Immediate Resection and Reconstruction of Encephalocele in the Craniofacial Region.

INTRODUCTION: Congenital meningoencephalocele is a herniation of brain and meninges through a skull base defect. It may result not only in neural defects, sensorimotor deficits, neurological morbidities, visual impairment, impaired nasal function, and a potential risk of intracranial infection. Goals of surgery include removal or repositioning of nonfunctional cerebral tissue, closure of the dura, and reconstruction of skeletal and cutaneous structures.
MATERIALS AND METHODS: The authors present the case of a 4-months-old infant who was found to have a frontoethmoidal encephalomeningocele that was only discovered after birth, the volume increased gradually. After multiple department discussions, the procedures were planned in 2-staged surgical protocol comprising of the first stage urgently performed by neurosurgeon and craniomaxillofacial surgeon, which aimed at removal or repositioning of nonfunctional cerebral tissue, closure of the dura, and reconstruction of skeletal; then second stage was performed by plastic surgeon to correct craniofacial hard and soft tissue deformities. RESULTS AND
CONCLUSIONS: The surgical procedures for frontoethmoidal encephalomeningocele are complicated, particularly for the infant. In order to achieve the final surgical purpose, it needs multiple department cooperation to make the surgical plans.

Congenital meningoencephalocele is a herniation of brain and meninges through a skull defect. Meningoencephaloceles can be categorized as occipital, parietal, basal, and sincipital lesions.[1,2] Suwanwela and Suwanwela[3] have subdivided sincipital encephaloceles into frontoethmoidal, interfrontal, and those associated with craniofacial clefts. The frontoethmoidal group is further subdivided into nasofrontal, nasoethmoidal, and naso-orbital types. Frontoethmoidal encephalomeningocele manifests as a clinically visible facial mass along the nose and its location and size varies depending on the variety.[4]

SURGERY PROCESS

A 4-months-old male infant presented with swelling between the forehead and nose, which had been present since birth, had progressively increased in size and easily been noticeable over the past 1 month, with an increased intercanthal due to the mass between the eyes. This mass looked/showed irregular in shape with little bumps and indistinct with surrounding tissue, with high local tension, almost to ruptured (Fig. 1A).

FIGURE 1

(A) A 4-months-old male infant swelling between the forehead and nose, had progressively increased in size and to be easily noticeable over the past 1 month, with an increased intercanthal because of the mass between the eyes. This mass irregular in shape with little bumps on it indistinct with surrounding tissue, with high local tension, almost break up. (B-F) CT scan (with 3D reconstruction) and MRI demonstrate a frontoethmoidal encephalocele. The ethmoidal plate of the anterior cranial fossa was absent, the brain parenchyma herniated forward and downward, and protruded into the bilateral orbit. The nasal bone was slightly everted, the bilateral eyeballs were compressed to the lateral deviation. The posterior horn of bilateral ventricles was enlarged, and the midline structure is centered. 3D, three-dimensional; CT, computed tomography; MRI, magnetic resonance imaging.

Computed tomography scan (with three-dimensional reconstruction) and magnetic resonance imaging revealed a frontoethmoidal encephalocele. The ethmoidal plate of the anterior cranial fossa was absent, the brain parenchyma herniated forward and downward, and protruded into the bilateral orbit. The nasal bone was slightly everted, the bilateral eyeballs were compressed to the lateral deviation. The posterior horn of bilateral ventricles was enlarged, and the midline structure was centered (Fig. 1B-F).

After multidisciplinary discussions, the surgical procedures were planned in 2 stages, the first stage was performed by a neurosurgeon, which aimed at removal or repositioning of nonfunctional cerebral tissue, closure of the dura, and reconstruction of skeletal; then second stage was performed by plastic surgeon to correct craniofacial soft tissue deformities.

The first surgical procedure was performed when the patient was 4 months old. The cranial approach was employed using the standard bicoronal incision. This incision should be as anterior as possible while staying behind the hairline (Fig. 2A). The incision does not always need to reach the tragus, but it at least should reach the level of the superior edge of the pinna. The scalp incision should leave the pericranium, temporalis muscle, and fascia intact (Fig. 2B). Elevate a vascularized pericranial graft as a separate layer. Monopolar electrocautery disconnects the posterior and lateral attachments of the pericranium (to the superior temporal line). This vascularized graft would be reflected and based anteriorly along the orbital rims. A single burr hole was placed over the anterior superior sagittal sinus, a bilateral coronal craniotomy was performed, the dura was then carefully dissected from the calvarium, burr holes in the region of the forehead were avoided for cosmetic reasons. After detaching all adherent dura from its undersurface, exposing the underlying frontal lobes of the brain (Fig. 2C).

FIGURE 2

(A) A bicoronal incision is designed (dark solid line). (B) The scalp incision should leave the pericranium, temporalis muscle, and fascia intact. (C) A bilateral coronal craniotomy was performed. (D) Craniomaxillofacial surgeon reconstructed the craniofacial deformity and correction of hypertelorism covered the surface of the reconstructed orbital rims using by the rest of the periosteum. (E) The bone flap was put back in place, fixed. (F) After the operation, the mass of the nose root was obviously reduced, and the local tension significantly reducted, we can see the correction of the hypertelorism.

The frontal lobes were carefully retracted epidurally, the large skull defect was found at the junction of frontal bone and ethmoid bone. After identifying the bone defect, the herniated portion of abnormality was opened and noted to contain brain tissues. Removing the herniated portion of brain tissue, separating the dura mater at the skull base, taking part of the periosteum to repair the dura mater and watertight closure of the dura (see Supplemental Digital Content, Video 1). Then craniomaxillofacial surgeon reconstructed the craniofacial deformity and corrected the hypertelorism by removal of central sections of bone and bringing the medial walls of both orbits closer together with suture, covered the surface of the reconstructed orbital rims using by the rest of the periosteum (Fig. 2D). The bone flap was put back in place and fixed with suture (Fig. 2E). After surgery, the mass of the nose root was obviously reduced, and the local tension significantly reduced. The correction of the hypertelorism was visible (Fig. 2F).

Antiepileptic medication and broad-spectrum antibiotics were used prophylactically. Postoperative magnetic resonance imaging demonstrates the total removal of the encephalocele (Fig. 3A-B). Postoperative courses were uneventful and complication free (Fig. 3B-D).

FIGURE 3

(A-B) Postoperative MRI demonstrates the total removal of the encephalocele. (C) Preoperative photographs of representative the patient. (D) 1 year postoperative appearance of the patient showing the mass of the nose root was disappeared unless there is some craniofacial soft tissue deformities on the skin and it will correct by plastic surgeon. MRI, magnetic resonance imaging.

DISCUSSION

The debate whether frontoethmoidal encephalomeningocele is a neural tube defect continuing as the pathogenesis itself is hardly understood. Many have defined it as a combination of genetic and environmental factors resulting in the pathogenesis.[5] Defects have been associated with folate deficiency and supplementation has been responsible for the decreased prevalence by up to 70%.[6]

Most are managed conservatively and repaired in a delayed manner, within months to years later, aiming to minimize surgical morbidity and mortality. However, in this case, the swelling between the forehead and nose had progressively increased in size the past 1 month, with an increased intercanthal because of the mass between the eyes, this mass looked irregular in shape with little bumps, with high local tension, almost to be ruptured anytime, if ruptured, it would result in wound infection, low intracranial pressure, local skin necrosis and cerebrospinal fluid (CSF) leakage, meningitis, etc. These were indication of urgent repair, therefore, emergency surgery was required.

Operative management could include many approaches. Treatment of frontoethmoidal is not a unique standardized procedure. In the literature, we found several different techniques, such as the classic approach of Tessier,[7,8] the Chula technique,[9] modified Chula techniques,[10] the HULA procedure and others.[5,11,12]

Because the volume of the tumor increased gradually, and the instant increase in the surface tension, possibly leading to rupture with unimaginable consequence, therefore, the operation must be carried out in emergency. (After multiple department discussions, the surgical treatment was planned in 2 stages, the first stage urgently performed by a neurosurgeon and craniomaxillofacial surgeon, which aims removal or repositioning of nonfunctional cerebral tissue, closure of the dura, and reconstruction of skeletal, second stage will be performed by plastic surgeon to correct craniofacial hard and soft tissue deformities.)

We used a modified intracranial–transcranial approach with no anterior facial surgical exposure. The advantage of this protocol was that performing the procedure with both the neurosurgeon and craniomaxillofacial surgeon present, assured an adequate elimination of the anomaly, complete dural closure, as well as correction of the craniofacial deformity.

For this procedure, a watertight and durable closure of the dural defect was particularly important, which gained by using the autologous pericranial graft harvested, whereas reflecting the scalp flap. In this way, many complications could be avoided after surgery, such as CSF leak, meningitis, epidural abscess, and brain herniation. Due to the great healing potential of the young child and the fusion of the cranial bones as a part of normal development, skull defects often heal very well,[13] therefore, no need to reconstruct the defect in the anterior cranial fossa base. The infant made an uneventful recovery and was discharged home to the care of his parents. We successfully followed up for 1 year, no CSF leakage, hydrocephalus, epidural abscess, and brain herniation was found, we planned to perform by plastic surgeon to correct craniofacial hard and soft tissue deformities.