"It's with a heavy heart that through this letter we share the news of the passing of the athlete Leandro Caetano de Souza," Andre Pederneiras, president of the Shooto promotion, wrote on Facebook (translated by MMAjunkie.com). "The athlete passed away at the emergency unit in Botafogo. The reasons are not yet known to us. We would like to express our condolences to all friends and family."
On Friday morning, Pederneiras announced that the Shooto Brazil 43 event was being canceled out of respect for Souza.
Souza, 26, who was 5-5 in 10 fights, was scheduled to fight Gabriel Brasil (1-1) in a flyweight bout Friday in Rio de Janeiro. The fighter was a member of Nova União, the same team of UFC champions Jose Aldo and Renan Barao. Dr. Turibio Leite de Barros, a physiologist in sports medicine, told UOL Esporte that dehydration may have caused the stroke. "Dehydration makes the blood more viscous. Viscous blood causes friction with the wall of the blood vessel is much larger and can break."