After the arrest of Bernardo Provenzano on 11 April 2006, Matteo Messina Denaro is often mentioned as his successor. His main rivals are supposed to be Salvatore Lo Piccolo — boss of the mandamento of San Lorenzo in Palermo – and Mimmo Raccuglia from Altofonte. Allegedly Provenzano nominated Messina Denaro in one of his pizzini — small slips of paper used to communicate with other mafiosi to avoid phone conversations. Messina Denaro used the pseudonym "Alessio" in his clandestine correspondence with former Mafia boss Provenzano. He suffers from severe myopia and received treatment for this condition at a clinic in Barcelona, Spain in 1994 and 1996.