Buenos Aires (CNN) -- Argentinian President Cristina Fernandez de Kirchner's cancer surgery Wednesday was successful, her spokesman said.
There were no complications during the 3 1/2 -hour operation to remove Fernandez's thyroid gland, presidential spokesman Alfredo Scoccimarro said.
Last week doctors said tests indicated that the papillary carcinoma detected in Fernandez's thyroid had not spread to her lymph nodes or grown beyond the gland.
The president was awake after Wednesday's surgery and will recover in a post-operation room for 72 hours, Scoccimarro said.
Hundreds of supporters waved flags and banners outside the Austral Hospital, located about 60 kilometers (35 miles) from Buenos Aires.
"The truth is I was praying a lot, with all my strength, and now I feel very happy. I think the Virgin has granted a miracle," supporter Sofia Godoy said shortly after the spokesman's announcement.
Some said they planned to stay camped outside the hospital until the president's release.
"We are going to wait a little more until she recuperates from everything and can come outside," Angel Cifo said. "We hope to wait to see if we can say hello."
Before the operation, Fernandez handed over power to Vice President Amado Boudou until January 24.
Fernandez, 58, was sworn in for a second four-year term last month after she won re-election with more than 54% of the vote.
She became Argentina's president in 2007. Her husband, Nestor Kirchner, was president from 2003 to 2007. He died in October 2010.
During Fernandez's presidency, Argentina's economy has enjoyed sustained growth of about 8% annually.
Papillary carcinoma is the most common type of thyroid cancer and has a high survival rate, according to the U.S. National Library of Medicine.
More than 95% of adults with papillary thyroid carcinoma survive at least 10 years, according to a description on the library's website. Treatment includes surgery, radioactive iodine and medication, the library says.
During Fernandez's surgery, doctors also likely took tissue samples from her lymph nodes to examine whether the cancer has spread, Washington-based oncologist Dr. Elmer Huerta told CNN.
"Now they are going to study them," Huerta said. "That's why it is very important that we wait for the next report, which will be in about 10 days."
CNN's Brian Byrnes, Javier Doberti, Patricia Janiot and Fernando del Rincon contributed to this report.