Help..C.C. Fistula

[Gary Johnson]

My son suffered serious head injury in a motorcycle accident.   The 
most serious of his injuries is damage to his carotid artery, 
including a Carotid Cavernous Fistula (which is communicating blood 
flow from the Carotid Artery to a vein serving the eye).  The best 
option for treating this condition, we are told, is with a silicon 
balloon based procedure to seal the fistula from inside the carotid 
artery.  This procedure is complicated, however, by a dissection (or 
internal tear) of the artery at a point through which the balloon 
would have to pass.  
The rarity of the condition and the complications (including a FDA 
restriction of usage of this balloon) translates to a relatively small 
number of physicians who can perform this procedure.   Any advice on 
information we can get on the risks, statistics, complications, etc 
for this condition?  Any advice on how we can determine and compare 
the "credentials" of the physicians (interventional neuroradiologists) 
available?  Is information available from the AMA?  Assistance is 
appreciated.

Gary