Operative Planning

• Physical exam
  
  
  
  
  • Distinguish metopic synostosis causing trigonocephaly, bitemporal constriction, ridging, and hypotelorism from a metopic ridge
    
  • Closed fontanelle does not indicate metopic synostosis (or any craniosynostosis); craniosynostosis is a problem of the sutures, not the fontanelles
  
  
• Review imaging
  
  
  
  
  • Three-dimensional computed tomography scan
    
    
    
    
    • Look for fused sutures; plain films are not helpful in ruling in or ruling out synostosis
      
    • Omega sign or omega notch: midline endocranial notch associated with ectocranial ridging of metopic synostosis
  
  
• Reconstructive procedure, discuss risk/benefit with family
  
• Ophthalmologic consult to rule out papilledema, especially if family elects not to perform surgery; if papilledema is present no longer only reconstructive
  
• Plastic surgery consult, combined procedure
  
• Discuss timing of surgery (8 to 10 months old)
  
• Discuss donor-directed blood

Special Equipment

• Handheld Hudson brace or perforator with pediatric burr
  
• 0 Prolene sutures
  
• Resorbable plates and screws
  
• Local anesthetic (bupivacaine 0.25% with 1:200,000 epinephrine; 1 mL/kg is maximum dose)

Anesthetic Issues

• Intravenous (IV) antibiotics (cefazolin 25 mg/kg/dose)
  
• Foley catheter
  
• Arterial line
  
• Begin blood transfusion at skin incision. Typically three units of packed red blood cells are reserved: donor-directed or banked autologous.

Positioning

• Patient supine
  
• Patient’s head is positioned on the bed in a neutral position
  
• Minimal reverse Trendelenburg
  
• Total shave
  
  
  
  
  • Hair clippers (hair is saved and given to the parents if first haircut)

Sterile Scrub and Prep

• Clean incision line and surrounding area with 70% ethanol followed by a prescrub with scrub brush followed by a two-step Betadine preparation, first with Betadine soap followed by Betadine scrub

Incision and Exposure

Plastic Surgery

• Sinusoidal or zigzag incision to minimize scarring and more accurate skin alignment at closure
  
• Elevate scalp leaving the pericranium attached to the bone to minimize bleeding. When 10 mm from the supraorbital rim, transition to subperiosteal exposure to expose the orbits and avoid injury to branches of the facial nerve (cranial nerve VII).
  
• Elevate anteriorly until the orbits are entirely exposed.
  
• Outline the border for the bone flap to be removed; anterior border ~10 mm superior to the orbital rim

Neurosurgery

Plastic Surgery

• Mark supraorbital bar osteotomy with methylene blue
  
• Begin laterally in temporal area, cutting extensions of supraorbital bar and more medially to the lateral orbital wall (oscillating saw)
  
• Divide bone at lateral orbital wall obliquely just anterior to the zygomatic-frontal suture
  
• Divide bone at the nasal root
  
• Repeat on the contralateral side
  
• Perform osteotomy along anterior cranial case, across orbital roofs, staying just anterior to the cribriform plate (oscillating saw)
  
• Use straight osteotome/mallet to connect anterior cranial base/orbital wall osteotomies on both sides
  
• Apply osteotome to midline of bar to ensure completion of nasofrontal osteotomy
  
• Supraorbital bar is now free and split in half on the back table; frontal bone flap is also split
  
• Harvest bone graft from posterior aspect of frontal bone flap (isolated by neurosurgery)
  
• Interpose bone graft between hemisupraorbital bar pieces to widen the construct (typically 20 mm)
  
• Use combination of bone grafts, wires, and resorbable fixation plates and screws to stabilize the expanded supraorbital bar to craniofacial skeleton.
  
• Replace frontal bone flap orthotopically and stabilize with resorbable plates, screws, and suture (2–0 PDS [Ethicon]).
  
• Leave in a subgaleal Jackson Pratt (JP) drain
  
• Closure: 3–0 Vicryl through the galea and a running 4–0 plain gut for skin

• Monitor hemoglobin
  
• Remove JP after 72 hours, if output is trending down