### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
hi drcan u help me?my sis is 6 years old and she had large arachinoid cyst but she didnt have any neurological symptom except difficult talking and decrease of concentration so she  did MRI   show large arachinioid cyst with middline shift to left . she didnt have any medical problem befor .  i consult neurisurgen he tell me she need shunt . my sis did cystoperitoneal shunt from 5 days now she in hospital but she comlpain after operation from vomiting sometime yellowish or light green sputum with out eating and sever frontal heddache that is decrease by adol . i told dr about her status is not well he describe me what he did in OR he told me when inserted the tube more amount of fluid escape out tube so he open 4 hole for drain only and another 4 hole is still not drain, he tell me maybe need another operatin and now my sis under observation she on plasil and antibiotic and omeparzol .   i need ur advice

### output:

Thank you, and pleased to answer you:The national institute of neurological disorders and stroke define arachnoid cysts as cerebrospinal fluid-filled sacs that are located between the brain or spinal cord and the arachnoid membrane. During the early weeks of gestation, developmental abnormalities in the brain and spinal cord can happen, and will cause Primary arachnoid cysts. Secondary arachnoid cysts more uncommon as primary cysts, are seen as a result of brain diseases (meningitis, tumors), or head injury, or as a complication of brain surgery.  Surgery depends mostly upon the size and the location of the cyst. As untreated, arachnoid cysts may complicate to neurological damage in case of size expansion of the cyst, I propose to your new surgery: microneurosurgical techniques and endoscopic tools allowing minimally invasive surgery (surgically remove the membranes of the cyst or open the cyst, so its fluid can Chat Doctor. 