Facial Nerve Repair Using a Microsurgical Robot System: A Preclinical Study Using a Rat Model.

Background: Robot-assisted surgery is increasingly common, and its success in supermicrosurgical vascular anastomoses suggests the potential for even finer tasks. This study evaluates a surgical assistant robot for facial nerve neurorrhaphy in a rat model, comparing its performance with that of conventional manual microsuturing. Methods: Two board-certified plastic surgeons performed coaptation on the facial nerves of rats. The hand group used manual suturing, whereas the robot group used a microsurgical robotic system for dissection, transection, and coaptation. Key evaluations included total suture time, immediate repair continuity, and gross and histological continuity at 14 weeks. Functional recovery was assessed by measuring whisker movement and a neural tracing study. Results: In the robot group, a single surgeon could complete the procedure unassisted by a second operator. Six of 12 robot-repaired nerves were ≤0.8 mm in diameter. Although the initial mean time per stitch was significantly longer for the robot, 1 surgeon achieved comparable suture times to the hand group by the third animal. At 14 weeks, no significant differences were observed between the robot and hand groups for either functional or morphological outcomes. Conclusions: This study demonstrates that a surgical assistant robot can reliably suture rat facial nerves (≤0.8 mm diameter), achieving functional and histological outcomes equivalent to conventional hand coaptation. These findings expand the potential clinical applications of robotic systems in trauma and nerve reconstruction surgery, extending supermicrosurgery to peripheral nerve repair.