Robotic platforms in neurosurgery: the great disappearing act

Robotic platforms in neurosurgery have evolved to match the demands of clinical practice over time. Indeed, the emergence of stereotactic neurosurgery has meant that most robots in regular use today are supervisory-control systems used for trajectory-planning for biopsies, deep brain stimulation (DBS) or stereoelectroencephalography (SEEG) lead implantation, or insertion of spinal pedicle screws. More recently however, neurosurgeons have turned to robots to provide other benefits including tremor control and dexterity at depth. Whilst teleoperated robots have been explored and have been commercially successful in other surgical fields, these large systems struggle with the narrow working corridors of neurosurgical approaches, and the inability to easily exchange instruments impairs their rapid response to intraoperative challenges. As a solution, modern handheld, shared-control robots have been developed which integrate seamlessly into the surgical workflow. This transition reflects the concept of the 'disappearing robot', whereby robotic assistance is becoming embedded within familiar-feeling surgical instruments, mirroring the evolution of computers into the modern smartphone. In this review, we examine the current landscape of neurosurgical robotics across supervisory-control, teleoperated and shared-control designs and discuss how handheld systems may recast the robot as a 'smart instrument'. Through this lens, we also consider how future robotic platforms may become further integrated into neurosurgical practice.