Although Prime Minister Ariel Sharon's doctors said Monday he will be put under general anesthesia at Jerusalem's Hadassah-University Hospital in Ein Kerem for 30 to 60 minutes for the insertion of an umbrella-like double clamp to close a small congenital hole in his heart, it is "preferable" for the procedure to be done with a new technique not requiring him to be put to sleep, according to Shaare Zedek chief cardiologist Prof. Dan Tzivoni in response to questions by The Jerusalem Post. Over the past month, Shaare Zedek interventional cardiologists have successfully implanted double clamps into the hearts of four patients, some of them similar in age to Sharon, without having to use general anesthesia, he told The Jerusalem Post Tuesday night. "For a person who is Sharon's age and weight, it is better for the patient to remain awake rather than to be put to sleep," Tzivoni said about the proposed treatment for the hole in Sharon's heart, called foramen ovale. "We recently purchased the equipment and obtained the training and know-how to perform the insertion without trans-esophageal echocardiography [TEE], which requires the patient be made unconscious with general anesthesia." "I have no information about how big the hole is, but on the basis of what his doctors said, I would recommend that the prime minister undergo this procedure rather than surgery too close it. "The device, I believe, has not yet been approved by the US Food and Drug Administration, but it has been by the Israeli and European authorities." Tzivoni said the technique that eliminated the need for general anesthesia involved the threading of an ultrasound catheter for imaging to the right atrium, next to the hole, instead of using TEE, which could not be done in a relatively long procedure when the patient was awake. Shaare Zedek's four patients were treated by Dr. David Meerkin, a highly experienced interventional cardiologist who worked at Shaare Zedek, then went to Hadassah for a year and about a year ago returned to Shaare Zedek. Hadassah spokeswoman Yael Bossem-Levy said, "We, too, perform the procedure without having to use general anesthesia, and we have done more than of few of these." But she could not explain why, at the press conference, Sharon's doctors said he would be put under general anesthesia for it. "It hasn't even been decided who will perform it," she said. At the Monday press conference, Hadassah's head of cardiology, Prof. Chaim Lotan, said the catheterization would be performed on Sharon in two weeks, during which he would be put to sleep for 30 to 60 minutes. The Hadassah/Sheba Medical Center team that outlined the prime minister's medical condition and history for political and diplomatic reporters (health reporters were not invited by the Prime Minister's Office) described the procedure as "routine" and did not specify who would do it at Hadassah. A foramen ovale is an opening in the wall between the right and left auricles of the heart that occurs naturally during fetal development and provides a bypass for blood that would otherwise flow to the fetal lungs. Normally, it begins to close after the baby takes its first breath, causing full blood circulation to the lungs and not between the two auricles. But in 10 percent to 15% of cases, it does not close fully. Channel 2 reported Tuesday night that Sharon underwent a heart examination two months ago at Sheba Hospital-Tel Hashomer, but even had the hole in his heart been discovered earlier, it still would not have prevented last week's mild stroke. Most people with a hole in their heart are never aware of it because it causes no harm, but in some cases, it can result in the formation of blood clots that travel in the body and can cause a stroke, as experienced by Sharon.