Operative Technique in Plastic Surgery – Kevin C.Chung

• Secure the airway with circumdental, circum-mandibular, or transalveolar
suturing/wiring to reduce intraoperative malposition of the endotracheal
tube.
■ For rib harvest, use of a shoulder roll and hip bump can improve exposure
(FIG 3).
■ Turning the table 90 or 180 degrees allows access to both sides of the patient.
■ Proper pressure relief is necessary due to potential lengthy time of operative
intervention.
FIG 3 • Exposure to rib harvest is improved with a
shoulder roll and hip bump.
■ Use foam or gel under the occiput, elbows, hips, knees, and heels.
■ Serial compression devices are used in older patients.
Approach
■ Approaches to the cranial defect may often be accomplished through
utilization of previous incision sites.
■ Complex or large defects may require extension of the previous craniotomy
incision or a conversion to a coronal incision for maximal exposure.
■ Wide exposure is critical for adequate bone debridement and the ability to
control hemostasis as well as reduce iatrogenic dural injury.

T E C H N I Q U E S
■ Cranial Defect Exposure
■ Hair is trimmed along the planned incision site approximately 2 cm in width
to prevent contamination during closure.
■ It is not necessary to shave the entire head or to use a straight razor.
■ A combination of alcohol and Betadine paint is used to cleanse the entire
scalp.
■ Ioban drapes may be used to help keep hair out of the incision site.
■ The planned incision site is infiltrated with dilute epinephrine and 10
minutes allowed to elapse.
■ It is the author’s preference to use 0.25 % Marcaine with epinephrine 1:200
000 in the pediatric population for ease of weight-based calculations.
■ The skin is incised sharply, and the small perforating vessels are controlled
with bipolar cautery to prevent hair root damage and resultant alopecia.
■ Skin hooks help elevation of the scalp in the subgaleal plane while exposing
the bony defect.
■ Creation of the Bony Defect
■ The periosteum is left undisturbed to the edge of the bony defect.
■ Electrocautery and periosteal elevators help separate the periosteum or
fibrous scar tissue from the bone-dural interface.
■ Once the defect edge is identified, assessing the quality of the tissue
overlying the dura is important.
■ Often, blunt sweeping with a periosteal elevator is all that is required to
elevate the scalp tissue off the dural surface.
■ When fibrous tissue is densely adherent to the dura, bipolar cautery may be
necessary to develop a dissection plane.
■ Extensive scar tissue overlying the dura should be left in place, and
electrocautery is utilized to divide this scar tissue in a location overlying
intact calvarial bone.
■ With neurosurgical team assistance, the dura is then reflected from the inner
table of the calvarium to allow screw or plate fixation safely.

■ Useful instruments include
• Penfield no. 1 or 4
• Cottle elevator
• Small bone curette
■ Rib Harvest
■ For ease of access, plan for harvesting the ribs on the same side of the
cranial defect.
■ The sixth or seventh rib is easiest to harvest.
■ Overlying skin incision length is usually around 3 to 6 cm depending on the
patient’s age.
■ Orientation should be horizontal in females for better concealment of scar
(TECH FIG 1A).
■ Be cognizant of breast bud location in the pediatric patient when multiple
rib removal is required.
■ Infiltrate the skin incision with local anesthesia and epinephrine.
■ Dissection should be over a palpable rib to prevent iatrogenic pleural cavity
injury.
■ Split the periosteum over the anterior portion of the rib sharply and preserve
the entire periosteal layer.
■ Limit electrocautery use when elevating the periosteum from the bone to
preserve its function and regenerative cambial layer.
■ Bluntly dissect the periosteum from the rib circumferentially with a
periosteal elevator (Freer or Molt no. 9) or a Doyen rib dissector.
■ Expose the rib medially and laterally until the desired length is required
(TECH FIG 1B).
■ The Freer elevator or no. 10 blade scalpel with the Doyen protecting the
pleura can be used to separate the costochondral junction (TECH FIG 1C).
■ Once the cranioplasty is completed, morselize any remaining bone and place
it back into the periosteal sleeve of the donor site.
■ Close the periosteum primarily to allow for maximal regeneration of rib
bone (TECH FIG 1D).9
■ Irrigate the wound and submerge the donor site.
■ Anesthesiologist should perform Valsalva of the patient to check for air

leak (bubbles) if pleural injury is suspected.
■ Close the remaining layers of tissue.
TECH FIG 1 • A. An incision is placed in the
inframammary fold providing access to ribs 4 to 8
while being aesthetically sensitive to scar location. B.
Oblique muscles are divided until rib periosteum is
identified and divided longitudinally to the level of
costocartilage junction. C. A Doyen rib elevator is
used to remain in the subperiosteal plane and avoid
plural injury. D. Following rib harvest, primarily close
the periosteum (arrow) for rib regeneration. A pleural
leak test is performed by submerging the donor site
under saline while in Valsalva maneuver to check for
air bubbles.

■ Split Rib Technique
■ Once the rib has been harvested, place the graft in normal saline or saline-
soaked gauze sponges.
■ The bicortical osteotomy is made by a Sonopet ultrasonic osteotome
(Stryker, Kalamazoo, MI).
■ Selected tips include the Nakagawa knife or an aggressive serrated tip.
■ Precise cuts can be made even in thin bone and unintended fracturing of
the bone is limited.
■ Alternatively, a reciprocating saw may be used with bone clamps to
provide stabilization.
■ Tessier bone-bending forceps help contour the bone to the curvature required
to fill the cranial defect (TECH FIG 2).
■ To prevent fracture, make small crisscross adjustments when applying
pressure with the forceps.
T E C H N I Q U E S
TECH FIG 2 • Contour ribs to fill defect with maximal
surface area contact to calvarial bone.

■ Cranioplasty Technique
■ Debride calvarial bone to healthy bleeding portions if the bone has
previously been infected or demonstrated nonhealing.
■ After contouring the split rib, rongeur forceps are used to tailor the shape to
fit the defect.
■ Lag screws or thin titanium plates can be used to fixate the rib with 3- to 4-
mm unicortical screws.
■ Rib graft remnants can be morselized and placed in the gaps.
■ Fibrin glue can help to secure the small pieces.
■ Demineralized bone matrix or other bone substitutes can be added to
smooth the rough edges of ribs or fill in small gaps.
■ Scalp Closure
■ After cranioplasty has been performed, a channel drain is placed near the
wound and exited through a separate puncture site in the scalp.
■ The incision is closed with interrupted Vicryl suture in the galea followed by
a running absorbable suture in the scalp.
■ Dermabond application reduces drainage from the incision postoperatively.
■ Telfa pads are placed over the incision.
PEARLS AND PITFALLS
Reducing
resorption
rates
■ Preserving overlying cranial periosteum adds improved regenerative
capacity and improved blood supply. Maximizing surface area contact
of the rib to calvarial edge improves outcomes.
Donor-site
contour
irregularity
■ All remaining unused bone graft should be morselized and placed into
the periosteal sleeve at the donor site. The periosteum/perichondrium
should be preserved and reapproximated during closure.
Pleural
cavity
disruption
■ Close the pleural defect around a red rubber catheter with a purse-
string suture, including the catheter. Anesthesia team delivers a
Valsalva breath to the patient; at the peak of the delivered breath,

remove the catheter as the purse string is tightened. A residual leak
after repair can be tested for by submerging the area with saline and
checking for bubble leaks with a second Valsalva maneuver.
Graft
failure
■ Ensure there is rigidity to the repair. Mobile bone graft has a higher
infection rate and will likely not integrate and will slowly resorb over
time.
Inadequate
coverage
of defect
with rib
graft alone
■ Multiple techniques can be combined including split calvarial grafts
or inner table particulate bone harvest along with allograft materials.
POSTOPERATIVE CARE
■ Antibiotics covering the skin flora are prophylactically given for 3 days
postoperatively if alloplastic materials are utilized.
■ The drain is removed when output is <30 cc for 2 consecutive days.
■ The absorptive dressing is removed approximately 2 days after surgery when
the hair and wound can be washed.
■ Bone healing and bridging are evident at 6 months.
■ Contact sports and strenuous physical activity that could expose the surgical
site to trauma should be limited during this time.
OUTCOMES
■ Complications reported in the literature are few.
■ There are two reported cases of infection and one case of bony resorption in a
meta-analysis of 138 patients in 17 studies undergoing split rib grafting in the
face and cranium.10
■ Structural integrity and bone integration are evident postoperatively by 6
months when imaged.11
■ Pneumothorax/hemothorax rates are <1% with only four reported cases.10,12
COMPLICATIONS
■ Infection
■ Resorption
■ Contour irregularities in the skull or donor site
■ Donor-site pneumothorax
■ Hemothorax

■ Respiratory problems
■ Donor-site pain
■ Unsightly donor-site scarring
■ Longer operative times
REFERENCES
1. Fearon JA, Griner D, Ditthakasem K, Herbert M. Autogenous bone
reconstruction of large secondary skull defects. Plast Reconstr Surg.
2017;139(2):427-438.
2. Wang J, Glimcher MJ. Characterization of matrix-induced osteogenesis in rat
calvarial bone defects: II. Origins of bone-forming cells. Calcif Tissue Int.
1999;65:486-493.
3. Gosain AK, Santoro TD, Song LS, et al. Osteogenesis in calvarial defects:
contribution of the dura, the pericranium, and the surrounding bone in adult
versus infant animals. Plast Reconstr Surg. 2003;112:515-527.
4. Reddy S, Khalifian S, Flores JM, et al. Clinical outcomes in cranioplasty: risk
factors and choice of reconstructive material. Plast Reconstr Surg.
2014;133:864-873.
5. Elsalanty ME, Genecov DG. Bone grafts in craniofacial surgery.
Craniomaxillofac Trauma Reconstr. 2009;2(3):125-134.
6. Gross AE, Kim W, Las Heras F, et al. Fresh osteochondral allografts for
posttraumatic knee defects: long-term followup. Clin Orthop Relat Res.
2008;466(8):1863-1870.
7. Ghosh TD, Skolnick G, Nguyen DC, et al. Calvarial thickness and diploic
space development in children with sagittal synostosis as assessed by
computed tomography. J Craniofac Surg. 2014;25(3):1050-1055.
8. Guyuron B, Shafron M, Columbi B. Management of extensive and difficult
cranial defects. J Neurosurg. 1988;69(2):210-212.
9. Kawanabe Y, Nagata S. A new method of costal cartilage harvest for total
auricular reconstruction: part II. Evaluation and analysis of the regenerated
costal cartilage. Plast Reconstr Surg. 2007;119(1):308-315.
10. Koksal V, Kayaci S, Bedir R. Split rib cranioplasty for frontal osteoma: a case
report and review of the literature. Iran Red Crescent Med J.
2016;18(7):e29541.
11. Sahoo NK, Roy ID, Rangarajan H. Cranioplasty in children with split rib
graft. Med J Armed Forces India. 2011;67(1):83-85.
12. Munro IR, Guyuron B. Split-rib cranioplasty. Ann Plast Surg. 1981;7(5):341-

346.

12
CHAPTER
Three-Dimensional Implant
Reconstruction for the
Cranial Vault
Barry L. Eppley and Sunil Tholpady
DEFINITION
■ Three-dimensional (3D) implant reconstruction of the cranial vault involves
the reconstruction of full-thickness skull defects with implants of various
materials made from a 3D computed tomography (CT) scan and by computer
design.1
ANATOMY
■ The external shape of the skull is composed of six bones—the frontal, parietal
(two bones), temporal (two bones), and occipital.
■ The only soft tissues of relevance to the external skull shape are the temporal
muscles on the side of the head.
■ The front to back shape of the skull is a convexity, whereas the sides of the
skull are more linear or slightly concave.
■ The thickness of the skull and its three layers (two cortices and diploid space)
vary widely at different positions of the skull as well as among different
genders and ethnicities.
PATHOGENESIS
■ Full-thickness skull defects can occur due to the following:
■ Craniotomy/surgical defects
■ Traumatic injuries
■ Congenital skull deformities
NATURAL HISTORY
■ Skull growth is complex and the result of both endochondral and

intramembranous ossification.
■ It becomes a more united and solid structure when both the fontanelles close
and the sutures become more rigid.
■ This occurs as early as 2 years of age; the thickness of the skull continues to
increase up until adulthood to accommodate brain growth and expansion.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Determine
■ Location and size of the skull defect
■ Quantity and quality of overlying soft tissue coverage
■ Underlying dural integrity
■ Frontal sinus proximity and potential exposure
■ Indwelling fixation hardware/alloplastic skull coverage (eg, metal mesh)
■ History of radiation
IMAGING
■ High-resolution (slices of 1 mm or less) 3D CT scan is essential to evaluate the
size and thickness of the skull defect as well as for computer design of the
reconstructive implant (FIG 1).
DIFFERENTIAL DIAGNOSIS
■ A full-thickness skull defect is obvious on physical exam and by 3D CT scan.
■ The following questions need to be addressed:
■ Is there adequate soft tissue coverage to cover an expanded bone contour?
■ Are the bone and soft tissues healthy (nonirradiated)?
■ Is there exposure of the frontal sinus into the defect, or will there be in order
to properly inset the implant?
NONOPERATIVE MANAGEMENT
■ There are no nonoperative methods to recreate the shape of the skull.
■ In large nonoperative skull defects, protective headwear may be recommended
for protection of the brain.

FIG 1 • Three-dimensional total custom skull implant
replacement design.
SURGICAL MANAGEMENT
■ Determine what type of implant material and size of custom skull implant that
are needed to rebuild the skull thickness and shape (HTR-PMI, Titanium,
PEEK, PEKK material options).1
■ Choice of implant is based on surgeon preference. There is no proven biologic
advantage to any implant material over any other. However, they do have
different handling characteristics.1,2
■ Ensure that adequate and healthy overlying soft tissue coverage exists.
■ If the skull defect has been previously irradiated, vascularized soft tissue
coverage will need to be completed first (eg, free flap).2
■ If the frontal sinus is exposed or will be in contact with the implant,
vascularized coverage must be needed (eg, pericranial flap).
Preoperative Planning
■ 3D CT imaging is needed for the computer design and fabrication process
from a manufacturer who offers this capability.
Positioning
■ The patient is placed in the supine or prone position on a Mayfield head rest
on the operative table depending upon the location of the skull defect.
■ The procedure can only be done under general anesthesia.
■ Hair may or may not be shaved depending upon the patient’s current hairstyle.

■ Local anesthetic such as 2% Xylocaine with 1:100 000 epinephrine is
infiltrated into the previous scalp incision, which exists in most cases.
■ If no incision is present, a coronal scalp incision can be considered.
T E C H N I Q U E S
■ Exposure and Pocket Creation
■ The previous scalp incision is fully opened for wide access to the skull
defect (TECH FIG 1).
■ In the event that no scalp incision exists or is inadequate for access,
extensions of the prior incision will be needed, or a new full coronal scalp
incision is made.
■ Wide subperiosteal undermining to raise the overlying scalp flaps is needed
for full skull defect exposure.
■ Any existing metal fixation hardware is removed.
■ The dura is elevated from the skull defect edges and repaired if its integrity
is violated.

TECH FIG 1 • Free flap coverage (latissimus dorsi
muscle) of previously irradiated full-thickness frontal
skull defect prior to placement of custom skull implant.
■ Implant Placement and Fixation
■ The custom skull implant is initially soaked/washed in an antibiotic solution
(gentamicin and Betadine) and placed into the skull bone defect.
■ The fit of the implant should be perfect due to the initial CT-based computer
design.
■ Any adjustments to make the external shape smooth and confluent with the
surrounding skull bone, as well as the edge transitions, is almost always done
on the implant but also is necessary on the skull edges and can be performed
with a handpiece and bur.
■ Fixation of the custom skull implant is advised and is best done by low-
profile plates and screws (1.1–1.6-mm plate profiles and screw diameters) in
at least three locations for a triangulation fixation effect (TECH FIG 2).
■ Wire and suture fixation can also be used, but low-profile plate and screw
fixation is preferred.

TECH FIG 2 • Plate and screw fixation.
■ Closure
■ Closure over the implant should be done in three layers—galea, dermal, and
epidermal skin.
■ Closure of any portion of the incision immediately over the implant must be
waterproof and tension-free.
■ If possible, avoid placing the incision directly over the implant.
■ The use of a surgical drain is often used but is up to the surgeon’s discretion.
PEARLS AND PITFALLS
Presurgical
■ A 3D CT scan is used to design the custom implant to precisely fit

assessment
with CT
the full-thickness skull defect.
Implant
material
selection
■ Custom implant material selection includes HTR, titanium, PEEK,
and PEKK. None of these materials have been proven to be
superior to the other; they all work equally well.
Subperiosteal
defect
exposure
■ Wide tissue release and exposure are needed, so take full
advantage of any existing scalp incisions or extend them as
needed.
Implant
positioning
■ The surgeon can modify the implant or the edges of the bone to
obtain the best transition between the implant and the outer bone
surface.
Implant
fixation
■ Plate and screw fixation is essential to optimally stabilize the
implant into the skull defect site.
Postoperative
management
■ Patients need to wait at least 12 weeks after surgery for an
accurate assessment of skull contour results.
POSTOPERATIVE CARE
■ A head dressing is applied for the first night of surgery. It is removed the
following day.
■ If a drain has been placed, it is also removed the day after surgery.
■ IV antibiotics are given as long as the patient is hospitalized. Oral antibiotics
with coverage of Staphylococcal organisms are given for 7 days after surgery
when the patient is discharged home.
OUTCOMES
■ Custom 3D skull implants always improve the outer cranial contour and
provides enhanced brain protection.3,4
■ The external aesthetic appearance is a reflection of adequate design and
surgical inset of the implant and having normal overlying soft tissue thickness
(FIG 2).

FIG 2 • A,B. Reconstruction result. Preoperative view
(A) of a patient with a left forehead and temporal defect,
with postoperative improvement in skull contour (B)
after implant placement.
COMPLICATIONS
■ Infection usually presents as swelling and drainage anywhere from 2 to 6
weeks after surgery. This is of greatest occurrence when the implant is close to
or has involved the frontal sinus.
■ Asymmetry/edging can be assessed no sooner than 6 weeks after surgery when
most of the swelling is gone to determine the true skull shape.
■ Overcorrection/undercorrection: One should allow a full 3 months after
surgery for all swelling to subside and for the patient to adjust to his or her new
look. Earlier interpretations, particularly that of overcorrection, may be
premature.
REFERENCES
1. Cho Y, Gosain AK. Biomaterials in craniofacial reconstruction. Clin Plast
Surg. 2004;31:377.
2. Eppley BL, Coleman JJ III, Kilgo M. Cranial reconstruction with computer-
generated HTR patient-matched implants: indications, surgical technique, and
long-term follow-up. Plast Reconstr Surg. 2002;109:864.
3. Lethaus B, Safi Y, Laak-Poort MT, Kesler P. Cranioplasty with customized

titanium and PEEK implants in a mechanical stress model. J Neurotrauma.
2011;29:1077.
4. Lin AY, Kinsella CR Jr, Rottgers SA, et al. Custom porous polyethylene
implants for large-scale pediatric skull reconstructions: early outcomes. J
Craniofac Surg. 2012;23:67-70.

13
CHAPTER
Alloplastic Reconstruction of
the Calvarium
Peter J. Taub
DEFINITION
■ Cranioplasty involves reconstruction of the bony anatomy of the skull.
■ This may be done with autogenous bone grafts, an alloplastic implant, or a
titanium mesh.
ANATOMY
■ The calvarium in the adult is composed largely of an outer cortex or cortical
bone, a matrix of cancellous bone and marrow, and an inner cortex of cortical
bone.
■ The specific curvature of the calvarium in the area of the defect should be
observed and taken into account when performing the reconstruction.
PATHOGENESIS
■ Loss of calvarium may have multiple etiologies.
■ Patients may require craniotomy for tumors, during which the resected bone
cannot be replaced at the index procedure secondary to cerebral swelling and
the need to avoid increased intracranial pressure.
■ The bone graft is left buried in the subcutaneous layer of the abdomen for
later replacement.
■ Occasionally, the graft becomes infected and can no longer be replaced.
■ Patients with benign or malignant osseous or soft tissue tumors that invade the
bone require resection of a portion of the calvarium (FIG 1).
■ In cases of trauma, portions of the skull may be shattered such that they cannot
be used for reconstruction.
■ The mechanism of injury is generally blunt rather than penetrating.

■ Prior to the routine installation of seat belts in automobiles, a preponderance
of cases was caused by motor vehicle accidents. More recently, assaults have
become more prevalent.
■ Other causes of skull injury include sports injuries, occupational incidents,
and falls.
NATURAL HISTORY
■ Patients should be medically stable prior to considering cranioplasty.
■ The timing may also be related to the presence of associated symptoms.
■ Postcraniectomy patients may present with “the syndrome of the trephined.”
This is an infrequent and delayed complication.
■ Common radiologic findings include paradoxical herniation, deviation of the
midline structures, and sunken skin flap.1
■ The spectrum of symptoms ranges from seizures to headaches to
neuropsychiatric disturbance to focal weakness to midbrain syndromes2 and
parkinsonian symptoms.2,3
PATIENT HISTORY AND PHYSICAL FINDINGS
■ In the acute setting, the primary concern for any patient with head injury is
possible cervical spine trauma.
■ Specific signs and symptoms of cervical spine injury include a neurologic
deficit, point-specific neck pain, and possible palpable step-off on neck exam.
■ There may be a noticeable area of deficient bony support for the overlying soft
tissues of the scalp (FIG 2).
■ The laxity of the soft tissues over the defect should be evaluated. Generally,
the amount of concavity produced by the defect will match the convexity of the
implant. Thus, preoperative tissue expansion is generally not required.
■ If soft tissues appear to be tight and firm to palpation, tissue expansion should
be considered prior to reconstruction.
IMAGING AND OTHER DIAGNOSTIC STUDIES
■ Preoperative evaluation should include a computed tomography (CT) scan to
evaluate the size and extent of the potential defect (FIG 3). The data may be
reformatted into a three-dimensional representation.

FIG 1 • Resected calvarial tumor specimen.
FIG 2 • Patient with a significant left parietal skull defect.

■ The CT should also be used to rule out additional craniomaxillofacial injuries.
■ A cervical spine series should be done at the time of injury to rule out cervical
spine fracture or dislocation. This is done prior to discontinuing the protective
collar.
FIG 3 • Preoperative axial CT scans of a tumor (A) and
of a left frontal defect (B).
SURGICAL MANAGEMENT
Preoperative Planning
■ The CT scan should be reviewed to determine where the screws may be placed
to fixate the titanium mesh in place.
■ Danger zones, including the midline sagittal suture, should be avoided.
Positioning
■ The patient is positioned supine with the head stabilized. This may be
achieved with a foam donut, a horseshoe extension of the operating table, or a
Mayfield headrest.
■ The torso should be restrained with a belt in case the table is rotated during the
procedure.

■ A strip of hair may be shaved where the coronal incision is to be made and
hair on either side combed away from the incision and gathered into elastics.
■ The surgical preparation should include the hair (and face if needed) to the
level of the headrest.
■ Avoid exposure keratitis by applying ointment to the eyes and using a more
dilute prepping solution near the eyes.
■ The face can be draped out of the operative field or incorporated into it based
on surgeon preference.
T E C H N I Q U E S
■ Alloplastic Cranioplasty
■ Existing incisions should be considered for exposure (TECH FIG 1A). If
insufficient, they can be extended while being cognizant of the vascular
pattern of the scalp.
■ A coronal incision provides ideal exposure for the entire calvarium.
Dissection proceeds through the skin, underlying soft tissue, and galea, to the
pericranium. The pericranium may be dissected from the bone or left in place
to hold loose fragments of the outer table together. Elevation of the
pericranium is performed with an Obwegeser-type periosteal elevator.
■ Bleeding from underlying perforating vessels to the periosteum may be
controlled with direct electrocoagulation or with a minimal amount of sterile
bone wax.
■ Bone around the margin of the defect should be exposed and freed of
overlying soft tissue to allow the implant to sit on the edge of the bone.
■ Most titanium mesh implants are thin enough to easily bend or conform to
the margins around any given defect (TECH FIG 1B).
■ Some implants are prebent by the manufacturer (TECH FIG 1C).
■ Excess mesh should be trimmed.
■ Sharp edges should be removed.
■ It should be noted that alloplastic implants are not completely inert and can
erode into the overlying soft tissues (TECH FIG 1D).
■ Dural tack-up sutures should be placed to minimize postoperative epidural
collection (TECH FIG 1E).

TECH FIG 1 • A. Intraoperative lateral photograph with
the prior anteriorly based scalp flap incision marked.
B. Standard titanium mesh plates and bending
forceps. C. Prebent titanium plates to address left
parietal, right parietal, or frontal defects. D. Erosion of

a titanium plate into the overlying soft tissues of the
scalp. E. Placement of dural tack-up sutures.
PEARLS AND PITFALLS
Implant
choice
■ Cranioplasty may be safely done with a variety of materials, including
autogenous bone graft(s), an alloplastic implant, or a titanium mesh.
Technique
■ The entire margin of the defect must be identified and freed of
overlying soft tissue.
■ Material, including screws and plates, should be as flush with the
bone as possible to minimize the risk of extrusion.
Monitoring
■ Postoperative observation should note any changes in hemodynamics
or mental status.
POSTOPERATIVE CARE
■ A simple dressing of Bacitracin and nonstick gauze is applied to the incision.
■ A gauze head wrap is applied.
■ If a drain is placed, it should be monitored and emptied daily (or twice daily,
as needed). The drain may be removed fairly early if the output is low and
there is no suspicion for CSF leak. The space between the scalp and bone is
limited and heals relatively quickly.

FIG 4 • Postoperative titanium mesh exposure following
cranioplasty.
OUTCOMES
■ Patients generally do well following cranioplasty with low reported rates of
complications.4
■ Some authors have reported that performing cranioplasty during a subsequent
hospitalization may reduce the risk of graft infection. They surmise it may be
related to a higher hemoglobin level and lower bacterial colonization.5
COMPLICATIONS
■ Dural or CNS injury
■ Epidural bleed
■ Wound infection
■ Hardware infection6

■ Hardware erosion (FIG 4)
■ Hardware malposition
REFERENCES
1. Vasung L, Hamard M, Soto MC, et al. Radiological signs of the syndrome of
the trephined. Neuroradiology. 2016;58(6 suppl):
557-568.
2. Gottlob I, Simonsz-Tòth B, Heilbronner R. Midbrain syndrome with eye
movement disorder: dramatic improvement after craniplasty. Strabismus.
2002;10:271-277.
3. Bijlenga P, Zumofen D, Yilmaz H, et al. Orthostatic mesodiencephalic
dysfunction after decompressive craniectomy. J Neurol Neurosurg Psychiatry.
2007;78:430-433.
4. Andrabi SM, Sarmast AH, Kirmani AR, Bhat AR. Cranioplasty: Indications,
procedures, and outcome: an institutional experience. Surg Neurol Int.
2017;8:91.
5. Rosseto RS, Giannetti AV, de Souza Filho LD, Faleiro RM. Risk factors for
graft infection after cranioplasty in patients with large hemicranial bony
defects. World Neurosurg. 2015;84(2 suppl):431-437.
6. Martin MP, Olson S. Post-operative complications with titanium mesh. Clin
Neurosci. 2009;16(8 suppl):1080-1081.

14
CHAPTERCraniopagus Twins
David J. Dunaway and Noor Ul Owase Jeelani
DEFINITION
■ Craniopagus twins (conjoined at the head; CPT) are extremely rare, occurring
in about 1:2.5 million live births. They account for 2% to 6% of all conjoined
twins.1–3
■ Classifications include (FIG 1)4:
■ Partial (localized) or total
■ Angular or vertical (types I to III)
■ The degree of union varies, and shared tissues may include skin, bone, dura,
brain, and venous drainage system.
■ The possibility of separation is dependent on the degree and pattern of tissue
sharing and whether or not this allows the possibility of leaving an uninjured
well-vascularized brain.
ANATOMY
■ Partial CPT is less common than total CPT and may involve any number of
tissue layers including the dura. The cortical gyri may interdigitate but are
usually separable. Significant intracranial dural venous cross circulation is rare.
Union is usually either frontal or occipital.

FIG 1 • Classification of craniopagus.
■ Total vertical CPT has a longitudinal stovepipe configuration, and the three
O’Connell subclasses describe the angulation of the twins (see FIG 1).
■ The scalp derives its blood supply from both twins allowing skin flaps to be
raised across the twins to aid reconstruction.
■ The calvarium is fused. Both sagittal sutures are absent and replaced by a
ring suture running circumferentially around the cylindrical skull.
■ The dura separating the two brains is single layered and usually incomplete.

■ Cerebral arterial supply is generally separate, although minor degrees of
crossover occur.
■ The cerebral venous drainage is shared and complex. The superior sagittal
sinus is absent from both twins and is replaced by a complete or incomplete
circumferential venous sinus (CVS). Mixing of the venous circulations occurs
and blood generally drains preferentially to one twin (FIG 2).5
■ The brains abut in a flattened, tilted plane that does not align with the
circumferential cranial suture. Areas of cerebral cortex may be fused.
■ Total angular CPT form a heterogeneous group, and there are several
classifications. Classification is generally by area of union. Winston proposed
a grading system based on the deepest structure involved, which is
prognostically useful.6
FIG 2 • CT angiography demonstrating the
circumferential venous sinus (CVS) and venous
drainage across the twins.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Diagnosis is usually made antenatally. Planning separation of CPT relies
primarily on information gained from imaging. The history and physical

examination are important in eliciting physiological effects in planning surgical
access.
■ Extracranial and general effects include the following considerations:
■ Airway: It may be difficult to position the twins to protect both airways.
Airway support or tracheostomy may be required.
■ Circulation: Total CPT results in significant mixing of venous blood that
usually drains preferentially to one twin. This has two major consequences:
• Cardiovascular: Increased venous return increases cardiac load and in
severe situations can lead to cardiac failure. The unequal venous drainage
and fluid distribution generally results in hypertension in one twin and
hypotension in the other. This asymmetrically shared blood supply has
significant anesthetic implications.
• Renal: Large volumes of urine are generally produced by the hypertensive
twin, whereas the other produces very low volumes of urine.
■ Nutrition: In situations where there is significant venous shunting, the high
metabolic demands placed on the twin with high cardiac output generally
produce an underweight twin.
IMAGING
■ Detailed multimodality imaging provides key information for general
management and is essential for surgical planning (FIG 3).7
■ CT: Visualizes bony morphology, sutural pattern, and the relationship of the
brain, skin, and dura to the skull
■ MRI: Delineates brain and dural anatomy indicating areas of possible cortical
fusion and dural defects
■ Digital subtraction angiography: Provides anatomical information about
arterial and venous systems and the extent and direction of vascular crossover
between the twins. This modality also characterizes the relationship between
the deep and superficial venous drainage systems of the brain for planning
separation.
■ CT angiography: Characterizes the anatomy of the dural venous sinuses
■ 3D medical modeling: Stereolithographic models assist in interpreting
complex venous and bony anatomy and improve surgical planning (FIG 4).8
NONOPERATIVE MANAGEMENT
■ It may not be possible to separate some pairs of CPT because of unfavorable
vascular anatomy and brain fusion. Even more straightforward cases carry a

risk of brain damage and death. The decision to attempt separation is based on
an assessment of risk to the two individuals, in addition to ethical and social
issues, and may be different for each individual. There are several examples of
unseparated twins who live fulfilling lives. A decision not to separate brings its
own challenges. These include potential psychosocial difficulties as life
progresses and the physiological challenges associated with a shared
circulatory system.
SURGICAL MANAGEMENT
■ CPT require complex multidisciplinary management and often present with
cardiac, renal, and general pediatric problems. General care is complicated by
difficulties in positioning. When planning separation, consideration must be
given to the issues of each twin, in turn, followed by shared issues.
■ Many approaches for the separation of CPT have been described, but they
essentially fall into two categories, a single-stage separation often preceded by
an episode of tissue expansion or a multistage approach.9–11 There is now
general agreement that a multistage separation encourages adaptation in the
blood supply to the brain and reduces the risk of cerebral damage and is the
procedure of choice for total extensive CPT.12 This chapter will describe our
experience with multistage separation.
FIG 3 • Radiological imaging. Twin A is at the top and
Twin B at the bottom. A. MRI delineates brain anatomy
and areas of cortical confluence. B. CT with 3D
reconstruction delineates skin bone and vascular

anatomy. C. Angiography showing injection from twin A.
D. Injection from twin B.
FIG 4 • 3D models used to plan incisions (A),
craniotomies (B), and vascular surgery (C).
Preoperative Planning
■ Detailed preoperative planning is essential for successful separation. CT, MRI,
angiography, and stereolithographic models provide essential information (see
FIGS 3 and 4). The surgical separation of CPT requires attention to planning
for the following tissue layers.
■ Skin
■ The form and position of the initial skin incision must allow access for the
separation and provide useful skin flaps that will give a watertight closure at
separation.
■ We have found that a sinusoidal-shaped incision running circumferentially
around the conjoined heads, centered on the proposed line of separation,
provides good access (FIG 5).
■ The sinusoidal design should produce a single broad-based flap for each twin
that can be enlarged by tissue expansion.13
■ Planning of the flaps is facilitated by the use of stereolithographic models.

■ Bone
■ Broad craniotomies over the line of fusion are required to gain access for the
intracranial separation.
■ In a staged approach, these craniotomies need to be rigidly plated back into
position at the end of each procedure to maintain the rigidity of the skull
during the multistage operative approach.
■ Dura
■ The two brains are usually separated by an incomplete single dural layer. The
dural layer must be given to one twin, leaving the other with a wide dural
defect.
■ The decision about which twin receives the dural layer is based on the venous
sinus anatomy. The ring sinus is donated to the twin who retains the shared
dural layer. The other twin must therefore rely on the remaining parts of the
superficial drainage system, along with the deep venous drainage system.
■ Staged separation encourages the formation of collateral drainage from the
superficial to deep system and reduces the risk of venous infarcts at final
separation.
■ Brain
■ The brains are usually separate, or minimally conjoined, in total CPT.
■ Extensive areas of cortical fusion may make separation impossible.
■ Veins
■ Decisions about sharing and separating the veins are discussed in the section
on managing the dura.
■ It is essential that the twin who loses the shared dural venous sinuses during
separation has an independently draining deep system capable of
accommodating the entire venous drainage of the brain.

FIG 5 • Incisions and flap design.
Positioning
■ Until separation, the twins are placed together on a single operating table. The
theater needs to be laid out so that the two anesthetic teams looking after each
twin have adequate access to the operating area.
■ Depending on the area of the skull that requires separation, the twins will be
either in the supine, lateral, or prone position. Depending on the McConnell
subtype, the position of each twin will vary.
■ We have found it helpful to elevate the conjoint heads above the level of each
body by placing a bolster beneath the heads.
■ This elevation reduces venous pressure and, because infant skulls are
flexible, provides a gentle force to retract the two parts of the conjoint head
during surgery.
■ In the final operation, once the twins had been separated, one twin is moved to
a separate operating theater.

Approach
■ A single-staged approach may be appropriate for partial CPT.
■ Most total CPT twins require the multistaged approach described below.
T E C H N I Q U E S
■ Stage 1: Defining Skin Flaps and First Stage
Neurovascular Separation
■ Sinusoidal incision line is marked to give access for craniotomies and
intracranial separation. This incision will be the only incision line and so
must give access circumferentially and form the flaps for cranial closure at
the final separation.
■ Skin flaps should be raised in a subperiosteal plane for maximum durability
over multiple procedures.
■ An access craniotomy is performed to widely expose the dura around the
area of proposed separation (TECH FIG 1A).
■ The dura is opened parallel to the CVS on the side where the parasagittal
veins are to be divided from the venous sinus.

TECH FIG 1 • A. Scalp flaps retracted with access
craniotomy. B. Venous tributaries from one twin
divided from the CVS. C. Silicone sheet placed
between cerebral hemispheres to prevent
revascularization. D. Craniotomy secured with titanium
plates to maintain a rigid connection between the
twins.
■ The parasagittal veins are serially divided with bipolar diathermy from the
CVS. The brain is carefully observed for signs of venous congestion, and
vein division is halted if there are venous drainage concerns (TECH FIG
1B).
■ A reinforced silicone sheet is placed in the area of division to prevent
adhesions and revascularization between the twins (TECH FIG 1C).
■ The dura is closed to ensure a watertight seal, and the craniotomy is replaced

using a 1.5 mm titanium unicortical plating system (TECH FIG 1D).
■ A vacuum drain is placed, and the wound is closed in layers.
■ Stages 2 and 3: Neurovascular Separation
■ The number of stages required for complete neurovascular separation will
depend on the venous anatomy and the degree of separation possible at each
stage before venous insufficiency is experienced. Ideally there should be a
minimum of 4 weeks between separation stages to allow complete
neovascularization.
■ Subsequent stages use the same incision plan as stage 1.
■ The twins are rotated to access the next area to be separated, and the
operative sequence of stage 1 is repeated.
■ These stages are repeated until complete intracranial separation is achieved
with silicone sheeting separating the twins. Rigid integrity of the calvarium
must be maintained to facilitate nursing in the interoperative period.
■ Tissue Expansion
■ Following completion of the neurovascular separation, it is necessary to
provide a considerable amount of skin to cover the expected defects. Extra
tissue (both length and breadth) is required in the area of the broad-based
flaps created by the sinusoidal incision.
■ The expanders are inserted into the subperiosteal plane through incisions in
the pre-existing sinusoidal scars. The full-thickness flaps are robust and will
expand easily with minimal risk of expander extrusion (TECH FIG 2).
■ High-profile rectangular smooth expanders with soft pliable bases are an
effective design for scalp expansion.
■ It is important to place injection ports away from areas where they may
cause pressure problems.

TECH FIG 2 • Tissue expanders are placed beneath
scalp flaps. The expanders must be positioned to
avoid possible pressure necrosis of the overlying
flaps. Injection ports are placed to avoid pressure
areas and to facilitate injection of saline.
■ Following insertion of the expanders, the wounds are allowed to heal for 2
weeks before starting twice-weekly injections of the expanders. The process
takes approximately 4 weeks, and the final stage separation should be
planned 2 weeks after the completion of expansion.
Final Separation
■ By this stage, the key elements of the separation are complete. The two
brains and intracranial blood supply have been separated with enough scalp
created for soft tissue reconstruction.
■ Careful logistical planning is required as the operation starts in a single
theater with one surgical team and finishes as two separate procedures.
■ Separation involves raising the skin flaps and reopening the now
circumferential craniotomy. Both bone and dura have healed by this stage.
There may be some final areas of cortical separation to undertake.
■ Once separate, dural reconstruction is undertaken. The area to reconstruct is
very large on the twin who did not receive the CPT and smaller or negligible
on the other twin. Our preference is to use autologous fascia lata to provide a

watertight seal rather than artificial alternatives.
■ Even in infancy, the calvarium has a rudimentary diploic cavity, and in our
experience, it is possible to split the calvarium to produce sufficient bone to
reconstruct the calvarial defects. The calvarial reconstruction is achieved by
suturing and wiring the bone fragments into place (TECH FIG 3).
■ Skin closure can generally be achieved with minimal tension. The sinusoidal
flap design results in a suture line distant from the dural reconstruction line
and helps to prevent CSF leaks.
TECH FIG 3 • CT images demonstrating bony and soft
tissue reconstruction of each twin.

PEARLS AND PITFALLS
Preoperative
planning
■ Careful planning is required from the whole multidisciplinary
team for all of the stages.
■ Use 3D models to plan circumferential incisions, which must give
access for all stages and provide local flaps for final
reconstruction.
■ Based on vascular imaging, decide which twin will retain the
circumferential venous sinus.
Nonsurgical
care
■ Nursing: Avoid pressure sores, and maintain nutrition.
■ Cardiac: Venous shunting across twins leads to asymmetric cardiac
load.
■ Renal: Shunting across twins may adversely affect renal function.
Decision-to-
separate
issues
■ Ethical and social issues must be discussed.
■ Identify risks to each twin and the combined risk.
■ Assess likely quality of life for the twins, either conjoined or
separate.
POSTOPERATIVE CARE
■ Immediate postoperative care is undertaken in a pediatric intensive care
(PICU) environment. Our preference is transfer of the children awake to the
PICU rather than ventilate them postoperatively.
■ CT and MRI scans are obtained immediately to assess both brain and quality
of reconstruction.
■ Early physiotherapy is required to mobilize the newly separated twins.
■ Consider orthotic molding helmets for head shape.
OUTCOMES
■ Mortality (per individual)
■ Total CPT 48%
■ Partial 14%
■ Single stage separation 46%
■ Multistage separation 21%11
■ Neurological disability
■ Mild-moderate or normal
• Total CPT 25%

• Partial CPT 73%1
■ Severe disability
• Total CPT 22%
• Partial CPT 14%1
COMPLICATIONS
■ Death (see above) commonly due to brain infarction, infection, and blood loss
■ Neurological damage/developmental delay
■ Hydrocephalus
■ CSF leaks
■ Wound infection
■ Wound breakdown
■ Plagiocephaly
■ Calvarial defects
REFERENCES
1. Stone JL, Goodrich JT. The craniopagus malformation: classification and
implications for surgical separation. Brain. 2006:1084-1095.
2. Baldwin M, Dekaban A. The surgical separation of Siamese twins conjoined
by the head followed by normal development. J Neurol Neurosurg Psychiatry.
1958;21:195-202.
3. Spitz L, Kiely EM. Conjoined twins. J Am Med Assoc. 2003;289(10
suppl):1307-1310.
4. O’Connell JEA. Craniopagus twins: surgical anatomy and embryology and
their implications. J Neurol Neurosurg Psychiatry. 1976;39:
1-22.
5. Lasjaunias P, Kwok R, Goh P, et al. A developmental theory of the superior
sagittal sinus(es)in craniopagus twins. Childs Nerv Syst. 2004;20(8-9
suppl):526-537.
6. Winston KR, Craniopagi: anatomical characteristics and classification.
Neurosurgery. 1987;21(6 suppl):769-781.
7. Martínez L, Fernández J, Pastor I, et al. The contribution of modern imaging
to planning separation strategies in conjoined twins. Eur J Pediatr Surg.
2003;13(2 suppl):120-124.
8. Christensen AM, Humphries SM, Goh KYC, Swift D. Advanced “tactile”
medical imaging for separation surgeries of conjoined twins. Childs Nerv Syst.
2004;20(8-9 suppl):547-553.

9. Sugar O, Grossman H, Greeley P, Destro V. The Brodie craniopagus twins.
Trans Am Neurol Assoc. 1953;78:198-199.
10. Staffenberg DA, Goodrich JT. Separation of craniopagus conjoined twins: an
evolution in thought. Clin Plast Surg. 2005;32:25-34.
11. Dunaway D, Jeelani NUO, The Staged separation of craniopagus twins.
Semin Pediatr Surg. 2015;24(5 suppl):241-248.
12. Goodrich JT, Staffenberg DA. Craniopagus twins: clinical and surgical
management. Childs Nerv Syst. 2004;20(8-9 suppl):618-624.
13. Antonyshyn O, Gruss JS, Zuker R, Mackinnon SE. Tissue expansion in head
and neck reconstruction. Plast Reconstr Surg. 1988; 82(1 suppl):58-68.

15
CHAPTER
Endoscopically Assisted
Approaches for
Craniosynostosis
Timothy W. Vogel and Brian S. Pan
DEFINITION
■ Craniosynostosis is a condition caused by the premature fusion of calvarial
sutures.
■ The fused suture restricts the growth of the developing brain, leading to
compensatory morphologic changes of the calvarium.
■ Endoscopically assisted approaches for the treatment of craniosynostosis entail
removal of the affected suture through small scalp incisions. The technique is
passive, dependent on the natural growth of the underlying brain to facilitate
correction once the site of growth restriction is released.
■ The use of postoperative molding helmets is commonly coupled with this
technique to actively direct the vectors of brain growth.1
■ Although variations in the timing of surgery exist between craniofacial
centers, this technique is generally reserved for patients less than 6 months of
age.
■ Decreased operative times, blood loss, cost, and length of hospital stays have
all been reported as advantages to this minimal access approach.2
ANATOMY
■ The normal calvarium is composed of five major bones and sutures (FIG 1A).
■ The bones include two frontal bones, two parietal bones, and a single
occipital bone.
■ The major sutures consist of three paired sutures (the coronal, lambdoidal,
and squamosal) and two single sutures (the sagittal and metopic)
■ There are six fontanelles, soft membranous gaps that represent the confluence

of the bones and the sutures of the skull. These include the anterior and
posterior fontanelles and the paired sphenoid and mastoid fontanelles (FIG
1B).
■ Partial or complete fusion of the affected suture can occur.
FIG 1 • Sutures and fontanelles of the skull. A. Met,
metopic suture; L cor, left coronal suture; Sag, sagittal
suture; L lamb, left lambdoid suture; A font, anterior
fontanelle; P font, posterior fontanelle. B. S font,
sphenoid fontanelle; M font, mastoid fontanelle.
■ Identification via palpation of the anterior and posterior fontanelles, or the
confluence of the affected sutures if the fontanelles have closed, is critical for
incision placement.
■ This allows adequate exposure of the targeted suture and avoids injury to the
underlying dura if the fontanelles are open.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Patients are usually diagnosed within the first few months of life, but the
diagnosis may not be readily apparent due to temporary deformation of the
head following birth.
■ A thorough clinical history should be obtained including length of gestation,
weight, and complications during gestation and following birth.

■ Sleeping position, overall health, and a family history regarding abnormal
head shape should also be obtained.
■ The neck should be assessed for torticollis, and hands and feet should be
inspected for abnormalities associated with syndromic craniosynostosis.
■ Although CT scans are routinely obtained for confirmation purposes, physical
examination alone has been shown to be 98% reliable for diagnosis in a level 1,
prospective multicenter study.3
■ Growth inhibition occurring perpendicular to the fused suture is the classic
teaching for determining the suture responsible for the morphological changes
of the calvarium in affected patients.
■ Growth inhibition is in actuality multidimensional, however, with the
remaining open sutures compensating for the area of restriction.4
■ Sagittal synostosis
■ In addition to an elongated head (dolichocephaly), there is a decrease in the
posterior skull width and height, often with narrowing of the occipital bulb.
■ Compensatory growth occurs anteriorly involving the coronal and metopic
sutures, which results in frontal bossing.
■ Clinocephaly, presenting as a saddle-shaped deformity dorsal to the open
coronal sutures, is often present as well.
■ Metopic synostosis
■ The classic physical examination findings include a triangular head shape
(trigonocephaly) with reduced bifrontal width, supraorbital pinching, and
increased posterior width of the calvarium.
■ The open sagittal and lambdoid sutures facilitate this compensatory growth
pattern.
■ Hypotelorism may also be appreciated.
■ Coronal synostosis
■ The growth restriction caused by closure of the coronal suture results in
ipsilateral flattening of the forehead, elevation of the orbit, and anterior
positioning of the auricle.
■ The dorsal aspect of the calvarium is often flattened.
■ The open coronal suture compensates leading to contralateral frontal bossing
and a more dorsally positioned auricle.
■ The nose is often deviated toward the fused suture.
■ Bicoronal synostosis
■ Symmetrical flattening of the forehead with widening of the bilateral

temporal regions and elevated height of the calvarium (turribrachycephaly) is
the result of fusion of the bilateral coronal sutures.
■ Concomitant elevation of the supraorbital aspect of the frontal bones may
lead to a proptotic appearance.
■ Lambdoid synostosis
■ The hallmark of lambdoid craniosynostosis is a mastoid bulge on the affected
side.
■ There is flatness and decreased height of the posterior skull on the affected
side as well.
■ The unaffected lambdoid and sagittal sutures compensate for the growth
restriction leading to a contralateral posterior bossing.
■ This presentation can be easily confused with deformational plagiocephaly.
IMAGING
■ A three-dimensional (3D) computed tomographic (CT) scan is the ideal study
for the diagnosis of craniosynostosis and preoperative planning and to facilitate
discussion with patient families.
■ The patency of sutures and fontanelles can be assessed, the skeletal deformity
visualized, and underlying brain abnormalities (eg, Chiari malformation) may
be ruled out.
SURGICAL MANAGEMENT
■ The authors offer a minimal access approach for infants between 6 and 12
weeks of age. In children with mild deformation, this approach may be
considered until 16 weeks of age.
■ In general, posterior vault distraction is recommended for children with
bicoronal, bilateral lambdoid, and synostosis.
■ The main objective of the endoscopic-assisted operation is to completely
remove the fused suture using a small incision that will be concealed with hair
growth and to avoid injury to the underlying dura.
■ The main steps of the procedure:
■ Strategically make incisions that exposes the fused suture or sutures.
■ Create an optical tunnel to see the fused suture and for removal of the bone.
■ Make a small craniotomy and enlarge it enough to place the endoscope and to
facilitate epidural dissection.
■ Perform craniectomy of the affected suture either en bloc or in multiple
pieces.

■ Achieve hemostasis that is confirmed with endoscopic visualization and close
the skin.
Preoperative Planning
■ The risks, benefits, and realistic expectations are discussed with the parents
prior to surgery.
■ The postoperative appointment with the orthotic supplier is confirmed.
■ The risks of bleeding, infection, cerebrospinal fluid leak, dural injury, seizure,
stroke, blood transfusion, and the potential need for secondary operations may
be reinforced.
■ The surgeon should confirm the availability of specialized instruments,
positioning equipment, and blood products before proceeding to the operating
room.
Positioning
■ The positioning of the patient during the operation depends on the affected
suture or sutures.
■ Appropriate positioning facilitates exposure and removal of the affected
suture, as well as the comfort of the surgeon during the operation.
■ Supine positioning on a well-padded horseshoe headrest is used for patients
with metopic, coronal, and bicoronal craniosynostosis.
■ A modified sphinx position is the authors’ preferred position to address sagittal
craniosynostosis (FIG 2).
■ Prone positioning is used for lambdoid craniosynostosis.
Approach
■ Incision placement is critical to permit removal of the affected suture(s) and
concealment within the hair. The general considerations made for incision
placement include the following:
■ Placement perpendicular to the affected suture
■ Limiting incisions to no more than 3 cm in length
■ Ensuring the incision placement to address the fused metopic suture is behind
the hairline using loupe magnification if needed
■ Using one (or possibly two incisions) to safely facilitate removal of the
sagittal, lambdoid, and coronal sutures

FIG 2 • A modified sphinx position is utilized to address
sagittal craniosynostosis.
T E C H N I Q U E S
■ Markings
■ The hairline is identified and marked. Use loupe magnification if hair is
difficult to visualize.
■ The hair-bearing scalp in the region of the planned incisions is clipped and
cleaned.
■ For sagittal craniosynostosis, the anatomic anterior incision is designed
dorsal to the anterior fontanelle, and the dorsal incision is designed anterior
to the posterior fontanelle (TECH FIG 1A).
■ The incision for metopic craniosynostosis is designed dorsal to the hairline
and anterior to the fontanelle (TECH FIG 1B).
■ The incision placement for coronal craniosynostosis is perpendicular to the
affected suture and lateral to the anterior fontanelle.
■ If visualization of the suture is inadequate, a second smaller incision may be
made caudally to facilitate suturectomy (TECH FIG 1C).
■ Similar to coronal synostosis, the incision for lambdoid synostosis is made
perpendicular to the suture with the cephalically oriented incision placed just