First Robot for Supermicrosurgery, Used for Lymphedema

Veronica Hackethal, MD

February 18, 2020

The first trial of robot-assisted, high-precision supermicrosurgery in humans has shown that the technique is safe for treating breast cancer–related lymphedema.

Although results are preliminary — only 20 patients participated, and a single highly skilled surgeon performed the supermicrosurgery — additional trials are underway to test the new robotic technique at other centers.

The pilot study was published online February 11 in Nature Communications.

The new device, known as MUSA, was supplied by MicroSure.

MUSA allows surgeons to connect tiny vessels, as small as 0.3–0.8 mm across, a technique referred to as supermicrosurgery. This technique can be used to connect blocked lymph vessels to veins, which can reestablish flow of lymphatic fluid and decrease arm swelling in women with breast cancer–related lymphedema, the researchers explain.

Only a few highly skilled surgeons worldwide can conduct supermicrosurgery using current surgical techniques, the authors comment.

"The success of supermicrosurgery is limited by the precision and stability of the surgeon's hands. Robot-assisted supermicrosurgery has the potential to overcome this obstacle because more refined and subtle movements can be performed. Before now, no robots were able to perform this type of surgery," coauthor Rutger M. Schols, MD, PhD, from the Maastricht University Medical Center in the Netherlands, told Medscape Medical News in an email.

Robot-assisted surgery is not new — the Da Vinci system was the first robotic surgery device to be approved by the US Food and Drug Administration. It was approved in 2000. However, Da Vinci was developed for minimally invasive surgery and is not precise enough for supermicrosurgery. And despite its $2 million price tag, Da Vinci has yet to show that it performs better than traditional surgery.

Designed Specifically for Supermicrosurgery

The MUSA robot was designed in the Netherlands by surgeons at Maastricht University Medical Center, engineers at the Eindhoven University of Technology, and the medical technology company Microsure specifically for reconstructive supermicrosurgery. Two of the authors of the article hold positions and are shareholders in the company.

Surgeons activate MUSA using foot pedals and operate forceps-like joysticks to control high-precision surgical instruments that filter out hand tremors and scale down motions. For example, moving the joystick 1 cm causes the robot to move 0.10 mm. MUSA also works with standard microscopes found in most operating rooms.

To test MUSA, Schols and colleagues at Maastricht University conducted a prospective, randomized trial that included 20 women with breast cancer–related lymphedema. The team randomly assigned eight women to undergo supermicrosurgery with MUSA and 12 women to undergo manual supermicrosurgery performed by a single surgeon. Two microsurgeons who were blinded to treatment groups evaluated the quality of the surgery using standardized scoring methods.

The results, which were adjusted for baseline factors, showed no significant differences in upper limb lymphedema between the two groups 1 and 3 months after surgery, nor were there significant differences between the two groups in quality of life.

A slightly higher percentage of women in the MUSA group were able to discontinue daily use of a compressive garment to treat arm swelling at 3 months, compared to the group that underwent manual supermicrosurgery (87.5% vs 83.3%).

Participants reported no serious adverse events.

For the group that underwent manual surgery, the quality of anastomosis was significantly better, compared to the MUSA group. Surgical competency was also significantly higher in the group that underwent manual surgery.

The MUSA group experienced a longer total surgery time (mean, 115 min) compared to the group that underwent manual surgery (mean, 81 min). But the authors note that duration of surgery declined steeply over time for the MUSA group, suggesting a learning curve in using the robot.

The researchers caution that the study may have been too small to detect significant differences between groups. Larger studies are needed to test MUSA with other surgeons operating in other centers, the authors note.

"With respect to treatment of breast cancer–related lymphedema, we are continuing trials with more patients, more surgeons, and more centers," Schols told Medscape Medical News.

"We expect that other centers — both national and international — are willing to test the MUSA," he added.

Schols and several coauthors have disclosed no relevant financial relationships. Two coauthors are shareholders and hold positions at MicroSure.

Nat Commun. Published online February 11, 2020. Full text

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