Year : 2006 | Volume
: 1 | Issue : 3 | Page : 16--18
Surgical repair of a giant naso-ethmoidal encephalocoele
AK Singh1, MS Sharma2, VK Agarwal2, S Behari2,
1 Department of Plastic Surgery, King George Medical University SGPGIMS, Lucknow, India
2 1Department of Neurosurgery, SGPGIMS, Lucknow, India
Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Rae Bareli Road,Lucknow - 226014,
Surgery for frontoethmoidal encephalocoeles involves correction of the cosmetic deformity, hypertelorism, orbital dystopia, elongation of the nose and other stigmata of midline or lateral facial defects. The technical aspects of a single stage correction of this disorder is presented. The coexistence of Chiari malformation (type 1), mild ventriculomegaly with the nasoethmoidal encephalocoele was a rare association in the reported case.
|How to cite this article:|
Singh A K, Sharma M S, Agarwal V K, Behari S. Surgical repair of a giant naso-ethmoidal encephalocoele.J Pediatr Neurosci 2006;1:16-18
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Singh A K, Sharma M S, Agarwal V K, Behari S. Surgical repair of a giant naso-ethmoidal encephalocoele. J Pediatr Neurosci [serial online] 2006 [cited 2022 Aug 11 ];1:16-18
Available from: https://www.pediatricneurosciences.com/text.asp?2006/1/1/16/17043
Frontoethmoidal encephalocoeles are easily recognized as midline facial masses often associated with hypertelorism, orbital dystopia, elongation of the nose and other stigmata of midline or lateral facial defects. ,,, Embryological dysgenesis may be explained by altered separation of surface ectoderm and neurectoderm during the fourth gestational week.
The authors report the surgical management of an extremely unusual coexistence of the Chiari malformation (type 1), mild ventriculomegaly and a nasoethmoidal encephalocoele.
An 11-month-old child presented with a congenital midline facial mass at the root of the nose with widely separated eyes [Figure 1]. The lesion had been slowly increasing in size without any corresponding increase or decrease in head size. The child had an insignificant perinatal history and the mother reportedly had supplemented her diet with folic acid prenatally. Developmental milestones were normal for age. There was no history to suggest secondary infection or CSF leak.
On examination, the child had a 4 x 3 x 3 cm, soft, nontransilluminant, fluctuant swelling at the root of the nose with a cry impulse. The anterior fontanelle was open and depressed in the supine position. The child had consistent ocular fixation and a normal cry. MRI revealed a large nasoethmoidal encephalocoele, mild ventriculomegaly and tonsillar descent. There was no evidence to suggest aqueductal stenosis [Figure 2]A-C. The child was advised a single stage correction of the dural defect with medial orbital advancement for correction of the hypertelorism.
The child was placed in a supine position on a horseshoe head support under a general anaesthetic delivered via endotracheal intubation.
The eyes were protected with an antibiotic ointment, gauze and a sterile transparent adhesive after the anterior scalp and the upper and middle parts of the face were prepared. Drapes were placed to provide simultaneous exposure.
A bifrontal free bone flap craniotomy was fashioned after a bicoronal scalp incision. Four burr holes were used - two on either side of the midline 5 cm above the orbital rim and one each just posterior to the zygomatic process of the frontal bone. Inferomedially, the bony defect at the level of the nasal bones was broadened to allow the dural separator and guide to go through. The bone flap was removed and bleeding from the region of the superior sagittal venous sinus was controlled using surgicel and local pressure. The dura was noted to be taut, thinned out and transparent at places. The bony defect was identified extradurally anteriorly and laterally at the base. To identify the posterior limit was impossible at this stage. The dura was opened in a rectangular fashion based at the orbital rims after ligating and transecting the superior sagittal venous sinus. The flaps were retracted and the gliosed, herniated brain excised first on the right and then the left side. This enabled direct visualization of the dural margins of the neck of the hernia sac, which was found to be extending posteriorly upto the planum sphenoidale. The dural defect at the anterior cranial fossa base was measured to be about 3 x 3 cm and an oval patch of pericranium was used to repair this using 4-0 Vicryl starting posteriorly and then laterally. The basal stitch line was reinforced with strips of pericranium and fibrin glue. After ensuring a watertight closure, the pericranium patch was sutured to the margins of the durotomy superficially. This stitch line was also reinforced by strips of pericranium and fibrin glue. Blood loss was estimated at 10 cm3sub for the entire procedure.
The periorbita was then further reflected for greater mobilization of the defect. The supraorbital rims, the lateral orbital margin and the zygomatic arches were exposed. The basal dura was also stripped off laterally to identify the orbital roof. To gain access to the infraorbital rim and the inferior and medial aspects of the bony defect, the encephalocoele sac was then partially excised in an S-shaped manner and the contents removed piecemeal till the pericranium flap and the vicryl stitch line could be observed. Lateral mobilization on either side enabled identification of the infraorbital rims. The nasal bones were found inferior to the bony defect and were excised. A Midas Rex C1 attachment was used to osteotomize the orbital plates of the frontal bones and the zygomatic arches. The lateral orbital wall was sectioned using a fine chisel, which was also used to perform a Le Fort II osteotomy. This dissection resulted in partial avulsion of the pericranial graft, which was again sutured extracranially and reinforced with pericranial strips and Fibrin glue [Figure 3]A-C.
Both the orbits were therefore mobilized and the medial orbital rims brought together and fastened with Nylon 2-0 passed through corresponding drill holes. The excised nasal bones were used as spacers and insinuated between the cut margins of the zygomatic arches and fastened similarly. The bone flap was partially excised inferiorly using the Midas Rex CI attachment to produce a rectangular graft, which was further refashioned to fill in the bony defect at the medial ends of the supraorbital rims to which it was similarly fastened. The grafts were also anchored to the bone flap, which was replaced in such a manner so as to create a bone defect at the vertex [Figure 3]D, E.
Hemostasis was secured and the scalp incisions were closed over suction drains. The child withstood the procedure well and was ventilated overnight. 24 h later CSF rhinorrhoea was observed and the child underwent an emergency ventriculoperitoneal shunt after a CT scan had been done to rule out an increase in hydrocephalus or the development of an intracerebral hematoma. At surgery, the CSF was under high pressure and a medium pressure Chhabra shunt assembly was used. The rest of the postoperative period was uneventful and the child was discharged on the seventh postoperative day.
One step corrective surgery for anterior encephalocoeles is a safe and recommended option. Further corrective nasal surgery may be advisable as the child grows. The Chiari malformation is a very rare association with sincipital encephalocoeles and may complicate the postoperative course with CSF leak. Such an event has to be managed with an emergent VP shunt as lumbar CSF drainage is contraindicated in the presence of tonsillar herniation. Although the anterior fontanelle and the encephalocoele may be lax preoperatively, this may be fallacious. The CSF hydrodynamics may change after sac excision resulting in higher CSF pressures than may be indicated by ventricular size on postoperative images, as seen in this case.
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