Open Operation for Nonsyndromic Craniosynostosis in Children

Sagittal Craniosynostosis – Posterior Vault Remodeling

• Variety of techniques: There are various ways to correct sagittal synostosis. Surgeons may correct the anterior cranial vault, the posterior cranial vault, or the complete cranial vault. Most believe that a complex cranioplasty gives better results than a simple suturectomy (unless a helmet is used afterward) (8, 9, 27, 34). Below is the description of the posterior two-thirds cranial vault reconstruction. In the author’s hands it does not require anterior cranial vault surgery as the barrel staving allows the bitemporal regions to expand the frontal bossing to regress.

Patient Positioning

• Prone: The patient should be placed in the prone position.

Surgical Approach (28, 34)

• Bicoronal scalp incision: A stealth bicoronal incision is marked and injected with normal saline. The skin is opened with two surgeons using needle tip electrocautery between 12 and 15W. The galea is opened from inside out.
• Scalp reflected in subgaleal plane: The periosteum is left on the bone initially. The galea and skin are dissected as a unit toward the posterior fossa past the most extensive portion of the bony prominence. The periosteum is elevated anteriorly just passed the coronal suture.
• Craniotomy incision line cleared of pericranium: The periosteum is incised along the midline, posterior to the coronal sutures and anterior to the lambdoids. This will leave three flaps with excellent blood flow to place over the reconstruction.

Intervention

• Biparietal craniotomy: A biparietal craniotomy is taken to just behind the coronal sutures and just anterior to the lambdoids. Two bur holes are placed anterior to the lambdoid sutures on either side of the sagittal suture, and two are placed at the squamosol/lambdoid junction. The anterior fontanelle is used for the anterior bur holes. Two bur holes are placed behind the coronal suture at the squamosol suture. The dura is removed off the inner table. The parietal craniotomy is taken to just behind the coronal sutures, down past the temporal squamosol suture, and in front of the lambdoids. The sagittal suture is left attached to the occipital bone. Next, the dura is removed from the posterior bone. It is difficult to remove at the site of the closed posterior fontanelle. The dura will be easier to remove if dissection is performed with a Penfield One Dissector from the lateral to the medial side. The occipital craniotomy is performed low in the occiput and must encompass the posterior bony prominence. The occipital bone is removed with the attached sagittal suture
• Barrel stave occiput: Barrel staving of the occipital bone is done to flatten and widen the skull posteriorly.   The occipital bone is replaced approximately 1 cm higher from the original position on the occiput. The top of the repositioned occipital bone flap should be parallel to the anterior skull.  About 1 cm of the anterior aspect of the sagittal suture is removed to decrease the AP length. The anterior portion is attached to the stable frontal bone with an absorbable plate. The occipital bone is similarly replaced. The 1-cm defect is filled in with bone pieces at the end.
• Rotate bone flaps for optimal contour: The parietal bones are flipped so that the prominent bossing is moved in the high parietal region. This is usually the anterior temporal region. The left usually goes on the right and vice versa. However, some removal of bone may be necessary to get perfect parietal bossing. Bone pieces are left, and these are used to fill in the defects.
• Barrel stave posterior frontal bone to widen: Barrel staving passed the coronal sutures is done to widen the narrowing that can be seen when only the posterior region is done.
• Resorbable material to stabilize bone plates: Bones may be replaced with absorbable monofilament suture through wire holes or absorbable plates.

Intraoperative bird’s-eye view, nose down: Extreme scaphocephaly is seen

 

Intraoperative bird’s-eye view, nose down: View after remodeling

 

Closure

• Standard closure: Periosteum is reapproximated with absorbable suture. The galea is closed with absorbable suture, and the skin is closed with a running absorbable suture. The hair is shampooed with nondrying shampoo such as baby shampoo. Bacitracin ointment is placed over the wound. No head dressing is placed.

Coronal Craniosynostosis

Patient Positioning

• Supine: The patient is placed in the supine position.

Surgical Approach (39, 41)

• Bicoronal scalp incision: A bicoronal stealth incision is made. The temporal branch of the facial artery and the superficial temporal artery must be avoided. 
• Turn scalp flaps: A subgaleal dissection is undertaken to the orbits to reflect the scalp forward and posterior to the parietal region.

Intervention

• Raise periosteal flaps: The periosteum can be divided along the orbital rims, extending posteriorly along the midline and inferiorly toward the temporal parietal region, leaving two large flaps.
• Free the periorbita: Extensive pressure on the orbit may cause a vagal response in the patient. The anesthetis must be informed about this maneuver.
• Expose bone of bandeau: The pericranium is dissected off the bone inferiorly past the nasofrontal and frontozygomatic sutures. 
• Undertake a bifrontal craniotomy: The plastic surgeon will usually mark the 1-cm bandeau and the bur holes needed for it. Bur holes should be kept out of the bandeau. Bur holes are placed in the following locations: a) just above the bandeau either on the midline or two on either side of the sagittal suture, b) adjacent to the anterior fontanelle (or the anterior fontanelle itself can be used to access the epidural space), and c) in the temporal regions.
• Expose floor of frontal fossa: The dura is elevated off the bone in the subfrontal region, around the orbits toward the sphenoid ridge and low temporal fossa. Care must be taken at the sphenoid ridge at the temporal tip, as this is a difficult dissection. It is also the location where the plastic surgeon’s reciprocating saw may be hard to visualize. Cut across the floor of the frontal fossa and walls of the middle fossa with the reciprocating saw to free the bandeau above the orbits (pterion to the crista galli to opposite pterion).
• Remove remnant of coronal suture: Attempt to remove suture along the sphenoid ridge.
• Reconstruction, usually by plastic surgeon: The plastic surgeon will reconstruct the bandeau so that the bilateral orbits and rims are similar. The rim is positioned 6-8 mm ventral to the cornea. Absorbable plates, absorbable monofilament suture, or tongue and groove technique may be used to attach. The bandeau is usually advanced 1 cm on the affected side. The unaffected side may be in the same place as prior to surgery. The forehead is replaced in a manner that follows the contour of the bandeau and lessens the flatness caused by the coronal suture.

Line drawing of coronal repair:

Shape of coronal bandeau prior to correction:

Remodeled coronal synostosis: Postoperative line drawing showing coronal defect left after advancement of forehead

Remodeled bandeau:

Closure

• Periosteum closed: The periosteum is reapproximated with absorbable suture. No hemovac is placed.
• Standard closure: The galea is closed with absorbable suture, and the skin is closed with a running absorbable suture. The hair is shampooed with nondrying shampoo such as baby shampoo. Bacitracin ointment is placed over the wound. No head dressing is placed.

Metopic Craniosynostosis

Patient Positioning

• Supine: The patient is placed in the supine position.

Surgical Approach

• Bicoronal incision: A bicoronal stealth incision is made. The temporal branch of the facial artery and the superficial temporal artery must be avoided. Periosteal flaps are reflected anteriorly and temporally. A subgaleal dissection is carried to the orbits and posterior to the parietal region (39, 41).

Stealth incision:

Intervention

• Periosteal flaps: The periosteum can be divided along the orbital rims, extending posteriorly along the midline and inferiorly toward the temporal parietal region, leaving two large flaps.
• Define orbital rim and roof orbit: The periorbita are freed.  Extensive pressure on the orbit may cause a vagal response in the patient. The anesthetist must be informed of this maneuver.
• Expose bandeau: Dissection must be carried past the nasofrontal and frontozygomatic sutures. 
• Bifrontal craniotomy: A bifrontal craniotomy is undertaken. The plastic surgeon usually will mark the 1-cm bandeau and the bur holes. Bur holes should be kept out of the bandeau. Bur holes are placed in the following locations: a) just above the bandeau either on the midline or two on either side of sagittal suture, b) adjacent to the anterior fontanelle (or use the anterior fontanelle itself to access the epidural space), and c) in the temporal regions.
• Expose floor of frontal fossa: The dura is removed from the subfrontal region, around the orbits toward the sphenoid ridge and low temporal fossa. Care must be taken at the sphenoid ridge at the temporal tip, as this is a difficult dissection and location where the plastic surgeon’s reciprocating saw may be hard to visualize. A 1-cm bandeau above the orbits is removed with the reciprocating saw (pterion to crista galli to opposite pterion).
• Remove remnant of coronal suture: Attempt should be made to remove the suture along the sphenoid ridge.
• Reconstruction by plastic surgeon: The plastic surgeon will reconstruct the bandeau so that the bilateral orbits and rims are similar. The orbital rim is positioned 6-8 mm ventral to cornea. Absorbable plates, absorbable suture, or a tongue and groove technique may be used to stabilize the bandeau advancement. The bandeau is usually advanced 1 cm on the affected side. The unaffected side may be in the same place as prior to surgery. A bone graft at the canthus may be needed. The forehead is replaced to follow the contour of the bandeau. The bone of the forehead should be replaced tightly against the advanced bandeau with the flattest portion of this bone flap being placed at the middle of the forehead. Many surgeons use the “floating forehead” technique, which leaves the back of the bifrontal craniotomy unattached, whereas others secure the posterior edge of the flap to the stable skull. 

Intraoperative view of trigonocephalic skull:

Metopic band prior to reshaping:

Metopic band after reshaping:

Bandeau replaced:

Skin closed:

Closure

• Periosteum closed: The periosteum is reapproximated with absorbable suture. No hemovac is placed.
• Standard closure: The galea is closed with absorbable suture, and the skin is closed with a running absorbable suture. The hair is shampooed with nondrying shampoo such as baby shampoo. Bacitracin ointment is placed over the wound. No head dressing is placed

Lambdoid Craniosynostosis

Reconstruction

The operation is similar to that done for sagittal craniosynostosis with the exception that the anterior portion of the operation does not extend past the coronal suture. Instead, the craniotomy needs to be based on the parietal prominence.

Patient Positioning

• Prone: The patient is placed in a prone position.

Surgical Approach (28, 34)

• Bicoronal scalp incision: A stealth bicoronal incision is marked and injected with normal saline. The skin is opened with two surgeons using needle tip electrocautery between 12 and 15W. The galea is opened from inside out.
• Subgaleal flap elevation: The periosteum is left on the bone. The galea and skin are dissected as a unit past the most extensive portion of the bony prominence to the subocciput. The scalp flap extends anteriorly just passed the parietal prominence.
• Periosteal flaps may be elevated: The periosteum is incised along the midline, down behind the coronal sutures and anterior to the lambdoid sutures in the posterior fossa. This will leave three flaps with excellent blood flow to place over the reconstruction.

Intervention

• Biparietal craniotomy: A biparietal craniotomy is taken to just behind the coronal sutures and just anterior to the lambdoids. Two bur holes are placed anterior to the lambdoid sutures on either side of the sagittal suture and two are placed at the squamosol/lambdoid junction. The anterior fontanelle is used for the anterior bur holes. Two bur holes are placed behind the coronal suture at the squamosol suture. The dura is removed off the inner table. The parietal craniotomy is taken to just behind the coronal sutures, down past the temporal squamosol suture, and in front of the lambdoids. The sagittal suture is left attached to the occipital bone. Next, the dura is removed from the posterior bone. It is difficult to remove at the site of the closed posterior fontanelle. It will be easier to remove, if you dissect with a Penfield #1 Dissector from lateral to medial. The occipital craniotomy is done low in the occiput and must encompass the posterior bony prominence. The occipital bone is removed with the attached sagittal suture
• Barrel stave occiput: Barrel staving of the remaining occipital bone is done to widen the flat side of the skull.   The occipital bone is replaced and may need to be turned based on anatomy.
• Rotate bone flaps for optimal contour: The parietal bones are flipped so that the prominent bossing is moved in the high parietal region. This is usually the anterior temporal region. The left usually goes on the right and vice versa. However, some removal of bone may be necessary to get the perfect parietal bossing. Bone pieces are left, and these are used to fill in the defects.
• Resorbable material to stabilize bone plates: Bones may be replaced with absorbable monofilament suture through wire holes or absorbable plates.

Posterior view of lambdoid craniosynostosis:

Intraoperative view of Lambdoid suture fusion:

Closure

• Periosteum closed: Periosteum is reapproximated with absorbable suture. No hemovac is placed.
• Standard closure: The galea is closed with absorbable suture, and the skin is closed with a running absorbable suture. The hair is shampooed with a nondrying shampoo such as baby shampoo. Bacitracin ointment is placed over the wound. No head dressing is placed.