Treatment for arachnoid cysts occurs when symptoms present themselves. A variety of surgical procedures may be used to decompress (remove pressure from) the cyst.

• There are a number of approaches in treating arachnoid cysts, the most common are:
  • Endoscopic fenestration and removal of the cyst wall (advances in neurosurgical techniques favor fenestration over shunt insertion as the preferred method for initial management).^[1]
  • Microsurgical fenestration;
  • Craniotomy followed by shunting.

• Neuroradiology imaging is needed to assess: location of the cyst and its size;
• It is still a controversy which is the best method, some studies state that the fenestration is associated with more complications^[2] while some argue that the endoscopic approach is superior with fewer surgical complications in comparison to craniotomy and shunting,^[3]
• Regarding symptoms, endoscopic approach has been preferred with hydrocephalus as this allows more space to execute the surgery.^[4]
• Location of the cyst also plays an important role on choosing the approach and possible outcomes:
  • Middle cranial fossa: endoscopy is still controversial; microsurgery may be a better option in this location.^[4]
    • Type I – microsurgical fenestration;
    • Type II – endoscopic cystocisternotomy, if it fails: microsurgical fenestration or shunting;
    • Type III – endoscopic cystocisternotomy, if it fails: microsurgical fenestration or shunting;
  • Suprasellar: usually present with hydrocephalus – endoscopic fenestration is the preferred treatment. Craniotomy is associated with increased morbidity. Endoscopic ventriculocystocisternostomy preferred over ventriculocystostomy.^[4]
  • Interhemispheric: may be:
    • Parasagittal: excision of the cyst;
    • Midline: associated with agenesis of the corpus callosum, fenestration is preferred.
  • Quadrigeminal:
    • Type I – Supratentorial
    • Type II – Infratentorial:
    • Type III – lateral extension toward the temporal lobe. May present with symptoms such as headaches, vomiting, lethargy, and impairment of upward gaze, macrocrania. If symptomatic, they must be treated
      • Endoscopic method is preferred for all of them due to the proximity with the pineal region.^[4]