Tiny wire fights cancer deep inside brain

A wire finer than a human hair that can reach blood vessels deep in the brain has been created, in what could be a breakthrough in the treatment of tumours.

For years, surgeons have used a very thin wire, inserted into an artery near the groin or leg and carefully guided up to the brain, to examine blood vessels in and around the brain.

Guided by a fluoroscope, an instrument that uses X-rays to picture blood vessels, the surgeon manually moves the wire into the damaged vessel. A catheter can then be threaded up along the wire to deliver drugs or devices to the affected region.

However, many peripheral vessels in the brain are unreachable with a catheter because they are too narrow and intricate. This has meant that a large portion of the brain is still inaccessible to surgeons.

Now scientists in Switzerland have created an ultra- flexible device less than 100 microns thick – thinner than a human hair. It is moved through capillaries by the flow of blood, reducing the potential for a catheter to hit the wall of a blood vessel. The wire also has a magnetic head that allows it to be guided by a surgeon working from outside the body.

In their report, published in the journal Nature Communications, the researchers said using the body’s blood flow to guide a catheter could reduce the time needed for an operation from several hours to a couple of minutes.

The ability to reach usually inaccessible blood vessels could help to deliver drug treatments to the centre of a tumour in the brain, they said, and could be used for inspecting and diagnosing conditions.

The researchers also said the technology could be used to guide a catheter to intricate and thin blood vessels in the spine, the heart, or the retina of the eye. A surgical robot could guide the wire to target locations.