American television host and comedian Jimmy Kimmel expressed relief and gratitude in an Instagram post as his seven-year-old son, Billy, underwent open-heart surgery for the third time. "We went...with a lot of optimism and nearly as much fear and came out with...new valve inside a happy, healthy kid," he wrote. "Billy, you are...toughest (and funniest) 7-year-old we know," Kimmel added.