Letter: A New Area of Neurosurgery: First Robotic Neurosurgery Clinical Case Series

To the Editor: The clinical case series by Eroglu et al1 represents a relevant milestone in the evolution of robotic cranial neurosurgery, reporting the first consolidated experience of da Vinci Xi–assisted neurosurgical procedures beyond stereotactic guidance. By demonstrating the feasibility of transoral odontoidectomy, skull base tumor resection, arachnoid cyst fenestration, and peripheral nerve decompression under robotic assistance, the authors1 move the field from conceptual adaptation to structured clinical implementation. This experience should, however, be contextualized within the experimental literature on the da Vinci platform. Over the past decade, different cadaveric and translational investigations have explored the Xi system across posterior fossa and keyhole corridors. Lee et al2 demonstrated feasibility in retrosigmoid, supracerebellar-infratentorial, and posterior occipitocervical junction approaches, highlighting the need for enlarged craniotomies to accommodate camera-instrument geometry. Similarly, Mohsan et al3 reported transorbital robotic access, expanding the spectrum of anterior skull base applications. In the vascular domain, Muto et al4 explored robotic-assisted middle cerebral artery-radial artery-internal carotid artery bypass constructs using the Xi system. In parallel, a substantial body of literature has documented transoral robotic surgery and hybrid transnasal–transoral approaches under da Vinci assistance, particularly targeting sellar, clival, and nasopharyngeal regions, as recently shown in systematic analyses.5 These studies collectively demonstrate that robotic manipulation within cranial corridors is technically achievable. The novelty of the current series lies less in conceptual innovation and more in clinical consolidation. The persistent limitation across these reports is architectural rather than procedural. Multiarm systems such as the Xi require external triangulation and spatial separation that conflict with the narrow funnel geometry of keyhole craniotomies. Human body donor analyses have shown that minimum bone windows larger than standard endoscopic openings are often necessary to avoid arm collision.5 For this reason, the da Vinci Single-Port (SP) configuration, acknowledged by the authors as potentially more suitable, deserves focused evaluation. By integrating camera and articulated instruments through a single cannula, the SP system may reduce steric conflict and external footprint. Its concentric design theoretically enhances coaxially within narrow working channels and may reduce the need for expanded craniotomies observed in Xi-based cadaveric studies. Nonetheless, neurosurgical validation of the SP system remains preliminary. Dedicated anatomic mapping under robotic conditions, quantifying surgical freedom, working angles, and steric footprint, is essential before broad clinical translation. Beyond geometric constraints, the absence of reliable haptic feedback remains the most critical technological limitation. In cranial microsurgery, tactile perception is essential for distinguishing tumor from parenchyma, assessing vessel compliance, and modulating traction during arachnoid dissection. Importantly, even in conventional microsurgery, this perception is not derived from direct touch but from vibratory information transmitted through microinstruments, allowing surgeons to interpret resistance and tissue consistency. Current robotic platforms mitigate tremor through motion scaling but do not reproduce these force-mediated cues. Experimental systems integrating force–torque sensors, such as SmartArm, illustrate potential solutions but remain investigational.5 The challenge is therefore not to recreate direct touch, but to restore interpretable signals of tissue resistance and compliance. Until clinically robust haptic integration becomes available, robotic cranial indications must remain carefully task-selected. Peripheral nerve surgery shares several microsurgical characteristics with cranial procedures but occurs in a less spatially constrained environment. Robotic nerve manipulation is not unprecedented,6 demonstrating that robotic platforms can facilitate precise nerve coaptation and microsuturing when anatomic exposure is adequate and force requirements are predictable. From this perspective, microvascular anastomosis represents a particularly coherent translational target. While the present series did not include bypass procedures, robotic vascular suturing has been explored in cadaveric neurovascular models with the Xi system4 and, more importantly, through dedicated microsurgical platforms such as Symani, which provides high-ratio motion scaling and tremor filtration with reproducible anastomotic geometry.7 Although not yet optimized for deep intracranial corridors, such systems demonstrate that robotic maturity may emerge first in highly standardized microsuturing tasks rather than broad tumor resections. The evolution of robotic cranial neurosurgery therefore depends not solely on technological refinement, but on disciplined translational methodology. Human body donors remain indispensable for evaluating steric footprint, working angles, instrument angulation, and trajectory alignment within realistic anatomic corridors.5 Quantitative anatomic validation allows objective measurement of surgical freedom and ergonomic strain, guiding iterative redesign of instruments and adaptation of materials to microsurgical demands. Without this structured translational cycle, encompassing anatomic validation, engineering refinement, and controlled clinical application, robotic integration risks remaining episodic rather than systematic. Eroglu et al1 appropriately emphasize structured training before clinical deployment; however, training must be embedded within anatomically grounded research frameworks to ensure reproducibility and safety. The future of robotic cranial neurosurgery depends on aligning corridor geometry, instrument design, and task specificity rather than simply expanding indications. At this stage, commercially available robotic platforms should be systematically evaluated and refined through structured cadaveric and translational studies to enable discipline-specific adaptation. This first clinical series consolidates feasibility, bridging to the next phase of prioritizing platform miniaturization, haptic integration, and task-driven validation through rigorous preclinical anatomic research.