Photoacoustic microscopy could be a new and promising method for monitoring stents through the skin without the need for surgery or radiation.
A new study reveals, for the first time, that photoacoustic microscopy can image stents through skin, potentially providing a safer and simpler way to monitor these life-saving devices.
Researchers used photoacoustic microscopy to visualise stents with fractures, compression and other clinical scenarios, such as overlapped stents or conditions mimicking lipid deposition.
Co-lead researcher Myeongsu Seong from Xi’an Jiaotong-Liverpool University in China said: ‘It is vital to monitor stents for issues like fractures or incorrect positioning, but traditional techniques require invasive procedures or radiation exposure. This motivated us to explore the potential of using photoacoustic imaging to monitor stents through the skin.’
The researchers demonstrated that photoacoustic microscopy can be utilised to visualise stents covered with mouse skin under various clinically relevant conditions, including simulated damage and plaque accumulation.
Co-lead researcher Sung-Liang Chen from Shanghai Jiao Tong University in China added: ‘Although our photoacoustic microscopy results are preliminary, further advancement could enable regular, non-invasive monitoring of stent conditions – without requiring surgery or X-ray exposure. This would make it easier and safer to assess the state of stents in patients.’
Photoacoustic imaging is a label-free technique that detects sound waves triggered when materials absorb light and release energy.
Since sound scatters less than light, this imaging method allows for higher-resolution images at greater depths than purely optical techniques.
Although other studies have employed photoacoustic imaging via an endoscope to visualise stents, this still involves invasive procedures.
In this study, the researchers examined whether photoacoustic microscopy might enable non-invasive stent monitoring through the skin.
In addition to simulating different stent scenarios, they also used butter to mimic plaque or blood clot deposits after stenting.
Using photoacoustic microscopy at various wavelengths, such as 670 nm and 1210 nm, they successfully imaged these conditions through excised mouse skin.
Seong said: ‘One of the most exciting outcomes is that we could easily distinguish between the butter used to imitate lipid plaque and the stent. Because plaque and stents absorb light differently, using two wavelengths helped us differentiate them.’
The researchers suggest that photoacoustic microscopy may be used to image stents placed in dialysis access sites, which are typically located just beneath the skin.
For stents located deeper, such as in the carotid artery, a related technique called photoacoustic computed tomography could be more suitable.
The team highlights that before photoacoustic imaging can be adopted for clinical non-invasive stent monitoring, in vivo animal studies and preliminary clinical trials would be needed. The system would also require optimisation for use in different regions of the body.
