CSF leak after spinal cord surgery.

My mother is having spinal cord problem. L5 and L6 discs got very near and between then sciatica nerve was struck causing problem for blood circulation to entire left leg. Spinal cord surgery was done in the month of may 2018. We thought that she was alright now after surgery. But at that operated area it's swelling and after MRI scan came to know that CSF(Cerebrospinal fluid) was leaking after the surgery. We consulted many doctors and they are saying that this is will become critical if it was not stopped now and it will brain in future if surgery is not done again. I want to know how this CSF leak problem can be treated, which hospital and which doctor is best for doing this surgery, what will be the estimated cost for this surgery and will there be any problem in the future if the surgery for CSF leak is done. One more thing which doctor will do the surgery like spinal cord specialist or a neurologist.