Dear Editor:

I read with interest El-Ghandour’s paper regarding endoscopic third ventriculostomy for the management of hydrocephalus associated with Chiari malformation type 2 in children [1]. El-Ghandour et al. successfully used serial lumbar punctures in 44%, in order to prevent early failure of the third ventriculostomy. Although lumbar puncture to initiate flow over the third ventriculostomy is a familiar procedure [2], it is a much less commonly used in the presence of myelomeningocele. In some guidelines the presence of a myelomeningocele is considered to be an absolute or relative contraindication for lumbar punctures [3, 4]. Since the authors used this procedure effectively, it may be of interest to know how this procedure is performed successfully and safe in children suffering from myelomeningocele. Building on this, it is of importance to know if there is an age difference between patients in whom ETV failed or succeeded, and how much CSF should be drained in order to successfully initiate flow over the ETV.