Article Text

Review
Robotics in neurointerventional surgery: a systematic review of the literature
1. William Crinnion1,2,
2. Ben Jackson1,
3. Avnish Sood1,
4. Jeremy Lynch3,
5. Christos Bergeles1,
6. Hongbin Liu1,
7. Kawal Rhode1,
8. Vitor Mendes Pereira4,
9. Thomas C Booth1,3
1. 1 School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
2. 2 NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
3. 3 Department of Neuroradiology, King's College Hospital NHS Foundation Trust, London, UK
4. 4 Division of Neuroradiology, Department of Medical Imaging and Division of Neurosurgery, Department of Surgery, University Health Network - Toronto Western Hospital, Toronto, Ontario, Canada
1. Correspondence to Dr Thomas C Booth, School of Biomedical Engineering & Imaging Sciences, Kings College London, London, UK; tombooth{at}doctors.org.uk

## Abstract

Background Robotically performed neurointerventional surgery has the potential to reduce occupational hazards to staff, perform intervention with greater precision, and could be a viable solution for teleoperated neurointerventional procedures.

Objective To determine the indication, robotic systems used, efficacy, safety, and the degree of manual assistance required for robotically performed neurointervention.

Methods We conducted a systematic review of the literature up to, and including, articles published on April 12, 2021. Medline, PubMed, Embase, and Cochrane register databases were searched using medical subject heading terms to identify reports of robotically performed neurointervention, including diagnostic cerebral angiography and carotid artery intervention.

Results A total of 8 articles treating 81 patients were included. Only one case report used a robotic system for intracranial intervention, the remaining indications being cerebral angiography and carotid artery intervention. Only one study performed a comparison of robotic and manual procedures. Across all studies, the technical success rate was 96% and the clinical success rate was 100%. All cases required a degree of manual assistance. No studies had clearly defined patient selection criteria, reference standards, or index tests, preventing meaningful statistical analysis.

Conclusions Given the clinical success, it is plausible that robotically performed neurointerventional procedures will eventually benefit patients and reduce occupational hazards for staff; however, there is no high-level efficacy and safety evidence to support this assertion. Limitations of current robotic systems and the challenges that must be overcome to realize the potential for remote teleoperated neurointervention require further investigation.

• device
• technology

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## Introduction

Recent advances in engineering have led to the first robotically performed neurointerventional procedures, including diagnostic cerebral angiography, carotid artery intervention, and the treatment of intracranial aneurysms.1 There have been several narrative reviews on the topic,1–3 but no study has used an evidence-based approach to determine the safety and efficacy for robotically performed neurointervention. The aim of this systematic review therefore is to determine the range of indications and robotic systems together with the technical success, clinical success, and the degree of manual assistance required for robotically performed neurointervention. We will first discuss the potential benefits of using a robot for neurointervention. Robotic percutaneous coronary intervention (PCI) was first performed in 2005,4 and several of the systems used in neurointerventional studies were initially designed to perform cardiac and peripheral intervention. We therefore present a brief summary of previously available commercial devices for cardiovascular intervention which have either been adapted for neurointervention or represent a prototype on which a neurointerventional system could be developed. Definitions of some robotic terminology that clinicians may find useful are detailed in online supplemental table 1.

### Why use a robot?

First, robotic surgery has the potential to allow the operator to perform procedures with greater precision, dexterity, and degrees of freedom while eliminating physiological tremors, operator fatigue, and allowing surgery to be performed in an optimum ergonomic position.5

Second, the use of robotic systems may reduce the occupational hazards to the operator, including radiation exposure and degenerative joint disease (particularly spinal), from wearing lead aprons.6 The ability to perform the procedure remotely may also reduce the potential transmission of infectious agents whether these are blood-borne pathogens from sharps injuries or airborne pathogens, including severe acute respiratory syndrome coronavirus 2.

Third, the use of teleoperated robots may allow the treatment of neurovascular disease from a remote location. This is of particular relevance to neurointerventional surgery, as a teleoperated platform could increase the number of eligible patients receiving mechanical thrombectomy (MT) for ischemic stroke. In the UK for example, 10% of all patients admitted for stroke are predicted to be eligible for MT,7 but currently only 1.4% of stroke admissions receive MT.8 This mismatch is primarily due to the relative paucity of trained operators and the widespread geographical distribution of ‘MT-capable’ stroke centers. MT is cost effective9 and level 1a evidence suggests that patients are more likely to achieve a good functional outcome after MT with a faster time to reperfusion.10 Recent data has also shown that patients arriving at a center unable to provide MT are likely to be deemed ineligible for MT if diagnosis and transfer is >3 hours.11 If proved to be safe, efficacious, and cost effective, a distributed network of teleoperated robotic systems could increase the number of eligible patients receiving MT who arrive at centers without a MT operator and additionally, improve the functional outcome for patients by reducing the delay to reperfusion.

### Endovascular robotic platforms applied to cardiac and peripheral vascular intervention

A summary of previous US Food and Drug Administration (FDA)-approved systems is shown in table 1, with their indication, mechanism of action, the advantages and potential limitations of each system. All current robotic platforms are controller-responder systems allowing control of interventional equipment by the operator from a workstation separated from the patient and protected from radiation.

Table 1

Summary of the previous commercial robotic systems used for cardiac and peripheral endovascular intervention, including the key advantages and disadvantages

The approved robotic systems designed for cardiac electrophysiology illustrate several different ways a catheter can be robotically manipulated. The Sensei robotic system (Hansen Medical, Mountain View, USA) uses a proprietary tendon-driven guide catheter, which allows precise tip deflection followed by manual delivery of a cardiac mapping or ablation catheter. The Niobe magnetic navigation system (Stereotaxis, St Louis, USA) combines two fixed external magnets in the operating room, which set up a magnetic field across the patient. This is manipulated to control movements of a catheter containing a magnet at its tip. The Amigo remote catheter system (Catheter Robotics, Mount Olive, USA) uses ‘off the shelf’ electrophysiological catheters, unlike the Sensei or Niobe systems, and essentially reproduces the movements made by a cardiologist during a procedure. All systems have been shown to be safe and effective in small clinical trials.12–14

The Magellan robotic system (Hansen Medical) was the first commercially available robotic system to be used for peripheral vascular intervention (PVI) and has been used clinically in over 1000 cases, including carotid artery stenting (CAS), aortic aneurysm repair, peripheral arterial angioplasty, venous procedures, and a broad range of embolization procedures.15 The Magellan system can use either a 10 Fr, 9 Fr or 6 Fr Magellan robotic catheter to navigate to the target. The Magellan uses the same technology as the Sensei robotic system, that being tendons within the catheter to control deflection of the catheter tip. This adds an additional degree of freedom for the operator alongside linear and rotational movement. A feasibility study, with the system successfully treating 20 patients with symptomatic femoropopliteal disease,16 led to FDA approval of the Magellan system in 2012 for PVI. A diagram of the Magellan robotic arm is shown in figure 1.

Figure 1

Robotic arm of the Magellan robotic system (Hansen Medical).This is one of two commercial systems to have been used for neurointervention. 1. Conveyor belt system for linear and rotational movement of guidewire. 2. Magellan steerable catheter. 3. Locking mechanism for steerable catheter. 4) Caterpillar-like control system for linear motion and steering of tendon driven catheter. 5. Locking mechanism for steerable sheath.

## Conclusion

It is plausible that robotically performed neurointerventional procedures will eventually benefit patients and reduce occupational hazards for staff; however, there is no high-level efficacy and safety evidence to support this assertion. If robust efficacy and safety evidence emerges, and if proved to be cost effective, one potential use would be for a fully functioning platform to perform teleoperated intervention which, if applied to MT in stroke, would accelerate the treatment of eligible patients in locations which are at a considerable distance from the operator.

Potential platforms currently require considerable refinement. First, to ensure that minimal interventional input is required by an operator within the operating room. Second, to allow the precise use of a wide range of neurovascular microcatheters and devices. Third, to develop haptic feedback systems that directly match manual operator movements; this has the potential to reduce training time, make use of the operator’s pre-existing skills, and mitigate risks from catheter and wire damage through the appreciation of subtle catheter and wire movements.

• ## Supplementary Data

This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

• ## Supplementary Data

This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

## Footnotes

• Correction notice Since this article was first published, the author name Thomas C Booth has been updated and figure 4 has been replaced to improve the figure quality.

• Contributors WC: manuscript preparation, review, editing. BJ, AS, CB, HL, KR and TCB: review, editing. JL, VMP – review, editing, video editing. TCB is the guarantor for this paper.

• Funding This work was supported by the NIHR Guy’s and St Thomas Biomedical Research Centre and the Wellcome/Engineering and Physical Sciences Research Council Centre for Medical Engineering (WT 203148/Z/16/Z).

• Competing interests VMP has acted as a consultant for Corindus and is an investigator in the Corpath GRX Neuro Study. The remaining authors have no conflicts of interest to declare.

• Provenance and peer review Not commissioned; externally peer reviewed.

• Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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