Endovascular approaches to neural interfacing: lessons from cardiovascular technologies

Endovascular neural interfaces (ENIs) have emerged as a minimally invasive alternative to traditional neural interfaces. These devices are implanted within blood vessels adjacent to neural tissue to record or stimulate neural activity across the vessel wall. This enables minimally invasive implantation through angiographic procedures and reduces the risk of neural tissue damage. As they are deployed in the intravascular space, ENIs have a similar technological evolution to cardiovascular devices and share many features and constraints. First-generation ENIs borrowed guide wires and catheters employed in cardiovascular procedures for endovascular neural recording but were limited to acute settings. Concurrently, the cardiovascular field explored the possibility of integrating electronics onto endovascular devices. Catheters have been used for endovascular stimulation as a treatment for cardiovascular conditions. Cardiovascular stents have been integrated with wireless sensors, enabling self-reporting stents to monitor implant health. In 2016, a breakthrough in the field of ENIs was achieved by leveraging the chronic stability of stents to support an electrode array. Exemplified by Synchron's Stentrode™, stent electrode arrays have been successfully employed as a brain-computer interface for chronic motor cortex recording. Subsequent research in the field has focused on expanding applications and improving spatial resolution. Incorporating valuable lessons from the field of interventional cardiology will be key to accelerate ENI development, especially in the areas of device miniaturisation, enhancement of stimulation capabilities, and wireless communication. Addressing these limitations could revolutionise the treatment of neurological disorders, enabling high spatial resolution recording and stimulation possible through minimally invasive, accessible procedures.