Arachnoidal Cysts

Hydrocephalus due to post-infectious multi-loculated ventricles, suprasellar arachnoidal cysts or trapped lateral ventricles can be difficult to manage, frequently requiring multiple shunts or open craniotomy. In 1992 a report was published on the use of endoscopes to treat 7 children with multi-loculated ventricles due to ventriculitis (infection within the brain's fluid spaces). In three cases intraoperative complications occurred with no long term sequelae but resulted in the need for open craniotomy to treat their pathology. All seven patients were described as improved.

A French surgeon described his groups experience in treating suprasellar arachnoidal cysts from 1972 to 1988 in a 1990 article. He described his groups' evolution in treatment, ultimately settling on the use of the endoscope to fenestrate the cysts into a lateral ventricle, frequently avoiding shunting all together.

A 1991 article described one group's treating of blocked ventricles by fenestrating either the cyst walls or septum pellucidum (a curtain dividing the two lateral ventricles) to create a singles CSF space so the patient only required a single shunt.

We have had the opportunity to treat many children with multi-loculated ventricles, trapped lateral ventricles and/or arachnoidal cysts. Most children with hydrocephalus due to a suprasellar cyst were successfully treated with opening a window in the cyst to drain it into a normal fluid space within the brain.

Children with trapped lateral ventricles have been successfully managed by fenestration of their septum pellucidum. resulting in a simplification in the management of their hydrocephalus (only a single shunt or, in some cases no shunt being needed).

 

Children with multi-loculated ventricles have been somewhat more difficult to manage and I have come to view these cases as the most difficult ones I do with the endoscope. The main problem is anatomical orientation given the distortion present. Authors have described using the ultrasound as a means of orientation but I have found this to be difficult at times. What I find to be most helpful in addition to starting in a normal area of the ventricle is to maintain an awareness of how far the scope has been advance into the head and in what direction. Most neurosurgeons use Computer Assisted Image Guidance to guide their work. I find that this ability to know where I am working greatly improves the success of the procedure and radically shortens its duration.

Mary Anne Gallagher, RN, C MA