Each year, around two million people in the U.S. receive a stent to restore blood flow in narrowed or blocked arteries. Monitoring these stents is critical to detect issues such as fractures or improper positioning. However, existing techniques often require invasive procedures or expose patients to radiation. While some studies have used endoscopic photoacoustic imaging to visualize stents, this still involves procedural intervention. Researchers have now demonstrated that a novel noninvasive technique can image stents through the skin, offering a potentially safer and easier monitoring method.

In a new study, researchers from Xi’an Jiaotong-Liverpool University (Jiangsu, China) and Shanghai Jiao Tong University (Shanghai, China) showed that this technique can successfully visualize stents under various clinically relevant conditions, including simulated damage and plaque buildup. The imaging method uses photoacoustic microscopy, a label-free imaging technology that detects sound waves generated when materials absorb light and release energy. Because sound scatters less than light, the method offers high-resolution imaging at greater depths compared to purely optical techniques. To test its potential, the team simulated various stent conditions—such as fractures, compression, and displacement—using stents covered with excised mouse skin. In their study, published in Optics Letters, they also mimicked post-stenting plaque or blood clot deposition using butter.

The researchers were able to differentiate stents from plaque-mimicking material using dual wavelengths, including 670 nm and 1210 nm, highlighting the method’s diagnostic specificity. The team further noted that photoacoustic microscopy could be particularly suited for imaging stents in dialysis access sites located just beneath the skin, while a related method, photoacoustic computed tomography, may be better for imaging deeper stents like those in the carotid artery. Going forward, the researchers plan to conduct in vivo animal experiments and preliminary clinical trials. The system will also need to be optimized for use in different parts of the body to move toward clinical adoption.

“While our photoacoustic microscopy results are preliminary, further development could enable frequent, noninvasive monitoring of stent status — without the need for surgical access or X-ray exposure,” said co-lead researcher Sung-Liang Chen from Shanghai Jiao Tong University. “This would make it easier and safer to monitor the condition of stents in patients.”

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