Non-invasive lasers shine light on liver damage

Currently, surgeons have no detailed or quantitative way of assessing if a liver is healthy enough to transplant into a new person. To assess if a donor’s liver is healthy and a good match, the surgeon conducts blood tests and inspects the organ by eye and feel.

Liver transplant tech shows life-saving potential

To improve the process, scientists and surgeons from Edinburgh University, the Edinburgh Transplant Centre and Strathclyde University used Raman spectroscopy (RS) to detect damage in pigs’ livers. In recent decades, RS has been used to detect breast, oesophageal and brain cancers.

By shining a laser onto tissue from pig liver biopsies and examining the light scattered back, the team was able to detect whether red blood cells had infiltrated the main body of the liver from its blood vessels, a form of damage called congestion.

According to Edinburgh University, the quick results from the handheld RS spectrometer matched those from the more painstaking ways of assessing a liver’s health, which involve blood biochemistry and gas analysis.

The tool was also used to assess the effectiveness of a new surgical technique - normothermic regional perfusion (NRP) - which was pioneered by the surgical team in the Edinburgh Transplant Centre. The procedure uses a machine to re-establish blood circulation to donated organs after death.

Researchers used RS to confirm that NRP decreased congestion in the transplanted liver, giving them more detail in explaining the positive results seen in clinical use of NRP. The team is now working to translate these findings in a way that can aid clinical decision making in real time.

“We found that we could detect liver damage in a way that simply relies on shining a laser at liver tissue and collecting the light scattered back,” said Dr Katherine Ember, Laboratory of Radiological Optics, Montreal, who carried out the analysis during her PhD at the Universities of Edinburgh and Strathclyde. “We didn’t expect to find such a clear difference in Raman signal between damaged and undamaged liver tissue. It’s very exciting and will be fascinating to see whether this technology can be brought successfully into a clinical setting. This could enable liver damage to be detected early in the transplant procedure, allowing more livers to be transplanted safely and effectively.”

The study is published in Hepatology and was funded via OPTIMA (EPSRC and MRC Centre for Doctoral Training in Optical Medical Imaging), an MRC Confidence in Concept Award and the Dutch Transplant Foundation.