Dygert was well on course to defend her world title after the halfway stage in the individual time trial event in Imola when she lost control of her bike on a descent.
Dygert suffered a significant laceration to her left leg, according to an update by USA Cycling.
"We are relieved that this crash was not worse than what it could have been", Miller said.
Unable to brake in time, Dygert's bike began wobbling uncontrollably and she approached the steel rails.
"All we know is that she is conscious and talking".
"Chloé is a gifted athlete", Kristen Armstrong, Dygert's coach, said in the statement.
"She is out of surgery, resting comfortably and is expected to make a full recovery", USA Cycling said on Friday. "We will post a report on her condition as soon as we have absolute clear confirmation as to her condition". "I have no doubt that this will be the case again". Dygert was last year's time trial world champion and she broke two records simultaneously with her performance-both becoming the youngest world champion ever in that discipline and winning by the biggest time margin in history.
Today, a storming second half of the ride saw her put in a time of 40 minutes 20 seconds to take the rainbow jersey from Switzerland's Marlen Reusser by 15.58 seconds, with a second Dutch rider, Ellen van Dijk, victor of the event in 2013, taking bronze, 31.46 seconds behind her compatriot.
In February she set a new world record in the individual pursuit at the Track World Championships in Berlin, and has already been was named on the U.S. cycling team which will compete in the rescheduled Olympic Games in Tokyo next summer.
Olympic road race champion Van der Breggen, who finished second behind Dygert previous year in Harrogate when the American won by a record margin, claimed victory in 40:20.14, 15 seconds quicker than Swiss Marlen Reusser with Ellen van Dijk (Netherlands) in third place.