J Neurosurg (4 Suppl Pediatrics) 107:332–337, 2007

332 J. Neurosurg: Pediatrics / Volume 107 / October, 2007

HE measurement of head circumference, a direct re-flection of head growth, is an important step in theevaluation of childhood growth and development.

Deviations from normal may be the first indication of an un-derlying congenital, genetic, or acquired problem. When thehead circumference is greater than two standard deviationsabove the mean for a given age, a diagnosis of macroceph-aly is made. The most common cause of macrocephaly ishydrocephalus. Untreated or partially treated hydrocephaluscan cause massive enlargement of the head. Rarely, macro-cephaly can give rise to serious problems in psychosocialdevelopment, hygiene, and aesthetics secondary to compro-mised head mobility from a heavy fluid-filled enlargedhead.1 Presentation of children with extreme macrocephaly(head circumference . 60 cm) secondary to hydrocephalusis uncommon due to the early treatment of hydrocephalususing various shunting devices and techniques.

History of Cranial Reduction Surgery and OperativeTechniques Used

A number of surgical techniques for performing reductioncranioplasty have evolved over the years. In all these tech-niques the common goal is reduction in cranial vault size.The positioning of the patient and the number of stages varywith surgical technique. While CSF shunting procedureswere still in their infancy, Ehni1 carried out reduction of headsize in a patient with advanced hydrocephalus, between theyears 1951 and 1953, using specialized gap-closing devicesdesigned by the patient’s father. The surgical treatmentswere performed in 13 stages over a 22-month period. Sincethen several operative techniques have evolved, involvingsingle or multiple stages and varying positioning of the pa-tient (Figs. 1–5). Some of these techniques are compared inTable 1.

In 1964, Sayers and Duran17 reported a reduction cra-nioplasty in a hydrocephalic patient; the surgery had been

Historical vignette

Vault reduction cranioplasty for extreme hydrocephalicmacrocephaly

MARLON S. MATHEWS, M.D.,1 WILLIAM G. LOUDON, M.D., PH.D.,1,2

MICHAEL G. MUHONEN, M.D.,1,2 AND MICHAEL J. SUNDINE, M.D.3

Department of 1Neurosurgery and 3Aesthetic and Plastic Surgery, University of California, Irvine; and2Neurosciences Institute, Children’s Hospital of Orange County, Orange, California

PPDue to early diagnosis and treatment of hydrocephalus, neurosurgeons rarely are called upon to treat patients withextreme hydrocephalic macrocephaly. Macrocephaly can limit mobility and hygiene. The critical evaluation and sur-gical correction of the morphological problem of macrocephaly secondary to hydrocephalus is complex. Various tech-niques such as quadrantal, picket fence, crossbar, and modified p techniques have been used to reduce the size of thecranial vault to decrease cranial volume while achieving good cosmesis. Limitations of vault reduction cranioplasty in-clude the inability to alter the anteroposterior and lateral diameters of the skull base, the inability to shorten the supe-rior sagittal sinus, and the need to avoid infolding of the brain due to the risk of venous infarcts. Reduction cranioplastyis indicated in the occasional patient whose large head size represents a mechanical or cosmetic problem of sufficientmagnitude to seriously interfere with motor development and functioning, with resultant development of pressure soresand difficulties with nursing care. Reduction cranioplasty should be avoided in patients under the age of 3 years. (DOI: 10.3171/PED-07/10/332)

KEY WORDS • cranioplasty • hydrocephalus • macrocephaly • pediatric neurosurgery •vault reconstruction • vault reduction

T

Abbreviation used in this paper: CSF = cerebrospinal fluid.

See the corresponding editorial in this issue, pp 330–331.

planned as a four-stage procedure, but the parents refusedthe final frontal reduction stage. The first stage was place-ment of a shunt, so the reduction cranioplasty involving theposterior two thirds of the calvaria was carried out in two ofthe three final procedures. In 1979, Vries and Habal22 de-scribed a five-stage procedure (two stages for cranial vaultreduction) in which they utilized a sagittal strut of bone asthe foundation to replace the reduced cranial pieces in con-junction with supraorbital repositioning. The first stage wasfor general reduction and was performed with the patient ina prone position; the final (fifth) stage was for supraorbitalrepositioning and was performed with the patient supine.The surgeons achieved a 63% reduction in intracranial vol-ume with no postoperative complications. Ventureyra andDa Silva21 completed a single-stage reduction in a 3-year-old hydrocephalic patient using semisitting positioning, bi-temporal incision, and a sagittal strut. Both halves of thecranial vault were fragmented, and the pieces were then fas-tened together in the desired dimensions using heavy silk.The procedure lasted 8 hours and required replacement of500 ml of blood. In 1985, Park and colleagues13 reportedperforming a reduction cranioplasty as a one-stage proce-dure in which they utilized their previously reported modi-fied prone positioning and were able to achieve a 50% re-duction in cranial vault volume. This modification allowedexposure from nasion to inion. The authors’ anterior crani-otomy was performed in a supraorbital position and includ-ed vertical osteotomies and greenstick fracturing as well asa crossbar craniotomy support structure supporting in sagit-tal and coronal directions.14 Piatt and Arguelles16 reported

on three patients treated with reduction cranioplasty for cra-niocerebral disproportion; the procedures involved com-plete removal of the calvaria, creation of a coronal crossbar,and delayed placement of a permanent shunt for CSF drain-age. In 1995, Winston et al.23 reported on reduction cranio-plasty in four patients with macrocephaly, in two of whoma two-stage procedure was used. Takahashi and colleagues19

also reported performing multistage reduction cranioplasty(one four-stage procedure and one two-stage procedure) intwo children with severe macrocephaly secondary to hydro-cephalus. In 1998, Erdinçler et al.2 reported using the mod-ified crossbar and modified p techniques in single-stageprocedures. Sundine et al.18 reported a single-stage proce-dure utilizing a modification of the procedure reported byPark and colleagues for prone positioning using a sagittalbandeau and frontal, temporoparietal, and occipital boneflaps bilaterally.

Indications for Reduction Cranioplasty

The consequences of untreated craniocerebral dispropor-tion are severe. Piatt and Arguelles16 described them as fol-lows: 1) mechanical instability of cortical mantle that maylead to intermittent hemorrhage and successful shunting be-coming problematic; 2) the need for repetitive shunt revi-sions that may result in infection; 3) extreme enlargement ofthe skull that may lead to failure of head control, problemswith positioning, and skin breakdown; and 4) deformity

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FIG. 1. Drawing showing the sagittal (open arrow) and occipital(solid arrow) bandeaus. The bandeaus are fashioned from the re-moved calvaria. The dura mater covering the superior sagittal sinusis suspended from the sagittal bandeau, eliminating the need fordural placation while maintaining adequate curvature of the sinus.Remaining portions of the calvaria are then fashioned in desireddimensions and attached to the sagittal and occipital bandeaus, aswell as the skull base, with absorbable plates and suture.

FIG. 2. Drawing illustrating the quadrantal technique. The cra-nial vault is removed in four quadrantal plates. After the CSF is re-moved via a ventricular catheter, the dura is imbricated. Each boneplate is reduced in size and molded as necessary. Some or all of theplates may be subdivided and then reassembled with wire or platefixation to produce a smaller, better-contoured quadrant. The newplates are then secured in place and the dural envelope is reinflatedwith CSF. Arrows indicate reinstitution of plates molded in requireddimensions.

leading to insurmountable obstacles to social acceptance.The indications for reduction cranioplasty are listed in Table2. Briefly, this procedure is indicated when extreme hydro-cephalic macrocephaly results in arrest of motor develop-ment and significantly limits mobility, hygiene, and the pro-vision of nursing care.

Because infants with macrocephaly often show only mildpsychomotor developmental delay later in life, cranial vaultreduction should be reserved until children are 3 years ofage of older.

Outcome in Published Cases

According to Ehni,1 preoperatively the child that he treat-ed used to lie on his back and would move about by dig-ging his heels into the carpet and dragging his heavy headbehind his body. After 13 procedures, Ehni reported a de-crease in the child’s inter-ear diameter from 53 to 42 cm.Postoperatively, the child developed the ability to walkusing a walker although he remained ataxic even while sit-

ting. The child remained alert, may have experienced im-provement in intellectual function, and demonstrated goodcontrol of his head. The aesthetic results of the surgical pro-cedure were reportedly considered to be an improvementover the child’s preoperative condition by the child’s par-ents and the operating physician as well as by other obser-vers.

Takahashi and colleagues19 operated on two patients forsevere macrocephaly. The first patient, an 8-year-old boy,experienced functional improvement—from not being ableto support his head without assistance to walking indepen-dently—postoperatively. His head circumference was re-duced from 85 to 68 cm as a result of the procedure. Thehead circumference of the second patient, a 3-year-old boy,was reduced from 54 to 50 cm, and the patient showed somedevelopmental progress.

Of the series of three patients reported on by Winston etal.,23 one patient died, another showed some improvementin head support, and the third showed good growth and de-velopment (although development was slightly delayed).The two patients reported on by Erdinçler et al.2 showed im-provements in head circumference and nasion–inion and bi-parietal distances, respectively, from 72, 70, and 70 cm to62, 44, and 43 cm in the first patient; and from 74, 71, and68 cm to 59, 46, and 42 cm in the second. The condition ofthe first patient improved to the point of his being able tostand and independently support his head, but the child died

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FIG. 3. Drawing illustrating the picket-fence technique. Rela-tively thin and malleable bone is a prerequisite for this technique.The anterior vault is removed and the bone plates are reduced insize, molded, and repositioned. After detailed planning, osteotomiesare carried out in the parietooccipital vault to create triangular pick-ets. The bone pickets are then bent and molded across the vertex andsecured with wires and microplates, establishing sound structuralstability. Drainage of CSF, imbrication of dura, and reinflation withCSF are carried out as in the quadrantal technique.

FIG. 4. Drawing illustrating the crossbar technique. Osteotomiesare made in the calvaria in the manner shown. The four quadrants(smaller than in the quadrantal technique) are removed. All fourlimbs of the crossbar are shortened (not necessarily equally). Struc-tural stability is established by firmly securing each limb of the cross-bar to the cranial base. Each remaining plate is reduced in size, con-toured as necessary, and then attached to the crossbar and also to thecranial base. Drainage of CSF, imbrication of dura, and reinflationwith CSF are the same as in the quadrantal and picket fence tech-niques.

M. S. Mathews et al.

4 months postoperatively from peritonitis possibly relatedto ventriculoperitoneal shunt infection. The second patient,who was unable to support the weight of her head preoper-atively, was able to stand up with minimal assistance post-operatively. She had a cosmetic defect, however, due to un-equal growth of her reconstructed bones. Mansour et al.8

reported significant improvements in the condition of a 1-year-old girl post–vault reduction with contraction osteo-genesis. The patient, who preoperatively was unable to liftthe weight of her own head, walk, or crawl, and had a GradeII occipital decubitus ulcer, was able to walk and hold herhead up in a stable midline position after treatment. Thom-son and Hoffman20 reported significant cosmetic benefits ina 2-year-old who presented with an unsightly enlarged headwith patent metopic sutures. At 2-year follow-up the childwas described as “rather attractive” with improved motorand cognitive function. Vries and Habal22 reported on a 6-year-old child who had been severely incapacitated by theweight of his head preoperatively and 6 months postopera-tively had developed full control of his head. The patient’shead circumference decreased from 73 to 50 cm represent-ing a 63% volume reduction. Ventureyra and Da Silva21 re-ported head circumference reduction and cognitive gains ina 3-year-old boy who underwent surgery for macrocephaly.Piatt and Arguelles16 reported the results of surgical cranialvault reduction in three infants (ages 3, 2, and 3 months)with successful reduction in head circumference in all three,compensatory development in the first child, and modestbenefits in the other two.

In a recent series of four cases reported by Sundine et al.,18

all the patients survived without any significant postoperativemorbidity. The indication for surgery in all patients was tofacilitate nursing care. The underlying conditions were con-genital hydrocephalus in two patients and holoprosencephalywith hydrocephalus in the other two. The averages for bloodloss, operating room time, and duration of intensive care unitstay were 1037.5 ml, 9.23 hours, and 16.25 days, respective-ly. All four patients had severe developmental delay preop-eratively; none had any language development, nor couldany of them walk. One of the four patients showed signifi-cant compensatory development at the 1-year follow-up ex-amination, including initiation of language development andwalking without assistance. In the other three patients no sig-nificant developmental advancement was seen, but nursingcare was significantly improved, with reduction of occipitaldecubitus ulceration and easier head lifting.

Discussion

Hydrocephalus is a pathological condition characterizedby increased ventricular volume that is not the result of pri-mary atrophy or dysgenesis of the brain. In most cases, thisaccumulation of CSF results from anatomical obstruction tothe egress of CSF and is associated with present or previouselevation of CSF pressure.11 Congenital hydrocephalus ishydrocephalus of unknown cause present in utero and dis-covered in the newborn.12 Quantitative measures of hydro-cephalus include absolute measurements, corrected for thereduction in size that occurs in imaging, as well as patientage and ratios of the width of the ventricles to standardlandmarks on the skull. Ratios most frequently used to as-sess hydrocephalus by computed tomography include theEvans ratio,3,4,15,24 the frontal horn ratio,5 the ventricular sizeindex,6 the Huckman number,7 and the cella media index.9,10

Once the diagnosis of hydrocephalus is made, early treat-ment generally allows for prevention of macrocephaly. To-tal cranial vault reduction cranioplasty is an uncommonprocedure. It is rare that a surgeon is called upon to evalu-

J. Neurosurg: Pediatrics / Volume 107 / October, 2007 335

FIG. 5. Drawing illustrating the modified p technique. Two para-median osteotomies are created after removal of a bifrontal boneflap. The craniotomy is extended first posteroinferiorly and then ant-eroinferiorly toward the temporal bone. The bifrontal bone flap isreformed to the desired shaped and size before being replaced. Thecalvaria that remains after removal of the two bone strips is then re-approximated with a resultant decrease in cranial vault size. The sizeof the bifrontal bone flap and the paramedian bone strips can be var-ied from patient to patient to achieve the desired results.

Vault reduction cranioplasty

M. S. Mathews et al.

ate or treat patients with macrocephalic hydrocephalus inthis era of early diagnosis and treatment of hydrocephalus.

Winston et al.23 discuss six tactical considerations for vaultreduction procedures, as follows. 1) Operative positioningshould be planned preoperatively with the anesthetists—thesize and weight of the head, calvarial thickness, and separa-tion of the sutures being important factors. 2) Careful atten-tion should be given to intraoperative CSF drainage, as inad-equate drainage can cause increased intracranial pressure onclosure, while overdrainage can cause the dural covering tolose its opposition to the overlying bone, sag, and fold overon itself from gravity. This can cause direct mechanical dam-age to the brain or ischemic damage from vascular impair-ment. 3) In the management of hydrocephalus, they proposethat the intracranial pressure in the immediate postoperativeperiod should be maintained slightly above normal to keepthe dura snugly against the calvarial bone. 4) Redundantdura can be imbricated along multiple longitudinal ellipticalstrips parallel to the superior sagittal sinus. 5) Kinking orobstruction of the venous sinuses should be avoided duringthe operative procedure, and dural imbrications should beplanned to avoid this complication. Sundine and colleagues18

suspended the dura around the superior sagittal sinus to thesagittal bandeau to avoid this complication. 6) Winston et al.recommend avoiding resection of redundant scalp in gener-al, although in patients with grossly excess scalps causingfolds, excision of excess scalp is suggested.

While the strategic goal of reduction cranioplasty is toimprove the patient’s quality of life, the technical goal isreduction of cranial volume. Macrocephaly exists in many

shapes, and the technique selected must fit the specificstructural configuration. No one technique is best for all pa-tients. It is extremely important to develop a surgical planpreoperatively in terms of the placement of osteotomies,the identification of areas of bone to be removed and con-toured, and the establishment of structural stability of thenew vault. Generally one-stage calvarial reconstruction ispreferable to multistage operations,13 although decisions re-garding staging should be made on a case-by-case basis.

One of the limitations of vault reduction cranioplasty isthat although the vault size can be reduced, the anteriopos-terior and lateral diameters of the skull base remain unal-tered. Also, the sagittal sinus cannot be shortened. Althoughit seems possible to shorten the anterior one third of thesagittal sinus, such an attempt would entail a risk of injuryto the brain. It is indeed possible that vault reduction resultsin marked folding of the brain with resultant venous in-farcts. These could go undetected in this patient populationunless specifically looked for.

While vault reduction cranioplasty may be an option inproperly selected patients, it is clearly not without risks. Onthe basis of our review on the procedure, we estimate amortality rate of 4.35% based on currently published data(one death in 23 reported cases). Because cases with ad-verse outcomes are unlikely to have been reported in the lit-erature, it is possible that the actual mortality rate is higher.The decision to proceed with total cranial vault reductioncranioplasty is complex. The surgeon should only proceedafter careful, critical analysis of the underlying cause of thepathological condition, clear discussions with all relevantparties regarding the risks, potential benefits, possible alter-natives, and proper preoperative planning.

Limitations of vault reduction cranioplasty include the in-ability to alter the anteroposterior and lateral diameters ofthe skull base, the inability to shorten the superior sagittalsinus, and the need to avoid infolding of the brain due to therisk of venous infarcts.

Conclusions

Reduction cranioplasty may be an option for patients withmacrocephalic hydrocephalus who have very large heads

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TABLE 1Advantages and disadvantages of various surgical techniques in reduction cranioplasty

Technique Advantages Disadvantages

quadrantal plate technique* excellent control of resulting contour of cranial vault difficulty in obtaining reliable structural stability equally satisfactory for all cranial sizes & shapes inappropriate for patients w/ malleable cranial

bonespicket fence technique* appropriate for patients w/ extremely thin & malle- difficult in older children & adults w/ a thick &

able cranial bones & those w/ widely separated rigid craniumsutures & large fontanelles removal of entire sagittal suture, potentially lim-

ideal in infants iting subsequent vertical expansionabsence of free bone flaps, maximizing chance of

healingcrossbar technique* good structural stability limits extent to which curvature of sagittal plane

well suited for staging can be alteredsagittal sinus not stripped from overlying bone, de- difficult in patients w/ large open anterior fonta-

creasing risk of tearing or kinking nelle or separated suturesmodified p technique† advantageous when large reduction in the anteropos- possibility of cosmetic problems due to improp-

terior diameter of the cranium is required (for ex- er apposition (stepping) between frontal & ample, in scaphocephaly) parietal bones

* As described by Mansour et al. † As described Vries and Habal.

TABLE 2Indications for reduction cranioplasty

large head size (.60 cm), patient age $3 yrs, & at least one of thefollowing due to head size &/or weight:

limitation of normal development or activitiesreduced quality of life (even if patient is neurologically impaired)impediment to nursing care (even if neurologically impaired)cosmetic impairment severe enough to interfere w/ psychosocial

development or function

and in whom the size and weight of the head significantlyinterfere with motor development. Not all patients are goodcandidates for reduction cranioplasty. The procedure is indi-cated in the occasional patient whose large head size is amechanical or cosmetic problem of sufficient magnitude toseriously interfere with motor development and function,with resultant development of pressure sores and difficultieswith nursing care. Reduction cranioplasty should be avoid-ed in patients under the age of 3 years.

References

1. Ehni G: Reduction of head size in advanced hydrocephalus: acase report. Neurosurgery 11:223–228, 1982

2. Erdinçler P, Kaynar MY, Canbaz B, Etus V, Ciplak N, KudayC: Two different surgical techniques for reduction cranioplasty.Childs Nerv Syst 14:372–377, 1998

3. Evans WA: An encephalographic ratio for estimating ventricu-lar enlargement and cerebral atrophy. Arch Neurol Psychiatry47:931–937, 1942

4. Evans WA Jr: An encephalographic ratio for estimating the sizeof the cerebral ventricles: further experience with serial obser-vations. Dis Child 64:820–830, 1942

5. Hahn FJY, Rim K: Frontal ventricular dimensions on normalcomputed tomography. AJR Am J Roentgenol 126:593–596,1976

6. Heinz ER, Ward A, Drayer BP, Dubois PJ: Distinction betweenobstructive and atrophic dilatation of ventricles in children. JComput Assist Tomogr 4:320–325, 1980

7. Huckman MS, Fox J, Topel J: The validity of criteria for theevaluation of cerebral atrophy by computed tomography. Ra-diology 116:85–92, 1975

8. Mansour N, Sobel L, Lee M, Larumbe J, Stelnicki E: A new meth-od for the treatment of macrocephaly caused by hydrocephalus.Cleft Palate Craniofac J 41:1–6, 2005

9. Meese W, Kluge W, Grumme T, Hopfenmüller W: CT evalua-tion of the CSF spaces of healthy persons. Neuroradiology 19:131–136, 1980

10. Meese W, Lankseh W, Wende S: Diagnosis and postoperative fol-low-up studies of infantile hydrocephalus using computerizedtomography, in Lanksch W, Kazner E (eds): Cranial Computer-ized Tomography. Berlin: Springer-Verlag, 1976, pp 424–429

11. Milhorat TH: Pediatric Neurosurgery. Philadelphia: F.A. Da-vis, 1978

12. Naidich TP, Schott LH, Baron RL: Computed tomography in eval-

uation of hydrocephalus. Radiol Clin North Am 20:143–167,1982

13. Park TS, Grady MS, Persing JA, Delashaw JB: One-stage re-duction cranioplasty for macrocephaly associated with advancedhydocephalus. Neurosurgery 17:506–509, 1985

14. Park TS, Haworth CS, Jane JA, Bedford JA, Persing JA: A mod-ified prone position for cranial remodeling procedures in childrenwith craniofacial dysmorphism: a technical note. Neurosurgery16:212–214, 1985

15. Pedersen H, Gyldensted M, Gyldensted C: Measurement of thenormal ventricular system and supratentorial subarachnoid spacein children with computed tomography. Neuroradiology 17:231–237, 1979

16. Piatt JH, Arguelles JH: Reduction cranioplasty for craniocere-bral disproportion in infancy: indications and technique. Pedi-atr Neurosurg 16:265–270, 1990–1991

17. Sayers MP, Duran RJ: Reduction cranioplasty in hydrocephalus,in Transaction of the Third International Congress of PlasticSurgery. Amsterdam: Excerpta Medica, 1964, pp 828–832

18. Sundine MJ, Wirth GA, Brenner KA, Loudon WG, MuhonenMG, Greene CS, et al: Cranial vault reduction cranioplasty in chil-dren with hydrocephalic macrocephaly. J Craniofac Surg 17:645–655, 2006

19. Takahashi Y, Tajima Y, Okura A, Tokutomi T, Shigemori M, Ki-yokawa K: Reduction cranioplasty for macrocephaly. Two casereports. Neurol Med Chir (Tokyo) 39:459–462, 1999

20. Thomson GH, Hoffman HJ: Intracranial use of a breast prosthe-sis to temporarily stabilize a reduction cranioplasty. Plast Re-constr Surg 55:704–709, 1975

21. Ventureyra EC, Da Silva VF: Reduction cranioplasty forneglected hydrocephalus. Surg Neurol 15:236–238, 1981

22. Vries JK, Habal MB: Cranio-orbital correction for massive en-largement of the cranial vault. Plast Reconstr Surg 63:466–472,1979

23. Winston KR, Ogilvy CS, McGrail K: Reduction cranioplasty.Pediatr Neurosurg 22:228–234, 1995

24. Zatz LM: The Evans ratio for ventricular size: a calculation er-ror. Neuroradiology 18:81, 1979

Manuscript submitted April 9, 2007.Accepted June 20, 2007.Address correspondence to: Marlon S. Mathews, M.D., 101 The

City Drive South, Bldg. 56, Suite 400, Orange, California 92868-3874. email: mmathews@uci.edu.

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