Guideline on Treatment and Management of Craniosynostosis: Patient and Family Version

CHAPTER 1. GENERAL INTRODUCTION Reasoning

Craniosynostosis is estimated to occur in 4.4 to 7.2 children per 10,000 live births. Syndromic craniosynostosis is expected to occur in 0.9 to 1.6 children per 10,000 live births.1,2 These ranges are defined by recent scientific studies in Norway3 and the Netherlands.4 Although we do not know the exact number of people with craniosynostosis across Europe, large differences across European countries are not expected. Different European countries have different health care systems and therefore the number of hospitals treating patients with craniosynostosis is different per country.5

Objective

This guideline document contains recommendations to support daily practice where craniosynostosis is suspected and after confirmation of this diagnosis. The guideline provides recommendations for health care providers in recognizing craniosynostosis, the logistics involved in parent referrals to craniofacial centres, multidisciplinary care within a craniofacial centre, and requirements that a craniofacial centre and its members must meet. Thus, the guideline provides a focus on uniform care in craniosynostosis and the implementation of this care in the Netherlands. This section looked at craniosynostosis of 1 cranial suture (isolated), multiple cranial sutures (multisuture), and syndromic craniosynostosis. The first guideline was issued in 2010. In 2017, the Dutch Society for Plastic and Reconstructive Surgery decided to revise the guideline as a number of items required an update based on recent scientific literature, and because the topics on prenatal detection and speech/language development were not yet included.

Target Group

This version of the guideline is primarily intended for parents and patients.

About Craniosynostosis

Craniosynostosis concerns a congenital skull defect, in which 1 or more cranial sutures are already fused before birth. The cranial sutures are located between the bone plates of the skull and allow for the rapid growth of the skull in the first 2 years of life. The growth of the skull is largely controlled by the growth of the brain.

Cranial sutures are essential for skull growth in the first 2 years (during the brain’s rapid growth). Premature fusion of cranial sutures prevents normal skull growth, resulting in characteristic shape deviations of the skull.

Craniosynostosis occurs in 1 in every 2100 to 2500 births and may occur as either nonsyndromic (also indicated as isolated) or syndromic. Syndromic craniosynostosis occurs when other birth defects are present in addition to craniosynostosis. In syndromic cases, several cranial sutures are often fused, usually involving both coronal sutures.

The distinction between nonsyndromic and syndromic is determined by a clinical geneticist doing a physical examination and through genetic testing.

The types of craniosynostosis are classified as follows:

Isolated (a single fused suture), nonsyndromic:

Sagittal suture synostosis (scaphocephaly; characterized by a long narrow head): (All images: ERN CRANIO, accessed September 19, 2022).6 Metopic suture synostosis (trigonocephaly; characterized by a triangular forehead): Coronal suture synostosis, 1-sided (frontal plagiocephaly; flattening of 1 side of the forehead):

Lambdoid suture synostosis (pachycephaly; flattening of the back of the head):

Multisuture (multiple fused sutures) or syndromic: Apert syndrome (FGFR2 mutation Ser252Trp and Pro253Arg, deletion exon IIIc, Alu insertion exon IIIc): Crouzon or Pfeiffer syndrome (FGFR2 mutations except Apert mutations, rarely FGFR1 mutations or—if combined with the skin condition acanthosis nigricans—FGFR3 mutations): Saethre-Chotzen syndrome (TWIST1 mutations or deletions): Muenke syndrome (Pro250Arg FGFR3 mutation):

Craniofrontonasal dysplasia (EFNB1 mutations) TCF12 associated craniosynostosis ERF associated craniosynostosis ILRA associated craniosynostoses Multisuture craniosynostoses (also called complex craniosynostoses), often 2 or more fused cranial sutures with no known genetic cause. CHAPTER 2. METHODOLOGY FOR GUIDELINE DEVELOPMENT

The following persons participated in updating and revising the guideline:

Nederlandse Vereniging voor Plastische Chirurgie (Dutch Association for Plastic Surgery) Prof I.M.J. Mathijssen, Erasmus Universitair Medisch Centrum (Erasmus University Medical Center), Rotterdam Dr S.L. Versnel, Erasmus University Medical Center, Rotterdam Patiënten- en oudervereniging LAPOSA (LAPOSA Patients and Parents Association) Ms B. Lieuwen, Msc, Ma Nederlands Instituut voor Psychologen (Dutch Association of Psychologists) + Landelijke Vereniging Medische Psychologie (National Association of Medical Psychology) Dr J.M.E. Okkerse, Erasmus University Medical Center, Rotterdam Mr J.J. Reuser, Radboud University Medical Center, Nijmegen Nederlands Oogheelkundig Gezelschap (Dutch Ophthalmic Society) Dr S.E. Loudon, Erasmus University Medical Center, Rotterdam Nederlandse Vereniging voor Anesthesiologie (Dutch Society of Anesthesiology) Mr A. Gonzalez Candel, Erasmus University Medical Center, Rotterdam Nederlandse Vereniging voor Keel-, Neus-en Oorheelkunde (Dutch Society for Ear Nose and Throat Surgery) Dr M.P. van der Schroeff, Erasmus University Medical Center/Sophia, Rotterdam Ms H.H.W. de Gier, Erasmus University Medical Center/Sophia, Rotterdam Nederlandse Vereniging voor Kindergeneeskunde (Dutch Pediatric Association) Dr K.F.M. Joosten, Erasmus University Medical Center/Sophia, Rotterdam Dr N. Bannink, Franciscus Gasthuis and Vlietland, Rotterdam and Schiedam Mr L.G.F.M. van ‘t Hek, Radboud University Medical Center, Nijmegen Nederlandse Vereniging voor Mondziekten, Kaak-en Aangezichtschirurgie (Dutch Association for Oral and Maxillofacial Surgery) Prof E.B. Wolvius, Erasmus University Medical Center, Rotterdam Dr W.A. Borstlap, Radboud University Medical Center, Nijmegen Nederlandse Vereniging voor Neurochirurgie (Dutch Society of Neurosurgery) Dr M.L.C. van Veelen, Erasmus University Medical Center, Rotterdam Dr H.H.K. Delye, Radboud University Medical Center, Nijmegen Vereniging Klinische Genetica Nederland (Dutch Society of Clinical Genetics) Dr M.F. van Dooren, Erasmus University Medical Center, Rotterdam Vereniging Klinische Genetische Laboratoriumdiagnostiek (Association of Clinical Genetic Laboratory Diagnostics) Dr R. Pfundt, Radboud University Medical Center, Nijmegen Nederlandse Vereniging voor Logopedie en Foniatrie (Dutch Society for Speech Therapy and Phoniatrics) Dr M.C.J.P. Franken, Erasmus University Medical Center/Sophia, Rotterdam Ms E. Kerkhofs, Radboud University Medical Center, Nijmegen Nederlandse Vereniging voor Obstetrie and Gynaecologie (Prenatale geneeskunde) (Dutch Society for Obstetrics and Gynecology (Prenatal Medicine)) Dr T.E. Cohen-Overbeek, Erasmus University Medical Center/Sophia, Rotterdam Ms M. Woiski, Radboud University Medical Center, Nijmegen Nederlandse Vereniging voor Orthodontisten (Dutch Union of Orthodontists) Dr S.T.H. Tjoa, Erasmus University Medical Center/Sophia, Rotterdam Nederlandse Vereniging voor Radiologie (The Radiological Society of the Netherlands) Dr M.H.G. Dremmen, Erasmus University Medical Center/Sophia, Rotterdam Nederlandse Vereniging Relatie-en gezinstherapie (Dutch Association for Relationship and Family Therapy) Ms F. Meertens, Erasmus University Medical Center/Sophia, Rotterdam Koninklijk Nederlands Genootschap voor Fysiotherapie/Nederlandse Vereniging voor Fysiotherapie in de Kinder- en Jeugdgezondheidszorg (Royal Dutch Society for Physiotherapy/Dutch Association for Physiotherapy in Child and Youth Health Care) Dr L.A. van Vlimmeren, Radboud University Medical Center, Nijmegen Nederlandse Vereniging voor Psychiatrie (Dutch Society for Psychiatry) Ms M.H.M. van Lier, Erasmus University Medical Center/Sophia, Rotterdam Nederlandse Vereniging voor Neurologie (Dutch Society for Neurology) Prof M.A.A.P. Willemsen, Radboud University Medical Center, Nijmegen Supported by: Ms B.S. Niël-Weise, medical microbiologist (nonpracticing), independent guideline methodologist, Deventer Dr J.J.A. de Beer, independent guideline methodologist, Utrecht Mr H. Deurenberg, SIROSS, information specialist, Oss CHAPTER 3. REFERRAL AND DIAGNOSTICS Question 3.1: What are the implications for pregnancy care once craniosynostosis is diagnosed prenatally?

Craniosynostosis is very rarely diagnosed during pregnancy. Testing (prenatal diagnosis) can be done in an academic hospital if craniosynostosis is already suspected during pregnancy. Once craniosynostosis has been diagnosed, the counseling and possible treatment will be taken over by the specialist centre. This is necessary because there is a higher risk of obstructed labor during childbirth with all forms of craniosynostosis. Furthermore, syndromic craniosynostosis requires proper care due to possible breathing problems in the baby during birth.

Question 3.2: What is the policy on recognition, referral, and radiological diagnostics in primary or secondary care in children with suspected craniosynostosis?

Craniosynostosis should be recognized in time for optimal treatment. Craniosynostosis patients, however, often turn out not to be recognized or to be referred at a late stage. This is often because it is thought that the child’s preferred posture is the cause of an abnormal skull shape, which is far more common than craniosynostosis. Because a special flowchart is used more and more in primary or secondary care (general practitioners, clinic doctors, and pediatricians), diagnosis and referral have improved considerably. The presence of an abnormal skull shape immediately after birth, whether or not there is a preferred posture and whether improvement has occurred in the skull shape, are points that are included in the flowchart.

Excessive diagnostics are often carried out before referral to an academic hospital (tertiary care), which leads to a further delay in referral, an additional burden and uncertainty for the patient and parents, and unnecessary costs. Testing can take place in the specialist centre to determine whether and which cranial sutures are fused. This is preferably done with an ultrasound scan of the head as this does not generate radiation. However, it does require more experience from the radiologist. An x-ray of the head can also be taken, but the assessment of this also requires a lot of experience and the examination does generate some radiation. A 3-dimensional computed tomography (3D-CT) scan of the skull is the most reliable examination and can usually be done quickly, but does generate radiation. In the case of syndromic craniosynostosis, magnetic resonance imaging (MRI) of the brain may be necessary.

Question 3.3 What is the policy regarding genetic diagnostics in a child with confirmed or suspected craniosynostosis?

In principle, genetic diagnosis is done in a craniosynostosis specialist centre as soon as the diagnosis is confirmed and once parents have agreed to it. The role of the clinical geneticist within a multidisciplinary craniofacial team is aimed at being able to answer the questions of both the parents and the treating physicians.

The most important questions of the parents are whether their child is otherwise healthy, what the cause of the condition is, how big the chance of recurrence is for any further children in their family and/or future grandchildren, and what the possibilities are of prenatal diagnosis. As to conducting genetic diagnostics, this depends on the parent’s values and preferences.

Recommendations

Question 3.1

If the general practitioner or obstetrician suspects craniosynostosis when doing an ultrasound, the pregnant woman should be referred to an academic hospital for prenatal diagnosis. If the diagnosis of craniosynostosis is made there, the pregnant woman will be referred to the craniosynostosis specialist centre for counseling and guidance.

Question 3.2

Use the flowchart to ensure craniosynostosis is better recognized in primary and secondary care. A child suspected to be suffering from craniosynostosis is referred to a craniosynostosis specialist centre as soon as possible, without additional diagnostics. This increases the likelihood that children may still qualify for a minimally invasive operation before the age of 6 months. Skull x-rays or an ultrasound of the skull are always done if there is a moderate suspicion of craniosynostosis. If there is a strong suspicion of craniosynostosis based on external features, a 3D-CT is immediately done for diagnostic purposes. Children with syndromic craniosynostosis are sometimes given additional MRI scans to assess other brain disorders and symptoms of increased intracranial pressure (ICP) before surgery.

Question 3.3

Genetic diagnosis is done in a specialist centre. Targeted genetic testing is done in children with proven craniosynostosis and obvious external features. More extensive and broader genetic testing is done in children with established craniosynostosis combined with other congenital disorders and/or developmental delays. CHAPTER 4. PERIOPERATIVE CARE Question 4.1 What is the perioperative surgical management of craniosynostosis?

The correction of craniosynostosis during childhood can be associated with relatively high blood loss. This risk increases with extensive and open skull surgery. Administering certain medications and collecting blood and returning it to the patient during surgery can reduce blood loss and blood transfusions. In addition to the surgical and anesthetic challenge, other conditions (comorbidities) that may be associated with the syndromic conditions must be taken into account. For this reason, strict organizational conditions must be imposed on the surgical process, before, during, and after the procedure.

Which medicines, blood products, or measures, like inducing low blood pressure or use of the cell saver are effective in reducing blood loss or the need for a blood transfusion?

The use of tranexamic acid (a medicine that prevents the breaking down of blood clots) probably ensures that far fewer blood products have to be administered as a result of blood loss.

The use of a cell saver (a device that collects lost blood and returns it to the patient) and erythropoietin (medicine that promotes the production of red blood cells) may result in fewer blood products having to be transfused due to the occurrence of less blood loss.

The effect of other strategies is still unproven.

By administering fibrinogen (a coagulation factor) based on an extensive coagulation measurement, in which a value of <13 mm is pursued on FIBTEM (part of the coagulation test), there may be less blood loss than when pursuing a value of <8 mm. Whether it is safe to administer fibrinogen at a limit value of 13 mm has not yet been demonstrated.

Administering fresh frozen plasma (blood plasma) before blood loss occurs, does not lead to less blood loss compared with when it is only administered when blood loss has already occurred and there is an immediate need.

No difference in actual blood loss is seen with a mean blood pressure between 55 mm Hg and 65 mm Hg. Therefore, striving for low-normal blood pressure is not of any added benefit.

It is unclear whether the administration of vitamin K1 (a substance that causes the production of clotting factors) leads to less blood loss and fewer blood transfusions.

Recommendations

Question 4.1

Children with craniosynostosis are only treated in a specialized pediatric centre. Use tranexamic acid during surgery to limit blood loss. Consider collecting the patient’s blood during surgery (using a cell saver) and then returning it to limit the number of blood transfusions. Use fresh frozen plasma and/or fibrinogen as soon as signs of abnormal coagulation develop during surgery. CHAPTER 5. SURGICAL TREATMENT OF ISOLATED, NONSYNDROMIC CRANIOSYNOSTOSIS Question 5.1 What is the surgical management of nonsyndromic craniosynostosis?

The 4 most common forms of isolated, nonsyndromic craniosynostosis are in order of occurrence: (1) sagittal suture synostosis, (2) metopic suture synostosis, (3) unilateral coronal suture synostosis, and (4) unilateral lambdoid suture synostosis. Unilateral coronal suture synostosis may be associated with a syndrome, such as Muenke or Saethre-Chotzen syndrome, and a possible genetic cause should be considered.

(1) What is the indication for surgical treatment?

Nonsyndromic craniosynostosis can present with varying severity of skull abnormality. Surgical treatment seems to be assessed based on: The associated risk of ICP Preventing or limiting associated brain abnormalities The external abnormality (with both esthetic and psychological consequences) Surgical treatment of sagittal suture, unilateral coronal suture, and unilateral lambdoid suture synostosis is indicated as no spontaneous improvement of the abnormal skull shape is expected. In children with a mild or moderate triangle-shaped skull (metopic synostosis), there is doubt as to the usefulness and necessity of surgery. Only with a pronounced “severe” triangle-shaped skull does surgery actually improve the appearance.

(2) What are the patient-relevant effects of different surgical techniques, in particular minimally invasive surgery versus open skull surgery for the 4 types of nonsyndromic synostosis?

Many different surgical techniques have been described for the treatment of unilateral, nonsyndromic craniosynostosis. Minimally invasive surgery (the removal of the fused cranial suture and helmet therapy or spring-assisted distraction) and open skull correction are the current techniques being used. Minimally invasive surgery is associated with less blood loss, fewer blood transfusions, shorter surgery duration and admission time, and a similar esthetic result in both sagittal sutures,7 metopic suture,8 unicoronal suture,9 and unilambdoid suture synostosis compared with “classic” open skull surgery of the metopic suture,10 coronal suture,11 sagittal suture,12 and lambdoid suture. Spring-assisted distraction in sagittal suture synostosis13 is probably less likely to lead to ICP in the years after surgery than an open skull correction. Ophthalmic results after a minimally invasive procedure with coronal suture synostosis may also be better than with an open correction. It is as yet unclear whether this is due to the type of operation, the severity of the abnormality, or the time, at which surgery is done. However, there is still little information on the occurrence of ICP in follow-up, the development of long-term appearance and neurocognitive outcomes in children who have undergone minimally invasive surgery. There is no scientific evidence to make a choice between the 2 methods of minimally invasive surgery (fused cranial suture removal and helmet therapy versus spring-assisted distraction).

(3) What are patient-relevant effects of the different timing of surgery, that is, “early” (under 6 mo of age) versus “late” (over 6 mo of age)?

Minimally invasive surgery is almost always performed before the age of 6 months. Open cranial corrections are mainly performed after this age. In children with sagittal suture synostosis, the likelihood of developing ICP increases over the course of the first year of life (from 2.5% at 6 mo to 10% at 11 mo). Surgery is therefore advisable before the age of 6 months. With metopic suture synostosis, the probability of ICP within the first year of life remains low. There is no need to perform the operation before the age of 6 months. An early endoscopic operation may lead to better ophthalmic results in coronal suture synostosis. This may be because of the early timing of the operation or because it is usually only children with a “mild” form who undergo this type of surgery. The early and late treatment for unilateral lambdoid suture synostosis may lead to a similar esthetic result. Results of the comparisons between open and minimally invasive corrections come from studies that collectively present weak evidence due to limitations in the studies themselves or because studies do not show quite the same results. Recommendations

Question 5.1

Do not operate on children with a bony ridge over the metopic suture or with a mild form of trigonocephaly. No recommendation is given as to whether or not to operate on children with a moderate form of trigonocephaly. At the age of 5 years, assess the appearance of children with a mild and moderate form of trigonocephaly who have not had surgery yet. Surgical correction of the abnormality is indicated in all other forms of isolated, nonsyndromic craniosynostosis. Perform minimally invasive surgery on a child with sagittal suture synostosis if younger than 5.5 to 6 months. If the child is older, an open correction is preferably done. No recommendation is given with regard to the type of surgery with metopic suture, unicoronal suture, and unilateral lambdoid suture synostosis. Surgery for isolated nonsyndromic craniosynostosis is done within the first year of life. With sagittal suture synostosis, the operation is preferably done before the age of 6 months. For metopic suture, unicoronal suture, and unilateral lambdoid suture synostosis, there is no recommendation with regard to the timing of the operation. Early referral to the specialist centre (well before the age of 6 mo) ensures the minimally invasive surgical option is possible. CHAPTER 6. SURGICAL TREATMENT OF SYNDROMIC CRANIOSYNOSTOSIS—THE CRANIAL VAULT Question 6.1 What is the policy on surgical treatment of the cranial vault in multisuture and syndromic craniosynostosis?

The distinction between multisuture craniosynostosis (multiple fused cranial sutures) and syndromic craniosynostosis is made based on external features. Multisuture craniosynostosis can occur in all variations of 2 or more affected cranial sutures. In this group, new genetic causes for craniosynostosis are still identified, such as the genes TCF12, ERF, and IL11RA. Multiple congenital defects are present in syndromic craniosynostosis. The 4 most common forms of syndromic craniosynostosis are: (1) Apert, (2) Crouzon (including Pfeiffer syndrome), (3) Saethre-Chotzen, and (4) Muenke syndrome.

(1) What are the patient-relevant effects of different indications for surgical treatment of multisuture and syndromic craniosynostosis, that is, routine treatment versus in response to signs of elevated intracranial pressure?

Internationally, there are different opinions regarding the type of operation that is carried out first and when this happens. In the various international centres, the first skull operation is sometimes an expansion of the occiput14 or the forward positioning of the forehead. The first skull expansion is often performed at a certain age, based on protocol, but in 1 specific centre, only when signs of ICP have been detected. The number of children with Apert or Crouzon syndrome who are operated on, when this is done according to protocol, is 10% to 20% higher than when surgery only takes place based on symptoms of ICP. The latter option can only be done safely if there is frequent testing for signs of ICP, such as through an ophthalmoscope or other ophthalmic examinations. However, these tests are not 100% reliable, so ICP can be missed. In patients with Saethre-Chotzen syndrome or multisuture craniosynostosis, surgery is required for both abnormal skull shape and the risk of ICP. For Muenke syndrome, an abnormal skull shape is the main indication for surgery, given the low risk of ICP. There is no relevant difference in the occurrence of ICP in Apert and Crouzon syndrome after 5 years of follow-up among patients who have had protocol-based surgery than with surgery after signs of ICP. With Saethre-Chotzen syndrome, Muenke syndrome, and multisuture craniosynostosis, there is as yet no clarity about this.

(2) What are the long-term surgical specific outcomes of different surgical techniques, in particular minimally invasive surgery (endoscopic strip craniectomy with helmet therapy or spring-assisted distraction or conventional distraction (slowly twisting bone elements apart) of the occiput versus open cranial correction (of forehead or occiput)?

An occipital expansion14 (with distraction or springs) in patients with Apert and Crouzon syndrome probably results in an increased skull circumference, increased cranial volume, less deviation in the positioning of the cerebellum (tonsillar herniation), and a reduced occurrence of ICP compared with an expansion of the forehead or an expansion of the occiput without distraction. These better outcomes of occipital surgery are found up to 5 years after surgery. Minimally invasive surgery through endoscopic removal of the fused coronal sutures with helmet therapy in syndromic craniosynostosis has a higher risk of repeat surgery due to delayed skull growth or signs of excessive intracranial pressure occurring within 1 year of surgery. An endoscopic operation does have less blood loss, shorter surgical time, and shorter hospitalization time than an open skull operation.

(3) What are the long-term results regarding cognition and esthetics (appearance) of the different timing of surgery, that is, “early”, defined as before the age of 12 months, versus “late”, that is, after the age of 12 months?

Patients with syndromic craniosynostosis or in whom both coronal sutures are fused, who undergo cranial surgery within the first 12 months, may have a higher Intelligence Quotient (IQ) than patients who are operated on after the first 12 months. Cranial surgery from the age of 6 to 9 months gives a better esthetic result in patients with Muenke syndrome than an earlier operation. Excessive intracranial pressure is relatively rare in this syndrome, and therefore this “later” operation cannot harm. Cranial surgery between 6 and 9 months in patients with Apert, Crouzon, or Saethre-Chotzen syndrome leads to better esthetic results than surgery before or after that period. Recommendations

Question 6.1

Operate on children with syndromic craniosynostosis or multisuture craniosynostosis. Patients should be screened regularly for ICP if it was decided to wait to operate. If ICP then occurs, it is necessary to operate. Evaluate the neurocognitive functioning and vision of children with multisuture or syndromic craniosynostosis at the age of 7. In patients with Apert and Crouzon syndrome and in patients with multisuture craniosynostosis where at least both occipital sutures are fused, the first cranial surgery is done on the back of the head using cranial distraction. Patients with Saethre-Chotzen and Muenke syndrome will have the first cranial surgery to enlarge the forehead with the upper half of the edge of the eye socket. In other forms of syndromic craniosynostosis, the type of surgery depends on the cranial deformity. Consider minimally invasive treatment in patients with nonsyndromic craniosynostosis in whom both coronal sutures are fused. In other multisuture craniosynostosis, the type of surgery being done depends on the cranial deformity. There is no evidence available as to whether open or minimally invasive surgery is better. In multisuture and syndromic craniosynostosis, the surgery takes place between 6 and 9 months. In Muenke syndrome, the surgery takes place between 9 and 12 months. Minimally invasive surgery for multisuture craniosynostosis should be performed as early as possible, and at the latest before the age of 6 months. CHAPTER 7. SURGICAL TREATMENT OF SYNDROMIC CRANIOSYNOSTOSIS—FACIAL Question 7.1 What is the surgical management of the face in syndromic craniosynostosis with underdevelopment of the upper jaw and eye sockets?

Apert and Crouzon syndrome are associated with underdevelopment of the upper jaw, too shallow eye sockets, and too far apart eyes and to a lesser extent with underdevelopment of the lower jaw. The indication for surgical correction varies from an acute drop in vision, breathing problems, the lower jaw not fitting on the upper jaw or an esthetic problem, and the resulting psychological consequences. Various different techniques are possible to correct these deformities, the timing of which has a major influence on the final result.

(1) What are the surgical specific factors that influence the choice between the different surgical techniques (internal versus external distraction and Le Fort III osteotomy versus variations on Le Fort III osteotomy) for the treatment of an underdeveloped midface (midface hypoplasia)?

A Le Fort III operation15 (midface from upper jaw to lower eye socket edges) with distraction (slowly twisting bone elements apart) can move the middle face further forward than a Le Fort III without distraction. There is also less recurrence of the forward displacement after the use of distraction. It is preferable to place an external frame instead of internal distractors because the direction of displacement can be better influenced. Possible other advantages of an external frame are better facial concavity correction and fewer wound infections. A monobloc operation (midface, forehead, and upper eye socket edges) with distraction16 (with external frame or internal distractors) corrects the too-shallow eye sockets and breathing problems. Complications such as the leakage of cerebrospinal fluid and problems with the equipment are hardly different from each other in both methods. In Apert syndrome, a facial bipartition17 (monobloc and bringing together of the eye sockets) with distraction is preferably performed with an external frame. A Le Fort II18 operation (upper jaw to nose) with distraction combined with bringing both sides of the cheekbones (forward also has better facial contour results than a Le Fort III operation) with distraction.

(2) What are the long-term surgical specific results of the different timing of surgery in the absence of a hard indication, that is, “early”, defined as before the age of 6 to 8 years, versus “late”, that is, after the age of 6 to 8 years?

A Le Fort III without distraction, performed before the age of 6 years, probably leads to a high risk of recurrent midface hypoplasia in adulthood. A Le Fort III with external distraction performed before the age of 8 years without overcorrection (more correction than necessary at the age of surgery) increases the risk of recurrent midface hypoplasia in adulthood. A monobloc (bringing forward the entire face and forehead) with external distraction seems to provide a good forward movement of the face, regardless of the age at which surgery is performed. This procedure performed before the age of 8 years seems to lead to a higher risk of recurrence of respiratory problems. Recommendations

Question 7.1

A midface advancement in children with Apert and Crouzon/Pfeiffer is actually always combined with distraction. An external frame is preferably used for a Le Fort III distraction and a facial bipartition. If an external frame is necessary, then the placement of internal distractors can also be considered. It is therefore possible to remove the frame earlier, as soon as the distraction is completed. The type of surgery required is determined based on the facial deformity of the individual patient. Perform a midface advancement with distraction in children with Apert syndrome and Crouzon between 8 and 12 years of age, or from 17 years of age. The operation should be performed earlier if there are serious breathing problems during sleep or the eyes cannot be closed properly and damage to the cornea may occur. A midface advancement should preferably not be carried out between the ages of 12 and 17 years, because there is a higher chance of psychosocial problems and unrealistic expectations of the treatment result. CHAPTER 8. INCREASED INTRACRANIAL PRESSURE Question 8.1 How is ICP in craniosynostosis treated?

The risk of ICP varies greatly depending on the type of craniosynostosis, with the multisuture form and syndromic form associated with a much higher risk than the isolated nonsyndromic form. However, the risk of these problems in the isolated nonsyndromic group is much less recognized and therefore possibly underdiagnosed if present. It is important to promptly detect and treat ICP. High intracranial pressure, for example, can lead to irreversible vision impairment. It is unclear, which method is most suitable for detecting ICP, which cutoff values should be used, and how often this examination should be carried out to detect problems in time.

Increased intracranial pressure is caused by craniocerebral imbalance, aberrant venous drainage, obstructive sleep apnea (OSA) syndrome, an abnormal location of the cerebellum, and hydrocephalus. The risk of ICP continues to increase as long as there is no surgery. Sometimes, ICP occurs in the years after cranial-expansion surgery.

(1) What is the occurrence of ICP in different types of craniosynostosis?

Sometimes, with unisutural craniosynostosis, ICP already exists before the operation. With sagittal suture synostosis, this is in 2.5% to 14% of children. With metopic suture synostosis, it occurs in 2% to 8% of children. With unicoronal suture synostosis, this is the case in 16% of children. In some situations, ICP still occurs in the years after the skull operation. For sagittal suture synostosis, this occurs in 2% to 9% and with metopic suture, in 1.5% of cases. How often this occurs with unicoronal suture synostosis is unknown. Before cranial surgery, ICP occurs in children with Apert syndrome in 9% to 83%, Crouzon syndrome in 53% to 64%, Saethre-Chotzen in 19% to 43%, and Muenke syndrome in 0% to 4% of cases. After cranial surgery, ICP occurs in 35% to 45% of children with Apert, 20% to 47% with Crouzon, 17% to 42% with Saethre-Chotzen, and 0% to 5% of children with Muenke syndrome. When several cranial sutures are fused, ICP after cranial correction occurs in 58% to 67% of cases. In bicoronal suture synostosis after cranial correction, it is present in 31% of children.

(2) What is the diagnostic accuracy of the following diagnostic tools for detecting or excluding ICP: (1) (abnormal) head circumference growth curves, (2) presence of imprint of the brain/blood vessels on the inside of the skull on x-ray, (3) optic nerve ultrasound, (4) presence or absence of papilloedema (fluid around the optic nerve) detected by fundoscopy and (5) OCT (optical coherence tomography—measuring the thickness of the retina)?

A deviating growth curve of the cranial circumference can be used to demonstrate ICP in metopic suture synostosis. This method is less suitable for sagittal suture synostosis. This is because a deviating growth curve does not always indicate the presence of ICP. The usefulness of the cranial circumference growth curve has not yet been investigated and described for unicoronal suture synostosis. The growth curve of the cranial circumference can probably be used in syndromic craniosynostosis to determine ICP. The presence or absence of visible imprints of the gyri of the brain on an x-ray, if a child is under 18 months of age may be unreliable for determining the presence of ICP. The presence of visible gyri of the brain on x-ray is a reliable sign of ICP, but the absence of these signs does not mean that intracranial pressure is normal. For children aged 18 months to 4 years using these signs as a screening method is more reliable. If a coronal suture also closes after the operation for sagittal suture synostosis in the first 2 years, this may lead to a higher risk of ICP. An ultrasound to check the thickness of the optic nerve does not seem to be a reliable screening method for determining ICP. Papilledema in an ophthalmoscope (fundoscopy) may be a sign of ICP, but the absence of papilledema in children under 8 years of age does not exclude ICP. Optical coherence tomography eye tests are probably a reliable method to screen for ICP, but can only be performed properly if the child cooperates properly.

(3) What are the craniosynostosis-specific factors at play in the choice between the different surgical techniques to treat ICP?

The reason for ICP in sagittal suture synostosis is often a skull that is too small. Therefore, treatment is aimed at enlarging the skull. There are multiple causes for syndromic craniosynostosis, such as a too small skull volume, moderate to severe breathing problems, hydrocephalus, or too high pressure in the veins in the brain. The treatment is aimed at removing the main cause of the ICP. Recommendations

Question 8.1

Screen annually for ICP in sagittal suture synostosis using an ophthalmoscope and/or OCT up to and including the age of 6 years. Screen annually for ICP in the metopic suture, unicoronal suture, and unilateral lambdoid suture synostosis by measuring the cranial circumference. If there is a deviating growth curve, an ophthalmoscopic, or OCT eye test is also done. Children with syndromic and multisuture craniosynostosis are screened for ICP up to and including the age of 6 years. In Crouzon syndrome, this is once every 4 months until the age of 2, then every 6 months until the age of 4, and then every year. Screen every 6 months with Apert syndrome, Saethre-Chotzen, and multisuture craniosynostosis, and every year for Muenke syndrome. The treatment of ICP depends on the causative factors and treatment should be adapted accordingly. CHAPTER 9. HYDROCEPHALUS Question 9.1 What is the surgical management of hydrocephalus in craniosynostosis?

Hydrocephalus is an increase in the width of the cranial chambers that accompanies signs of ICP. This should be distinguished from enlarged chambers containing cerebrospinal fluid without ICP (ventriculomegaly). These disorders can cause problems in the functioning and development of children. Both disorders are almost nonexistent (0.88%) in nonsyndromic craniosynostosis and therefore are not discussed further in this chapter.

(1) How common is hydrocephalus in children with craniosynostosis and how can it be detected?

Ventriculomegaly occurs regularly (8% in Muenke; 6%–17% in Saethre-Chotzen; 24% in multisuture craniosynostosis) to common (13%–56% in Crouzon; 39%–71% in Apert) in syndromic craniosynostosis. Patients with Apert syndrome and a Chiari (partial sagging of the lower part of the cerebellum in the foramen magnum that impedes the flow of the cerebrospinal fluid) have a greater chance of ventriculomegaly. Hydrocephalus occurs in 6% to 26% of children with Crouzon/Pfeiffer, 0% to 6% in Apert, and 5% to 12% in multisuture craniosynostosis, and does not occur or is very rare in Saethre-Chotzen and Muenke syndrome.

(2) What are the factors in the location and structure of the brain that influence the choice between different surgical techniques for the treatment of hydrocephalus?

The factors that predict a successful treatment are not known. Hydrocephalus in craniosynostosis can possibly be treated properly with an expansion of the skull or the placement of a drain from the ventricle to the abdomen to allow for the discharge of excessive cerebrospinal fluid (ventriculoperitoneal shunt). It is also possible to make a hole in the bottom of the third ventricle so that cerebrospinal fluid can flow off in another way (endoscopic third ventriculostomy) or to enlarge the foramen magnum (foramen magnum decompression). Both good and bad results have been described for all these treatments. If the treatment performed has not helped sufficiently, another follow-up treatment may be necessary. Recommendations

Question 9.1

Screen all patients with Crouzon syndrome and multisuture craniosynostosis with MRI upon referral. Patients with ventriculomegaly should be given a second MRI to exclude hydrocephalus. When this is done, depends on the progress of the condition itself and what symptoms occur over time. Treat hydrocephalus by cranial expansion with or without decompression of the foramen magnum by placing a ventriculoperitoneal shunt or making a hole in the bottom of the third ventricle. The treatment being used is adapted per patient, and depends on the MRI results, among other things. The posttreatment effect is monitored well by MRI scans. If the treatment does not reflect the desired result, an additional treatment is used

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