Hi and welcome to the Chiari forum.
There are a few Drs in the Baltimore, MD, DC and N.C area that are true Chiari specialists....you will want to research them see a few and see which is best for you.
http://www.medhelp.org/posts/Chiari-Malformation/-Chiari--Drs-list--links-2015/show/2415432
Since a syrinx is already formed, you ust have a CSF obstruction.....it would be in your interest that the Dr do more testing for other related conditions as it can help the Dr know the best way to proceed with treatment.
Knowing surgery is not a cure but a means to slow progression and restore CSF flow....symptoms can remain or return during the healing process.....
Take your time in selecting your Dr....and when you do have a surgery date add it to the list your surgery date thread so a prayer thread can be posted for you.....wishing you the best.