An arachnoid cyst that does not cause any symptoms may not require treatment at all — a neurosurgeon might typically recommend follow-up imaging every so often to monitor the cyst’s growth.
If an arachnoid cyst is causing symptoms, however, it may be necessary to operate. If left untreated, an arachnoid cyst may not only continue to cause headaches and other symptoms, it may also create pressure against healthy brain tissue and lead to neurological damage. Surgery for arachnoid cysts is generally safe, with good outcomes.
There are three surgical options for treating an arachnoid cyst:
A pediatric neurosurgeon may place a permanent drainage system, a type of shunt, to drain fluid from the cyst and reduce pressure on the brain. A permanent shunt drains fluid from the cyst into the abdomen, where it is reabsorbed harmlessly into the body. This is a relatively simple surgical procedure but is usually done as a last resort by the pediatric neurosurgeons at Weill Cornell Medicine.
An open surgical procedure called fenestration is more complex than the surgery to install a shunt, but the success rates are very good. In a cyst fenestration, the pediatric neurosurgeon opens the skull to gain access to the cyst, then opens the cyst to release pressure allowing the contents to be absorbed naturally by the brain. Opening the cyst is a permanent solution, and it avoids the need to permanent implanted shunt hardware.
Endoscopic cyst fenestration is an advanced technique that has the benefits of fenestration without requiring open surgery, combined with the simplicity of shunting without the risk of shunt complications. It’s a short, safe procedure in which the neurosurgeon uses an endoscope (a type of tube with a camera), to drain the cyst internally. The procedure takes only 30 minutes to an hour to perform, and patients can return home the following day.
An experienced pediatric neurosurgeon will discuss the options with you and recommend a treatment plan. Pediatric neurosurgeons with advanced training in all three techniques are best qualified to evaluate an arachnoid cyst and make an individual treatment recommendation.
Reviewed by: Jeffrey Greenfield, M.D., Ph.D.
Last reviewed/last updated: March 2021