The development of minimally invasive surgical methods has revolutionized the treatment of brain diseases: Doctors push fine catheters through the blood vessels to penetrate a damaged brain region.

However, many areas in the brain remain inaccessible.

On the one hand because the vessels are too narrow, on the other hand there is a risk of injury: If catheters have to be advanced in order to follow the convolutions of the vessels, there is a risk that they will perforate a very fine vessel wall.

That could change in the future.

Swiss medical technicians have developed a wafer-thin catheter that can even penetrate into tiny blood vessels in the brain.

This could one day improve the diagnosis and therapy of tumors, aneurysms or strokes, writes the team around Selman Sakar from the École Polytechnique Fédérale in Lausanne (EPFL) in the journal "Nature Communications".

The team explains that the vascular system supplies the entire body with oxygen and other substances, giving doctors the opportunity to reach many regions with catheters.

"Large parts of the brain are inaccessible because the tools available are bulky, and it is extremely difficult to explore the tiny, nested vasculature of the brain without damaging the tissue," said Sakar in a statement from the university.


The researchers have now developed an extremely flexible micro-catheter based on a new form of navigation.

The catheter is made of biocompatible polymer and with a cross-section of 4 by 25 micrometers (thousandths of a millimeter) is thinner than a hair, which is about 70 micrometers thick on average.

When injected into a blood vessel, it follows the flow even through the most tortuous turns.

Because it has a magnetic tip, it can be directed into a junction with computer-controlled magnetic fields if necessary.

Source: WORLD infographic

The researchers navigated the catheter both through artificial systems of various diameters and through the vessels of an isolated rabbit ear to various destinations.

In principle, measurements of flow velocity and temperature can be made, but therapeutic substances can also be brought into the brain or retinal tissue, the scientists write.

“We can imagine that a surgical robot uses a detailed map of the vascular system, which is created by MRI or CT, to guide devices autonomously to target locations,” explains Sakar.

The catheter has not yet been tested in an organism.

Veit Rohde from the University Hospital Göttingen speaks of a very interesting and technologically clever development.

The catheter could possibly be used, for example, in the chemotherapy of tumors, says the director of the neurosurgical clinic, who was not involved in the study.

“I think that could work.” Ultimately, however, according to the expert, possible applications for such a catheter still have to be clarified.