Ariel Sharon was stable but critical after an emergency surgery to remove nearly 2 feet of his large intestines, his seventh operation since suffering a debilitating stroke last month, the hospital treating the premier said Sunday.

The four-hour operation on Saturday was successful, but the Israeli leader's already slim chances for recovery were even dimmer, doctors said. Sharon has yet to awaken since his stroke on Jan. 4.

Israelis closely followed their 77-year-old leader's latest ordeal, with TV stations repeatedly breaking into regular programming for updates, but the country already has come to terms with his departure from politics.

Sharon's political heir, Ehud Olmert, quickly took the reins as acting prime minister after Sharon's stroke, and appears poised to lead Sharon's centrist Kadima Party to victory in March 28 elections.

Sharon was rushed to surgery Saturday morning after doctors, who had noticed abdominal swelling, conducted a CT scan and a laparoscopy, or insertion of a small camera through the abdominal wall.

Surgeons detected necrotic — or dead — tissue in the bowels and removed 50 centimeters (20 inches), or one-third, of the large intestine, said Hadassah Hospital director Dr. Shlomo Mor-Yosef. It was his seventh operation since suffering the stroke.

The necrosis was either caused by infection or a drop in the blood supply to the intestines, something common in comatose patients, the hospital director said. Mor-Yosef said doctors did not find blocked blood vessels.

Mor-Yosef said Saturday's surgery was relatively simple, and that Sharon's main medical problem continues to be the coma. Asked whether Sharon could come out of the coma, Mor-Yosef said: "All possibilities remain open, but with each passing day, the chances are lower."

The hospital statement Sunday morning said, "Prime Minister Ariel Sharon's condition stabilized after surgery, but it is still described this morning as critical and stable. The prime minister is in the general intensive care unit."

Since the stroke, Sharon has been hooked up a breathing tube. A feeding tube was inserted in his stomach on Feb. 1.

Dr. R. Sean Morrison, a professor of geriatrics at the Mount Sinai School of Medicine in New York City, said that "long-term comatose patients typically die of complications like this," referring to necrosis.

Morrison said Sharon's prognosis was extremely grave even before the latest complication, and that chances for survival are now "extremely small, almost zero."

In recent months, the obese Sharon had repeatedly brushed aside questions about his health, but his condition became an issue after he suffered a mild stroke Dec. 18.

At the time Sharon was at the height of his popularity, following last summer's successful pullout from the Gaza Strip and his break with the hard-line Likud Party.

Voters widely expected Sharon to draw Israel's final borders, with or without the Palestinians, if elected for a third term. Polls suggested Kadima would become by far the largest party in parliament.

After his mild stroke, aides played down his health problems, while doctors treated him with anti-clotting agents and scheduled a heart procedure for Jan. 5. Just hours before the scheduled procedure, Sharon suffered a massive stroke, including heavy bleeding in the brain, and slipped into a coma.

After being admitted to Hadassah on Jan. 4, Sharon underwent three back-to-back brain surgeries. These were followed by three smaller procedures, including insertions of feeding and breathing tubes — a sign that doctors were preparing for a long-term coma. Throughout the past five weeks, he had been in critical but stable condition.

Before dawn Saturday, Sharon's condition deteriorated sharply and his life was in danger, hospital officials said. After consultation with his sons, Omri and Gilad, doctors decided to operate, said Mor-Yosef.

"During the operation, we found necrosis in part of his large intestine and ... the decision was to remove part of his large intestine," said the hospital director.

Sharon's sons have acquired guardianship over the prime minister since his incapacitation. Under Israeli law, any decision to perform emergency surgery or to discontinue medical treatment would require their consent, said Jonathan Davies, a leading Israeli medical law expert.