Ferromagnetic tumour removal

Surgeons would be able to retract tumours in minimally invasive procedures using a technique that renders them ferromagnetic so they can be lifted from the body.

Dundee and St Andrews universities have received over £1.2m from the EPSRC to prove their method works on a large scale. Their efforts follow a previous EPSRC-sponsored pilot project that confirmed the feasibility of rendering small areas of tissue ferromagnetic (The Engineer 7 Aug 2006).

Alfred Cuschieri, director of the Institute of Medical Science and Technology, Dundee and St Andrews universities, said their original work involved injecting tissues with a ferro-fluid solution.

The technique was effective at making localised areas of tissue ferromagnetic, he added, but the team are now looking for methods that are injection free.

Cuschieri said novel ferromagnetic plastic films that adhere to the wet surfaces of the internal organs could be the answer. These types of co-adhesive biocompatible films are already available for drug-delivery applications, he said, and it would be theoretically possible to redesign them so they incorporate iron particles.

He added that in minimally invasive bowel surgeries the polymers could be applied to the damaged area of the bowel with an endoscope. ‘We’ve done some modifications to these polymers to make them so they bond very strongly to bowel,’ said Cuschieri.

The long, narrow retraction instrument would enable the surgeon to switch its magnetic properties. Once inside the small surgical access point, the end of the instrument would expand into a bell shape and the surface would become magnetic. The surgeon would move the magnetic retraction device using an adjustable magnetic force system.

‘We think we can develop the technology to do what is known as suspended magnetic elevation,’ he said. ‘In other words, the instrument lifts the tumour without the tumour touching the instrument.’

Cuschieri said this could have ‘immense’ implications. ‘If you pick up a tumour with any force, you risk shedding tumour cells. If we can manipulate the tumour… without actually touching it, that would be a very significant development.’

The researchers are currently performing experiments on animal tissue, but clinical trials could begin once their four-year research programme is completed.

If successful, their method will replace retractors currently used in minimally invasive surgery.

Siobhan Wagner