The neurosurgeon talked me through the procedure last week.  I’ll share it here, for those who are interested.  According to the neurosurgeon (and lots of other specialists we have seen), this surgery is the lowest risk (easiest) surgery that a neurosurgeon can perform.  In fact, the risk of not going through with the surgery is greater than the risk of having the surgery.  If we didn’t go through with surgery, the nerve damage could be permanent.  The risks associated with the surgery include a CSF (cerebrospinal fluid) leak and infection.

The surgery involves a small incision at the L4/L5 postion.  A very small amount of bone will need to be removed between the vertebrae, but should not effect the stability of the girl’s spine.  The neurosurgeon will not need to perform a total laminectomy, but will work between the vertebrae to expose the dura (outer layer).  The filum will be located (dissected) from among a lot of nerve roots (the spinal cord is not this low).  According to the surgeon, it’s kind of like looking at a broom with all yellow bristles and one black one.  The filum would be the black bristle.  It looks different.  It also is not a nerve, so will not respond to stimulation.  Before anything is cut, the surgeon will stimulate everything (including the filum) and record the response (to the legs and other lower anatomy).  The filum should not have a measured response…and so it will be cut.  He will cut half-way, then re-stimulate before he finishes with the cut.  After the filum is released, he will stitch everything back together.

image credit: http://www.imaios.com/en/e-Anatomy/Spine/Spinal-cord-diagrams

The girl will spend 3 days in the hospital with her head at the same level as the incision.  This is to keep the CSF pressures equal along the spinal canal, and it should help prevent a CSF leak.  Then we get to go home and we will spend 2 weeks as still as a 3 year old can be.

I found this video that might be of interest (not the girl’s doctor):