With its rotating laser tip that snaps and sends detailed images from inside arteries, a new probe developed by Guillermo Tearney '98, an HMS professor of pathology at Massachusetts General Hospital, and Farouc Jaffer, an HMS assistant professor of medicine at the hospital, could provide physicians with news of clot formations in arterial stents well in advance of trouble. The probe, which marries optical-frequency domain imaging and near-infrared fluorescence imaging, two microimaging technologies, produces images that show arterial microstructures and provides molecular information on the inner surfaces of arteries, the very surfaces on which troublesome plaques can assemble.
In addition to providing sweeping views of arterial walls, the probe is capable of detecting fluorescing chemical tags that attach preferentially to fibrin. This protein, key to clot formation, can be problematic for people who have had stents surgically inserted to open blocked arteries. Although healthy cells can develop along the stent to help integrate it into the artery, fibrin clots can also develop on unhealed stents—leading to future blockages and risk of heart attack. In an animal model, a stent coated with fluorescent fibrin-rich microthrombi was implanted into the iliac artery and then imaged with the probe. The device successfully detected the fluorescing fibrin.
In future studies of patients with stents, the light-seeking probe could help assess the quality of healing in the stent and the need for anticlotting medications that could avert stent thrombosis, a life-threatening event.