Autosport said:Felipe Massa has successfully undergone surgery for the injuries he suffered in his accident in qualifying in Hungary.
Ferrari said the driver will now remain under observation in the intensive care unit at the AEK hospital in Budapest, where the Brazilian was taken after being hit by a spring during Q2.
Massa had suffered a damaged skull and brain concussion, as well as a cut on his forehead.
Brawn confirmed the spring belonged to a damper from Rubens Barrichello's Brawn car, weighing around 800 grams.
Last week, Henry Surtees was hit by a wheel when he was travelling at 120mph during a F2 race at Brands Hatch, and he died later from fatal head injury. Massa was lucky that only a spring hit him, not a wheel. But who will be his replacement? Test drivers are Luca Badoer and Marc Gené.