Is Meningocele Repair In An Infant Risky?

My 3 month old granddaughter is scheduled to have Meningocele Repair in the morning about 10 hours from now, I m concerned that her parents have not been made fully aware of the risks to her immediate and future health. She has a 12mm round cyst on her lower spine which is covered with a thin membrane, it is sometimes more or less flat (raised around the edge) and sometimes raised to about 13mm. Since birth she is a normal happy interactive baby with normal strength in her legs and normal bowel & urinary function, she responds to touch on her legs & feet. The Specialist has said the spinal cord is in its NORMAL LOCATION inside the spine, there is NO nerve tissue inside the cyst and so the risk is insignificant, any functional or sensory disruption would be only short term. From various internet sources it seems even with no nerve tissue present in the cyst / meningocele there is still significant risk of permanent motor / sensory / urinary / bowel function LOSS. What is the truth ?.