Magnetic steering for curved trajectories in neurosurgery – Applications and challenges in the brain and spinal cord

Current neurosurgical interventions are constrained to linear trajectories to reach targets in the brain and spinal cord, limiting access to anatomically complex targets and increasing the risk of tissue injury. Magnetic steering has emerged as a transformative strategy, enabling non-linear, real-time deflection of flexible probes through externally applied magnetic fields. By embedding magnetic elements within catheters or needles, these systems achieve curved trajectory navigation with sub-millimeter accuracy, offering advantages for stereotactic procedures such as deep brain stimulation, biopsies, laser ablation, spinal cord stimulation, etc. Recent advances include magnetically actuated flexible probes, microrobots, and hybrid magnetic–mechanical systems, supported by closed-loop integration with imaging and tracking platforms. Despite significant progress and validation in in-vitro and ex-vivo models, key challenges remain in magnetic field generation, biocompatible materials, imaging compatibility, workflow integration, and safety validation. Future directions center on translation and application in humans, machine learning–driven closed-loop navigation and multimodal sensing for real-time feedback. Together, these innovations chart a pathway toward the clinical translation of magnetic steering, with the potential to redefine minimally invasive neurosurgery by improving precision, adaptability, and patient safety.