Pitfalls in precision stereotactic surgery

Abstract

Precision is the ultimate aim of stereotactic technique. Demands on stereotactic precision reach a pinnacle in stereotactic functional neurosurgery. Pitfalls are best avoided by possessing in-depth knowledge of the techniques employed and the equipment used. The engineering principles of arc-centered stereotactic frames maximize surgical precision at the target, irrespective of the surgical trajectory, and provide the greatest degree of surgical precision in current clinical practice. Stereotactic magnetic resonance imaging (MRI) provides a method of visualizing intracranial structures and fiducial markers on the same image without introducing significant errors during an image fusion process. Although image distortion may potentially limit the utility of stereotactic MRI, near-complete distortion correction can be reliably achieved with modern machines. Precision is dependent on minimizing errors at every step of the stereotactic procedure. These steps are considered in turn and include frame application, image acquisition, image manipulation, surgical planning of target and trajectory, patient positioning and the surgical procedure itself. Audit is essential to monitor and improve performance in clinical practice. The level of stereotactic precision is best analyzed by routine postoperative stereotactic MRI. This allows the stereotactic and anatomical location of the intervention to be compared with the anatomy and coordinates of the intended target, avoiding significant image fusion errors.

Review on Factors Affecting Targeting Accuracy of Deep Brain Stimulation Electrode Implantation between 2001 and 2015

“…Findings on WTE indicate that the average targeting accuracy of DBS has increased to about 1-2 mm. The popular statement ‘DBS has an average targeting accuracy of about 2-3 mm' [30,36] appearing in some of the latest publications would be obsolete. Besides, findings acquired in this study can help clarify the debate over the superiority in targeting accuracy between frame-based and frameless systems.…”

“…It can be represented by TE in 3 different ways, the Euclidean error d , the vector error Δ and the trajectory error r (fig. 1) [20,22,31,32,33,34,35,36]. d is the distance between the target and a specific position (commonly the clinically effective electrode contact) on the DBS lead; vector errors Δ x , Δ y and Δ z are, respectively, the projections of d in the x- (lateral-medial), y- (anterior-posterior) and z-directions (superior-inferior); r is the shortest distance between the target and the DBS lead.…”

Review of Robotic Technology for Stereotactic Neurosurgery

“…Specially in the case of functional neurosurgery in deep-seated targets, frame-based is still the preferred solution. This is because the frameless approach maximises accuracy and precision at the entry point rather than at the target point, as in the arc-centred approach [85], [86]. Improving efficiency and developing new frameless registration/fixation methods constitutes a timely endeavour and a research opportunity.…”

Neurosurgery and brain shift: review of the state of the art and main contributions of robotics

“…Other neurosurgery assisting robots focus on the location of electrodes in deep brain areas and on shared control for craniotomy, but few of them on endoscopic management of the endonasal approach. Also, there are brain lesions at the base of the skull such as pituitary tumors, chordomas, craniopharyngioma, cysts or meningiomas that are difficult to access using the techniques mentioned above [50].…”