Doctors at Jerusalem's Hadassah Hospital have inserted a feeding tube into the stomach of Israeli Prime Minister Ariel Sharon.
A hospital statement says Mr. Sharon remained in critical but stable condition after the procedure, called a gastrostomy. It did not say why the operation was necessary.
One stroke expert says the procedure is recommended when patients are not expected to make a swift recovery.
Mr. Sharon suffered a massive stroke on January 4. Surgical teams at the hospital operated twice on the prime minister to reduce swelling in the brain. Since then, attempts to bring Mr. Sharon out of a coma have been unsuccessful. Mr. Sharon did open his eyes briefly.
Medical experts have said it is unlikely that the prime minister, if he does emerge from the coma, will be able to resume normal activities.
Deputy prime minister Ehud Olmert is serving as acting prime minister.
Some information for this report was provided by AP and Reuters.