Sounds like when it started it was a fairly localized phenomena:
"From 1960 onwards, vale tudo would remain an underground sub-culture, with most of the fights taking place in martial arts dojos or small gymnasiums.[citation needed] The vale tudo sub-culture was mainly based in Rio de Janeiro, but many fights also took place in the northern region, as well as the southern region and the Bahia state, where Capoeira is prevalent. The scene in Rio de Janeiro focused mainly on the intense rivalry between Brazilian jiu-jitsu and Luta Livre, whereas fights in the other regions featured more diverse martial arts competing in the events.[citation needed]"
http://en.wikipedia.org/wiki/Vale_tudo