April 19, 2007
Strandness found new way to diagnose vascular disease
In the 1960s, Dr. Eugene Strandness examined a patient with diabetes who was facing amputation of his leg because of his disease. Prior to surgery, Strandness took the patient’s blood pressure in the arm and found it to be normal.
On a hunch, Strandness measured the blood pressure in the good leg. It was the same as the arm pressure. Then he measured the leg that was to be amputated and found the blood pressure to be extremely low. In that moment, Strandness pioneered a now-standard way to determine the severity of disease by taking blood pressure in a patient’s extremities.
Because Strandness was a physician, he saw first-hand the problems patients faced. Because he also was a researcher, he could find solutions.
“He saw a need for a way to measure blood flow and assess arterial blockage that was clinically useful, but not invasive to the patient,” said Molly Zaccardi, a vascular clinic manager who worked closely with Strandness at UW Medical Center for nearly 30 years.
The premise of Strandness’ work, said Dr. Alexander Clowes, UW professor and chief of the Division of Vascular Surgery, was to apply research “to the daily care of the patients. Strandness’ work has transformed how we diagnose vascular disease.”
In the 1970s, Strandness, who worked at the UW from 1961 until his death in 2002, was the first to use a Doppler to measure blood flow through the arteries. Later, he and a small group of UW engineers combined the Doppler with B-mode ultrasound to create the duplex scanner. The non-invasive B-mode scanner shows an image of the artery, and the Doppler measures the velocity of the blood flow at the same time. This indicates whether a patient’s blood flow is restricted, which can cause a number of life-threatening problems, including stroke.
The duplex scanner is now used throughout the world to diagnose vascular disease.
Prior to the duplex scanner, physicians diagnosed arterial disease by physical examination, which wasn’t always accurate. Arteriography — an invasive procedure in which physicians inject dye into the blood vessels and use X-rays to get images — was used to assess blood flow. Now, those conditions can be diagnosed with the duplex scanner.
In addition to developing non-invasive ways to diagnose disease, UW Medical Center’s vascular clinic has studied the same patients consistently for years to determine how disease progresses.
“We can see some patients who are deteriorating faster than others, and we can identify the cause, which allows us to treat them more appropriately,” Zaccardi said.
