In a surgery described by his tapped successor as "complex," Cuban surgeons were indeed able to remove cancerous tissue from Venezuelan President Hugo Chavez. VP Nicolas Maduro called the six-hour operation a "complete success," adding, "we've lived through complex moments of tension." Some of those moments were spent at a vigil, where Maduro and Chavez supporters sang the national anthem—over a recording of Chavez doing the same. The BBC reports that it was the president's fourth surgery for cancer since June 2011; the latest came after tests identified cancerous cells, once again, in the pelvic region. (More Hugo Chavez stories.)