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.

Neuro-stimulation in focal epilepsy: A systematic review and meta-analysis

OBJECTIVES

Different neurostimulation modalities are available to treat drug-resistant focal epilepsy when surgery is not an option including vagus nerve stimulation (VNS), responsive neurostimulation (RNS), and deep brain stimulation (DBS). Head-to-head comparisons of efficacy do not exist between them nor are likely to be available in the future. We performed a meta-analysis on VNS, RNS, and DBS outcomes to compare seizure reduction efficacy for focal epilepsy.

METHODS

We systematically reviewed the literature for reported seizure outcomes following implantation with VNS, RNS, and DBS in focal-onset seizures and performed a meta-analysis. Prospective or retrospective clinical studies were included.

RESULTS

Sufficient data were available at years one (n = 642, two (n = 480), and three (n = 385) for comparing the three modalities with each other. Seizure reduction for the devices at years one, two, and three respectively were: RNS: 66.3%, 56.0%, 68.4%; DBS- 58.4%, 57.5%, 63.8%; VNS 32.9%, 44.4%, 53.5%. Seizure reduction at year one was greater for RNS (p < 0.01) and DBS (p < 0.01) compared to VNS.

CONCLUSIONS

Our findings indicate the seizure reduction efficacy of RNS is similar to DBS, and both had greater seizure reductions compared to VNS in the first-year post-implantation, with the differences diminishing with longer-term follow-up.

SIGNIFICANCE

The results help guide neuromodulation treatment in eligible patients with drug-resistant focal epilepsy.

Responsive Neurostimulation Targeting the Anterior, Centromedian and Pulvinar Thalamic Nuclei and the Detection of Electrographic Seizures in Pediatric and Young Adult Patients

Background

Responsive neurostimulation (RNS System) has been utilized as a treatment for intractable epilepsy. The RNS System delivers stimulation in response to detected abnormal activity, via leads covering the seizure foci, in response to detections of predefined epileptiform activity with the goal of decreasing seizure frequency and severity. While thalamic leads are often implanted in combination with cortical strip leads, implantation and stimulation with bilateral thalamic leads alone is less common, and the ability to detect electrographic seizures using RNS System thalamic leads is uncertain.

Objective

The present study retrospectively evaluated fourteen patients with RNS System depth leads implanted in the thalamus, with or without concomitant implantation of cortical strip leads, to determine the ability to detect electrographic seizures in the thalamus. Detailed patient presentations and lead trajectories were reviewed alongside electroencephalographic (ECoG) analyses.

Results

Anterior nucleus thalamic (ANT) leads, whether bilateral or unilateral and combined with a cortical strip lead, successfully detected and terminated epileptiform activity, as demonstrated by Cases 2 and 3. Similarly, bilateral centromedian thalamic (CMT) leads or a combination of one centromedian thalamic alongside a cortical strip lead also demonstrated the ability to detect electrographic seizures as seen in Cases 6 and 9. Bilateral pulvinar leads likewise produced reliable seizure detection in Patient 14. Detections of electrographic seizures in thalamic nuclei did not appear to be affected by whether the patient was pediatric or adult at the time of RNS System implantation. Sole thalamic leads paralleled the combination of thalamic and cortical strip leads in terms of preventing the propagation of electrographic seizures.

Conclusion

Thalamic nuclei present a promising target for detection and stimulation via the RNS System for seizures with multifocal or generalized onsets. These areas provide a modifiable, reversible therapeutic option for patients who are not candidates for surgical resection or ablation.

Research progress and development trend of surgical robot and surgical instrument arm

BACKGROUND

In recent years, surgical robots have become an indispensable part of the medical field. Surgical robots are increasingly being used in the areas of gynaecological surgery, urological surgery, orthopaedic surgery, general surgery and so forth. In this paper, the development of surgical robots in different operations is reviewed and analysed. In the type of master-slave surgical robotic system, the robotic surgical instrument arms were located in the execution terminal of a surgical robot system, as one of the core components, and directly contact with the patient during the operation, which plays an important role in the efficiency and safety of the operation. In clinical, the arm function and design in different systems varies. Furtherly, the current research progress of robotic surgical instrument arms used in different operations is analysed and summarised. Finally, the challenge and trend are concluded.

METHODS

According to the classification of surgical types, the development of surgical robots for laparoscopic surgery, neurosurgery, orthopaedics and microsurgery are analysed and summarised. Then, focusing on the research of robotic surgical instrument arms, according to structure type, the research and application of straight-rod surgical instrument arm, joint surgical instrument arm and continuous surgical instrument arm are analysed respectively.

RESULTS

According to the discussion and summary of the characteristics of the existing surgical robots and instrument arms, it is concluded that they still have a lot of room for development in the future. Therefore, the development trends of the surgical robot and instrument arm are discussed and analysed in the five aspects of structural materials, modularisation, telemedicine, intelligence and human-machine collaboration.

CONCLUSION

Surgical robots have shown the development trend of miniaturisation, intelligence, autonomy and dexterity. Thereby, in the field of science and technology, the research on the next generation of minimally invasive surgical robots will usher in a peak period of development.

Operative Technique and Lessons Learned From Surgical Implantation of the NeuroPace Responsive Neurostimulation® System in 57 Consecutive Patients

BACKGROUND

The Responsive Neurostimulation (RNS)® System (NeuroPace, Inc) is an implantable device designed to improve seizure control in patients with medically refractory focal epilepsy. Because it is relatively new, surgical pearls and operative techniques optimized from experience beyond a small case series have yet to be described.

OBJECTIVE

To provide a detailed description of our operative technique and surgical pearls learned from implantation of the RNS System in 57 patients at our institution. We describe our method for frame-based placement of amygdalo-hippocampal depth leads, open implantation of cortical strip leads, and open installation of the neurostimulator.

METHODS

We outline considerations for patient selection, preoperative planning, surgical positioning, incision planning, stereotactic depth lead implantation, cortical strip lead implantation, craniotomy for neurostimulator implantation, device testing, closure, and intraoperative imaging.

RESULTS

The median reduction in clinical seizure frequency was 60% (standard deviation 63.1) with 27% of patients achieving seizure freedom at last follow up (median 23.1 mo). No infections, intracerebral hemorrhages, or lead migrations were encountered. Two patients experienced lead fractures, and four lead exchanges have been performed.

CONCLUSION

The techniques set forth here will help with the safe and efficient implantation of these new devices.

Treatment of Multi-Focal Epilepsy With Resective Surgery Plus Responsive Neurostimulation (RNS): One Institution's Experience

Objective: Patients with medically refractory focal epilepsy can be difficult to treat surgically, especially if invasive monitoring reveals multiple ictal onset zones. Possible therapeutic options may include resection, neurostimulation, laser ablation, or a combination of these surgical modalities. To date, no study has examined outcomes associated with resection plus responsive neurostimulation (RNS, Neuropace, Inc., Mountain View, CA) implantation and we describe our initial experience in patients with multifocal epilepsy undergoing this combination therapy.

Methods: A total of 43 responsive neurostimulation (RNS) devices were implanted at UCI from 2015 to 2019. We retrospectively reviewed charts of patients from the same time period who underwent both resection and RNS implantation. Patients were required to have independent or multifocal onset, undergo resection and RNS implantation, and have a minimum of six-months for follow-up to be included in the study. Demographics, location of ictal onset, location of surgery, complications, and seizure outcome were collected.

Results: Ten patients met inclusion criteria for the study, and seven underwent both procedures in the same setting. The average age was 36. All patients had multifocal ictal onset on video electroencephalogram or invasive EEG with four patients undergoing subdural grid placement and four patients undergoing bilateral sEEG prior to the definitive surgery. Five patients underwent resection plus ipsilateral RNS placement and the remainder underwent resection with contralateral RNS placement. Two minor complications were encountered in this group. At six months follow up, there was an average of 81% ± 9 reduction in seizures, while four patients experienced complete seizure freedom at 1 year.

Conclusion: Patients with multifocal epilepsy can be treated with partial resection plus RNS. The complication rates are low with potential for worthwhile seizure reduction.