Surgeons are increasingly turning to less-invasive techniques, such as utilizing long, thin needles – instead of scalpels – to access targets within the body. A new needle, with a steerable tip, could make such procedures faster and easier.
Ordinarily, surgical needles are completely rigid. While this quality helps them to maintain a straight path through tissue, it also doesn't allow that path to be altered if it looks like they're going to miss their target. Instead, they're typically withdrawn from the patient's body then reinserted at a slightly different angle. Not only does doing so take some time but it also results in more tissue damage, made by multiple insertions.
Seeking a more adaptable alternative, EPFL's Charles Baur and Strasbourg University's Lennart Rubbert developed what is known as the ARC needle.
The device is essentially a tube within a tube. Its outer tube takes the form of a rigid shaft with a beveled end (meaning it's been cut at an angle), much like a regular needle. The narrower inner tube is made of three linked segments.
When the needle is initially inserted, the inner tube stays withdrawn inside the outer tube. If the needle's path subsequently needs to be corrected, the surgeon pushes a slider control on the handle, causing the inner tube to extend out the end of the outer tube. As the three articulated segments slide out, they don't just go straight, but instead follow the angle of the outer tube's beveled tip. By twisting the needle within the tissue, the surgeon is thus able to determine the direction in which the inner tube will go.
Prototypes created so far have had outer diameters ranging from 0.9 to 4.5 mm, and have been made of both stainless steel and glass. While steel has proven to be best overall for soft tissue surgery, advantages of glass include the fact that it doesn't produce reflections which might obscure target areas viewed via imaging systems.
The ARC needle technology is now being commercialized by French company Conectus. It is hoped that human preclinical trials will begin soon.
The needle is demonstrated in the following video.
Sources: EPFL, ARC needle
