Valhalla - Twin 11-month-old girls who were formerly conjoined have been separated after undergoing a marathon surgery at a suburban New York City children's hospital.A team of more than 50 medical professionals helped perform the delicate 21-hour operation to separate Ballenie and Bellanie Camacho at Maria Fareri Children's Hospital in Valhalla over two days beginning January 17.The twins had been connected by a bone at the base of the spine. The girls and their parents met the media on Tuesday. The family is from the Dominican Republic.Surgeon Dr Samir Pandya calls it "a very long and complex surgery" that will give the twins "chances for better lives. "The twins, who were born in the Dominican Republic, will spend several weeks recovering at the hospital. Doctors say their prognosis is good.