Zanardi, a former Formula One driver who had both his legs amputated after a motor racing accident two decades ago, suffered serious head injuries when he lost control of his handbike during a race on a Tuscan road nearly two weeks ago and crashed into an oncoming truck.
“Twenty-four hours after the operation the patient’s clinical condition is unchanged while his neurological development is stable and remains serious,” said the Santa Maria alle Scotte in Siena in a statement.
Doctors added that Zanardi, 53, is still in intensive care, “where he remains in an induced coma with an uncertain prognosis”.
The hospital also said that they had agreed with Zanardi’s family that they would no longer do medical updates unless there were significant changes to his condition.
Zanardi suffered head injuries with multiple facial factures after the crash on June 19.
An investigation has begun into the circumstances surrounding the accident on the ‘Obiettivo Tricolore’ stage relay race which sees participants journey across Italy on handbikes, wheelchairs or cycles.
Zanardi has become one of the great figures in disabled sports following the 2001 motor racing accident on the Lausitzring track in Germany.
He raced for Jordan, Minardi and Lotus in F1 in the early 1990s before switching to the CART championship in the United States where he was series champion in 1997 and 1998.
He returned to F1 with Williams in 1999 before heading back to CART.
Zanardi brought back two gold medals from the 2012 London Paralympic Games and four years later won two more in Rio de Janeiro.
He won the Rome marathon in 2010 and the New York race the following year.
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