Paracyclist Alex Zanardi remained in a coma on Tuesday after a CT scan on Monday revealed that he needed a second neurosurgical procedure. The surgery lasted two and a half hours, and Zanardi was returned to the intensive care unit, where he remains sedated and intubated.

According to a press release issued by the University Hospital of Siena, Zanardi is stable from a cardiopulmonary and metabolic standpoint, but from a neurological standpoint his condition is more serious.

"This intervention represents a phase that was hypothesized by the team. Our experts will continue to assess the situation on a daily basis."

According to the latest press release issued by the hospital, Zanardi's clinical condition was stable Tuesday afternoon.

"No other medical information will be released unless there are significant developments in agreement with the family," Tuesday's statement said.

Zanardi was participating in the "Obiettivo tricolore" relay race near Pienza, Tuscany. The 53-year-old, who has four Paralympic gold medals, was riding with former road pro Daniele Bennati on Friday, June 19.

Zanardi was airlifted to a Siena hospital, where he underwent three hours of neurological and maxillofacial (chin and face) surgery before being taken to the intensive care unit.

On Tuesday, it was announced that the Ferrari F1 racing team will display the message "Forza Alex" on its cars at this weekend's Austrian Grand Prix. Zanardi competed in Formula One twice in the 1990s and also competed in the CART series until 2001, when he lost both legs in an accident at the Lausitzring in Germany.

Zanardi then returned to racing in the World Touring Car Championships, where he began handcycling and had great success on his bike, winning four gold medals at the 2012 and 2016 Paralympics, as well as marathons in Venice, Rome, and New York, He has also won the Paracycling World Championships 12 times.