Surgery for Nonsyndromic Single-Suture Craniosynostosis Treatment & Management

Updated: Feb 22, 2019
  • Author: John A Jane, Jr, MD; Chief Editor: Brian H Kopell, MD  more...
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Treatment

Approach Considerations

No medical treatment exists for craniosynostosis, and helmet therapy alone does not correct the head shape. Because of the progressive nature of the cranial deformity, most children with craniosynostosis are recommended for surgery. However, children with mild deformities or those who present late without signs of increased intracranial pressure (ICP) are occasionally treated without surgery.

The literature is mixed with respect to the ability of surgery to affect cognitive outcomes. [10]  Nevertheless, there has been some evidence to suggest that earlier more comprehensive cranial vault reconstructions are associated with improved cognitive outcomes as compared with less comprehensive procedures or comprehensive procedures performed later. [11, 12]  Even with early comprehensive surgery, studies suggest that subtle learning disabilities persist. [13]

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General Principles of Surgical Therapy

Surgical options

Although there are several options for the treatment of single-suture craniosynostosis (SSC), each is designed to return the skull shape toward a more normal contour. The two basic types of techniques are as follows:

  • Cranial vault reconstruction (CVR)
  • Suturectomy (strip craniectomy), which is most often followed by the use of a molding helmet

CVR has the advantage of immediately correcting the cranial shape but the disadvantage of being a more extensive operation associated with larger incisions, higher rates of transfusion, and longer hospital stays.

A national longitudinal comparison of strip craniectomy (n = 251) with CVR (n = 1811) for craniosynostosis management identified socioeconomic disparities between strip craniectomy patients and CVR patients. [14] CVR was found to be more commonly performed in underrepresented minorities and patients with Medicaid, whereas strip craniectomy was common in the white population and patients with private insurance. Although CVR was associated with higher hospital charges and complication rates than strip craniectomy, the differences were less than expected.

Alternatives to these procedures have also been described, including spring-mediated [15] and external distraction devices. [16] Spring-assisted surgery has gained popularity. It originated in 1997 with Lauritzen in Sweden. [17]  Lauritzen’s group in Gothenburg preferentially uses spring cranioplasty in children up to age 6 months and the modified pi-plasty in older children. [18]  Initial use of this approach has focused on SSC, particularly sagittal synostosis. Distraction osteogenesis for unicoronal craniosynostosis has been described. [19]

Timing of surgical intervention

Although there is not a standard of care regarding the exact timing of surgery for craniosynostosis, surgery is generally recommended during the first year of life. The age at which surgery is performed is somewhat technique-dependent. Endoscopic-assisted suturectomies followed by molding helmet therapy are generally performed prior to 4 months, [20] before the compensatory deformities become more of an issue and while the skull is more malleable. More comprehensive CVRs are generally performed in the second half of the first year of life.

Although earlier surgery may be associated with improved cognitive outcomes, the risk of surgical morbidity and mortality must also be considered. In addition, there is evidence to suggest that earlier surgery is associated with a higher incidence of recurrence and a more frequent requirement for repeat procedures. [21]  The true impact of timing of surgery on neurodevelopmental outcomes has not been defined with certainty. [22]  

Preparation for surgery

CVR procedures to correct craniosynostosis are known to result in extensive blood loss. Bleeding is the main cause of mortality after surgery to correct craniosynostosis. Meticulous hemostasis and early transfusion can mitigate the results of blood loss. [23, 24]

Tranexamic acid (TXA) has been described in the literature as an adjuvant for reducing blood loss and transfusion requirements. A double-blind, placebo-controlled trial was performed with TXA during correction of craniosynostosis. [25] Patients were loaded with 50 mg/kg of TXA after induction of anesthesia, before incision, which was followed by infusion of 5 mg/kg/hr during surgery. These patients were compared with those receiving placebo and found to have lower perioperative mean blood loss (65 mL/kg vs 119 mL/kg) and lower perioperative mean blood transfusion (33 mL/kg vs 56 mL/kg).

Another group, in a randomized double-blind study, pretreated patients with erythropoietin (600 U/kg) once a week for 3 weeks leading up to surgery. [26] The volume of packed erythrocytes transfused was reduced by 85% intraoperatively and by 57% throughout the study period. Other studies in children undergoing cardiac surgery or spinal surgery for scoliosis have found similar benefits.

The mechanism by which TXA works is not well understood; moreover, the studies have been criticized for the heterogenous populations and attenuated power of the studies. [27] Research is ongoing in this area, in particular with regard to TXA dosing.

Controlled hypotension to reduce blood loss during fronto-orbital advancement was studied by Seruya et al. [28] Mean arterial pressure (MAP) and calculated blood loss were evaluated. An inverse relationship between MAP and calculated blood loss was discovered; however, on further evaluation, it was found that blood loss was the cause of changes in MAP.

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Sagittal Craniosynostosis Repair

In sagittal synostosis, the skull is long and narrow. Correction requires reconstruction of the skull so that it is shorter and wider. One factor that must be taken into account during preoperative planning and repair is compensatory growth, which can be anterior, posterior, or both. Frontal bossing can be quite significant, particularly when compensatory growth is anterior.

Surgical goals are to shorten and widen the skull. Additionally, a bifrontal craniotomy is required to correct the frontal bossing. In similar fashion, if the compensatory growth involves the occipital bone, an occipital craniotomy may be beneficial. If compensation involves both the frontal and occipital bones, then surgery often must be performed with the patient in a modified prone position and must include both a bifrontal and an occipital craniotomy. However, some surgeons do not advocate occipital craniotomy, because of the risk of injury to the torcula and transverse sinuses.

Permanent marker is used to outline the areas of frontal bossing and to delineate the planned incision line. The incision line is planned in a curved manner to allow a more cosmetically pleasing result as the child ages. (See the image below.)

Sagittal craniosynostosis (scaphocephaly) repair. Sagittal craniosynostosis (scaphocephaly) repair. Delineation of planned incision.

The bicoronal incision is made, and Raney clips are placed on both sides of the wound to maintain meticulous hemostasis. (See the image below.) One of the more significant risks to an infant undergoing CVR is blood loss. The surgical team and the anesthesiology team must work together to reduce risks and treat blood loss quickly to avoid complications.

Sagittal craniosynostosis repair. Bicoronal incisi Sagittal craniosynostosis repair. Bicoronal incision with placement of Raney clips.

The image below depicts full exposure of the skull with scalp flaps retracted. Note the periorbita anteriorly.

Sagittal craniosynostosis repair. Full view of sku Sagittal craniosynostosis repair. Full view of skull from patient's right.

Permanent marker is used to outline the areas of frontal bossing (see the circles on the anterior portion of the skull in the image below). The margins of the planned cuts to remove the sutures with the craniotome are also drawn with a marker.

Sagittal craniosynostosis repair. Intraoperative p Sagittal craniosynostosis repair. Intraoperative planning.

The anterior fontanelle must be teased away from the surrounding skull before the craniotome can be used to create the cuts that will remove the sutures of interest (see the image below). Care must be taken not to disturb the superior sagittal sinus.

Sagittal craniosynostosis repair. Separation of an Sagittal craniosynostosis repair. Separation of anterior fontanelle from surrounding skull.

The cuts to remove the suture are made with the craniotome (see the image below). The sutures are then easily removed and placed aside to use as part of the final construct.

Sagittal craniosynostosis repair. Removal of sutur Sagittal craniosynostosis repair. Removal of sutures with craniotome.

After the sutures are removed, the skull is assessed to determine how best to use the sutures in the final construct (see the image below).

Sagittal craniosynostosis repair. After suture rem Sagittal craniosynostosis repair. After suture removal.

The area of frontal bossing is removed with the craniotome and a high-speed saw. The bone is then reshaped to remove the bossing effect for a more cosmetic result (see the image below).

Sagittal craniosynostosis repair. Reshaping bossed Sagittal craniosynostosis repair. Reshaping bossed frontal bone.

The frontal bone demonstrating bossing has been removed, split, and reshaped, and it is being evaluated for best orientation (see the image below). The frontal bone is placed so as to obtain the best cosmetic result, independent of the original orientation.

Sagittal craniosynostosis repair. Evaluating place Sagittal craniosynostosis repair. Evaluating placement of reshaped frontal bones.

In the final configuration (see the image below), the frontal bones have been reshaped and reoriented for the best cosmetic result. The sagittal suture and coronal sutures have been removed and cut into smaller pieces. They are reconfigured into the final construct, being attached to the skull with absorbable plates and sutures.

Sagittal craniosynostosis repair. Final configurat Sagittal craniosynostosis repair. Final configuration secured in place.

After closure (see the images below), the reduced anterior-posterior length is apparent. In addition, the frontal bossing noted in the preoperative photo is absent.

Sagittal craniosynostosis repair. Final result aft Sagittal craniosynostosis repair. Final result after closure.
Sagittal craniosynostosis repair. 3D rendering of Sagittal craniosynostosis repair. 3D rendering of thick-slice CT scan performed on postoperative day 1 following a bifrontal craniotomy, bioccipital craniotomy, and and H-type sagittal suturectomy with postcoronal and prelambdoid strip craniectomies.
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Unilateral Coronal Craniosynostosis Repair

The unilateral coronal craniosynostosis produces a forehead that is typically bossed on one side and recessed on the other. In this case, a bifrontal craniotomy is required with reconstruction of the frontal bone. In particular, the bossed area must be recessed and reduced. An orbital rim advancement is also required.

In patients with left unilateral coronal craniosynostosis, the bossed right forehead (child's right) and the recessed left forehead are readily apparent (see the image below).

Unilateral coronal craniosynostosis repair. Left u Unilateral coronal craniosynostosis repair. Left unilateral craniosynostosis.

Upon reflection of the scalp, one can appreciate the recessed left forehead and a bossed right forehead with much more clarity (see the image below). The goal of correction is to bring the left forehead forward and the right forehead back slightly, in relation to each other, so that as the child grows, the forehead will be even when viewed from above. Some centers advocate “overcorrecting” the recessed/synostotic side to prevent recrudescence. The superior orbital rim will be advanced on the left as well, with the use of some autologous bone from the suturectomies.

Unilateral coronal craniosynostosis repair. Reflec Unilateral coronal craniosynostosis repair. Reflection of scalp.

The frontal bones are removed with the craniotome (see the image below).

Unilateral coronal craniosynostosis repair. Remova Unilateral coronal craniosynostosis repair. Removal of frontal bones.

The superior orbital rim is removed with a combination of a high-speed saw and osteotomes (see the first image below). The periorbita is protected with a malleable retractor. Once the superior orbital rim is removed (see the second image below), it is remodeled.

Unilateral coronal craniosynostosis repair. Remova Unilateral coronal craniosynostosis repair. Removal of superior orbital rim.
Unilateral coronal craniosynostosis repair. Excise Unilateral coronal craniosynostosis repair. Excised superior orbital rim.

The superior orbital rim is remodeled in this case by extending the left side with autologous bone and absorbable plates (see the image below). A high-speed drill is also used to achieve a better cosmetic result.

Unilateral coronal craniosynostosis repair. Remode Unilateral coronal craniosynostosis repair. Remodeling of superior orbital rim.

Once the superior orbital has been remodeled to correct the recessed left side and bossed right side (see the image below), it is ready to be reattached with absorbable plates to the surrounding bones, including the frontal bones, which have already been reshaped.

Unilateral coronal craniosynostosis repair. Superi Unilateral coronal craniosynostosis repair. Superior orbital rim remodeled.

The corrected frontal bones and superior orbital rim have been reattached with absorbable plates. The left frontal region is no longer recessed, and the right frontal region is no longer bossed. (See the image below.)

Unilateral coronal craniosynostosis repair. Comple Unilateral coronal craniosynostosis repair. Completed correction of left unilateral coronal craniosynostosis.

With the closure complete (see the image below), the symmetry of the frontal bones is more obvious. The advancement of the left side and partial recession of the right frontal region can be appreciated.

Unilateral coronal craniosynostosis repair. Closur Unilateral coronal craniosynostosis repair. Closure is complete.
Unilateral coronal craniosynostosis repair. 3D-ren Unilateral coronal craniosynostosis repair. 3D-rendered standard CT performed on postoperative day 1 in child with right unilateral craniosynostosis. Note “overcorrected” right previously recessed right forehead.
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Bilateral Coronal Craniosynostosis Repair

The bilateral coronal synostosis produces a skull that is excessively tall and short. The surgery to correct this should produce a skull that is longer in the anterior-posterior dimension and shorter in the superior-inferior dimension. As with the unilateral coronal synostosis, an orbital rim advancement is required. Decreasing the vertical height of the skull can be challenging but can be accomplished using a variety of techniques, each with their particular advantages and limitations.

The example illustrated (see the images below) was performed in two stages. First, a biparieto-occipital osteotomy was performed, with external detractors designed to lengthen the skull but also decrease the vertical height. After the bone consolidated, a standard fronto-orbital approach was performed to correct the recessed forehead and orbital rims.

Bilateral coronal craniosynostosis repair. 3D rend Bilateral coronal craniosynostosis repair. 3D rendering of standard CT performed on postoperative day 1 after consolidation and then months later. Note lengthening of skull, as well as decrease in vertical height.
Bilateral coronal craniosynostosis repair. 3D rend Bilateral coronal craniosynostosis repair. 3D rendering of standard CT performed on postoperative day 1 after subsequent fronto-orbital advancement.
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Metopic Craniosynostosis Repair

Metopic synostosis is characterized by trigonocephaly. The forehead appears ridged, and the patient has hypotelorism and proptosis. This condition is repaired by advancing the orbital rims, which are noted to be recessed, in addition to removing the fused metopic suture. The forehead requires careful reconstruction. Some institutions perform an endoscopic strip suturectomy through a small incision and then helmet the child to reshape the head as the child grows. [29] (See the image below.)

Metopic craniosynostosis repair. 3D rendering of s Metopic craniosynostosis repair. 3D rendering of standard CT performed on postoperative day 1 following fronto-orbital advancement procedure.
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Lambdoid Craniosynostosis Repair

Lambdoid synostosis is characterized by unilateral flattening of the ipsilateral parietal bone and, particularly, the ipsilateral occiput. Compensatory changes include overgrowth of the ipsilateral mastoid bone with inferior deflection of the ipsilateral ear as well as overgrowth of the contralateral parietal bone. This creates a skull that is parallelogram-shaped when viewed from behind.

The goals of surgery are to create a rounder ipsilateral parieto-occipital region, remove and elevate the ipsilateral overgrown mastoid, and reduce the contralateral overgrown parietal bone. (See the image below.) Care should be taken to protect the major venous sinuses during this approach; preoperative computed tomography (CT) venography can be helpful. Multiple options are available to accomplish the reshaping and are less standardized than the options for other craniosynostoses.

Lambdoid craniosynostosis repair. 3D rendering of Lambdoid craniosynostosis repair. 3D rendering of standard CT performed on postoperative day 1 following reconstruction. Bilateral parietal craniotomies were performed, leaving sagittal suture in place. Bioccipital craniotomy was accomplished, and overgrown mastoid bone was removed and then elevated with bone grafts from craniotomies. Bone from contraleral parietal bone was used for occipital reconstruction. Ipsilateral partietal bone was placed contralaterally, and bone from bioccipital craniotomy was used to reconstruct ipsilateral parietal bone.
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Postoperative Care

After cranial vault remodeling procedures, patients are monitored in the pediatric intensive care unit (ICU). Serial hemoglobin and coagulation parameters are evaluated until stabilization is achieved. Patients receive transfusions as needed according to set cutoffs.  Postoperative imaging may be performed to assess for early postoperative complications and to demonstrate the new arrangement of the bony architecture of the cranial vault. 

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Complications

Complications are rare after craniofacial surgery. Hypovolemic shock can occur if significant intraoperative blood loss has not been replaced in a timely manner. Blood loss during surgery has been shown to increase with longer operating times, particularly in excess of 5 hours. Additionally, recognized craniofacial syndromes and pansynostosis have also been associated with increased blood loss during surgery. [30]

Intraoperative dural tears that remain unrecognized can cause postoperative cerebrospinal fluid (CSF) leaks and resultant infection or subgaleal fluid collections. Epidural or subdural hematoma can occur.

Almost all patients develop facial swelling postoperatively, more prominently around the eyes, which rarely causes problems; however, parents and caregivers should be counseled appropriately. Wound infections are generally rare. The frequency of these complications is less than 10%.

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Long-Term Monitoring

Restenosis, though rare, can occur. Long-term follow-up is warranted. Patients are also assessed at regular intervals to monitor for the ossification of cranial defects left during the reconstruction. Serial head circumference measurements are obtained to confirm proper growth of the skull. Although ophthalmologic evaluations do not effectively rule out intracranial hypertension, they can be a useful adjunct in monitoring for its occurrence. 

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