GENEVA-Swiss scientists have developed a very small steerable magnetic catheter to perform minimally invasive surgery, which would allow surgeons to perform more complex operations inside the human body with lower risk of injury, Swiss Federal Institute of Technology in Zurich (ETH Zurich) said Wednesday.

For patients with cardiac arrhythmia, surgeons routinely perform a minimally invasive procedure to ablate sections of the heart that cause unwanted electrical impulses. The physician inserts a catheter through a vein into the heart that locally generates heat to ablate the relevant sections.

To navigate the catheter tip through the blood vessels with a high level of precision, the surgeon can bend the tip manually using a pull wire inside the catheter. However, the catheter can be moved in only two directions: to the left and to the right. However, the new catheter developed by the ETH Zurich team has a magnetic head that is operated from a computer via an external magnetic field rather than being steered manually. This enables the front part of the catheter to be bent in any direction with the highest level of precision.

According to the researchers, the new catheter can be steered through more complex blood vessels better than a conventional catheter, and since the magnetic catheter does not require a pull wire, it can be made much thinner. As a result, the Swiss scientists have managed to develop the smallest ever steerable catheter.

With the new catheter, the stiffness of the front part can be adjusted too, thanks to a low melting point alloy placed in three of its sections.

With power supplied through fine copper wires inside the catheter, these sections can be heated and thus made flexible.

For surgeons to work with these magnetic catheters, patients must lie on a magnetic navigation system, an apparatus used to produce directed magnetic fields. In addition to ETH Zurich developers, commercial providers also offer these devices which are currently in use at some 100 hospitals around the world.