On March 31, Joel Dyels celebrated his 72nd birthday by having coronary bypass surgery at Stanford Hospital. He also became the third patient at Stanford - and in the United States - to benefit from a new imaging system that lets doctors see the blood pathways they have created while the patient's chest is still open.
Until now, doctors were almost never able to confirm whether bypass surgery had been successful while the patient was still on the operating table. In most cases, only after the chest had been closed could doctors get an image of the heart and see whether blood was flowing through the newly created vessels.
"The new technology now is just fantastic," Dyels said. He went home five days after his surgery, which was performed by Robert Robbins, MD, professor and chair of cardiothoracic surgery at the Stanford University School of Medicine. "Anything I can do to help advance the technology is great."
This new technique has "turned on the lights in the surgical suites," said Peter Fitzgerald, MD, PhD, associate professor of cardiovascular medicine. Fitzgerald and his colleagues Scott Mitchell, MD, professor of cardiothoracic surgery, and assistant professor Marc Pelletier, MD, used the new technology in surgery for the first time in the United States on March 16.
The technology, called the SPY Intra-operative Imaging System, was approved in January by the U.S. Food and Drug Administration for use in coronary artery bypass surgery, the most common open-heart surgery in the country with more than 300,000 patients undergoing the procedure every year. The system, made by Novadaq Technologies, has been used successfully for several years in Asia, Europe and Canada, where Pelletier had used it on a number of occasions as a cardiac surgeon at the University of Toronto. Fitzgerald was instrumental in bringing the system to the United States. Both he and Robbins are on Novadaq's scientific board.
Coronary artery bypass is done when blood flow to the heart is impaired because of blocked vessels that can't be unclogged through drugs, mechanical scraping or the use of a stent to hold an obstructed artery open. The procedure involves grafting vessels from other parts of the body to create alternative conduits of blood flow to the heart. Traditionally the grafts are created from leg veins, but surgeons now frequently use arteries from the forearm and thorax.
"When the patient is open in the operating room and the surgeons have spent all this time and technical skill to restore blood flow for the patient, they look at the heart as it starts beating and see if all of the grafts look fine," explained Fitzgerald. "But this is without any objective criteria."
Around 5 to 8 percent of the time, he said, a graft that initially looked fine doesn't work well. This can lead to unsatisfactory results and sometimes may require another procedure such as coronary stenting or repeat coronary bypass surgery. What surgeons have needed is the ability to see whether blood was flowing so that any needed corrections could be made on the spot. Until now, there have been few good options.
The SPY system uses a fluorescent green dye that attaches to proteins in the blood and emits light when stimulated by a very low-energy laser. The technique does not heat up heart tissue and does not pose any risk to the staff in the operating room. The injected dye lights up blood flowing through the veins and arteries in real time, an action that can be projected on a screen and saved.