Robin Williams

Robin Williams is recovering after heart surgery in Ohio.

The actor, 57, had a procedure to replace an aortic valve March 13, a spokesperson told The Associated Press. Williams is expected to recover within six to eight weeks.

"His heart is strong and he will have normal heart function in the coming weeks with no limitations on what he'll be able to do," Dr. A. Marc Gillinov, a cardiothoracic surgeon at Cleveland Clinic, said. "A couple of hours after surgery, he was entertaining the medical team and making us all laugh."

Williams' heart condition forced him to cancel part of his one-man comedy tour earlier this month, after he experienced shortness of breath. The sold-out show, "Weapons of Self-Destruction," is expected to resume this fall.

In the meantime, the actor expressed his appreciation for the medical personnel at the two hospitals where he was treated. "I can't thank them enough for their kindness and dedication while I was in their care," he said in a statement. "I must also thank all the people who have expressed their love and concern for me. I have been deeply touched by their support."

Williams' recovery time, however, hasn't been all down time. "I got some great new material for the tour and can't wait to get back on the road," he said. "I'm thinking the next leg of the tour will be "Weapons of Self-Destruction and Reconstruction.'"