|Year : 2016 | Volume
| Issue : 1 | Page : 42-45
Transnasal endoscopic repair of pediatric meningoencephalocele
Amit Kumar Keshri, Saurin R Shah, Simple D Patadia, Rabi N Sahu, Sanjay Behari
Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
|Date of Web Publication||27-Apr-2016|
Amit Kumar Keshri
Department of Neurosurgery, C Block, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Rae Bareli Road, Lucknow - 226 014, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: Encephaloceles in relation to the nose are rare lesions affecting the skull base. In the pediatric population, majority are congenital lesions manifesting as nasal masses requiring surgical intervention. Materials and Methods: A retrospective study of 6 consecutive patients below 12 years of age with intranasal meningoencephalocele treated by endonasal endoscopic approach at our tertiary centre was done. The follow up period ranged from 6 months to 2 years. A detailed clinical and radiological evaluation of these cases was done. Endonasal endoscopic repair (gasket seal/fat plug) was carried out in all cases. Results: Out of 6 patients, 4 patients had post-traumatic and rest 2 cases had congenital meningo-encephaloceles. All patients were asymptomatic in post-operative follow up period. One patient had minor complication of nasal alar collapse due to intra-operative adherence of encephalocele to cartilaginous framework. Conclusion: Transnasal endoscopic repair of anterior skull base meningoencephalocele is a minimally invasive single stage surgery, and has advantage in terms of lesser hospital stay, cost of treatment, and better cosmesis. The repair technique should be tailored to the size of defect to provide a water-tight seal for better outcome.
Keywords: Fat plug, fascia-cartilage “gasket” seal, pediatric encephalocele, transnasal endoscopic repair, vascularized flap
|How to cite this article:|
Keshri AK, Shah SR, Patadia SD, Sahu RN, Behari S. Transnasal endoscopic repair of pediatric meningoencephalocele. J Pediatr Neurosci 2016;11:42-5
| Introduction|| |
A meningoencephalocele is the extracranial herniation of brain tissue with meninges through a defect in the skull. Sincipital and basal encephaloceles present as masses in relation to the nose and may cause external nasal deformity and hypertelorism. Congenital lesions arise due to defect in the developing anterior neuropore in the region of foramen cecum. In the Asian population, the incidence is relatively higher at around 1 in 6000 live births. Traumatic meningoencephalocele usually occurs following head injury or extended skull base surgeries.
Sincipital meningoencephalocele may be of nasofrontal, nasoethmoidal, or naso-orbital type. Transethmoidal type is the most common basal encephalocele which also includes sphenoethmoidal, transsphenoidal, and sphenoorbital type.
Pediatric meningoencephalocele has been traditionally addressed with transcranial approaches which have obviously higher complication rates. Untreated children may present with recurrent meningitis and/or epilepsy not controlled by medications.
Following the first report by Wigand in 1981, the transnasal endoscopic approach has evolved tremendously for repair of cerebrospinal fluid (CSF) rhinorrhea. Advances in available instruments and surgical expertise have also led to effective management of meningoencephalocele via a single stage exclusively endoscopic approach in select cases.
Although literature is now emerging, a search on PubMed with the keywords such as “children,” “encephalocele,” and “endoscopic” used in combination revealed about 20 studies (out of 51 hits) addressing this condition. We describe the patient profile, surgical nuances, and outcomes of transnasal endoscopic repair of pediatric intranasal meningoencephalocele in the review of six cases operated at our center.
| Materials and Methods|| |
A retrospective study involving six consecutive patients below 12 years of age with intranasal meningoencephalocele treated by endonasal, endoscopic approach at our tertiary center from July 2013 to June 2014 has been carried out. The follow-up period ranged from 6 months to 2 years.
A detailed history and clinical evaluation with specific emphasis on duration, mode of onset, associated congenital malformations, features of raised intracranial pressure, meningitis, and nasal endoscopy (if possible) were included in the initial workup.
For the radiological evaluation, a spiral computed tomography (CT) scan of the paranasal sinuses with 1–2 mm sequential sections and a magnetic resonance imaging of the brain with paranasal sinuses with cisternography sequences were carried out in all cases to localize the defect in the anterior skull base, to decide the surgical exposure necessary, and to rule out any associated pathologies, especially hydrocephalus [Figure 1].
|Figure 1: Preoperative radiological evaluation of patient 4 showing a transethmoidal variety of encephocele on noncontrast computed tomography and magnetic resonance – T1 and T2 imaging|
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Nasal fluid evaluation for confirming CSF rhinorrhea was however not possible in all cases due to either scanty leaks or for want of the child's cooperation.
Following a fitness for general anesthesia and with due consent of the child's guardian, an endonasal endoscopic repair was carried out in these cases. The child was placed under cover of the 3rd generation cephalosporin antibiotic for 7 days starting from the time of surgery. No antiepileptic drug was added for the surgery unless the child was already on treatment.
An endonasal endoscopic repair was carried out following lumbar drain insertion under general anesthesia. CSF sample was subjected to routine analysis including microbiology. Four millimeters endoscopes, 0° and 30°, were used for surgery. Following topical and infiltration decongestion, the first step was to delineate the lesion in its entirety. An initial attempt was made to localize the site of the fistula between the cranium and the nose, thereby estimating the tissue required for repair.
Defining the site endoscopically in terms of relation to the skull base and turbinates and correlating with the imaging findings were imperative in delineating the defect in the skull base with maximum precision. After circumferential release of mucosal adhesions, the protruding mass was reduced using bipolar coagulation under constant irrigation flush to the level of skull base. Bulky masses if yet not reducible were debulked with microneurosurgery instruments. If middle turbinectomy was necessary, only the vertical lamella was fractured and the turbinate preserved for use as a vascularized mucosal flap.
The mucosa at the margin of the defect was coagulated to create a raw area and promote healing. The dural defect was smaller than the size of the encephalocele in all cases. Repair of the defect was tailored to its size. Defects <1 cm in size were repaired using a fat plug (intracranial, extradural) and an onlay fascia (extracranial) for support. Defects >1 cm in size were managed with an initial fascia-cartilage “gasket” (intracranial, extradural) with fascia overlying the bony margins and fat-fascia (extracranial) for support. Cartilage was harvested from the nasal septum and fascia lata from the thigh. The entire repair site was covered with either the middle turbinate mucosal flap or nasoseptal mucosal flap harvested from the same side and fibrin glue applied [Figure 2] and [Figure 3].
|Figure 2: Site of defect in ethmoid roof as seen on sagittal computed tomography sequence with schematic representation of fascia-cartilage “gasket” seal; blue – fascia, yellow – cartilage, red – vascularized
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|Figure 3: (a) Encephalocele in right middle meatus, (b) encephalocele being reduced to identify skull base, (c) encephalocele reduced and bony margins of defect identified, (d) repair with fascia-cartilage
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A polyvinyl acetate nasal pack was placed on the operated side at the end of the surgery.
The child was nursed under cover of antibiotics with complete bed rest for 72 h. The nasal pack and lumbar drain were removed 48–72 h after the surgery. Laxatives, antitussives, and osmotic diuretics were used to avoid elevation in intracranial pressure during the phase of primary healing for the 1st week.
Following 5 days of care on indoor basis, the child was discharged and followed up at 2 weeks, 1 month, and then monthly for the first 6 months.
Serial endoscopic evaluation was done on follow-up and imaging reserved for patients with history of rhinorrhea, meningitis, or seizures in the postoperative period.
Observation [Table 1]
|Table 1: Patient profile, causative factors, significant history, radiological findings, surgical technique and
follow up of the enrolled cases|
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| Discussion|| |
Trauma leading to fracture of the anterior skull base is a frequent cause of encephalocele in the pediatric age group, especially for the transethmoidal type of basal encephaloceles (4 out of 6 cases in our series). Larger series in literature however report congenital encephalocele as the most common variety.
Untreated meningoencephalocele/CSF rhinorrhea leads to recurrent episodes of meningitis (5 out of 6 patients). Delayed presentation with meningitis has also been reported in literature, and surgery is the treatment of choice with no benefits of prophylactic antibiotic. Very few studies addressing endoscopic transnasal management of encephalocele in pediatric population are available in literature. Castelnuovo et al. reported a series of 11 cases with congenital encephaloceles managed endoscopically with a favorable outcome.
In the present study, a total endoscopic repair was done in all cases with autologous fascia and/or fat harvested from the thigh. The use of endoscope permitted easy localization of the defect in the skull base intraoperatively without the use of fluorescein dye.
Congenital encephalocele with adherence to the cartilaginous framework of the nose was difficult to dissect intraoperatively (2 out of 6 cases). In these children, inadvertent resection of the nasal cartilaginous framework during surgical repair can lead to cosmetic deformity (1 out of 2 cases).
In consistency with excellent results reported in recently published literature, we achieved both successful repair of the defect and avoidance of further episodes of meningitis or seizures in all cases. No patients in our series had recurrence or postoperative CSF leak. The repair site was found to be well epithelialized on endoscopy at 2 months postoperatively.
The endoscopic approach hence provides an obvious advantage of being a minimally invasive procedure without need for cerebral retraction and a faster recovery than open approaches. Anosmia and recurrence are frequent with transcranial repair techniques.
The working space available in pediatric patients with an endoscopic approach is restricted; hence, the procedure may be challenging in children below 5 years of age without use of special instruments such as a 2.7 mm endoscope. We have not yet used this approach in children below 5 years of age; however, the literature reveals successful endoscopic repair in even younger children.
Patients with associated soft-tissue deformity of the craniofacial area are definite candidates for transcranial/transfacial/combined endoscopic and external approaches. Potential effects on the developing craniofacial skeleton are always a concern for surgery in the pediatric patient, endoscopic, or external.
| Conclusion|| |
Transnasal endoscopic repair of anterior skull base meningoencephalocele is a favorable technique in select cases. Being a minimally invasive single stage surgery, results in terms of hospital stay, cost of treatment, and cosmesis are obviously superior to conventional transcranial approaches.
Noncontrast CT of the peripheral nervous system with magnetic resonance cisternography permits excellent localization of the skull base defect and hence, invasive procedures such as CT cisternography can be avoided. Serial postoperative radiological evaluation can be avoided in asymptomatic cases.
Surgery can be performed without image guidance and requires conventional endoscopic instruments only in children over 5 years of age. The size of the defect in skull base is frequently smaller than the size of the encephalocele; hence, repair following defect localization is feasible endoscopically. Furthermore, use of fluorescein dye is not imperative.
The repair technique tailored to the size of defect as adapted by us provides a water-tight seal of the CSF fistula and avoids recurrence. Notably, children tolerate nasal packing well in contrast to common belief. Prolonged use antibiotics and lumbar drain insertion can be avoided in cases successfully treated by the endoscopic route.
Careful study of preoperative radiology and meticulous surgery bring about excellent outcomes in transnasal endoscopic repair of pediatric meningoencephalocele. A longer follow-up and a larger number of cases will help us produce consistently favorable results.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]