Ventricular reservoir migration into the lateral ventricle through the endoscopic tract after unsuccessful third ventriculostomy.

We report a case of reservoir migration into the lateral ventricle through an enlarged endoscopic tract. A full-term female infant with a myelomeningocele, which was repaired surgically after birth, came to us with hydrocephalus, and a reservoir was placed after an unsuccessful endoscopic third ventriculostomy. The tract gradually enlarged and the reservoir eventually slipped into the lateral ventricle 16 days after implantation. This complication may be unique to children, in whom the bone is malleable. As endoscopic surgery is being used more often in infants, the risk of this complication may also be increasing with concurrent reservoir implantation. We believe this complication can be avoided with careful attention to several key points during surgery.