His foundation said Gorbachev underwent an operation on November 21 on the carotid artery, a key artery in the neck that supplies blood to the brain.
The 75-year-old Gorbachev was hospitalized on November 19.
AN UNCERTAIN LEGACY: According to a recent Harris poll, some 59 percent of European Union residents regard former Soviet President Mikhail Gorbachev as the best Soviet/Russian leader. Just 12 percent named Russian President Vladimir Putin and 4 percent picked former Russian President Boris Yeltsin. Within Russia, the situation is quite different, with only 12 percent of Russians saying they have a positive impression of Gorbachev in a recent poll.
Gorbachev has been a frequent guest in RFE/RL's studios, offering his assessment of key domestic and international events.