45 Surgical management of encephaloceles


In this retrospective study, we present our experience of 16 patients with encephaloceles managed surgically at Tribhuvan University Teaching Hospital (TUTH) over an eight and a half year period. The demographic profile, clinical features, surgical
management, and outcome of this patient population have been analyzed and recommendations in the technical aspect of
neurosurgical intervention is presented. In addition, we review the pertinent literature.
Key Words: classification, encephalocele, surgical outcome





Encephalocele is defined as protrusion of cranial contents (meninges and cerebral tissue) beyond the normal
confines of the skull through a defect in the cranium. The
population incidence of this congenital anomaly is estimated
to vary from 1 per 300 to 1 per 10000 live births. 1- 4 In respect to the incidence, cranial dysraphism, particularly
encephaloceles, is far less common compared to its spinal
counterpart, namely, myelomeningocele, accounting for
only 8-19% of all dysraphism. 4-9 In this retrospective review, we present our experience in a consecutive series of 16 patients managed successfully
in our institution. Materials and Methods TUTH is a tertiary level Teaching Hospital providing neurosurgical services since 1995. Sixteen patients
diagnosed with encephaloceles, based on clinical findings
and computerized tomography (CT) and or magnetic
resonance imaging (MRI) scans of the head, were treated at
the Division of Neurosurgery at TUTH from April 1995 to
October 2003. All patients were operated and diagnosis was
confirmed at surgery. Demographic, clinical, radiological






and operative data of this patient population were reviewed
from the hospital charts and computerized data bank of the
Division of Neurosurgery. In addition we describe the
short-term outcome at discharge from the hospital.
Management Protocol Each patient with suspected encephalocele was evaluated by the neurosurgical team and all patients
underwent either MRI or CT scan of the head. The size and
anatomical location of the lesion were noted. Associated
findings, such as, large head size, suggesting underlying
hydrocephalus, were also noted. Detailed neurological
examination was performed noting specifically presence or
absence of any neurological deficit. The modified
classification as proposed by Rosenfeld, 1 0 as shown in the Table 1, was used to classify the encephaloceles
anatomically. All patients with encephaloceles were
routinely offered surgery. Depending upon the anatomical
location, either direct excision and repair of the lesion or
craniotomy and repair from inside was done. In some cases
a combined approach was used. In a situation where the
bony defect was significant, bone graft (split calvarial or
split rib) was utilized. Figure 1 shows an example of a Original article Sushil K. Shilpakar, MS
Division of Neurosurgery
Tribhuvan University Teaching Hospital
Maharajgunj, Kathmandu
Nepal

Mohan R. Sharma, MS
Division of Neurosurgery
Tribhuvan University Teaching Hospital
Maharajgunj, Kathmandu
Nepal
Address for correspondence:
Sushil K. Shilpakar, MS
Department of Neurosurgery
Tribhuvan University Teaching Hospital
Maharajgunj, Kathmandu
Nepal
Email:
sshilpak@hotmail.com Received, December 1, 2003
Accepted, December 20, 2003 J Neuroscience 1:45-48, 2004 46 patient who underwent combined repair with good cosmetic
result.
Convexity
Occipital
Parietal
Sagittal
Occipitocervical
Sincipital
Frontoethmoidal
Nasofrontal
Nas oethmoidal
Nasoorbital
Interfrontal
Craniofacial cleft
Basal
Intranasal
Sphenoorbital
Sphenomaxillary
Sphenopharyngeal
Atretic
Table 1. Modified Classification of encephalocle
The short -term outcome at discharge was assessed at the time of hospital discharge. Results The neurosurgical data of patients with encephaloceles who were admitted and treated at TUTH over the eight and
a half year period from April 1995 to October 2003 was
retrospectively studied. Age groups
No. of cases Percentage <1
1-5
6-10 6
3
7 37.5
18.7
43.8 Table 2. Distribution of patients based on the age groups. Demographics and Clinical Presentation There were a total of 16 patients. Seven were males and 9 females. The average age of the patient at the time of
presentation was 3.4 years, ranging from 11 days to 8 years.
Table 2 summarizes the distribution of patients on the basis
of age groups.
All patients presented with swelling on the head. Six
patients (37.5%) presented with enlarged head
circumference with associated hydrocephalus and two
patients (12.5%) with hypertelorism. None of the patients
had neurological deficit or evidence of mental retardation.

Groups
No. of cases Percentage Occipital
Sagittal
Anterior fontanel
Posterior fontanel
Frontoethmoidal
Nasoethmoidal
Nasofrontal
Nasoorbital

6
2
1
1
8
4
3
1 37.5
12.5


50
Table 3. Anatomical location of encephaloceles in the patients with cranial dysraphism

Classification Patients with encephaloceles were d ivided into different groups on the basis of modified classification as proposed
by Rosenfeld et al. (Table 3). The results suggest that majority of the cases were of frontoethmoidal type (50%) followed by occipital type
(37.5%).
Surgical approach No. of cases Percentage Direct excision & repair Direct repair
Fascia lata graft
Repair &split rib cranioplasty Craniotomy and repair
Pericranium/muscle graft
Split cranial graft
Split rib graft Associated HCP requiring VPS* 10
4
4
2

2
2
1
3 62.5
25
25
12.5

12.5
18.75
6.25
18.75
*HCP, hydrocephalus; VPS, ventriculoperitoneal shunt
Table 4. Various surgical approaches in the series of 16 patients.

Surgical Approach Encephalocele is surgically approached in various ways, mainly on the basis of its location and type. For frontonasal,
cranial vault and occipital encephaloceles, direct
extracranial repair may be feasible. For nasoethmoidal and
nasoorbital type, intracranial repair may be needed. And for



47






















older children with larger encephaloceles, the combined
efforts of a neurosurgeon and a plastic surgeon are
necessary to deal with the lesion effectively. The various
surgical approaches in our patients are summarized in Table
4.
Outcome The surgical outcome in our series was satisfactory. None of the patient had any anesthetic or procedure related
complications. None of the patients had cerebrospinal fluid
leak. There was no mortality. In 1 patient there was delayed
recurrence of occipital encephalocele 9 months after the
initial surgery, which required revision of repair and rib
cranioplasty. Discussion From the anatomic aspect, the most common sites for encephaloceles are occipital and frontonasal regions. In Asia
and Africa, there is a predominance of the frontonasal group
while 80-90% are found in the occipital region in the
Western Hemisphere. Approximately 70% of occipital
encephaloceles occur in females, but there is no sex
predominance noted in the frontobasal type. In our series,
the most common sites were the frontoethmoidal and
occipital regions (50% and 37.5% respectively). The incidence of hydrocephalus in patients with encephaloceles is reported to be about 50%. In our series,
only 3 out of 16 (20.%) patients had overt hydrocephalus
requiring permanent cerebrospinal fluid (CSF) diversion.

























In planning the strategy of management of encephalocele, one needs to take into consideration the site,
size, contents, state of CSF pathway, neurological status,
associated anomalies and overall general condition of the
patient. The principle of repair is analogous to the
management of hernias in general surgery, which includes
dissection of the sac, isolation of the neck, adequate closure
at the neck and reinforcement. The herniated part of the
brain is usually gliosed and non-viable and can usually be
safely amputated. Dural defect should be closed in a
watertight fashion, using graft if necessary. Ideally,
reinforcement of bony defect with bone graft (split cranium,
split rib, or acrylic) will prevent reprotrusion through the
defect. Reconstruction of bony abnormalities may be
necessary at times for better cosmetic results. Associated
hydrocephalus should be treated by shunting before
managing the encephalocele. As mentioned before, surgical
approaches for encephaloceles, based on its location and
type, can be direct, indirect or both. In our study, out of 16
cases of encephaloceles, 10 cases underwent direct repair
and 6 patients underwent craniotomy, of which 2 cases were
performed in collaboration with the plastic surgeon. The end result of encephalocele surgery is usually not determined by the neurosurgical procedure per se, but by the
underlying brain involvement and presence or absence of
other congenital defects. In long-term follow up, cases with
anterior defect have better prognosis and more than half
have normal intelligence quotient (IQ). Limitations of our study merit mention. Our study is retrospective in nature. Though we wanted to include as
many patients as possible, due to the uncommon nature of
Figure 1. This 9 month old girl child had large nasoethmoidal encephalocele which was managed successfully. Left, preoperative photograph of the patient and right, same patient 10 days after the operation. 48 this problem our sample size is small; so inherent biases due
to small sample size cannot be ruled out. Conclusions Encephalocele is a relatively uncommon neurosurgical entity largely seen in the pediatric population. Treatment of
this condition can be rewarding if properly managed early.
Occipital, parietal, frontal, and frontonasal types may be
approached without opening the cranium, while sinciputal
and basal encephaloceles usually require craniotomy. In this
series we present our experience in the operative
management of encephaloceles with good outcome and also
share our recommendation in technical consideration for
surgical approaches. References 1. Caviness CS Jr, Evrard P: Occipital encephalocele: A pathologic and anatomic analysis. Acta Neuropath (Berlin), 32:245-255, 1975 2. Karch SB, Urich H: Occipital encephalocele: A morphological study. J Neurol Sci 15:89-112, 1972 3. Lorber J: The prognosis of occipital encephalocele. Develop Med Child Neurol (Suppl.) 13: 75-86, 1967 4. Mealey J Jr, Dzenitis AJ, Hockey AA: The prognosis of encephaloceles. J Neurosurg 32:209-218, 1970 5. Barrow N, Simpson DA: Cranium bifidum: Investigation, prognosis and management. Aust
Paediat J 2: 20-26, 1996 6. Eckstein HB, MacNab GH: Myelomeningocele and hydrocephalus. Lancet 1:842 -845, 1966 7. Fisher RG, Uihlein A, Keith HM: Spina bifida and cranium bifidum: Study of 530 cases. Mayo Clin Proc 27:33-38, 1952 8. Matson DD: Neurosurgery of infancy and childhood, ed 2. Springfield III: Charles C Thomas, 1969 9. Schwidde JT : Spina bifida: Survey of 225 encephaloceles, meningoceles and myeomeningoceles. Amer J Dis Child 84:35-51, 1952 10. Rosenfeld JV, Watters DAK: Hydrocephalus and congenital abnormalities. In Rosenfeld JV, Watters
DAK (eds): Neurosurgery in the Tropics. London,
Macmillan, 2000, pp12