A minimally invasive robotic spinal surgical system for anterior lumbar nerve decompression

Lumbar degenerative diseases, primarily caused by pathological tissues compressing spinal nerves, typically necessitate surgical intervention-specifically lumbar nerve decompression-to alleviate pain. Although the anterior decompression approach demonstrates notable advantages, such as reduced bleeding and shorter postoperative hospitalization stays, compared with the conventional posterior approach, patients may still experience incomplete decompression because of various instrumental shortcomings, including restricted visibility and insufficiency of distal dexterity. In this study, we present a robotic surgical system for minimally invasive anterior lumbar nerve decompression, which comprises three slender robotic arms (2 millimeters in outer diameter) with high dexterity (18 degrees of freedom), facilitating effective navigation through the narrow intervertebral disc space to reach the posterior area. Each robot arm is based on concentric push-pull robot structure, forming three robotized instruments: an endoscope for visualization, a laser optical fiber for hemostasis and resection, and a gripper for tissue manipulation. These components are integrated through the hollow lumen of a slender trocar, and multi-instrument coordination enables effective decompression procedure with wide view. System performance was first validated using a three-dimensional-printed vertebral phantom model to confirm accessibility to bilateral articular processes. Subsequently, in vivo animal experiment and human cadaver tests were conducted to further demonstrate the full capabilities in performing minimally invasive lumbar nerve decompression. This study demonstrates the potential of the robotic system to facilitate surgical procedures in narrow, confined, and tortuous anatomical spaces, addressing the key limitations of conventional instruments in anterior lumbar nerve decompression.