A tiny, bendable wrist designed for surgery in small spaces may make minimally invasive surgery possible in the head, face and neck.
A team of engineers and doctors at Vanderbilt University’s Medical Engineering and Discovery Laboratory developed a surgical robot that navigates needles with mechanical wrists that are less than 2mm thick. The purpose of the flexible wrist is to add dexterity to delicate operations.
Surgeons will be able to perform precise operations that haven’t been possible before, but it will also allow the use of needles in places that have been beyond their reach, such as the nose, throat, ears and brain.
“It should be useful for a number of other operations as well,” said team head Robert Webster, Associate Professor of Mechanical Engineering in a statement. “We think once we give this tool to surgeons they will find all kinds of applications we haven’t thought of.”
The flexible wrist component, which would be attached to needle-sized surgical equipment, could perform operations with incisions so small, they would usually heal without a scar.
“The smaller you can make surgical instruments the better…as long as you can maintain an adequate degree of dexterity,” said Professor of Urological Surgery S. Duke Herrell, who is consulting on the project. “In my experience, the smaller the instruments, the less post-operative pain patients experience and the faster they recover.”
These operation techniques, called mini- or micro-laparoscopy, have been around since the 1990s. Largely, these surgeries remove diseased tissue by scraping or burning it away, according to Engineer
Newer techniques, referred to as needlescopic surgery, use tiny surgical instruments instead — shrunk to the diameter of a sewing needle. This newer form of surgery could advance options in minimally-invasive surgery.
These wrist-like devices are made from telescoping tubes that are made out of nitinol, a nickel-titanium alloy, which is known a “memory metal” because it retains its shape. A surgeon operating the device can steer the tip to follow a curving path through the body. A robot would be needed to guide this fine-sized needles.
Robotic surgery has been dominated by Intuitive Surgical’s da Vinci Surgical System, a robotic surgical system designed specifically for the minimally invasive approach.
“Although it works very well for abdominal surgery, the da Vinci uses a wire-and-pulley system that is extremely difficult to miniaturize any further, so it won’t work in smaller spaces like the head and neck,” said Webster.
Robotic surgery is not yet standard practice, but its use is growing. In 2012, there were an estimated 400,000 robotic operations, as compared to 26.8 total surgeries.
The Vanderbilt team applied for a provisional patent and will need to move through the FDA for approval to test the technique in clinical trials. “Our best case scenario is that the system could be available to surgeons in four to five years,” Webster said.
