Cranial fissure, cranionasal meningoencephalocele repair

Craniotomy is a congenital skull defect, and its cause is generally thought to be related to dysplasia of the neural tube during embryonic period and stagnation of mesodermal development. The neural tube is incompletely closed during development, or is completely separated from the ectoderm, causing developmental disorders such as the skull, meninges and arachnoid membrane formed by the mesodermal leaves, and thus deformity occurs. The cranial fissure occurs in the midline of the skull, and a few are on one side, and the cranial top and the skull base can occur. The bottom of the skull can bulge from the base of the nose, the nasal cavity, the nasopharyngeal cavity or the eyelids, and the roots are mostly. According to the contents of the bulging sac, it can be classified as follows: 1 meningocele, only the pia mater and the arachnoid, the dura mater is often absent, and the sac is filled with cerebrospinal fluid. 2 encephalocele, with pia mater and brain tissue, no cerebrospinal fluid. 3 encephalomingocele, there are meninges, brain parenchyma and cerebrospinal fluid. 4 Encephalocystocele, there are meninges, brain parenchyma and part of the ventricle, but no cerebrospinal fluid exists between the brain parenchyma and the meninges. 5 Encephalomeningocystocele, the content is similar to 4, but there is cerebrospinal fluid between the brain parenchyma and the meninges. Common clinical types are meningocele and meningeal bulging. The size of skull defects in various brain bulges varies greatly, most of them are small, and the smallest ones only allow the probe to pass, and the capsule contains only cerebrospinal fluid. A few large, diameter up to several centimeters, round or oval, often with brain tissue bulging. Nasal brain meningeal bulging can cause facial deformities, such as wide nose, widening of the pupil, narrowing of the sacral cavity. The eyes are triangular, and the eyes are squeezed to the outside. In severe cases, the eyes are closed and the nasal cavity cannot be breathed. The bulging sac gradually grows up in the first few months after birth, and the facial deformity is more and more obvious. Some of the sick children have mental retardation and even brain damage symptoms. After the diagnosis is clear, surgery should be performed. Treatment of diseases: skull defects Indication Craniotomy, cranial nasal meningeal bulging repair is applicable to: 1. The nasal roots are large and have facial deformities. 2. The nose is hugely bulged, and the mass covers the nose and mouth, affecting the breathing. 3. Bulging deformity combined with mental retardation, symptoms of brain damage such as convulsions. The best time for surgery is 6 to 12 months after birth. If the wall of the capsule is ruptured, the obstruction of the nasopharyngeal cavity or the displacement of the eyeball is urgently needed, and surgery should be performed in advance. Contraindications 1. Local skin ulcers, cystic rupture, secondary infection, or suppurative meningitis. 2. Giant brain membrane bulging, there is a large brain parenchyma, causing severe symptoms such as hemiplegia. 3. Patients with severe hydrocephalus (can be treated with hydrocephalus first, then repaired). Preoperative preparation Take the X-ray film of the lateral side of the skull to determine the location and size of the skull defect. If necessary, perform CT scan and MRI examination of the brain and eyes and nose to understand the bulging range and the contents of the capsule. Surgical procedure 1. Epidural repair (1) Incision: a coronal incision in the hairline, the flap is turned over to the maxillofacial region as much as possible to expose the base of the nose. (2) Bone craniotomy: Do a midline bone flap and open it to one side. You can also do two bone flaps and turn them to the sides. The lower edge of the bone flap is as close as possible to the upper edge of the frontal sinus to expose the base of the bulging sac. If the frontal sinus is opened, it should be handled properly. (3) Exposing the base of the bulging sac: lifting the frontal lobes from the outside of the dura mater, peeling off the dura mater and the skull base, finding the base of the bulging sac, and further dissecting the capsular neck. The bone defect is generally located in the midline of the anterior cranial fossa or near the sieve plate. (4) severing the neck: repairing the dura mater, and cutting the dura mater in a circular shape 1 to 2 cm from the talar talus defect, that is, seeing some brain tissue bulging out of the skull. The bulging small one is still in the cranial after being dissociated; the larger one is cut off with an electric knife or ligation at the base. The dura mater can be sutured continuously. If the dura mater is large and can not be sutured, a periosteum or diaphragmatic fascia can be repaired. (5) Treatment of the contents of the bulging capsule: the contents of the sac are mostly denatured brain tissue, which can be removed by a suction device. If the capsule protrudes into the nasopharyngeal cavity, the wall of the capsule and the nasal mucosa should not be damaged during suction to avoid contact with the nasopharyngeal cavity and infection. The bulged cyst wall can be retained, and after it is mechanized, the nasal root deformity can recover well after surgery, but if the cyst wall is thick or the brain tissue is too much, it is difficult to handle during surgery, or the postoperative bulging part is still ugly. Can be used for second-stage extracranial plastic surgery. (6) Repair of skull defect: Most authors advocate that the skull defect needs to be repaired, and the repair material can be made of plexiglass or titanium mesh. A few small holes are drilled at the edges and fixed with a silk suture on the adjacent periosteum, which can also be fixed with medical adhesive (Fig. 4.13.2-6). (7) Bone flap reduction: After the repair of the skull base, the bone flap was restored, and the periosteum was fixed by wire suture. (8) Closing the incision: After the flap is completely hemostasis, it is rinsed with physiological saline, and the drainage is placed under the cap-like diaphragm, and the incision is sutured according to the layer. 2. Dura mater repair (1) scalp incision and bone flap craniotomy with the epidural method. (2) The dura mater was cut transversely along the front of the bone window, and the front of the superior sagittal sinus was ligated at two points in the midline, and cut in between. (3) Lift the frontal lobe, find the bulged cyst neck, and treat the brain tissue outside the cranial cavity with the epidural method. Then, a piece of plexiglass is placed on the skull defect, and the wire is fixed on the dura mater, and then a dura mater is folded over the neck of the capsule to cover the plexiglass sheet, and then sutured. Regular cranial. complication Subdural hematoma Because there is brain tissue protruding into the sac, it is necessary to stop bleeding carefully after treating the neck of the capsule and cutting off the brain tissue. Otherwise, postoperative hemorrhage will form a subdural hematoma. The sick children have poor reaction ability. After the hematoma, there may be fewer clinical symptoms and it is easy to miss the diagnosis. Therefore, strict monitoring is needed after surgery. If irritability, vomiting, or gradual deterioration, the CT scan should be performed without hesitation. Clearing the hematoma in time can be completely restored. 2. Cerebrospinal fluid nasal The main causes of cerebrospinal fluid rhinorrhea are: 1 dural suture is not strict; 2 skull base defect is not repaired. Cerebrospinal fluid rhinorrhea does not heal for a long time, can cause purulent meningitis, severe control can lead to death. Individual cerebrospinal fluid rhinorrhea can be cured by itself. If it has not stopped after 3 to 5 days, it should be re-treated according to the original incision, and the dural fistula should be tightly sutured or strengthened.