Perspectives on Remote Robotic-Assisted Stroke Treatment: A Commentary Paper

Telepresence System.

The physical distance between the remote operator and bedside team will demand effective real-time communication between sites. A telecommunication system that can reliably transmit audio and visual information between sites, including the live radiographic imaging, will be required for the remote operation to be performed safely. Minimum telepresence system (Cisco) requirements will need to be defined, such as the number and positions of cameras and microphones to give the operator full confidence and maximum safety during the intervention. We suggest a minimum requirement of a moveable, side camera above the patient to allow the remote operator to assess the condition of the catheters and devices, to monitor the incision site, and to assess the patient for changes in symptoms. An ideal setup would also include a camera for room view and a second side camera to visualize the robotic arm and supervise loading and unloading maneuvers and perfusions. Also, a private audio feed between the remote operator and bedside technologist will be important to effectively communicate the next steps of the procedure, such as when to exchange devices. A room microphone and speaker may be useful to provide the remote operator additional information on the room environment and the possibility of communicating to the whole team or other team members than the bedside technologist. We strongly believe that these challenges should not be overlooked and should be balanced with the safety limits of defined transmission lag.

Angiographic Imaging Control.

During a neuroendovascular procedure, the C-arm can be controlled by the local physician or an x-ray technologist. Fluoroscopy and intermittent DSA runs must be acquired for navigation, and appropriate working projections must be selected to facilitate navigation through tortuous vascular anatomy. Communication of these desired processes may be more challenging in a remote scenario, so the idea of providing remote control of the angiographic system to the remote physician is suggested to make procedures faster, reduce the radiation dose (for both the patient and the bedside technologist), and improve safety. Autonomous control of working projections by an intelligent system may also aid faster navigation, though no specific solutions are currently available.

Robotic System.

Finally, the minimum requirements of robotic capabilities should be considered for maximum remote safety and success. The current version of the Corindus CorPath-GRX system allowed simultaneous control of only 1 microcatheter with 1 guidewire or device. This control means that a local physician was required to perform navigation of the aortic arch to place the guide catheter in the internal carotid or vertebral artery at the neck. It also precludes the ability to use a combined approach or contact aspiration for MT.^2,13 Robotic control of a full triaxial system composed of 4 devices should be considered for maximum safety in the next-generation robotic systems. Additional functionality such as control of aspiration or inflation of balloons should also be considered to give the physician full control of the stroke intervention.

The robotic-assisted approach for neurovascular disease treatment has been mostly used for intracranial aneurysm embolization, and for these procedures, all patients were under general anesthesia (GA).^4,5 The choice of GA for future RRAPs, or at least in the early phases, is suggested to ensure patient safety during the procedure, because movement of the patient with a fixed robotic system may carry an increased risk of dissection. A secondary advantage of using GA would be to use the imaging to improve artificial intelligence–based algorithms for automatic correction of the robotic movements, which require minimum motion artifacts. Indeed, engineering and mechatronic implementation are adding a large contribution to the robotic-based approach with encouraging results in terms of automated navigation to reduce the occurrence of unexpected movement of the devices,³ which may be of great use in a remote setting.

Connectivity.

The RRAP will be entirely based on connection systems ensuring a reliable, fast, and stable transmission of data. Although RRAPs have been performed, none of these ever included a remote neuro-endovascular procedure. Five RRAPs of percutaneous coronary interventions were successfully performed in India in 2018,¹⁴ using an optical fiber connection with the CorPath-GRX system, whereas 5G has been successfully used for orthopedic screw placement between Beijing and Zhejiang through the TiRobot system (Tinavi Medical Technologies Co., Beijing, China).¹⁵ Some groups have tested latency requirements for RRAP, and thresholds of non-perceptibility ranged between <400¹⁶ and <250 ms;¹⁷ however, these should be validated in the context of a stroke procedure because neurosurgical procedures carry higher risks. Furthermore, in our opinion, these studies were incomplete because latency is not the only metric that will define safety. Other parameters such as bandwidth, jitter, the use of virtual private networks, and the transmission pathway affect the network performance^1,8 and should be comprehensively studied. We foresee a rigorous testing in each new remote location to find the most reliable and effective connectivity network to link to the operator site with an acceptable latency (<250 ms). A primary network should be used as a default and tested constantly, and a secondary network should be in place in case the first one fails during a procedure.

Nevertheless, several questions should be addressed before accurately assessing latency. These include but are not limited to the telecommunication system requirements, the quality of the angiographic images to be transferred, the transmission pathway, the digital weight of the new-generation robot control, and other potential tools to be added (such as the remote C-arm control). Indeed, these will determine the number of data packages to be transmitted, which will affect overall latency.