Mid-surgery analysis of patient tissue could improve treatment

Metabolic profiling of tissue samples could transform the way surgeons make decisions in the operating theatre, say researchers at Imperial College London.

In partnership with clinicians at Imperial College Healthcare NHS Trust, the researchers have installed a solid-state nuclear magnetic resonance (NMR) spectrometer at St Mary’s Hospital to perform such procedures.

Researchers there will use the machine to analyse intact tissue samples from patients to investigate whether it can ultimately give surgeons detailed diagnostic information while they are undergoing surgery.

The science of metabonomics, which involves comprehensively measuring the metabolic changes in a person’s body, has been pioneered by the Imperial team over the last 20 years. Techniques from analytical chemistry, such as NMR spectroscopy and mass spectrometry, can allow researchers to measure simultaneously all of the chemicals produced by the body’s metabolism.

With knowledge of which molecules correspond to which conditions in the body, this ‘metabolic fingerprint’ can provide a wealth of information about the state of a person’s health.

Metabonomics has previously been applied to samples of bodily fluids such as blood and urine to look for indicators of disease or of how a person might respond to a particular drug. Now the Imperial team’s NMR machine will analyse solid tissue samples from patients undergoing surgery with Imperial College Healthcare.

Lord Ara Darzi, chairman of the Institute of Global Health Innovation at Imperial College London and an honorary consultant surgeon with Imperial College Healthcare NHS Trust, said: ‘People respond differently to the physical trauma of surgery, but currently the tools we have to measure how they respond are very limited. Blood tests are slow and they can only measure one chemical component at a time - the doctor simply looks at whether a particular measure has gone up or down. Using NMR, we can simultaneously measure all of the chemicals that the body is producing and analyse those data to give the surgeon real-time information about the patient’s condition that will help him make decisions.’

Surgeons will be able to take tissue samples and have them loaded straight into the NMR machine without the need to prepare them. The research team think it will be possible to give the surgeon a readily interpretable readout from the analysis within 20 minutes, which would provide information such as whether the tissue is infected or how good its blood supply is. Surgeons might also use the technology to determine exactly which areas of tissue are cancerous.

One project the team will undertake is to develop an ‘intelligent knife’. Surgeons commonly use a technique called electrocautery in operations to seal blood vessels by burning them with a hot iron. By sucking up the smoke produced in this procedure into a mass spectrometer, researchers believe they will be able to tell the surgeon whether the tissue they are burning is healthy, cancerous or infected.

Prof Jeremy Nicholson, a leading researcher in biomolecular medicine and head of the Department of Surgery and Cancer at Imperial College London, said: ’This is a radical change of approach that doesn’t just apply to surgery. Before surgery, metabonomics could tell the doctor how risky surgery might be for that patient, or how best to prepare him for surgery. After the operation, metabonomics might help the doctor to monitor the patient’s recovery and prescribe the most suitable drugs or diet.’

To help realise their vision, Imperial has partnered with two of the world’s leading spectroscopic instrument manufacturers, Bruker BioSpin and the Waters Corporation, who will help to develop, optimise and implement NMR and mass spectrometric technologies for real-time diagnostics and prognostic modelling.