x-ray, open sutures appear to be dark lines, whereas fused sutures appear as white lines. However, it can sometimes be hard to tell if a suture is open or closed on a plain x-rat; therefore, the next test ordered is usually a CT scan. These scans are the best x-ray test to determine whether or not a suture is open or closed, and they are also the most commonly performed test when there are questions about possible craniosynostosis. However, some doctors have raised questions about the effects of the radiation associated with CT scans (which is significantly more than with plain x-rays); more specifically, about the possibility that this radiation might have a negative effect on intellectual development and might also lead to an increased risk for tumors, especially in infants with growing brains (these concerns have been substantiated by a study published in Lancet in 2012). As it turns out, when a suture fuses shut, the resulting reduction in growth in one area, along with the compensatory over-growth of the other sutures, produces a characteristic skull shape that is uniquely different for each of the various single sutures. We have published a study (along with co-authors at 3 other craniofacial centers) that showed that a physical examination performed by a craniofacial surgeon is very accurate (98%) at diagnosing craniosynostosis compared with CT scans (see Publication # 26). Therefore, at our center in Dallas, we have stopped routinely getting CT scans on our patients, reserving them for those extremely rare cases where the physical examination is particularly unclear.

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Problems Caused by Sutural Fusion

 

Does a single sutural synostosis affect a child’s development or intelligence? This is a difficult question to answer. At the current time, we believe it either doesn’t affect a child’s mental development, or if it does, it cannot be measured by current testing. Some studies have shown raised pressure inside of the skull in children with craniosynostosis (however, the risk of this seems to be low in the first year, but may increase up as kids get older). We believe that if the growing brain is kept from enlarging inside the skull because a fused suture, then pressure can build up inside the skull that might hurt the brain. However, studies suggest that only a small percentage of children born with a single fused suture will have raised intracranial pressure. The problem is no one is sure what the normal pressure is inside an infant’s skull, so it is hard to determine exactly what level of pressure is necessary to cause lasting problems. In addition, we know that pressure inside the skull normally varies up and down and does not stay constant. At the current time, it is my opinion that it probably takes years for pressure to go up significantly in children with single sutural synostosis.

Some studies have been published that suggest that children with single sutural synostosis may have a higher rate of experiencing some minor developmental or behavioral problems. However, if one performs developmental testing (or looks for behavioral issues) on a large group of children without craniosynostosis, about 20% of all children would be expected to show some problems. Currently, we cannot be sure if single sutural craniosynostosis is more likely to cause developmental or behavioral issues. We also do not know the answers to a number of other good questions such as: does surgery help to prevent developmental problems? Are there different problems specific to the different fused sutures? Is the brain less affected in those cases where the skull is less affected? It has been our experience that the vast majority of children with a single sutural synostosis are normal children who just have early closure of one of their sutures.

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Does Craniosynostosis Need Treatment?

Why is an operation recommended for children with single sutural synostosis? If one considers all that is known about brain growth and development, reviews all the studies examining raised intracranial pressure and blood flow to the brain, the current final conclusion is that most children do need surgical treatment. However, it is important to realize that surgery cannot create a functioning suture. Once a suture is fused shut, a new growth center cannot be created. Surgery is meant to return the skull shape and size to where it should be, which is most likely to result in normal blood flow to the brain. If children do not look normal, their appearance can have a profound effect on their personality, their willingness to socially interact with their peers, even their desire to go to school. The most difficult decision for surgeons and parents is for those children who are very mildly affected. When the skull is only slightly involved, it would seem less likely that there is a significant impact both on the brain and on a child’s appearance; so in these cases, we often recommend not operating. You can get more information on how corrections are done in the Treatment section.

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Listed below are the four types of single sutural synostoses:

 

Coronal Craniosynostosis (Unilateral Coronal Synostosis, Plagiocephaly)

“Plagiocephaly” is the term used to describe the shape that results from craniosynostosis of either the right, or left, sides of the coronal suture. The coronal suture runs across the top of the skull extending almost from ear to ear. The soft spot, or fontanel, is located midway between the right and left coronal sutures at the top of the skull and is usually closed in children with plagiocephaly. On the side of the skull, where the suture has closed, one can often feel a raised ridge of bone. When viewed from above, the forehead on the fused side is further back than the opposite side, which typically has slightly overgrown further forward in order to compensate for the brain’s inability to grow on the side that has fused. In looking directly at the child, the eyebrow is higher on the fused side, which makes the eye seem more open. Often, it is many parents’ first impressions that it is the eye on the normal side that seems abnormally closed, when actually it is the other eye that is abnormally more open-appearing. Some may notice that their child’s nose is slightly off-center, angled or pointed towards the side of the fused suture. It is common for parents to say that their child looks worse in a mirror, which may be related to the fact that a mirror flips the image around so the right side becomes the left, etc. Instead of seeing your child as you are used to seeing him, or her, with the flatness on one side, you now see a different child with flatness on the opposite side.

The incidence of plagiocephaly is estimated to be about 1 in 3500 births. Almost all children affected with plagiocephaly require surgical treatment. Rarely, children with one coronal suture fused shut can have a gene mutation (up to 20%), which may signify a condition called Muenke syndrome. The treatment for plagiocephaly is discussed in the Treatment section. Return to Menu

 

 

 

 

 

 

 

 

Sagittal Craniosynostosis (Scaphocephaly)

Scaphocephaly is the term used to describe the shape that results from craniosynostosis of the sagittal suture. This suture runs from front to back starting at the fontanel (soft spot) at the top of the head, and extending backwards along the middle of the skull. Sometimes the soft spot will be closed when this suture is fused. A ridge can be seen, or felt, running along the top of the head in between the right and left halves of the skull. When viewed from above, the skull will be wider near the forehead and gets narrower towards the back of the skull (which is the opposite of what is normal: the back of the skull should be wider than the front). When looking straight on at the child’s face, the forehead may seem bigger, and the sides of the skull look narrow. Perhaps the most characteristic finding of sagittal synostosis is that in looking at your child from the side, the back of the skull is lower than the front, which is the opposite of normal. Most children with scaphocephaly will have very high head circumferences. This is because in response to the reduced width and height of the back of the skull, the length grows abnormally longer to compensate.

The incidence of scaphocephaly is about 1 in 2,000 births. It is the most common form of craniosynostosis. Almost all children affected with scaphocephaly require surgical treatment. The treatment for this condition is discussed in the Treatment section.

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Metopic Craniosynostosis (Trigonocephaly)

Trigonocephaly is the term used to describe the shape that results from craniosynostosis of the metopic suture. The metopic suture runs from the top of the head at the fontanel, or soft spot, down the center of the forehead stopping just above the nose. A ridge can usually be seen running down the center of the forehead and the forehead will look narrow. Often, the eyes are spaced closer together than is normal. The most characteristic finding is, when looking down from above, the forehead will have a triangular shape like the bow of a boat.

The incidence of trigonocephaly is somewhere between 1 in 2,500 to 1 in 3,500 births. Trigonocephaly has been reported to occur in mothers who have taken Valproic Acid (Depakene, Depakote, and Convulex) for seizures. Not all children with metopic synostosis require treatment. Sometimes it can be very difficult to determine if a child has significant trigonocephaly, or not. Those who are very mildly affected may not require any surgery. The metopic suture is different from all the other sutures of the skull because it is the only one that actually normally fuses shut, beginning this process well before a year of age. Therefore, x-rays showing that this suture has fused are not all that helpful. In some children, as the suture normally closes it can create a very prominent ridge running down the center of their forehead, without producing the triangular-shaped forehead. Only those children who have overt trigonocephaly need treatment. Children with an isolated ridge running down their foreheads do not require surgery (see Publications, Book Chapters #3). The treatment for this condition is discussed in the Treatment section.

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Lambdoid Craniosynostosis (Posterior Plagiocephaly)

Posterior plagiocephaly is the term used to describe the skull shape that results from craniosynostosis of one of the two lambdoid sutures. It is important to differentiate this condition from positional plagiocephaly, which is a deformation caused by outside pressure on the skull, without sutural fusion. The lambdoid sutures are located on the back of the skull, with one on the right side and one on the left side, making a shape like an upside down “V.” Usually, only one side fuses shut, but rarely both sides will be closed. When viewed from above, the side with the fused suture is flatter than the opposite side. One sign that the lambdoid suture might be fused is the presence of a low bump (mastoid bulge) behind the ear on the same side as the fused suture. Another sign of lambdoid synostosis is that the height of the skull is lower on the flattened side. Finally, if the back of the skull seems to grow outwards on the opposite side of the flatness, a fused lambdoid suture is likely. On the other hand, if there is no reduction in skull height on the affected side, no compensatory bossing on the other side of the skull and no low mastoid bulge, then a skull deformation should be suspected instead of a fused suture. It is critically important to determine whether or not a child truly has a fused suture because skull deformations almost never need to be surgically treated. There have been articles in the news media about children who underwent operations for flatness on the back of the head for presumed lambdoid synostosis when, in fact, the child had a deformation and could easily have been treated without surgery (primarily by doing nothing). Making the diagnosis even more difficult is the fact that on plain skull x-rays, the lambdoid suture can be misdiagnosed as being fused shut. Ideally, the diagnosis of lambdoid synostosis is made by either by an experienced craniofacial surgeon who can usually tell by an examination alone, or by a CT scan performed by those with less experience with craniosynostosis. Children who have lambdoid synostosis, and significant flattening of the skull, typically require surgery to fix this condition. Experienced craniofacial surgeons will also discuss the potential for Chiari malformations with lambdoid synostosis (where a part of the brain called the “cerebellar tonsils” can push on the spinal cord), how to diagnose a Chiari, and how treatment might be different if this is found.

The incidence of posterior plagiocephaly from a fused lambdoid suture is currently unknown, but is probably even rarer than one in 50,000 births. One reason for the difficulty in estimating how often this fusion occurs is that it has probably been over-diagnosed in the past. It is certainly one of the most uncommon types of craniosynostosis treated at craniofacial centers, and therefore, is probably best managed at one of the busier centers. The treatment for this condition is discussed in the Treatment section. .

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Other Synostoses

 

Sometimes, more than one suture can fuse shut. When both coronal sutures are affected, it is more likely that the child might have a syndrome. For a good starting point, please refer to the sections on Apert, Crouzon, and Pfeiffer syndromes. There are also some even more rare conditions in which multiple sutures are fused in different combinations, sometimes referred to as “complex craniosynostoses.” For more information on these, see our publication on this condition (Publication #27, 33) Once again, these extremely rare forms of craniosynostosis are best treated at the busiest national centers.

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Treatment

 

 

Introduction

 

Children with a single sutural synostosis usually undergo an evaluation by a craniofacial team prior to deciding on surgical treatment. If necessary, surgery is performed by both a craniofacial surgeon and a pediatric neurosurgeon working together as a team (if parents meet a neurosurgeon who recommends operating without a craniofacial surgeon, or visa versa, then I strongly recommend seeking another opinion). Craniofacial surgeons are the ones with the greatest expertise in treating craniosynostosis; it is their role to decide which parts of the skull are to be removed. It is the role of the neurosurgeon to safely remove the bone. Finally, the craniofacial surgeon then rebuilds the skull into a normal shape. The specifics of this procedure vary from surgeon to surgeon, and with which sutures are involved.

It is common assumption that if your child has a fused suture, all that needs to be done is to open up the fusion so that the brain can grow normally. Unfortunately, once a suture has fused shut, it cannot be recreated. As our understanding of the sutures has improved, we have come to better understand how complicated the biology of these sutures actually are. Once a suture has fused shut, there can never be sutural growth in this area again. Fortunately, the skull can also grow by other ways (adding layers of bone on the outside, while dissolving away the inner side). Parents are often given the impression that it is important to operate quickly in order to release the skull, and once this is done, the child will grow normally. However, this is not true. We have performed studies at our center that show that growth is not normal after craniosynostosis corrections and it appears that the earlier the surgery is performed, the less well the skull will grow afterwards. We believe that operations performed too early are more likely to need second operations later in life to correct a recurrent problem. This means that craniofacial surgeons need to balance how long it is safe to delay surgery, because the longer you wait, the better the long-term result. Doing the wrong operation, not doing the best job, and choosing the wrong time to perform the operation all have the potential to increase the chance that your child will need a second (or even third) operation, in order to get the good result that they deserve. There are many different ways of treating craniosynostosis, and the following provides a brief overview of some of the more common techniques.

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Older Treatments

 

The earliest treatments for single sutural synostoses were performed by neurosurgeons operating alone. These early procedures were called “strip craniectomies” (one variation is called a “Pi” procedure). These operations all involve permanently removing a strip of bone around the fused suture, along with additional normal areas of the skull, in hopes of releasing the restriction to growth. However, when studies were done looking at the results of strip craniectomies, it appeared that these types of operations were not as effective as hoped. Depending upon the age of the child at the time of surgery, the removed sections of bone may quickly regrow resulting in a very limited improvement. But sometimes, especially in older infants, the skull will not grow back completely, leaving permanent open spaces of unprotected skull that later need surgery to fill in. The bottom line is that the strip craniectomy procedure is not the best at normalizing the skull shape, and when this procedure is performed, it probably increases the chance that a second corrective operation will be necessary to further correct the deformity. In addition, because bone is discarded, there is a greater likelihood that some children will need to have another operation to fill in skull defects that never completely heal in. More recent updates on the traditional strip craniectomy procedures (i.e. endoscopic-assisted with head banding, springs, and distraction devices) are described in more detail below. 

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Remodeling Procedures

 

Recognizing that the strip procedures do not fully correct the abnormal skull shape, craniofacial surgeons came to realize that instead of just removing the fused sutures, it was best to remodel and enlarge the skull. There are many variations on the remodeling procedure, but they can all be broken down into three basic techniques: 1. Surgery is limited to the area of the skull near the fused suture and is done in a single operation (this is my preference; see “The Dallas Procedure” below). 2. The entire skull is removed and remodeled in one operation (I think that this bigger operation increases the risk for complications, and actually may end up looking worse). 3. The skull is treated with two separate operations, one on the back, and then a second one in the front (why double the risks of surgery, when the problem can be fixed with only one operation?).  

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Endoscopic or “Minimally Invasive” Procedures

 

Recently, a few surgical teams have gone back to performing a modification of the older “strip craniectomy” procedures. One of the updates to this older procedure is the use of an endoscope (operating through a small tube) to remove the skull off the dura (the covering of the brain). Probably the biggest advantage of this technique is the smaller incision in the scalp; however, there is an associated disadvantage: the surgeon has a limited view of what going on during the surgery. This technique relies on the use of a restrictive molding headband, which the child must wear for up to a year after surgery, to force changes in the skull shape. Some surgeons use the term “minimally invasive” to describe this procedure; but it is my opinion, there is nothing “minimally invasive” about removing part of the skull from an infant, especially while looking down a tube though a tiny incision. It would seem that the term “minimally invasive” is more of a marketing term that suggests that this procedure is a much safer operation than any of the other techniques used to treat craniosynostosis. In fact, there is no data showing that the risks of death are lowered by using an endoscope. If anything, the opposite may be true: this technique might actually carry higher serious complication rates than remodeling procedures. One reason for higher complication rates with “minimally invasive” endoscopic surgery is that the surgeons’ view is more restricted by the tiny incision and having to look down a long tube to see what is going on. This limited ability to see the bigger picture may prevent the surgeon from noticing a bleeding area that needs to be stopped, or a tear in the dura (the covering of the brain) that requires a repair.

Not only may complication rates be actually higher with endoscopic surgery, there are also issues associated with the headbands and helmets that must be worn for months (up to a year) after the operation. Most parents are understandably unhappy about the need for their baby to constantly wear a headband for so long after the procedure, but few may recognize that the operation itself did little to correct the abnormal skull shape. Instead, changes in the skull shape are left up to the therapist, or head-banding technician, who works to mold the skull shape, not the surgeon. This means that the final result is largely dependent upon the skill of the technician actually doing the molding, along with the ability of the parents to keep the headband on their child for the full course of treatment. Finally, if one considers that the primary reason that most parents subject their child to an operation in the first place is treat the effects of raised intracranial pressure on the brain caused by sutural fusion, the use of a restrictive headband makes little sense. The way that these bands and helmets work is basically by preventing growth everywhere around the skull except where the technician wants the skull to fill in. This is quite similar to what happens with craniosynostosis, where fusion of a suture restricts growth. Why would anyone put a restrictive helmet on a child who already had restrictions from craniosynostosis just to change appearance? It makes more sense to not restrict growth, and instead to provide more room while normalizing shape. This is exactly what a remodeling procedure does.

 

So in summary, endoscopic strip craniectomies have:

 

Advantages:

 

  • Shorter scalp incision.
  • Shorter operation (about 45 minutes less operating time than a Dallas Remodeling procedure).

 

Disadvantages:

 

  • Correction is not achieved at surgery, so infants must wear a headband up to a year afterwards.
  • Headbands function similar to craniosynostosis in that both restrict growth, therefore, how can this improve the effects of craniosynostosis on the brain?
  • These procedures are not as effective in normalizing appearance (depending on the age surgery is performed and skill of head banding therapist), so the risks of secondary surgery are probably higher.
  • These procedures result in the removal of bone, which is not replaced; so risks of second operation to rebuild holes in the skull are higher.
  • These procedures may be slightly more dangerous for the child because of the restricted view that the surgeon has, potentially resulting in higher risks for serious complications.

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Spring Cranioplasties

 

Another newer variation on the older strip craniectomy technique is the placement of springs into the skull. At the current time there are only a few surgeons in the U.S. who will recommend that craniosynostosis be treated by performing a strip craniectomies and placement of metal springs. These springs are used to slowly widen the surgically-created gap of bone, and I believe that they are fairly effective at widening a narrow skull. One big problem is that the surgeon then needs to do a second operation to remove the springs. Let’s examine the advantages and disadvantages of this technique.

 

Advantages:

 

  • The initial operation to remove a strip of bone and place the springs is shorter compared to a remodeling procedure.
  • The springs are very effective at widening narrow parts of the skull, or making the skull longer (depending upon which direction they are put in).

 

Disadvantages:

 

  • This procedure requires two operations, this doubles the risk of anesthesia (and there are some more recent studies raising questions about how anesthesia might negatively influence development in infants).
  • The surgeon cannot be exactly sure how much widening the springs will cause. Your child’s skull shape will ultimately depend on many factors: how big the original bone gap is, how thick and rigid the skull, the strength of the spring, how much tension is placed on the spring, etc. Basically, it is hard to predict exactly how much widening will occur. It seems like rolling dice.
  • Springs can only widen in one direction, yet they are used to treat a three-dimensional problem. This operation does not shorten the skull in any dimension. This is a problem because with craniosynostosis, not only is there reduced growth caused by the fused suture, there is also compensatory overgrowths elsewhere that need to be corrected. Just widening the skull is treating only one part of a 3-dimensional problem.
  • This procedure removes a section of bone, and then widens this gap with a spring. The resultant skull defect is therefore even bigger. So, there is a much higher chance that a third operation (after one to place the spring and a second to remove it) will be needed later on to fill in holes left in the skull (unless these surgeons decide to just leave them alone, and not fill them in).

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The Dallas Remodeling Procedure.

 

At The Craniofacial Center, the surgery to correct a single suture craniosynostosis is always performed with both a craniofacial surgeon and a pediatric neurosurgeon working together through the entire operation. We believe that having two experienced surgeons working side-by-side improves the speed and safety of the operation. In addition, only pediatric anesthesiologists with extensive craniofacial surgical experience are selected. Having the same experienced team working together brings not only better results, but also helps to prevent serious complications. Given our primary focus at the Craniofacial Center is on treating craniosynostosis, we have developed specific treatment protocols for each type, and we routinely re-evaluate our outcomes. This has resulted in our having shorter operative times, and total hospital lengths of stay, compared with any other center’s published data for all the different major types of craniosynostosis. During the operation, the family is given hourly updates as to their child’s condition. The typical correction takes just under four hours from start to finish, although the actual surgical time is much shorter, averaging about an hour and 45 minutes (about half of the total time in the operating room is spent preparing the child for surgery, and then slowly waking the child up afterwards). We do not shave any hair for surgery, although many centers still prefer to do so. The surgery is performed though an incision that is made from ear to ear across the very top of the head. Many years ago, I developed a wavy, “zigzag” incision to replace the standard straight-line incision so that when children get their hair wet, the hair won’t part on a straight-line scar making it obvious to others (see Publications #10). Recently, I have shortened the length of this incision, keeping it about an inch above the top of both ears, so that the scar will be even less noticeable.

The goal of the operation is to remove the areas of skull that were affected by the fused suture and rebuild the skull into a normal shape. Studies performed at our center have shown that after surgery, skull growth is not entirely normal, with a tendency for the skull to grow back the way it was (see Publications #25, 30). Based on these studies, we recommend a slight over-correction, which is just one of the ways we seek to reduce the chance that future surgery would be necessary. In order to rebuild the skull, it is necessary to somehow hold the bones together so that they can heal. Most surgeons use plates and screws to set the bones; however, I prefer to use dissolving stitches for a number of reasons. To begin with, some time ago after operating on children who had initially undergone surgery at other centers, we discovered that when other surgeons had used metal plates and screws for fixation, with the subsequent growth of the skull these plates will end up on the inside of the skull with the screws poking into the dura and brain (see Publications #12). Other studies have noted the same thing happens with dissolving plates and screws: they can also end up inside the skull against the brain before they dissolve away. While I am not aware of any cases in which this has caused a problem, I have nevertheless decided to only use dissolving stitches to hold the bones together, to avoid any potential problems (see Publications #20). We have also found that when dissolving plates and screws are used, they can end up leaving a weak space inside of the skull bones that can make additional operations (if needed) much more technically difficult. Finally, in a small percentage of cases, dissolving plates and screws will melt into a liquid that collects in a pocket under the skin that will eventually open up a hole and drain out. Given all these potential problems, I am convinced that even though it is technically more difficult to use dissolving sutures to rebuild a skull, and that almost all craniofacial surgeons are using these plates, I would not want them for my own child. Exactly how the skull is reconstructed varies depending upon which suture is fused. The specific techniques we use have changed considerably based on what we have learned by following our patients many years after their correction (I like to follow my patients into teenage years, when growth is complete). In particular, we have found that certain area of bone can thicken up over time, whereas, other areas will not. Also, any seams between different bones that are brought together during reconstruction can become visible after many years, especially under the forehead skin. These observations have helped us to change the way we reconstruct the forehead, which we believe results in even better aesthetic results, and an even lower chance that a second repair will later be necessary (currently, our published rate of second operations for single sutural craniosynostosis is about 2%). For example, currently I am striving to utilize just one single piece of bone to reconstruct the entire forehead, so that no visible seams will show up many years later.

Another fairly unique aspect of treatment in Dallas is that we typically do not leave any open areas in the skull. Those surgeons who are now performing variations on the older strip craniectomy procedures (such as strip craniectomies with headbanding and strip craniectomies with metal springs) all leave holes in the skull, with the hopes that the body will eventually fill in these holes. Although remodeling procedures also creates bony gaps (because the skull is being enlarged), it is possible to fill in these gaps using the child’s own bone before closing the scalp. However, filling in all the bony gaps is not possible with endoscopic strip craniectomies and spring cranioplasties, only remodeling procedures. Furthermore, this can be technically challenging in young children (especially for less experienced surgeons). Perhaps for this reason, most surgeons do not take the time to perform this additional step. In Dallas, it is our goal to completely fill in all the open areas using the child’s own bone. We are convinced that this reduces the risk that a child will later need a second operation just to fill in holes left by the initial repair.

When the skull reconstruction has been completed, we close the scalp with dissolving stitches. We never use metal staples or non-dissolving sutures, as these can hurt when they are removed. We also do not put any bandages on the child and do not use any drainage tubes (I believe that these tubes make the recovery actually slightly more complicated, and are also painful to remove). Instead, the child is given a shampoo before leaving the operating room and the hair is then combed away from the incision. Many surgeons use head wrap bandages, which may be indicative of a more traditional approach to surgery. While these bandages are not “wrong,” children find them very uncomfortable, and they are completely unnecessary.

Our patients typically spend only one night in the pediatric intensive care unit, and are then transferred to the floor the following day. While most might be ready to leave the hospital 24 hours after their operation, I recommend that all my patients stay for a total of two nights in the hospital (2 nights is our average hospital stay for all craniosynostosis). The risks of the surgery are very small at the more experienced centers. In a published report (see Publications #15), we looked at our combined experience with another center and reported the lowest infection rates following craniosynostosis repairs. We also found that there were no infections in infants undergoing first time operations for craniosynostosis (although an infection is always a possibility).

When craniosynostosis corrections are performed on older children, they tell us that they feel almost no pain (they do say that their heads feels “tight” when the swelling peaks 24-48 hours after surgery). Nevertheless, we have a policy of playing soft music in children’s’ rooms after surgery. This is based on a study that showed that playing soft music relaxes children and reduces the amount of pain that they feel after an operation (it also reduces the amount of pain medicine required). At the most experienced centers, craniosynostosis corrections can be performed at any age, including even adults.

 

Let’s examine the advantages and disadvantages of the Dallas technique.

 

Advantages:

 

  • In a single operation the skull is both enlarged, and the shape is normalized.
  • We have the shortest published length of surgery for any center performing remodeling procedures.
  • We also have the shortest length of hospital stay for any center performing remodeling procedures.
  • No hair is shaved, no metal staples put in the scalp, no drainage tubes inserted, and no head wrap bandages are used.
  • We believe that we have one of the very best safety records published.
  • We have the lowest transfusion rate published for remodeling procedures (18%), which is similar to many reported series of endoscopic repairs.
  • We also have the lowest published rate of secondary revision skull surgeries (2%).
  • We strive for personalized “family doctor-type” care.

 

Disadvantages:

 

  • Families need to travel to Dallas; it is stressful enough having to deal with the diagnosis of craniosynostosis and the prospect of your child needing surgery, travel may increase this stress (however, it is perfectly safe for children to fly or drive home after surgery - 90% of Dr. Fearon’s patients travel from outside Dallas for treatment).
  • Slightly longer scalp incisions are used than with endoscopic repairs (but our incisions are much shorter than most doing remodeling procedures).

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When is the best time to do the operation?

 

Surgery to correct craniosynostosis may be performed at any age, including adults. Below are some of the pros and cons of earlier vs. late surgery. 

 

In favor of an earlier correction are a number of factors:

 

  • With early operations the skull is less rigid and easier to shape. 
  • The younger the infant, the better the chance that any small skull defects that might be left at the end of the operation will later fill in with new bone. Somewhere between 9 and 12-months of age, babies pretty much lose their ability to make new skull bone. So, when operating on an older child, a few extra steps are necessary in order to fill in all open areas.  
  • The longer a child grows with a fused suture, the more that other areas of the skull may over-expand in order to compensate, which further changes the skull shape in an abnormal way. A study done at our center suggested that for children born with trigonocephaly, surgery before six months of age allowed slightly better growth between the eyes, which is an area abnormally narrowed by the fused metopic suture (see Publications #14). 

 

In favor of operating at a later age are a number of factors:

 

  • The operation may be safer. The worst possible complication following any craniosynostosis operation (both endoscopic and remodeling) is that the child would not survive the operation. We have published the results of a detailed review of the experience of two major craniofacial centers, along with a national Internet survey, which was performed in order to assess the risks of the most serious complications following craniosynostosis operations (see Publication #34). Our study showed that the most common reason that a child did not wake up following craniosynostosis repairs (which fortunately was extremely rare) was usually due to excessive blood loss. For this reason, our center has a major focus on reducing blood loss, and recycling lost blood during craniosynostosis repairs. As an infant gets bigger, the child has more blood to lose, there may be a lower likelihood that a blood transfusion would be necessary, and the surgery may be safer. At our center, before surgery I routinely recommend that infants be given a drug called erythropoietin (see Procrit Information), which raises the child’s blood levels before surgery. We have published a study that shows this helps to prevent the need for blood transfusions, hopefully improving the overall safety of the operation (see Publications #19 and #22). I also use a “cell-saver” that sucks up most all of the blood lost during the operation, filters it, and lets us return it back to the child. These two different techniques (and many other smaller things that are also being done), when combined together, make blood transfusions fairly uncommon at our center. One other reason to avoid transfusion is that some research suggests that patients who get blood transfusions are more likely to get infections after surgery.
  • The other benefit to operating at a later age is that the results are more likely to last a lifetime. Research done in our center examined the long-term growth of the skull for over 10 years following corrections for sagittal synostosis (see Publications # 25). In one of the first studies of its kind, we found that children’s skulls do not grow as they should following the operation (even though the skull shape was completely normalized after surgery); with the skull tending to grow back towards the way it was before the correction. As a result of this research, I have been over-correcting the skull shapes for some time. Perhaps this is why very few of my patients have needed second operations (less than 2%, thus far), even though the reported rates for secondary surgery at other centers is fairly high (between 6% and 35%). Operating on older children, and over-correcting the skull shape during the operation, probably significantly reduces the chance that a child will need a second operation 10 years or more after the first. Another recent study at our center, looking at growth after surgery for all the individual single sutural synostoses, showed that not only is growth abnormal following correction, earlier surgery seems to result in even worse growth, than later operations (see Publication #30).

  

Balancing all of the above factors, it seems that the ideal time to correct single sutural craniosynostosis is somewhere between 10-12 months of age, depending on which suture is involved, the severity of the abnormal skull shape, and a number of other factors.

 

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Final Thoughts

 

It is important to discuss the specifics of any proposed operation with your craniofacial surgeon to make sure that you understand what is being done. Don’t be afraid to ask your local doctors how they will perform your child’s operation and why they choose their particular technique. For more information on what kinds of questions to ask, click on “Choosing a Doctor.” Should you decide that you want the most experienced and specialized care for your child, you can learn more by clicking on “About our Center.

 

 

  

  
    

    
  

  

Examples of a plagiocephaly (left), trigonocephaly (middle) and scaphocephaly (right) seen before surgery (above) and after (below).

Jeffrey Fearon, MD, FACS, FAAP

Director, The Craniofacial Center

7777 Forest Lane, Suite C-700

 Dallas, Texas U.S.A.

972-566-6464

cranio700@gmail.com

 

*** For those who wish to contact Dr. Fearon by e-mail, it is recommended that you add his e-mail address to your address book.  Sometimes e-mail spam filters may block his response to you and there is no way for him to know that you never received his answer.  If you send e-mail and do not get a response, please re-send your e-mail after adding cranio700@gmail.com to your address book, or call us by phone.

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