Operative Planning

• Physical exam
  
  
  
  • Distinguish coronal synostosis from positional plagiocephaly.
    
  • Unicoronal look for the Harlequin eye (ipsilateral eyebrow is displaced superiorly), flattening of the ipsilateral frontal bone and narrowing of the temple region, and a ridge along the involved coronal suture
    
  • Bicoronal often syndromic with a towering skull, flattened forehead
    
  • Closed fontanelle does not indicate coronal synostosis (or any craniosynostosis); craniosynostosis is a problem of the sutures, not the fontanelles
    
  • Genetics consult in all cases; up to 30% of uni- and bicoronal synostosis have a spontaneous mutation in FGFR3 gene (Muenke syndromes)

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 and then 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
  
• Unicoronal: if deformity confined to one side, unifrontal craniotomy. If compensatory deforming changes exist on opposite side, then a bifrontal approach, as in bicoronal, is performed.

Neurosurgery

Plastic Surgery

• Mark supraorbital bar osteotomy with methylene blue
  
• Unicoronal cases: a hemisupraorbital bar is osteotomized to the point where the bar returns to a normal contour
  
• 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 interior to the zygomaticfrontal suture. A half-Z osteotomy is performed to anticipate and maximize stability of the advanced bar at this level in unicoronal cases.
  
• Medial osteotomy is performed at the point where there is a transition between dysmorphic and normal bone.
  
  
  
  • In bicoronal cases, the entire supraorbital bar is removed and so the two previous steps are performed for 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 if needed)
  
• 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)
  
• Hemisupraorbital bar/supraorbital bar is advanced to achieve symmetry
  
• 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. The flaps may need to be rotated (or “switched” in bilateral cases) to achieve best fit.
  
• Stabilize bone flap with resorbable plates, screws, and suture (2–0 PDS)
  
• 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