Dr. Wilfred G. Bigelow, the Canadian surgeon who in the late 1940s pioneered the technique of lowering body temperature to make open-heart surgery possible even though other physicians were certain the procedure would be lethal, died Sunday in his hometown, Toronto. He was 91.
Bigelow's research on hypothermia also led to his invention of the cardiac pacemaker, but it was not until the invention of the transistor a decade later that the device became practical.
He was "a legendary figure in Canadian medicine and global cardiac surgery," said Dr. David Naylor, dean of the faculty of medicine at the University of Toronto.
While stationed at a hospital in England early in World War II, Bigelow treated many soldiers with frostbitten limbs, observing that the lowered temperatures reduced the metabolic rate and oxygen requirement of the affected tissue. He and an engineer constructed a device to cool the extremities, allowing him to warm frostbitten limbs more slowly in order to minimize damage.
At war's end, Bigelow underwent training in cardiovascular surgery at Johns Hopkins University, where Dr. Alfred Blalock was developing surgical techniques to treat "blue babies," who suffered severe heart defects. Bigelow was in the operating room when the first such surgery was performed in 1947. But the surgery was difficult because patients' hearts could not be stopped long enough to allow significant manipulation.
One night, Bigelow awoke with the idea of cooling the entire body to reduce oxygen requirements while the heart was stopped for surgery. His idea contradicted conventional thinking, which held that hypothermia was to be avoided at all costs.
In 1949, back in Toronto, he performed his first heart surgery on a dog whose body temperature had been lowered to 68 degrees. After the heart had been stopped for 15 minutes, Bigelow rewarmed the dog and brought it back to life without apparent damage.
When he reported his results in 1950 at a meeting of the American Surgical Assn., he later recalled, "there was no discussion. It was one of the very few basic medical discoveries where no one stood up to say they'd done something similar."
Three years later, the first successful use of the technique in humans was reported by other researchers.
The development of the heart-lung machine in the 1960s largely supplanted the use of hypothermia during heart surgery, but the two techniques are now often used together when surgeons are performing particularly long operations.
