Doctors have used a robot to perform extremely delicate surgical operations on breast cancer patients in the first human trial of the technology.

Eight women had the robot-assisted procedure at Maastricht University Medical Center, in the Netherlands, to alleviate a common complication of breast cancer surgery.

The robot helped a specialist surgeon divert thread-like lymphatic vessels, as narrow as 0.3mm, around scar tissue in the patients’ armpits, and connect them to nearby blood vessels.

The operation, which requires immense care and precision, is offered to some breast cancer patients to reduce swelling in the arms that builds up when the lymphatic system cannot drain properly. Because the vessels are so small, surgeons need exceptionally steady hands to perform the operation well.

“This is the first time in the world that such an operation has been performed with a robot,” said Tom van Mulken, a consultant plastic surgeon at the hospital. “It’s a very delicate and tricky procedure.”

Breast cancer-related lymphedema, as the condition is known, affects about one-third of breast cancer survivors within two years of having surgery to remove their tumours. The problem can arise when surgeons remove lymph nodes from the armpit to investigate whether the cancer has spread. In some cases, scar tissue forms and blocks the lymphatic system, the network of vessels that carries immune cells around the body and drains away its cellular waste.

Writing in Nature Communications, researchers in Maastricht and at Eindhoven University of Technology describe a pilot trial in which a specialist surgeon used the robot to re-route lymphatic vessels around women’s scar tissue. The surgeon operated on 20 women and used the robot in eight of those procedures.

The robot works by cancelling out tiny tremors in the surgeon’s hands and scaling down their hand movements. For example, if the surgeon moves one of the robot’s joysticks one centimetre, the fine tweezers at the end of the robot arm may move only a tenth of a millimetre.

“We suture the vessels together with very fine needles and thread, so if you have a tremor you rupture the vessels,” Van Mulken said. “It’s very delicate surgery and only a few people are very good at it. It shouldn’t be like that if you use a robot.”

The trial showed that, on average, the specialist surgeon took more than twice as long, about 25 minutes, to perform the procedure when they used the robot. But over time, the surgeon became quicker with the robot and by the end of the trial had the time down to 16 minutes.

Because so few women were enrolled in the trial, it was impossible to discern any meaningful differences between the quality of the surgery, a question that will need to be answered by larger trials in the future.

Van Mulken believes the results are encouraging because they demonstrate how robots can be used for extremely fine surgical procedures. If larger trials prove their worth, the robots could allow more surgeons to perform very delicate operations, and smooth out variations in their day-to-day performance.

“We already enhance our eyes with microscopes, but up until now, we still had to do the surgery with our hands. The microscopes are getting stronger and stronger, so our eyes are not the problem, but our hands cannot keep up any more,” Van Mulken said.

More operations are likely to benefit from robotic assistance, he added, including neurosurgery and the reattachment of severed fingers, where fine nerves and blood vessels must be sewn back together.

“Right now, if a piece is too small, we have to throw it in the bin,” he said.