A 1-day-old male newborn is scheduled for a repair of a meningo-myelocele. At the time of birth, examination of the newborn revealed a lumbosacral defect that was partially epithelialized. The defect was covered with a sterile dressing, and the child was placed in a partial lateral decubitus position.
The meningomyelocele may occur with several presentations. Most commonly, fusion of the neural tube fails in the middle or caudal neural groove, resulting in a thoracic or lumbosacral meningomyelocele. When the site of failed closure occurs more cephalad, encephaloceles result. The defective neural tissue in meningomyeloceles is in open communication with the environment; thus, an early closure to minimize bacterial contamination is recommended.
There can be an association with hydrocephalus and Chiari malformation. Most congenital lesions of the central nervous system (CNS) are not associated with an increased incidence of anomalies of other organ systems.
The incidence of meningomyelocele is about 1-6 in every 1000 live births.
Positioning for induction and intubation in order to avoid physical trauma to the neuroplaque may be a challenge. The patient should be supported by portions of the back that are not involved using rolled towels or a “doughnut” ring cushion.
Inhalational or IV induction may be used.
Maintenance of anesthesia is done with an inhalational agent in an air-oxygen mixture. Muscle relaxants may be used if the surgeon does not expect to use a nerve stimulator. Use narcotics judiciously.
Succinylcholine is not associated with excessive hyperkalemia in these patients.
Monitoring includes urine output and temperature. Invasive monitoring is not required for the healthy patient.
Conservation of body heat is important, since autonomic control below the defect is usually impaired.
Blood loss is usually small, but it may increase if the surgeon has to undermine a large area of skin and fascia to achieve primary closure.
Keep up with ongoing insensible fluid losses.
You may consider keeping the patient intubated and ventilated at the end of the case because of the age of the patient and the potential association with the Chiari malformation, which can be associated with an abnormal ventilatory response to hypoxia.
A ventriculoperitoneal shunt can be placed at the time of initial closure of the meningomyelocele, but some surgeons prefer waiting for a few days, especially in patients without apparent hydrocephalus at birth.
For lumbosacral repair, the surgeon may want to use direct muscle stimulation to spare neurological tissue; thus, large doses of nondepolarizing muscle relaxants that create profound muscle relaxation may not be a ...