Wire in the brain

Probe uses tiny blood vessels to reach tumours

A MINUTE wire-like probe has been created that can delve deep into the brain, with scientists heralding the innovation as a major breakthrough in the treatment of tumours.

The ultra-flexible device is swept along in the body’s capillaries by the flow of blood and has a magnetic head which allows it to be guided externally.

This overcomes one of the drawbacks of larger probes – that they have to be pushed manually.

The method means there will be less need to cut a hole in a patient’s head to operate – which can cause a risk to brain tissue in the way of the diseased area.

Guiding wires through blood vessels is a l ong- established technique to reach sites deep within the body.

The problem is that, until now, the wires have been too large to get into smaller blood vessels – particularly in the brain. But the new device is l ess than 100 microns thick – thinner than a human hair.

In tests, it was flexible enough to pass through capillaries without damaging the walls.

Researchers say the probe will be able to deliver drug treatments to the centre of a tumour, and could also be used for diagnosis and investigation.

The authors demonstrated the feasibility of their system in a series of laboratory experiments and in tests inside the blood vessels of a rabbit ear.

The scientists, led by Selman Sakar of the Ecole Polytechnique Federale de Lausanne in Switzerland, said the probe would enter the body via a standard needle injection. The researchers say the technology would also be useful in navigating delicate blood vessels in the spine, heart and in the arteries of the retina.

Writing in the journal Nature Communications, the authors said: ‘For the first time, we showed that accessing deep brain regions through the endovascular path [inside the blood vessel] is technically feasible. Such access might open new therapeutic options to treat deep-seated or very peripheral tumours inside the brain.’