Former President Bill Clinton's (search) heart bypass, expected Monday, likely will be an ordinary replumbing of his ailing heart, not some new whiz-bang robotic or "keyhole" surgery, leading surgeons say.

A source close to the former president who spoke on condition of anonymity said Clinton has told him the surgery was scheduled for Monday morning. Clinton has been hospitalized since Friday after suffering chest pains and shortness of breath.

Medical reasons could explain the surgery delay. Some suggested it might have been put off to allow his body to clear dye, injected for diagnosis purposes, and Plavix (search), a blood-thinner Clinton was reportedly given that could cause excessive bleeding during and after the bypass.

"I think it's convenience of scheduling and possibly waiting to let the Plavix clear from his system," said Dr. Timothy Gardner, a cardiac surgeon at the University of Pennsylvania and an American Heart Association (search) spokesman.

But just as his operation is likely to be the same as the average American's, the delay in his surgery also suggests a problem typical for many patients: doctors and nurses off for the holiday weekend.

"I am surprised they are waiting that long," said Dr. Mamdouh Bakhos, chairman of cardiovascular surgery at Loyola University Health System, who along with other surgeons speculated about staffing shortages. Bakhos spoke in response to initial reports that the surgery could be as late as Tuesday.

The former president and his family issued a statement on the Clinton Foundation's Web site on Sunday, saying they felt "blessed and grateful for the thousands of prayers and messages of good will we have received these past few days."

"While bypass surgery certainly isn't something to look forward to, we are very lucky that the condition was detected in time to have this procedure before something more serious occurred," the statement said.

Clinton spokesman Jim Kennedy said more than 26,000 get well messages have been posted on the Web site. He declined to be more specific about when Clinton would have the surgery, saying, "I don't think there's going to be an announcement about it ahead of time."

Officials at New York Presbyterian Hospital/Columbia, where the former president is hospitalized, have refused to comment.

Clinton's tests showed no heart attack, but a source close to the family said there were three or four clogged arteries. Several surgeons uninvolved in Clinton's care said they didn't think his doctors would risk treating him with newer, experimental approaches like robotic surgery or laparoscopy, sometimes called keyhole surgery.

"With three-vessel disease in a president, I don't think I'd be doing it," said Dr. W. Randolph Chitwood, chief of cardiovascular surgery at East Carolina University in Greenville, N.C., and a spokesman for the American College of Cardiology.

Because Clinton is only 58 and in good health, "he'll do fine" with traditional open-heart surgery, Chitwood said.

Clinton's problem is one faced by hundreds of thousands of Americans each year, especially those who smoke, are overweight, or have high blood pressure or high cholesterol.

Arteries get clogged by fat, which hardens into deposits that can cause a heart attack if they block one of the three main coronary arteries, each of which has one to three branches. Partial blockages can cause chest pain as the heart struggles to get by on less oxygen and nutrients than it needs.

Doctors sometimes do angioplasty, in which a balloon is inserted through a tube into a leg vessel and snaked to the blockage, where it is inflated to flatten the gunk against the artery wall, allowing blood to flow again. Tiny mesh scaffolds called stents may be placed to prop the vessel open.

But if the blockage is somewhere hard to reach or if many arteries are clogged, the best option may be bypass, surgery in which a vessel from elsewhere in the body is sewn in to detour blood around blockages.

"If somebody has three-vessel disease, they generally send them to surgery," said Chitwood, who had a bypass five years ago for this reason.

A chest artery usually is used to replumb the heart arteries but that's often not enough. Doctors frequently take a long vein in the leg, but that leaves another large wound to heal. In recent years, they've removed just part of this vein through small cuts in the leg, or used an artery from the patient's arm or stomach instead.

"They may not touch his legs at all," Dr. Tyrone Krause, chief of cardiothoracic surgery at Robert Wood Johnson University Hospital in New Brunswick, N.J., said of Clinton's doctors.

A bigger change has been doing the operation while the heart is beating, rather than stopping the heart and putting a patient on a heart-lung machine, which carries a small risk of stroke and neurological complications.

More than one-fifth of bypasses are done "off pump" today, but there's disagreement about whether it's better. Some surgeons say these bypasses aren't as good and are harder to do, and that patients' blood pressure can drop dramatically during the operation.

"It's a tradeoff," said Krause, who speculated that Clinton might be offered this option.

"It really depends upon the preference of the surgeon and the confidence of the patient," said Gardner, the heart association spokesman.

Last week, the heart association and the cardiology group published new guidelines for caring for patients after bypass. They recommend aspirin, cholesterol-lowering statins and other heart drugs such as beta blockers for all, plus blood thinners like warfarin if rhythm abnormalities develop.

Clinton should spend less than a week in the hospital, and may have some mood swings, loss of appetite or constipation, difficulty sleeping or other problems afterward, but should fully recover in a month or two.

"For a young, healthy guy like him, I really expect a good recovery," Bakhos said.