In late afternoon last Dec. 31, Dr. Michael E. DeBakey, then 97, was alone at home in Houston in his study preparing a lecture when a sharp pain ripped through his upper chest and between his shoulder blades, then moved into his neck.

Dr. DeBakey, one of the most influential heart surgeons in history, assumed his heart would stop in a few seconds.

“It never occurred to me to call 911 or my physician,” Dr. DeBakey said, adding: “As foolish as it may appear, you are, in a sense, a prisoner of the pain, which was intolerable. You’re thinking, What could I do to relieve myself of it. If it becomes intense enough, you’re perfectly willing to accept cardiac arrest as a possible way of getting rid of the pain.”

But when his heart kept beating, Dr. DeBakey suspected that he was not having a heart attack. As he sat alone, he decided that a ballooning had probably weakened the aorta, the main artery leading from the heart, and that the inner lining of the artery had torn, known as a dissecting aortic aneurysm.

No one in the world was more qualified to make that diagnosis than Dr. DeBakey because, as a younger man, he devised the operation to repair such torn aortas, a condition virtually always fatal. The operation has been performed at least 10,000 times around the world and is among the most demanding for surgeons and patients.

Over the past 60 years, Dr. DeBakey has changed the way heart surgery is performed. He was one of the first to perform coronary bypass operations. He trained generations of surgeons at the Baylor College of Medicine; operated on more than 60,000 patients; and in 1996 was summoned to Moscow by Boris Yeltsin, then the president of Russia, to aid in his quintuple heart bypass operation.

Now Dr. DeBakey is making history in a different way — as a patient. He was released from Methodist Hospital in Houston in September and is back at work. At 98, he is the oldest survivor of his own operation, proving that a healthy man of his age could endure it.

“He’s probably right out there at the cutting edge of a whole generation of people in their 90s who are going to survive” after such medical ordeals, one of his doctors, Dr. James L. Pool, said.

But beyond the medical advances, Dr. DeBakey’s story is emblematic of the difficulties that often accompany care at the end of life. It is a story of debates over how far to go in treating someone so old, late-night disputes among specialists about what the patient would want, and risky decisions that, while still being argued over, clearly saved Dr. DeBakey’s life.

It is also a story of Dr. DeBakey himself, a strong-willed pioneer who at one point was willing to die, concedes he was at times in denial about how sick he was and is now plowing into life with as much zest and verve as ever.

But Dr. DeBakey’s rescue almost never happened.

He refused to be admitted to a hospital until late January. As his health deteriorated and he became unresponsive in the hospital in early February, his surgical partner of 40 years, Dr. George P. Noon, decided an operation was the only way to save his life. But the hospital’s anesthesiologists refused to put Dr. DeBakey to sleep because such an operation had never been performed on someone his age and in his condition. Also, they said Dr. DeBakey had signed a directive that forbade surgery.

As the hospital’s ethics committee debated in a late-night emergency meeting on the 12th floor of Methodist Hospital, Dr. DeBakey’s wife, Katrin, barged in to demand that the operation begin immediately.

In the end, the ethics committee approved the operation; an anesthesiology colleague of Dr. DeBakey’s, who now works at a different hospital, agreed to put him to sleep; and the seven-hour operation began shortly before midnight on Feb. 9. “It is a miracle,” Dr. DeBakey said as he sat eating dinner in a Houston restaurant recently. “I really should not be here.”

The costs of Dr. DeBakey’s care easily exceeded $1 million. Methodist Hospital and his doctors say they have not charged Dr. DeBakey. His hospitalizations were under pseudonyms to help protect his privacy, which could make collecting insurance difficult. Methodist Hospital declined to say what the costs were or discuss the case further. Dr. DeBakey says he thinks the hospital should not have been secretive about his illness.