gms | German Medical Science

Objective: Meningomyelocele (MMC) has become a rare finding most often diagnosed in routine ultrasound during pregnancy. In many of these cases, hydrocephalus is diagnosed at the same time with herniation of the cerebellar tonsils into the upper cervical canal (Arnold Chiari malformation type II). The management of hydrocephalus in these patients depends on the clinicial representation of signs of raised intracranial pressure such as tight anterior fontanelle, head circumference, bradycardia and Resistance Index. Here, we evaluate the frequency of MMC patients treated in our clinic necessitating ventriculoperitoneal (VP) shunt implantation for treatment of hydrocephalus. We also analyzed when VP shunt implantations were needed.

Methods: Over a decade, 29 patients underwent surgical closure of MMC in our clinic. In three cases, the diagnosis of MMC was unknown before birth, thereof one patient had a wrong prenatal diagnosis teratoma. 28 patients were born by caesarian sectio, one patient by vaginal route. Two patients had a diastematomyelia associated with MMC. All patients underwent cerebral and spinal MRI. Spinal and cerebral follow-up MRI were performed on a regular basis.

Results: 26 out of 29 patients needed CSF drainage for hydrocephalus due to Arnold Chiari malformation type II. 25 infants underwent VP shunt implantation, 1 premature infant had a Rickham reservoir first which was replaced by a VP shunt later on. Four infants needed VP shunt implantation on the first day of life, thereof two devices were implanted before MMC surgery due to tight anterior fontanelle and bradycardia. In 13 patients, CSF drainage was implemented between day 1 and 5 after birth. By the end of the second week of life, 22 patients had received CSF diversion. Two shunts were implanted in the third week of life, one shunt in the fourth week and one on the 30th postnatal day. In 7 infants hydrocephalus was diagnosed before birth.

Conclusion: MMC is frequently associated with hydrocephalus, probably more often than has been assumed previously. The optimal timing for implantation of CSF diversion varies within the first four weeks of life. The optimal timing can be established on an individual basis depending on the manifestation of raised intracranial pressure.