In vivo measurement of the frame-based application accuracy of the Neuromate neurosurgical robot

Efficacy and safety of robot-assisted deep brain stimulation for Parkinson's disease: a meta-analysis

Objective

This meta-analysis aims to assess the effectiveness and safety of robot-assisted deep brain stimulation (DBS) surgery for Parkinson's disease(PD).

Methods

Four databases (Medline, Embase, Web of Science and CENTRAL) were searched from establishment of database to 23 March 2024, for articles studying robot-assisted DBS in patients diagnosed with PD. Meta-analyses of vector error, complication rate, levodopa-equivalent daily dose (LEDD), Unified Parkinson's Disease Rating Scale (UPDRS), UPDRS II, UPDRS III, and UPDRS IV were performed.

Results

A total of 15 studies were included in this meta-analysis, comprising 732 patients with PD who received robot-assisted DBS. The pooled results revealed that the vector error was measured at 1.09 mm (95% CI: 0.87 to 1.30) in patients with Parkinson's disease who received robot-assisted DBS. The complication rate was 0.12 (95% CI, 0.03 to 0.24). The reduction in LEDD was 422.31 mg (95% CI: 68.69 to 775.94). The improvement in UPDRS, UPDRS III, and UPDRS IV was 27.36 (95% CI: 8.57 to 46.15), 14.09 (95% CI: 4.67 to 23.52), and 3.54 (95% CI: -2.35 to 9.43), respectively.

Conclusion

Robot-assisted DBS is a reliable and safe approach for treating PD. Robot-assisted DBS provides enhanced accuracy in contrast to conventional frame-based stereotactic techniques. Nevertheless, further investigation is necessary to validate the advantages of robot-assisted DBS in terms of enhancing motor function and decreasing the need for antiparkinsonian medications, in comparison to traditional frame-based stereotactic techniques.Clinical trial registration: PROSPERO(CRD42024529976).

Current state of the art of traditional and minimal invasive epilepsy surgery approaches

Introduction

Open resective surgery remains the main treatment modality for refractory epilepsy, but is often considered a last resort option due to its invasiveness.

Research question

This manuscript aims to provide an overview on traditional as well as minimally invasive surgical approaches in modern state of the art epilepsy surgery.

Materials and methods

This narrative review addresses both historical and contemporary as well as minimal invasive surgical approaches in epilepsy surgery. Peer-reviewed published articles were retrieved from PubMed and Scopus. Only articles written in English were considered for this work. A range of traditional and minimally invasive surgical approaches in epilepsy surgery were examined, and their respective advantages and disadvantages have been summarized.

Results

The following approaches and techniques are discussed: minimally invasive diagnostics in epilepsy surgery, anterior temporal lobectomy, functional temporal lobectomy, selective amygdalohippocampectomy through a transsylvian, transcortical, or subtemporal approach, insulo-opercular corticectomies compared to laser interstitial thermal therapy, radiofrequency thermocoagulation, stereotactic radiosurgery, neuromodulation, high intensity focused ultrasound, and disconnection surgery including callosotomy, hemispherotomy, and subpial transections.

Discussion and conclusion

Understanding the benefits and disadvantages of different surgical approaches and strategies in traditional and minimal invasive epilepsy surgery might improve the surgical decision tree, as not all procedures are appropriate for all patients.

Neurosurgical robots in China: State of the art and future prospect

Neurosurgical robots have developed for decades and can effectively assist surgeons to carry out a variety of surgical operations, such as biopsy, stereo-electroencephalography (SEEG), deep brain stimulation (DBS), and so forth. In recent years, neurosurgical robots in China have developed rapidly. This article will focus on several key skills in neurosurgical robots, such as medical imaging systems, automatic manipulator, lesion localization techniques, multimodal image fusion technology, registration method, and vascular imaging technology; introduce the clinical application of neurosurgical robots in China, and look forward to the potential improvement points in the future based on our experience and research in the field.

The clinical application of neuro-robot in the resection of epileptic foci: a novel method assisting epilepsy surgery

During surgery for foci-related epilepsy, neurosurgeons face significant difficulties in identifying and resecting MRI-negative or deep-seated epileptic foci. Here, we present a neuro-robotic navigation system that is specifically designed for resection of MRI negative epileptic foci. We recruited 52 epileptic patients, and randomly assigned them to treatment group with either neuro-robotic navigation or conventional neuronavigation system. For each patient, in the neuro-robotic navigation group, we integrated multimodality imaging including MRI and PET-CT into the robotic workstation and marked the boundary of foci from the fused image. During surgery, this boundary was delineated by the robotic laser device with high accuracy, guiding resection for the surgeon. For deeply seated foci, we exploited the neuro-robotic navigation system to localize the deepest point with biopsy needle insertion and methylene dye application to locate the boundary of the foci. Our results show that, compared with the conventional neuronavigation, the neuro-robotic navigation system performs equally well in MRI positive epilepsy patients (ENGEL I ratio: 71.4% vs 100%, p = 0.255) systems and show better performance in patients with MRI-negative focal cortical dysplasia (ENGEL I ratio: 88.2% vs 50%, p = 0.0439). At present, there are no documented neurosurgery robots with similar function and application in the field of epilepsy. Our research highlights the added value of using neuro-robotic navigation systems in resection surgery for epilepsy, particularly in cases that involve MRI-negative or deep-seated epileptic foci.

MER and increased operative time are not risk factors for the formation of pneumocephalus during DBS

Although only recently directional leads have proven their potential to compensate for sub-optimally placed electrodes, optimal lead positioning remains the most critical factor in determining Deep Brain Stimulation (DBS) outcome. Pneumocephalus is a recognized source of error, but the factors that contribute to its formation are still a matter of debate. Among these, operative time is one of the most controversial. Because cases of DBS performed with Microelectrode Recordings (MER) are affected by an increase in surgical length, it is useful to analyze whether MER places patients at risk for increased intracranial air entry. Data of 94 patients from two different institutes who underwent DBS for different neurologic and psychiatric conditions were analyzed for the presence of postoperative pneumocephalus. Operative time and use of MER, as well as other potential risk factors for pneumocephalus (age, awake vs. asleep surgery, number of MER passages, burr hole size, target and unilateral vs. bilateral implants) were examined. Mann-Whitney U and Kruskal-Wallis tests were utilized to compare intracranial air distributions across groups of categorical variables. Partial correlations were used to assess the association between time and volume. A generalized linear model was created to predict the effects of time and MER on the volume of intracranial air, controlling for other potential risk factors identified: age, number of MER passages, awake vs. asleep surgery, burr hole size, target, unilateral vs. bilateral surgery. Significantly different distributions of air volume were noted between different targets, unilateral vs. bilateral implants, and number of MER trajectories. Patients undergoing DBS with MER did not present a significant increase in pneumocephalus compared to patients operated without (p = 0.067). No significant correlation was found between pneumocephalus and time. Using multivariate analysis, unilateral implants exhibited lower volumes of pneumocephalus (p = 0.002). Two specific targets exhibited significantly different volumes of pneumocephalus: the bed nucleus of the stria terminalis with lower volumes (p < 0.001) and the posterior hypothalamus with higher volumes (p = 0.011). MER, time, and other parameters analyzed failed to reach statistical significance. Operative time and use of intraoperative MER are not significant predictors of pneumocephalus during DBS. Air entry is greater for bilateral surgeries and may be also influenced by the specific stimulated target.

Feasibility and Accuracy of Robot-Assisted, Stereotactic Biopsy Using 3-Dimensional Intraoperative Imaging and Frameless Registration Tool

BACKGROUND

Robot-assisted stereotactic biopsy is evolving: 3-dimensional intraoperative imaging tools and new frameless registration systems are spreading.

OBJECTIVE

To investigate the accuracy and effectiveness of a new stereotactic biopsy procedure.

METHODS

Observational, retrospective analysis of consecutive robot-assisted stereotactic biopsies using the Neurolocate (Renishaw) frameless registration system and intraoperative O-Arm (Medtronic) performed at a single institution in adults (2019-2021) and comparison with a historical series from the same institution (2006-2016) not using the Neurolocate nor the O-Arm.

RESULTS

In 100 patients (55% men), 6.2 ± 2.5 (1-14) biopsy samples were obtained at 1.7 ± 0.7 (1-3) biopsy sites. An histomolecular diagnosis was obtained in 96% of cases. The mean duration of the procedure was 59.0 ± 22.3 min. The mean distance between the planned and the actual target was 0.7 ± 0.7 mm. On systematic postoperative computed tomography scans, a hemorrhage ≥10 mm was observed in 8 cases (8%) while pneumocephalus was distant from the biopsy site in 76%. A Karnofsky Performance Status score decrease ≥20 points postoperatively was observed in 4%. The average dose length product was 159.7 ± 63.4 mGy cm. Compared with the historical neurosurgical procedure, this new procedure had similar diagnostic yield (96 vs 98.7%; P = .111) and rate of postoperative disability (4.0 vs 4.2%, P = .914) but was shorter (57.8 ± 22.9 vs 77.8 ± 20.9 min; P < .001) despite older patients.

CONCLUSION

Robot-assisted stereotactic biopsy using the Neurolocate frameless registration system and intraoperative O-Arm is a safe and effective neurosurgical procedure. The accuracy of this robot-assisted surgery supports its effectiveness for daily use in stereotactic neurosurgery.

The accuracy of a novel self-tapping bone fiducial marker for frameless robot-assisted stereo-electro-encephalography implantation and registration techniques

BACKGROUND

We aimed to evaluate the accuracy and safety of a novel self-tapping bone fiducial as a registration technique for stereoelectroencephalography (SEEG) implantation.

METHODS

Each patient was installed with five bone fiducial markers. All procedures were performed using the same Sinovation robot system. The accuracy was determined by calculating the target point error (TPE) and the entry point error (EPE) of electrodes.

RESULTS

Fourteen patients underwent SEEG implantation surgery; and the average installation time of the markers per patient was 86.1 s. In the operating theatre, the average registration time was 206.6 s, and the average registration error was 0.18 mm. The average TPE of 174 electrodes was 1.98 mm and the average EPE was 0.88 mm.

CONCLUSION

Our study provided a bone fiducial marker installation and registration technique that was convenient and fast, highly accurate in registration, and highly tolerated by patients.

Deep Brain Stimulation in the Treatment of Tardive Dyskinesia

Tardive dyskinesia (TD) is a phenomenon observed following the predominantly long-term use of dopamine receptor blockers (antipsychotics) widely used in psychiatry. TD is a group of involuntary, irregular hyperkinetic movements, mainly in the muscles of the face, eyelid, lips, tongue, and cheeks, and less frequently in the limbs, neck, pelvis, and trunk. In some patients, TD takes on an extremely severe form, massively disrupting functioning and, moreover, causing stigmatization and suffering. Deep brain stimulation (DBS), a method used, among others, in Parkinson's disease, is also an effective treatment for TD and often becomes a method of last resort, especially in severe, drug-resistant forms. The group of TD patients who have undergone DBS is still very limited. The procedure is relatively new in TD, so the available reliable clinical studies are few and consist mainly of case reports. Unilateral and bilateral stimulation of two sites has proven efficacy in TD treatment. Most authors describe stimulation of the globus pallidus internus (GPi); less frequent descriptions involve the subthalamic nucleus (STN). In the present paper, we provide up-to-date information on the stimulation of both mentioned brain areas. We also compare the efficacy of the two methods by comparing the two available studies that included the largest groups of patients. Although GPi stimulation is more frequently described in literature, our analysis indicates comparable results (reduction of involuntary movements) with STN DBS.

Accuracy and efficiency using frameless transient fiducial registration in stereoelectroencephalography and deep brain stimulation

OBJECTIVE

Stereotactic surgical methods continue to advance technologically. Frameless transient fiducial registration (FTFR) systems have been developed and avoid the need to move or position a patient in a frame after already receiving registration imaging. One such system, Neurolocate, has recently become available as a robotic attachment for the Neuromate stereotactic robot. This study is the largest in the literature to evaluate the accuracy of frameless registration using Neurolocate versus frame-based registration (FBR) methods in both deep brain stimulation (DBS) and stereoelectroencephalography (SEEG). Additionally, the authors sought to reevaluate factors affecting accuracy in both procedures.

METHODS

This study was a retrospective chart and imaging review of 88 consecutive procedures (involving 621 electrodes) implanting either DBS or SEEG at the authors' institution over a 5-year period from March 2015 to March 2020. Registration duration, radial target entry point, and Euclidean target implantation accuracies, as well as factors affecting accuracy, were recorded for each patient.

RESULTS

SEEG procedures included 38 patients and 525 implanted electrodes (294 using FBR and 231 using FTFR). DBS procedures included 50 patients and 96 implanted electrodes (65 using FBR and 31 using FTFR). Overall, FTFR registration was significantly more accurate (median 0.1 mm, IQR 0-0.4 mm) compared with FBR (median 1.3 mm, IQR 0.9-1.5 mm; p = 0.04). Likewise, FTFR had a significantly shorter duration of registration (median 84 minutes, IQR 77.3-95.3 minutes) when compared with FBR (median 110.5 minutes, IQR 107.3-138 minutes; p = 0.02). No significant differences were found when examining the radial entry point and Euclidean target implantation errors of each method.

CONCLUSIONS

FTFR with the Neurolocate system represents a technique that may decrease operative time while maintaining the high accuracy previously demonstrated by other stereotactic methods, despite an initial surgeon learning curve. It should be investigated in future studies to continue to improve stereotactic accuracies in neurosurgery.

A New Noninvasive Frameless Registration System for Stereotactic Cranial Biopsy: A Technical Note

BACKGROUND

Although frame-based stereotactic biopsy is still considered the gold standard for brain biopsies, frameless robot-assisted stereotactic systems are now able to provide an equal level of safety and accuracy. However, both systems suffer from a lack of efficiency of the operative workflow.

OBJECTIVE

To describe the technique of a new frameless and noninvasive registration tool Neurolocate (Renishaw). This tool, combined with an intraoperative cone-beam computed tomography imaging system like O-ARM (Medtronic), might facilitate the achievement and workflow of robot-assisted stereotactic intracranial biopsies.

METHODS

Neurolocate is a 3-dimensional fiducial tool fixed directly on the Neuromate (Renishaw) robot arm. It consists of 5 radio-opaque spherical fiducials, whose geometry is constant. This tool made it possible to carry out the coregistration then the biopsy in the same operating time, following a five-step procedure described here. We retrospectively extracted selected preliminary results from our initial experience.

RESULTS

Over 1 year, 23 consecutive adult patients were biopsied with Neurolocate in our center. The mean overall operative time, from patient's installation to skin closure, was 97 minutes ± 27 (SD). The entire procedure took place in a single location unit (operating room), which facilitated workflow and surgical planning. No invasive gesture was performed outside of the operating time.

CONCLUSION

Neurolocate is a new frameless and noninvasive registration tool that could improve workflow and flexibility for operating room management and surgical planning. It may also increase the comfort of patients undergoing robot-assisted intracranial stereotactic biopsies. The accuracy and safety profile should be addressed in specific studies.

Learning curves in robotic neurosurgery: a systematic review

The transition to performing procedures robotically generally entails a period of adjustment known as a learning curve as the surgeon develops a familiarity with the technology. However, no study has comprehensively examined robotic learning curves across the field of neurosurgery. We conducted a systematic review to characterize the scope of literature on robotic learning curves in neurosurgery, assess operative parameters that may involve a learning curve, and delineate areas for future investigation. PubMed, Embase, and Scopus were searched. Following deduplication, articles were screened by title and abstract for relevance. Remaining articles were screened via full text for final inclusion. Bibliographic and learning curve data were extracted. Of 746 resultant articles, 32 articles describing 3074 patients were included, of which 23 (71.9%) examined spine, 4 (12.5%) pediatric, 4 (12.5%) functional, and 1 (3.1%) general neurosurgery. The parameters assessed for learning curves were heterogeneous. In total, 8 (57.1%) of 14 studies found reduced operative time with increased cases, while the remainder demonstrated no learning curve. Six (60.0%) of 10 studies reported reduced operative time per component with increased cases, while the remainder indicated no learning curve. Radiation time, radiation time per component, robot time, registration time, setup time, and radiation dose were assessed by ≤ 4 studies each, with 0-66.7% of studies demonstrated a learning curve. Four (44.4%) of 9 studies on accuracy showed improvement over time, while the others indicated no improvement over time. The number of cases required to reverse the learning curve ranged from 3 to 75. Learning curves are common in robotic neurosurgery. However, existing studies demonstrate high heterogeneity in assessed parameters and the number of cases that comprise the learning curve. Future studies should seek to develop strategies to reduce the number of cases required to reach the learning curve.

Application of the robot-assisted implantation in deep brain stimulation

INTRODUCTION

This work aims to assess the accuracy of robotic assistance guided by a videometric tracker in deep brain stimulation (DBS).

METHODS

We retrospectively reviewed a total of 30 DBS electrode implantations, assisted by the Remebot robotic system, with a novel frameless videometric registration workflow. Then we selected 30 PD patients who used stereotactic frame surgery to implant electrodes during the same period. For each electrode, accuracy was assessed using radial and axial error.

RESULTS

The average radial error of the robot-assisted electrode implantation was 1.28 ± 0.36 mm, and the average axial error was 1.20 ± 0.40 mm. No deaths or associated hemorrhages, infections or poor incision healing occurred.

CONCLUSION

Robot-assisted implantation guided by a videometric tracker is accurate and safe.

Modular robotic platform for precision neurosurgery with a bio-inspired needle: System overview and first in-vivo deployment

Over the past 10 years, minimally invasive surgery (MIS) has shown significant benefits compared to conventional surgical techniques, with reduced trauma, shorter hospital stays, and shorter patient recovery times. In neurosurgical MIS procedures, inserting a straight tool (e.g. catheter) is common practice in applications ranging from biopsy and laser ablation, to drug delivery and fluid evacuation. How to handle tissue deformation, target migration and access to deep-seated anatomical structures remain an open challenge, affecting both the preoperative planning phase and eventual surgical intervention. Here, we present the first neurosurgical platform in the literature, able to deliver an implantable steerable needle for a range of diagnostic and therapeutic applications, with a short-term focus on localised drug delivery. This work presents the system's architecture and first in vivo deployment with an optimised surgical workflow designed for pre-clinical trials with the ovine model, which demonstrate appropriate function and safe implantation.

Robot-Assisted Deep Brain Stimulation: High Accuracy and Streamlined Workflow

BACKGROUND

A number of stereotactic platforms are available for performing deep brain stimulation (DBS) lead implantation. Robot-assisted stereotaxy has emerged more recently demonstrating comparable accuracy and shorter operating room times compared with conventional frame-based systems.

OBJECTIVE

To compare the accuracy of our streamlined robotic DBS workflow with data in the literature from frame-based and frameless systems.

METHODS

We retrospectively reviewed 126 consecutive DBS lead placement procedures using a robotic stereotactic platform. Indications included Parkinson disease (n = 94), essential tremor (n = 21), obsessive compulsive disorder (n = 7), and dystonia (n = 4). Procedures were performed using a stereotactic frame for fixation and the frame pins as skull fiducials for robot registration. We used intraoperative fluoroscopic computed tomography for registration and postplacement verification.

RESULTS

The mean radial error for the target point was 1.06 mm (SD: 0.55 mm, range 0.04-2.80 mm) on intraoperative fluoroscopic computed tomography. The mean operative time for an asleep, bilateral implant without implantable pulse generator placement was 238 minutes (SD: 52 minutes), and skin-to-skin procedure time was 116 minutes (SD: 42 minutes).

CONCLUSION

We describe a streamlined workflow for DBS lead placement using robot-assisted stereotaxy with a comparable accuracy profile. Obviating the need for checking and switching coordinates, as is standard for frame-based DBS, also reduces the chance for human error and facilitates training.

Development of a miniaturized robotic guidance device for stereotactic neurosurgery

OBJECTIVE

Consistently high accuracy and a straightforward use of stereotactic guidance systems are crucial for precise stereotactic targeting and a short procedural duration. Although robotic guidance systems are widely used, currently available systems do not fully meet the requirements for a stereotactic guidance system that combines the advantages of frameless surgery and robotic technology. The authors developed and optimized a small-scale yet highly accurate guidance system that can be seamlessly integrated into an existing operating room (OR) setup due to its design. The aim of this clinical study is to outline the development of this miniature robotic guidance system and present the authors' clinical experience.

METHODS

After extensive preclinical testing of the robotic stereotactic guidance system, adaptations were implemented for robot fixation, software usability, navigation integration, and end-effector application. Development of the robotic system was then advanced in a clinical series of 150 patients between 2013 and 2019, including 111 needle biopsies, 13 catheter placements, and 26 stereoelectroencephalography (SEEG) electrode placements. During the clinical trial, constant modifications were implemented to meet the setup requirements, technical specifications, and workflow for each indication. For each application, specific setup, workflow, and median procedural accuracy were evaluated.

RESULTS

Application of the miniature robotic system was feasible in 149 of 150 cases. The setup in each procedure was successfully implemented without adding significant OR time. The workflow was seamlessly integrated into the preexisting procedure. In the course of the study, procedural accuracy was improved. For the biopsy procedure, the real target error (RTE) was reduced from a mean of 1.8 ± 1.03 mm to 1.6 ± 0.82 mm at entry (p = 0.05), and from 1.7 ± 1.12 mm to 1.6 ± 0.72 mm at target (p = 0.04). For the SEEG procedures, the RTE was reduced from a mean of 1.43 ± 0.78 mm in the first half of the procedures to 1.12 ± 0.52 mm (p = 0.002) at entry in the second half, and from 1.82 ± 1.13 mm to 1.57 ± 0.98 mm (p = 0.069) at target, respectively. No healing complications or infections were observed in any case.

CONCLUSIONS

The miniature robotic guidance device was able to prove its versatility and seamless integration into preexisting workflow by successful application in 149 stereotactic procedures. According to these data, the robot could significantly improve accuracy without adding time expenditure.

Techniques of Frameless Robot-Assisted Deep Brain Stimulation and Accuracy Compared with the Frame-Based Technique

Background: Frameless robot-assisted deep brain stimulation (DBS) is an innovative technique for leads implantation. This study aimed to evaluate the accuracy and precision of this technique using the Sinovation SR1 robot. Methods: 35 patients with Parkinson’s disease who accepted conventional frame-based DBS surgery (n = 18) and frameless robot-assisted DBS surgery (n = 17) by the same group of neurosurgeons were analyzed. The coordinate of the tip of the intended trajectory was recorded as x_i, y_i, and z_i. The actual position of lead implantation was recorded as xa, ya, and za. The vector error was calculated by the formula of √(x_i − x_a)² + (y_i − y_a)² + (z_i − z_a)² to evaluate the accuracy. Results: The vector error was 1.52 ± 0.53 mm (range: 0.20–2.39 mm) in the robot-assisted group and was 1.77 ± 0.67 mm (0.59–2.98 mm) in the frame-based group with no significant difference between two groups (p = 0.1301). In 10.7% (n = 3) frameless robot-assisted implanted leads, the vector error was greater than 2.00 mm with a maximum offset of 2.39 mm, and in 35.5% (n = 11) frame-based implanted leads, the vector error was larger than 2.00 mm with a maximum offset of 2.98 mm. Leads were more posterior than planned trajectories in the robot-assisted group and more medial and posterior in the conventional frame-based group. Conclusions: Awake frameless robot-assisted DBS surgery was comparable to the conventional frame-based technique in the accuracy and precision for leads implantation.

Accuracy of Robotic and Frame-Based Stereotactic Neurosurgery in a Phantom Model

Background

The development of robotic systems has provided an alternative to frame-based stereotactic procedures. The aim of this experimental phantom study was to compare the mechanical accuracy of the Robotic Surgery Assistant (ROSA) and the Leksell stereotactic frame by reducing clinical and procedural factors to a minimum.

Methods

To precisely compare mechanical accuracy, a stereotactic system was chosen as reference for both methods. A thin layer CT scan with an acrylic phantom fixed to the frame and a localizer enabling the software to recognize the coordinate system was performed. For each of the five phantom targets, two different trajectories were planned, resulting in 10 trajectories. A series of five repetitions was performed, each time based on a new CT scan. Hence, 50 trajectories were analyzed for each method. X-rays of the final cannula position were fused with the planning data. The coordinates of the target point and the endpoint of the robot- or frame-guided probe were visually determined using the robotic software. The target point error (TPE) was calculated applying the Euclidian distance. The depth deviation along the trajectory and the lateral deviation were separately calculated.

Results

Robotics was significantly more accurate, with an arithmetic TPE mean of 0.53 mm (95% CI 0.41–0.55 mm) compared to 0.72 mm (95% CI 0.63–0.8 mm) in stereotaxy (p < 0.05). In robotics, the mean depth deviation along the trajectory was −0.22 mm (95% CI −0.25 to −0.14 mm). The mean lateral deviation was 0.43 mm (95% CI 0.32–0.49 mm). In frame-based stereotaxy, the mean depth deviation amounted to −0.20 mm (95% CI −0.26 to −0.14 mm), the mean lateral deviation to 0.65 mm (95% CI 0.55–0.74 mm).

Conclusion

Both the robotic and frame-based approach proved accurate. The robotic procedure showed significantly higher accuracy. For both methods, procedural factors occurring during surgery might have a more relevant impact on overall accuracy.

Frameless robot-assisted stereotactic biopsies for lesions of the brainstem-a series of 103 consecutive biopsies

PURPOSE

Targeted treatment for brainstem lesions requires above all a precise histopathological and molecular diagnosis. In the current technological era, robot-assisted stereotactic biopsies represent an accurate and safe procedure for tissue diagnosis. We present our center's experience in frameless robot-assisted biopsies for brainstem lesions.

METHODS

We performed a retrospective analysis of all patients benefitting from a frameless robot-guided stereotactic biopsy at our University Hospital, from 2001 to 2017. Patients consented to the use of data and/or images. The NeuroMate® robot (Renishaw™, UK) was used. We report on lesion location, trajectory strategy, histopathological diagnosis and procedure safety.

RESULTS

Our series encompasses 96 patients (103 biopsies) treated during a 17 years period. Mean age at biopsy: 34.0 years (range 1-78). Most common location: pons (62.1%). Transcerebellar approach: 61 procedures (59.2%). Most common diagnoses: diffuse glioma (67.0%), metastases (7.8%) and lymphoma (6.8%). Non conclusive diagnosis: 10 cases (9.7%). After second biopsy this decreased to 4 cases (4.1%). Overall biopsy diagnostic yield: 95.8%. Permanent disability was recorded in 3 patients (2.9%, all adults), while transient complications in 17 patients (17.7%). Four cases of intra-tumoral hematoma were recorded (one case with rapid decline and fatal issue). Adjuvant targeted treatment was performed in 72.9% of patients. Mean follow-up (in the Neurosurgery Department): 2.2 years.

CONCLUSION

Frameless robot-assisted stereotactic biopsies can provide the initial platform towards a safe and accurate management for brainstem lesions, offering a high diagnostic yield with low permanent morbidity.

Deformable 3D-2D registration for high-precision guidance and verification of neuroelectrode placement

Purpose.Accurate neuroelectrode placement is essential to effective monitoring or stimulation of neurosurgery targets. This work presents and evaluates a method that combines deep learning and model-based deformable 3D-2D registration to guide and verify neuroelectrode placement using intraoperative imaging.Methods.The registration method consists of three stages: (1) detection of neuroelectrodes in a pair of fluoroscopy images using a deep learning approach; (2) determination of correspondence and initial 3D localization among neuroelectrode detections in the two projection images; and (3) deformable 3D-2D registration of neuroelectrodes according to a physical device model. The method was evaluated in phantom, cadaver, and clinical studies in terms of (a) the accuracy of neuroelectrode registration and (b) the quality of metal artifact reduction (MAR) in cone-beam CT (CBCT) in which the deformably registered neuroelectrode models are taken as input to the MAR.Results.The combined deep learning and model-based deformable 3D-2D registration approach achieved 0.2 ± 0.1 mm accuracy in cadaver studies and 0.6 ± 0.3 mm accuracy in clinical studies. The detection network and 3D correspondence provided initialization of 3D-2D registration within 2 mm, which facilitated end-to-end registration runtime within 10 s. Metal artifacts, quantified as the standard deviation in voxel values in tissue adjacent to neuroelectrodes, were reduced by 72% in phantom studies and by 60% in first clinical studies.Conclusions.The method combines the speed and generalizability of deep learning (for initialization) with the precision and reliability of physical model-based registration to achieve accurate deformable 3D-2D registration and MAR in functional neurosurgery. Accurate 3D-2D guidance from fluoroscopy could overcome limitations associated with deformation in conventional navigation, and improved MAR could improve CBCT verification of neuroelectrode placement.

Full-field MRI measurements of in-vivo positional brain shift reveal the significance of intra-cranial geometry and head orientation for stereotactic surgery

Positional brain shift (PBS), the sagging of the brain under the effect of gravity, is comparable in magnitude to the margin of error for the success of stereotactic interventions ([Formula: see text] 1 mm). This non-uniform shift due to slight differences in head orientation can lead to a significant discrepancy between the planned and the actual location of surgical targets. Accurate in-vivo measurements of this complex deformation are critical for the design and validation of an appropriate compensation to integrate into neuronavigational systems. PBS arising from prone-to-supine change of head orientation was measured with magnetic resonance imaging on 11 young adults. The full-field displacement was extracted on a voxel-basis via digital volume correlation and analysed in a standard reference space. Results showed the need for target-specific correction of surgical targets, as a significant displacement ranging from 0.52 to 0.77 mm was measured at surgically relevant structures. Strain analysis further revealed local variability in compressibility: anterior regions showed expansion (both volume and shape change), whereas posterior regions showed small compression, mostly dominated by shape change. Finally, analysis of correlation demonstrated the potential for further patient- and intervention-specific adjustments, as intra-cranial breadth and head tilt correlated with PBS reaching statistical significance.

The Clinical Application of Robot-Assisted Ventriculoperitoneal Shunting in the Treatment of Hydrocephalus

Background

This work aims to assess the effectiveness and safety of robotic assistance in ventriculoperitoneal shunting and to compare the results with data from traditional surgery.

Methods

We retrospectively analyzed 60 patients who had undergone ventriculoperitoneal shunting, of which shunts were implanted using a robot in 20 patients and using traditional surgical methods in the other 40 patients. Data related to surgery were compared between the two groups, and the accuracy of the drainage tube in the robot-assisted group was assessed.

Results

In the robot-assisted surgery group, the operation duration was 29.75 ± 6.38 min, intraoperative blood loss was 10.0 ± 3.98 ml, the success rate of a single puncture was 100%, and the bone hole diameter was 4.0 ± 0.3 mm. On the other hand, the operation duration was 48.63 ± 6.60 min, intraoperative blood loss was 22.25 ± 4.52 ml, the success rate of a single puncture was 77.5%, and the bone hole diameter was 11.0 ± 0.2 mm in the traditional surgery group. The above are statistically different between the two groups (P < 0.05). Only one case of surgery-related complications occurred in the robot-assisted group, while 13 cases occurred in the traditional surgery group. There was no significant difference in the hospitalization time. In the robot-assisted surgery group, the average radial error was 2.4 ± 1.5 mm and the average axial error was 1.9 ± 2.1 mm.

Conclusion

In summary, robot-assisted implantation is accurate, simple to operate, and practical; the duration of surgery is short; trauma to the patient is reduced; and fewer postoperative complications related to surgery are reported.

Cranial neurosurgical robotics

OBJECT

The purpose of this review is to highlight the major factors limiting the progress of robotics development in the field of cranial neurosurgery.

METHODS

A literature search was performed focused on published reports of any Neurosurgical technology developed for use in cranial neurosurgery. Technology was reviewed and assessed for strengths and weaknesses, use in patients and whether or not the project was active or closed.

RESULTS

Published reports of 24 robots are discussed going back to 1985. In total, there were 9 robots used in patients (PUMA, Robot Hand, EXPERT, Neuromate, Evolution 1, ROSA, iSYS1, NeuroArm and NeuRobot) and only 2 active today (ROSA, NeuroArm). Of all clinically active systems, only three were used in more than 30 patients (ROSA, iSYS1 & NeuroArm). Projects were limited by cost, technology adoption, and clinical utility to actually improve workflow. The most common use of developed robots is for Stereotaxis.

CONCLUSIONS

There is a clear void in the area of cranial neurosurgery regarding robotics technology despite success in other fields of surgery. Significant factors such as cost, technology limitations, market size and regulatory pathway all contribute to a steep gradient for success.

Robotic Applications in Cranial Neurosurgery: Current and Future

Robotics applied to cranial surgery is a fast-moving and fascinating field, which is transforming the practice of neurosurgery. With exponential increases in computing power, improvements in connectivity, artificial intelligence, and enhanced precision of accessing target structures, robots are likely to be incorporated into more areas of neurosurgery in the future-making procedures safer and more efficient. Overall, improved efficiency can offset upfront costs and potentially prove cost-effective. In this narrative review, we aim to translate a broad clinical experience into practical information for the incorporation of robotics into neurosurgical practice. We begin with procedures where robotics take the role of a stereotactic frame and guide instruments along a linear trajectory. Next, we discuss robotics in endoscopic surgery, where the robot functions similar to a surgical assistant by holding the endoscope and providing retraction, supplemental lighting, and correlation of the surgical field with navigation. Then, we look at early experience with endovascular robots, where robots carry out tasks of the primary surgeon while the surgeon directs these movements remotely. We briefly discuss a novel microsurgical robot that can perform many of the critical operative steps (with potential for fine motor augmentation) remotely. Finally, we highlight 2 innovative technologies that allow instruments to take nonlinear, predetermined paths to an intracranial destination and allow magnetic control of instruments for real-time adjustment of trajectories. We believe that robots will play an increasingly important role in the future of neurosurgery and aim to cover some of the aspects that this field holds for neurosurgical innovation.

The Path to Surgical Robotics in Neurosurgery

Robotic systems may help efficiently execute complicated tasks that require a high degree of accuracy, and this, in large part, explains why robotics have garnered widespread use in a variety of neurosurgical applications, including intracranial biopsies, spinal instrumentation, and placement of intracranial leads. The use of robotics in neurosurgery confers many benefits, and inherent limitations, to both surgeons and their patients. In this narrative review, we provide a historical overview of robotics and its implementation across various surgical specialties, and discuss the various robotic systems that have been developed specifically for neurosurgical applications. We also discuss the relative advantages of robotic systems compared to traditional surgical techniques, particularly as it pertains to integration of image guidance with the ability of the robotic arm to reliably execute pre-planned tasks. As more neurosurgeons adopt the use of robotics in their practice, we postulate that further technological advancements will become available that will help achieve improved technical capabilities, user experience, and overall patient clinical outcomes.

Two Hundred Twenty-Six Consecutive Deep Brain Stimulation Electrodes Placed Using an "Asleep" Technique and the Neuro|MateTM Robot for the Treatment of Movement Disorders

BACKGROUND

Robotics in neurosurgery has demonstrated widening indications and rapid growth in recent years. Robotic precision and reproducibility are especially pertinent to the field of functional neurosurgery. Deep brain stimulation (DBS) requires accurate placement of electrodes in order to maximize efficacy and minimize side effects. In addition, asleep techniques demand clear target visualization and immediate on-table verification of accuracy.

OBJECTIVE

To describe the surgical technique of asleep DBS surgery using the Neuro|MateTM Robot (Renishaw plc, Wotton-under-Edge, United Kingdom) and examine the accuracy of DBS lead placement in the subthalamic nucleus (STN) for the treatment of movement disorders.

METHODS

A single-center retrospective review of 113 patients who underwent bilateral STN/Zona Incerta electrode placement was performed. Accuracy of implantation was assessed using 5 measurements, Euclidian distance, radial error, depth error, angular error, and shift error.

RESULTS

A total of 226 planned vs actual electrode placements were analyzed. The mean 3-dimensional vector error calculated for 226 trajectories was 0.78 +/- 0.37 mm. The mean radial displacement off planned trajectory was 0.6 +/- 0.33 mm. The mean depth error, angular error, and shift error was 0.4 +/- 0.35 mm, 0.4 degrees, and 0.3 mm, respectively.

CONCLUSION

This report details our institution's method for DBS lead placement in patients under general anaesthesia using anatomical targeting without microelectrode recordings or intraoperative test stimulation for the treatment of movement disorders. This is the largest reported dataset of accuracy results in DBS surgery performed asleep. This novel robot-assisted operative technique results in sub-millimeter accuracy in DBS electrode placement.

Early Deformation of Deep Brain Stimulation Electrodes Following Surgical Implantation: Intracranial, Brain, and Electrode Mechanics

Introduction

Although deep brain stimulation is nowadays performed worldwide, the biomechanical aspects of electrode implantation received little attention, mainly as physicians focused on the medical aspects, such as the optimal indication of the surgical procedure, the positive and adverse effects, and the long-term follow-up. We aimed to describe electrode deformations and brain shift immediately after implantation, as it may highlight our comprehension of intracranial and intracerebral mechanics.

Materials and Methods

Sixty electrodes of 30 patients suffering from severe symptoms of Parkinson’s disease and essential tremor were studied. They consisted of 30 non-directional electrodes and 30 directional electrodes, implanted 42 times in the subthalamus and 18 times in the ventrolateral thalamus. We computed the x (transversal), y (anteroposterior), z (depth), torsion, and curvature deformations, along the electrodes from the entrance point in the braincase. The electrodes were modelized from the immediate postoperative CT scan using automatic voxel thresholding segmentation, manual subtraction of artifacts, and automatic skeletonization. The deformation parameters were computed from the curve of electrodes using a third-order polynomial regression. We studied these deformations according to the type of electrodes, the clinical parameters, the surgical-related accuracy, the brain shift, the hemisphere and three tissue layers, the gyration layer, the white matter stem layer, and the deep brain layer (type I error set at 5%).

Results

We found that the implanted first hemisphere coupled to the brain shift and the stiffness of the type of electrode impacted on the electrode deformations. The deformations were also different according to the tissue layers, to the electrode type, and to the first-hemisphere-brain-shift effect.

Conclusion

Our findings provide information on the intracranial and brain biomechanics and should help further developments on intracerebral electrode design and surgical issues.

Comparison of clinical outcomes and accuracy of electrode placement between robot-assisted and conventional deep brain stimulation of the subthalamic nucleus: a single-center study

BACKGROUND

Several surgical methods are used for deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD). This study aimed to compare clinical outcomes and electrode placement accuracy after robot-assisted (RAS) versus frame-based stereotactic (FSS) STN DBS in Parkinson's disease.

METHODS

In this single-center open-label study, we prospectively collected data from 48 consecutive PD patients who underwent RAS (Neuromate®; n = 20) or FSS (n = 28) STN DBS with the same MRI-based STN targeting between October 2016 and December 2018 in the university neurological hospital of Lyon, France. Clinical variables were assessed before and 1 year after surgery. The number of electrode contacts within the STN was determined by merging post-operative CT and pre-operative MRI using Brainlab® GUIDE™XT software.

RESULTS

One year after surgery, the improvement of motor manifestations (p = 0.18), motor complications (p = 0.80), and quality of life (p= 0.30) and the reduction of dopaminergic treatment (p = 0.94) and the rate of complications (p = 0.99) were similar in the two groups. Surgery duration was longer in the RAS group (p = 0.0001). There was no difference in the number of electrode contacts within the STN.

CONCLUSION

This study demonstrates that RAS and FSS STN DBS for PD provide similar clinical outcomes and accuracy of electrode placement.

Targeting accuracy of robot-assisted deep brain stimulation surgery in childhood-onset dystonia: a single-center prospective cohort analysis of 45 consecutive cases

OBJECTIVE

Deep brain stimulation (DBS) is an established treatment for pediatric dystonia. The accuracy of electrode implantation is multifactorial and remains a challenge in this age group, mainly due to smaller anatomical targets in very young patients compared to adults, and also due to anatomical abnormalities frequently associated with some etiologies of dystonia. Data on the accuracy of robot-assisted DBS surgery in children are limited. The aim of the current paper was to assess the accuracy of robot-assisted implantation of DBS leads in a series of patients with childhood-onset dystonia.

METHODS

Forty-five children with dystonia undergoing implantation of DBS leads under general anesthesia between 2017 and 2019 were included. Robot-assisted stereotactic implantation of the DBS leads was performed. The final position of the electrodes was verified with an intraoperative 3D scanner (O-arm). Coordinates of the planned electrode target and actual electrode position were obtained and compared, looking at the radial error, depth error, absolute error, and directional error, as well as the euclidean distance. Functional assessment data prospectively collected by a multidisciplinary pediatric complex motor disorders team were analyzed with regard to motor skills, individualized goal achievement, and patients' and caregivers' expectations.

RESULTS

A total of 90 DBS electrodes were implanted and 48.5% of the patients were female. The mean age was 11.0 ± 0.6 years (range 3-18 years). All patients received bilateral DBS electrodes into the globus pallidus internus. The median absolute errors in x-, y-, and z-axes were 0.85 mm (range 0.00-3.25 mm), 0.75 mm (range 0.05-2.45 mm), and 0.75 mm (range 0.00-3.50 mm), respectively. The median euclidean distance from the target to the actual electrode position was 1.69 ± 0.92 mm, and the median radial error was 1.21 ± 0.79. The robot-assisted technique was easily integrated into the authors' surgical practice, improving accuracy and efficiency, and reducing surgical time significantly along the learning curve. No major perioperative complications occurred.

CONCLUSIONS

Robot-assisted stereotactic implantation of DBS electrodes in the pediatric age group is a safe and accurate surgical method. Greater accuracy was present in this cohort in comparison to previous studies in which conventional stereotactic frame-based techniques were used. Robotic DBS surgery and neuroradiological advances may result in further improvement in surgical targeting and, consequently, in better clinical outcome in the pediatric population.

Robot-Assisted Stereotaxy Reduces Target Error: A Meta-Analysis and Meta-Regression of 6056 Trajectories

BACKGROUND

The pursuit of improved accuracy for localization and electrode implantation in deep brain stimulation (DBS) and stereoelectroencephalography (sEEG) has fostered an abundance of disparate surgical/stereotactic practices. Specific practices/technologies directly modify implantation accuracy; however, no study has described their respective influence in multivariable context.

OBJECTIVE

To synthesize the known literature to statistically quantify factors affecting implantation accuracy.

METHODS

A systematic review and meta-analysis was conducted to determine the inverse-variance weighted pooled mean target error (MTE) of implanted electrodes among patients undergoing DBS or sEEG. MTE was defined as Euclidean distance between planned and final electrode tip. Meta-regression identified moderators of MTE in a multivariable-adjusted model.

RESULTS

A total of 37 eligible studies were identified from a search return of 2,901 potential articles (2002-2018) - 27 DBS and 10 sEEG. Random-effects pooled MTE = 1.91 mm (95% CI: 1.7-2.1) for DBS and 2.34 mm (95% CI: 2.1-2.6) for sEEG. Meta-regression identified study year, robot use, frame/frameless technique, and intraoperative electrophysiologic testing (iEPT) as significant multivariable-adjusted moderators of MTE (P < .0001, R2 = 0.63). Study year was associated with a 0.92-mm MTE reduction over the 16-yr study period (P = .0035), and robot use with a 0.79-mm decrease (P = .0019). Frameless technique was associated with a mean 0.50-mm (95% CI: 0.17-0.84) increase, and iEPT use with a 0.45-mm (95% CI: 0.10-0.80) increase in MTE. Registration method, imaging type, intraoperative imaging, target, and demographics were not significantly associated with MTE on multivariable analysis.

CONCLUSION

Robot assistance for stereotactic electrode implantation is independently associated with improved accuracy and reduced target error. This remains true regardless of other procedural factors, including frame-based vs frameless technique.

Stereotactic depth electrode placement surgery in paediatric and adult patients with the Neuromate robotic device: Accuracy, complications and epileptological results

OBJECTIVE

The number of patients requiring depth electrode implantation for invasive video EEG diagnostics increases in most epilepsy centres. Here we report on our institutional experience with frameless robot-assisted stereotactic placement of intracerebral depth electrodes using the Neuromate® stereotactic robot-system.

METHODS

We identified all patients who had undergone robot-assisted stereotactic placement of intracerebral depth electrodes for invasive extra-operative epilepsy monitoring between September 2013 and March 2020. We studied technical (placement) and diagnostic accuracy of the robot-assisted procedure, associated surgical complications and procedural time requirements.

RESULTS

We evaluated a total of 464 depth electrodes implanted in 74 patients (mean 6 per patient, range 1-12). There were 27 children and 47 adults (age range: 3.6-64.6 yrs.). The mean entry and target point errors were 1.82±1.15 and 1.98±1.05 mm. Target and entry point errors were significantly higher in paediatric vs. adult patients and for electrodes targeting the temporo-mesial region. There were no clinically relevant haemorrhages and no infectious complications. Mean time for the placement of one electrode was 37±14 min and surgery time per electrode decreased with the number of electrodes placed. 55 patients (74.3%) underwent definitive surgical treatment. 36/51 (70.1%) patients followed for >12 months or until seizure recurrence became seizure-free (ILAE I).

CONCLUSION

Frameless robot-guided stereotactic placement of depth electrodes with the Neuromate® stereotactic robot-system is safe and feasible even in very young children, with good in vivo accuracy and high diagnostic precision. The surgical workflow is time-efficient and further improves with increasing numbers of implanted electrodes.

Preclinical Evaluation of the Stealth Autoguide Robotic Guidance Device for Stereotactic Cranial Surgery: A Human Cadaveric Study

INTRODUCTION

Stereotactic procedures are routinely performed for brain biopsies, deep brain stimulation, and placement of stereoelectroencephalography (SEEG) electrodes for epilepsy. The recently developed Stealth Autoguide (Medtronic, Minneapolis, MN, USA) device does not require patients to don a stereotactic frame. In this preclinical study, we sought to quantitatively compare the Stealth Autoguide robotic system to 2 devices commonly used in clinical practice: the Navigus biopsy system (Medtronic) and the Leksell stereotactic frame (Elekta Ltd., Stockholm, Sweden).

METHODS

In the first experimental setup, we compared target accuracy of the Stealth Autoguide to the Navigus system by using phantom heads filled with gelatin to simulate the brain tissue. In the second experimental setup, we inserted SEEG electrodes to targets within cadaveric heads in a simulated operating room environment.

RESULTS

Using a homogeneous gelatin-filled phantom 3D reconstruction of a human head, we found that using the Stealth Autoguide system, while maintaining accuracy, was faster to use than the Navigus system. In our simulated operating room environment using nonliving human cadaveric heads, we found the accuracy of the Stealth Autoguide robotic device to be comparable to that of the Leksell frame.

DISCUSSION/CONCLUSION

These results compare the use of the Stealth Autoguide robotic guidance system with commonly used stereotactic devices, and this is the first study to compare its use and accuracy with the Leksell frame. These findings provide mounting evidence that Stealth Autoguide will have potential clinical uses in various stereotactic neurosurgical procedures.

Targeting of the Subthalamic Nucleus in Patients with Parkinson's Disease Undergoing Deep Brain Stimulation Surgery

Precise stereotactic targeting of the dorsolateral motor part of the subthalamic nucleus (STN) is paramount for maximizing clinical effectiveness and preventing side effects of deep brain stimulation (DBS) in patients with advanced Parkinson's disease. With recent developments in magnetic resonance imaging (MRI) techniques, direct targeting of the dorsolateral part of the STN is now feasible, together with visualization of the motor fibers in the nearby internal capsule. However, clinically relevant discrepancies were reported when comparing STN borders on MRI to electrophysiological STN borders during microelectrode recordings (MER). Also, one should take into account the possibility of a 3D inaccuracy of up to 2 mm of the applied stereotactic technique. Pneumocephalus and image fusion errors may further increase implantation inaccuracy. Even when implantation has been successful, suboptimal lead anchoring on the skull may cause lead migration during follow-up. Meticulous pre- and intraoperative imaging is therefore indispensable, and so is postoperative imaging when the effects of DBS deteriorate during follow-up. Thus far, most DBS centers employ MRI targeting, multichannel MER, and awake test stimulation in STN surgery, but randomized trials comparing surgery under local versus general anesthesia and additional studies comparing MER-STN borders to high-field MRI-STN may change this clinical practice. Further developments in imaging protocols and improvements in image fusion processes are needed to optimize placement of DBS leads in the dorsolateral motor part of the STN in Parkinson's disease.

Postoperative intracerebral haematomas following stereotactic biopsies: Poor planning or poor execution?

BACKGROUND

Postoperative intracerebral haematomas represent a serious complication following stereotactic biopsy. We investigated the possible underlying causes - poor planning or poor execution - of postoperative intracerebral haematomas following stereotactic biopsies.

METHODS

We performed a technical investigation using a retrospective single-centre consecutive series of robot-assisted stereotactic biopsies for a supratentorial diffuse glioma in adults. Each actual biopsy trajectory was reviewed to search for a conflict with an anatomical structure at risk.

RESULTS

From 379 patients, 12 (3.2%) presented with a postoperative intracerebral haematoma ≥20 mm on postoperative CT-scan (3 requiring surgical evacuation); 11 of them had available intraoperative imaging (bi-planar stereoscopic teleangiography x-rays at each biopsy site). The actual biopsy trajectory was similar to the planned biopsy trajectory in these 11 cases. In 72.7% (8/11) of these cases, the actual biopsy trajectory was found to contact a structure at risk (blood vessel and cerebral sulcus) and identified as the intracerebral haematoma origin.

CONCLUSIONS

Robot-assisted stereotactic biopsy is an accurate procedure. Postoperative intracerebral haematomas mainly derive from human-related errors during trajectory planning.

A comparison of the efficacy, safety, and duration of frame-based and Remebot robot-assisted frameless stereotactic biopsy

OBJECTIVE

The aim of this study was to compare the efficacy, safety, and duration of Remebot robot-assisted frameless brain biopsy with those of standard frame-based stereotactic biopsy.

PATIENTS AND METHODS

A retrospective analysis of 66 patients undergoing stereotactic brain biopsy in our department from January 2015 to January 2019 was performed. We divided the patients into two groups: the frame-based group (n = 35) and the Remebot robot group (n = 31). Data on clinical characteristics, total procedure length, overall discomfort, diagnostic yield, complications, and postoperative length of hospital stay were retrospectively reviewed and compared between these two groups.

RESULTS

No significant difference in diagnostic yield was detected in the two groups, with frame-based biopsy having a diagnostic yield of 91.4% and Remebot robot-assisted frameless brain biopsy having a diagnostic yield of 93.5%. The duration of the total procedure was 116.5 min for the frame-based biopsy and 80.1 min for the Remebot robot-assisted frameless brain biopsy (p < 0.001). There were no statistically significant differences in complication rate or postoperative duration of hospitalization between the two groups. The overall patient discomfort in the frame-based group was significantly greater than that in the Remebot robot group (visual analog scale score 2.7 ± 1.2 versus 1.5 ± 0.7, p = 0.001).

CONCLUSIONS

Remebot robot-assisted frameless brain biopsy was as efficacious and safe as standard stereotactic frame-based biopsy. However, frameless biopsy can alleviate the suffering of the patient and reduce the total duration of the procedure. Remebot robot-assisted frameless brain biopsy is easy to use and better accepted by patients than frame-based biopsy.

Ice coating -A new method of brain device insertion to mitigate acute injuries

BACKGROUND

Reduction of insertion injury is likely important to approach physiological conditions in the vicinity of implanted devices intended to interface with the surrounding brain.

NEW METHODS

We have developed a novel, low-friction coating around frozen, gelatin embedded needles. By introducing a layer of thawing ice onto the gelatin, decreasing surface friction, we mitigate damage caused by the implantation.

RESULTS AND COMPARISON WITH EXISTING METHODS

The acute effects of a transient stab on neuronal density and glial reactions were assessed 1 and 7 days post stab in rat cortex and striatum both within and outside the insertion track using immunohistochemical staining. The addition of a coat of melting ice to the frozen gelatin embedded needles reduced the insertion force with around 50 %, substantially reduced the loss neurons (i.e. reduced neuronal void), and yielded near normal levels of astrocytes within the insertion track 1 day after insertion, as compared to gelatin coated probes of the same temperature without ice coating. There were negligible effects on glial reactions and neuronal density immediately outside the insertion track of both ice coated and cold gelatin embedded needles. This new method of implantation presents a considerable improvement compared to existing modes of device insertion.

CONCLUSIONS

Acute brain injuries following insertion of e.g. ultra-flexible electrodes, can be reduced by providing an outer coat of ultra-slippery thawing ice. No adverse effect of lowered implant temperature was found, opening the possibility of locking fragile electrode construct configurations in frozen gelatin, prior to implantation into the brain.

Frameless stereotaxy in subthalamic deep brain stimulation: 3-year clinical outcome

Background

In most centers, the surgery of deep brain stimulation (DBS) is performed using a stereotactic frame. Compared with frame-based technique, frameless stereotaxy reduces the duration of surgical procedure and patient’s discomfort, with lead placing accuracy equivalent after the learning curve. Although several studies have investigated the targeting accuracy of this technique, only a few studies reported clinical outcomes, with data of short-term follow-up.

Objective

To assess clinical efficacy and safety of frameless bilateral subthalamic nucleus (STN) DBS in Parkinson’s disease (PD) patients at 1- and 3-year follow-up.

Methods

Consecutive PD patients who underwent bilateral STN-DBS with a manual adjustable frameless system were included in the study. The data were collected retrospectively.

Results

Eighteen PD patients underwent bilateral STN-DBS implant and were included in the study. All patients completed 1-year observation and ten of them completed 3-year observation. At 1-year follow-up, motor efficacy of STN stimulation in off-med condition was of 30.1% (P = 0.003) and at 3-year follow-up was of 36.3%, compared with off-stim condition at 3-year follow-up (P = 0.005). Dopaminergic drugs were significantly reduced by 31.2% 1 year after the intervention (P = 0.003) and 31.7% 3 years after the intervention (P = 0.04). No serious adverse events occurred during surgery.

Conclusions

Frameless stereotaxy is an effective and safe technique for DBS surgery at 1- and 3-year follow-up, with great advantages for patients’ discomfort during surgery.

How technology is driving the landscape of epilepsy surgery

This article emphasizes the role of the technological progress in changing the landscape of epilepsy surgery and provides a critical appraisal of robotic applications, laser interstitial thermal therapy, intraoperative imaging, wireless recording, new neuromodulation techniques, and high-intensity focused ultrasound. Specifically, (a) it relativizes the current hype in using robots for stereo-electroencephalography (SEEG) to increase the accuracy of depth electrode placement and save operating time; (b) discusses the drawback of laser interstitial thermal therapy (LITT) when it comes to the need for adequate histopathologic specimen and the fact that the concept of stereotactic disconnection is not new; (c) addresses the ratio between the benefits and expenditure of using intraoperative magnetic resonance imaging (MRI), that is, the high technical and personnel expertise needed that might restrict its use to centers with a high case load, including those unrelated to epilepsy; (d) soberly reviews the advantages, disadvantages, and future potentials of neuromodulation techniques with special emphasis on the differences between closed and open-loop systems; and (e) provides a critical outlook on the clinical implications of focused ultrasound, wireless recording, and multipurpose electrodes that are already on the horizon. This outlook shows that although current ultrasonic systems do have some limitations in delivering the acoustic energy, further advance of this technique may lead to novel treatment paradigms. Furthermore, it highlights that new data streams from multipurpose electrodes and wireless transmission of intracranial recordings will become available soon once some critical developments will be achieved such as electrode fidelity, data processing and storage, heat conduction as well as rechargeable technology. A better understanding of modern epilepsy surgery will help to demystify epilepsy surgery for the patients and the treating physicians and thereby reduce the surgical treatment gap.

Robot-assisted versus manual navigated stereoelectroencephalography in adult medically-refractory epilepsy patients

OBJECTIVE

Stereoelectroencephalography (SEEG) has experienced a recent growth in adoption for epileptogenic zone (EZ) localization. Advances in robotics have the potential to improve the efficiency and safety of this intracranial seizure monitoring method. We present our institutional experience employing robot-assisted SEEG and compare its operative efficiency, seizure reduction outcomes, and direct hospital costs with SEEG performed without robotic assistance using navigated stereotaxy.

METHODS

We retrospectively identified 50 consecutive adult SEEG cases at our institution in this IRB-approved study, of which 25 were navigated with image guidance (hereafter referred to as "navigated") (02/2014-10/2016) and 25 were robot-assisted (09/2016-12/2017). A thorough review of medical/surgical history and operative records with imaging and trajectory plans was done for each patient. Direct inpatient costs related to each technique were compared.

RESULTS

Most common seizure etiologies for patients undergoing navigated and robot-assisted SEEG included non-lesional and benign temporal lesions. Despite having a higher mean number of leads-per-patient (10.2 ± 3.5 versus 7.2 ± 2.6, P = 0.002), robot-assisted cases had a significantly shorter mean operative time than navigated cases (125.5±48.5 versus 173.4±84.3 min, P = 0.02). Comparison of robot-assisted cases over the study interval revealed no significant difference in mean operative time (136.4±51.4 min for the first ten cases versus 109.9±75.8 min for the last ten cases, P = 0.25) and estimated operative time-per-lead (13.4±6.0 min for the first ten cases versus 12.9±7.7 min for the last ten cases, P = 0.86). The mean depth, radial, target, and entry point errors for robot-assisted cases were 2.12±1.89, 1.66±1.58, 3.05±2.02 mm, and 1.39 ± 0.75 mm, respectively. The two techniques resulted in equivalent EZ localization rate (navigated 88 %, robot-assisted 96 %, P = 0.30). Common types of epilepsy surgery performed consisted of implantation of responsive neurostimulation (RNS) device (56 %), resection (19.1 %), and laser ablation (23.8 %) for navigated SEEG. For robot-assisted SEEG, either RNS implantation (68.2 %) or laser ablation (22.7 %) were performed or offered. A majority of navigated and robot-assisted patients who underwent epilepsy surgery achieved either Engel Class I (navigated 36.8 %, robot-assisted 31.6 %) or II (navigated 36.8 %, robot-assisted 15.8 %) outcome with no significant difference between the groups (P = 0.14). Direct hospital cost for robot-assisted SEEG was 10 % higher than non-robotic cases.

CONCLUSION

This single-institutional study suggests that robotic assistance can enhance efficiency of SEEG without compromising safety or precision when compared to image guidance only. Adoption of this technique with uniform safety and efficacy over a short period of time is feasible with favorable epilepsy outcomes.

Frameless ROSA® Robot-Assisted Lead Implantation for Deep Brain Stimulation: Technique and Accuracy

BACKGROUND

Frameless robotic-assisted surgery is an innovative technique for deep brain stimulation (DBS) that has not been assessed in a large cohort of patients.

OBJECTIVE

To evaluate accuracy of DBS lead placement using the ROSA® robot (Zimmer Biomet) and a frameless registration.

METHODS

All patients undergoing DBS surgery in our institution between 2012 and 2016 were prospectively included in an open label single-center study. Accuracy was evaluated by measuring the radial error (RE) of the first stylet implanted on each side and the RE of the final lead position at the target level. RE was measured on intraoperative telemetric X-rays (group 1), on intraoperative O-Arm® (Medtronic) computed tomography (CT) scans (group 2), and on postoperative CT scans or magnetic resonance imaging (MRI) in both groups.

RESULTS

Of 144 consecutive patients, 119 were eligible for final analysis (123 DBS; 186 stylets; 192 leads). In group 1 (76 patients), the mean RE of the stylet was 0.57 ± 0.02 mm, 0.72 ± 0.03 mm for DBS lead measured intraoperatively, and 0.88 ± 0.04 mm for DBS lead measured postoperatively on CT scans. In group 2 (43 patients), the mean RE of the stylet was 0.68 ± 0.05 mm, 0.75 ± 0.04 mm for DBS lead measured intraoperatively; 0.86 ± 0.05 mm and 1.10 ± 0.08 mm for lead measured postoperatively on CT scans and on MRI, respectively No statistical difference regarding the RE of the final lead position was found between the different intraoperative imaging modalities and postoperative CT scans in both groups.

CONCLUSION

Frameless ROSA® robot-assisted technique for DBS reached submillimeter accuracy. Intraoperative CT scans appeared to be reliable and sufficient to evaluate the final lead position.

Robotic Stereotaxy in Cranial Neurosurgery: A Qualitative Systematic Review

BACKGROUND

Modern-day stereotactic techniques have evolved to tackle the neurosurgical challenge of accurately and reproducibly accessing specific brain targets. Neurosurgical advances have been made in synergy with sophisticated technological developments and engineering innovations such as automated robotic platforms. Robotic systems offer a unique combination of dexterity, durability, indefatigability, and precision.

OBJECTIVE

To perform a systematic review of robotic integration for cranial stereotactic guidance in neurosurgery. Specifically, we comprehensively analyze the strengths and weaknesses of a spectrum of robotic technologies, past and present, including details pertaining to each system's kinematic specifications and targeting accuracy profiles.

METHODS

Eligible articles on human clinical applications of cranial robotic-guided stereotactic systems between 1985 and 2017 were extracted from several electronic databases, with a focus on stereotactic biopsy procedures, stereoelectroencephalography, and deep brain stimulation electrode insertion.

RESULTS

Cranial robotic stereotactic systems feature serial or parallel architectures with 4 to 7 degrees of freedom, and frame-based or frameless registration. Indications for robotic assistance are diversifying, and include stereotactic biopsy, deep brain stimulation and stereoelectroencephalography electrode placement, ventriculostomy, and ablation procedures. Complication rates are low, and mainly consist of hemorrhage. Newer systems benefit from increasing targeting accuracy, intraoperative imaging ability, improved safety profiles, and reduced operating times.

CONCLUSION

We highlight emerging future directions pertaining to the integration of robotic technologies into future neurosurgical procedures. Notably, a trend toward miniaturization, cost-effectiveness, frameless registration, and increasing safety and accuracy characterize successful stereotactic robotic technologies.

Accuracy of the robot-assisted procedure in deep brain stimulation

INTRODUCTION

The use of a robot-assisted technology becomes very competitive. The aim of this work was to define the accuracy of robotic assistance in deep brain stimulation surgery and to compare results with that in the literature.

METHODS

We retrospectively reviewed the accuracy of lead implantation in 24 consecutive patients who had robot-assisted (ROSA, Zimmer-Biomet) surgery for the treatment of movement disorders. Intended stereotactic coordinates (x, y, z) of contact 0 (the most distal contact at the tip of the electrode) of each definitive lead were compared with actual coordinates obtained by a postoperative CT scan. For each lead, the euclidian 3D distance between the actual and intended location of contact 0 was calculated.

RESULTS

The euclidian 3D distances between the intended and actual location of the contact 0 were 0.81 mm on the right side and 1.12 mm on the left side.

DISCUSSION

Robot-assisted technology for stereotactic surgery is safe and accurate. The association with a 3D flat-panel CT scan is an optimized procedure for deep intracranial electrode implantation.

Deep Brain Stimulation Programming for Movement Disorders: Current Concepts and Evidence-Based Strategies

Deep brain stimulation (DBS) has become the treatment of choice for advanced stages of Parkinson's disease, medically intractable essential tremor, and complicated segmental and generalized dystonia. In addition to accurate electrode placement in the target area, effective programming of DBS devices is considered the most important factor for the individual outcome after DBS. Programming of the implanted pulse generator (IPG) is the only modifiable factor once DBS leads have been implanted and it becomes even more relevant in cases in which the electrodes are located at the border of the intended target structure and when side effects become challenging. At present, adjusting stimulation parameters depends to a large extent on personal experience. Based on a comprehensive literature search, we here summarize previous studies that examined the significance of distinct stimulation strategies for ameliorating disease signs and symptoms. We assess the effect of adjusting the stimulus amplitude (A), frequency (f), and pulse width (pw) on clinical symptoms and examine more recent techniques for modulating neuronal elements by electrical stimulation, such as interleaving (Medtronic®) or directional current steering (Boston Scientific®, Abbott®). We thus provide an evidence-based strategy for achieving the best clinical effect with different disorders and avoiding adverse effects in DBS of the subthalamic nucleus (STN), the ventro-intermedius nucleus (VIM), and the globus pallidus internus (GPi).

Electrode Placement Accuracy in Robot-Assisted Asleep Deep Brain Stimulation

Deep brain stimulation (DBS) involves the implantation of electrodes into specific central brain structures for the treatment of Parkinson's disease. Image guidance and robot-assisted techniques have been developed to assist in the accuracy of electrode placement. Traditional DBS is performed with the patient awake and utilizes microelectrode recording for feedback, which yields lengthy operating room times. Asleep DBS procedures use imaging techniques to verify electrode placement. The objective of this study is to demonstrate the validity of an asleep robot-assisted DBS procedure that utilizes intraoperative imaging techniques for precise electrode placement in a large, inclusive cohort. Preoperative magnetic resonance imaging (MRI) was used to plan the surgical procedure for the 128 patients that underwent asleep DBS. During the surgery, robot assistance was used during the implantation of the electrodes. To verify electrode placement, intraoperative CT scans were fused with the preoperative MRIs. The mean radial error of all final electrode placements is 0.85 ± 0.38 mm. MRI-CT fusion error is 0.64 ± 0.40 mm. The average operating room time for bilateral and unilateral implantations are 139.3 ± 34.7 and 115.4 ± 42.1 min, respectively. This study shows the validity of the presented asleep DBS procedure using robot assistance and intraoperative CT verification for accurate electrode placement with shorter operating room times.

Frameless robot-assisted pallidal deep brain stimulation surgery in pediatric patients with movement disorders: precision and short-term clinical results

OBJECTIVE

The purpose of this study was to verify the safety and accuracy of the Neuromate stereotactic robot for use in deep brain stimulation (DBS) electrode implantation for the treatment of hyperkinetic movement disorders in childhood and describe the authors' initial clinical results.

METHODS

A prospective evaluation of pediatric patients with dystonia and other hyperkinetic movement disorders was carried out during the 1st year after the start-up of a pediatric DBS unit in Barcelona. Electrodes were implanted bilaterally in the globus pallidus internus (GPi) using the Neuromate robot without the stereotactic frame. The authors calculated the distances between the electrodes and their respective planned trajectories, merging the postoperative CT with the preoperative plan using VoXim software. Clinical outcome was monitored using validated scales for dystonia and myoclonus preoperatively and at 1 month and 6 months postoperatively and by means of a quality-of-life questionnaire for children, administered before surgery and at 6 months' follow-up. We also recorded complications derived from the implantation technique, "hardware," and stimulation.

RESULTS

Six patients aged 7 to 16 years and diagnosed with isolated dystonia ( DYT1 negative) (3 patients), choreo-dystonia related to PDE2A mutation (1 patient), or myoclonus-dystonia syndrome SGCE mutations (2 patients) were evaluated during a period of 6 to 19 months. The average accuracy in the placement of the electrodes was 1.24 mm at the target point. At the 6-month follow-up, patients showed an improvement in the motor (65%) and functional (48%) components of the Burke-Fahn-Marsden Dystonia Rating Scale. Patients with myoclonus and SGCE mutations also showed an improvement in action myoclonus (95%-100%) and in functional tests (50%-75%) according to the Unified Motor-Rating Scale. The Neuro-QOL score revealed inconsistent results, with improvement in motor function and social relationships but worsening in anxiety, cognitive function, and pain. The only surgical complication was medial displacement of the first electrode, which limited intensity of stimulation in the lower contacts, in one case.

CONCLUSIONS

The Neuromate stereotactic robot is an accurate and safe tool for the placement of GPi electrodes in children with hyperkinetic movement disorders.

Expanding the Spectrum of Robotic Assistance in Cranial Neurosurgery

BACKGROUND

Robotic automation and haptic guidance have multiple applications in neurosurgery.

OBJECTIVE

To define the spectrum of cranial procedures potentially benefiting from robotic assistance in a university hospital neurosurgical practice setting.

METHODS

Procedures utilizing robotic assistance during a 24-mo period were retrospectively analyzed and classified as stereotactic or endoscopic based on the mode utilized in the ROSA system (Zimmer Biomet, Warsaw, Indiana). Machine log file data were retrospectively analyzed to compare registration accuracy using 3 different methods: (1) facial laser scanning, (2) bone fiduciary, or (3) skin fiduciary.

RESULTS

Two hundred seven cranial neurosurgical procedures utilizing robotic assistance were performed in a 24-mo period. One hundred forty-five procedures utilizing the stereotactic mode included 33% stereotactic biopsy, 31% Stereo-EEG electrode insertion, 20% cranial navigation, 7% stereotactic catheter placement, 6% craniofacial stereotactic wire placement, 2% deep brain stimulation lead placement, and 1% stereotactic radiofrequency ablation. Sixty-two procedures utilizing the haptic endoscope guidance mode consisted of 48% transnasal endoscopic, 29% ventriculoscopic, and 23% endoport tubular access. Statistically significant differences in registration accuracies were observed with 0.521 ± 0.135 mm (n = 132) for facial laser scanning, 1.026 ± 0.398 mm for bone fiduciary (n = 22), and 1.750 ± 0.967 mm for skin fiduciary (n = 30; ANOVA, P < .001).

CONCLUSION

The combination of accurate, automated stereotaxy with image and haptic guidance can be applied to a wide range of cranial neurosurgical procedures. The facial laser scanning method offered the best registration accuracy for the ROSA system based on our retrospective analysis.

Techniques for placement of stereotactic electroencephalographic depth electrodes: Comparison of implantation and tracking accuracies in a cadaveric human study

OBJECTIVE

Stereotactic electroencephalography (SEEG) is used for the evaluation and identification of the epileptogenic zone (EZ) in patients suffering from medically refractory seizures and relies upon the accurate implantation of depth electrodes. Accurate implantation is critical for identification of the EZ. Multiple electrodes and implantation systems exist, but these have not previously been systematically evaluated for implantation accuracy. This study compares the accuracy of two SEEG electrode implantation methods.

METHODS

Thirteen "technique 1" electrodes (applying guiding bolts and external stylets) and 13 "technique 2" electrodes (without guiding bolts and external stylets) were implanted into four cadaver heads (52 total of each) according to each product's instructions for use using a stereotactic robot. Postimplantation computed tomography scans were compared to preimplantation computed tomography scans and to the previously defined targets. Electrode entry and final depth location were measured by Euclidean coordinates. The mean errors of each technique were compared using linear mixed effects models.

RESULTS

Primary analysis revealed that the mean error difference of the technique 1 and 2 electrodes at entry and target favored the technique 1 electrode implantation accuracy (P < 0.001). Secondary analysis demonstrated that orthogonal implantation trajectories were more accurate than oblique trajectories at entry for technique 1 electrodes (P = 0.002). Furthermore, deep implantations were significantly less accurate than shallow implantations for technique 2 electrodes (P = 0.005), but not for technique 1 electrodes (P = 0.50).

SIGNIFICANCE

Technique 1 displays greater accuracy following SEEG electrode implantation into human cadaver heads. Increased implantation accuracy may lead to increased success in identifying the EZ and increased seizure freedom rates following surgery.

A new tool for touch-free patient registration for robot-assisted intracranial surgery: application accuracy from a phantom study and a retrospective surgical series

OBJECTIVE The purpose of this study was to compare the accuracy of Neurolocate frameless registration system and frame-based registration for robotic stereoelectroencephalography (SEEG). METHODS The authors performed a 40-trajectory phantom laboratory study and a 127-trajectory retrospective analysis of a surgical series. The laboratory study was aimed at testing the noninferiority of the Neurolocate system. The analysis of the surgical series compared Neurolocate-based SEEG implantations with a frame-based historical control group. RESULTS The mean localization errors (LE) ± standard deviations (SD) for Neurolocate-based and frame-based trajectories were 0.67 ± 0.29 mm and 0.76 ± 0.34 mm, respectively, in the phantom study (p = 0.35). The median entry point LE was 0.59 mm (interquartile range [IQR] 0.25-0.88 mm) for Neurolocate-registration-based trajectories and 0.78 mm (IQR 0.49-1.08 mm) for frame-registration-based trajectories (p = 0.00002) in the clinical study. The median target point LE was 1.49 mm (IQR 1.06-2.4 mm) for Neurolocate-registration-based trajectories and 1.77 mm (IQR 1.25-2.5 mm) for frame-registration-based trajectories in the clinical study. All the surgical procedures were successful and uneventful. CONCLUSIONS The results of the phantom study demonstrate the noninferiority of Neurolocate frameless registration. The results of the retrospective surgical series analysis suggest that Neurolocate-based procedures can be more accurate than the frame-based ones. The safety profile of Neurolocate-based registration should be similar to that of frame-based registration. The Neurolocate system is comfortable, noninvasive, easy to use, and potentially faster than other registration devices.