A Novel Low-Profile Self-Expanding Epidural Lead Array System that is Fully Collapsible, Deployable, and Retrievable.

Objective: Introduced in 1970s, Spinal Cord Stimulator (SCS) devices have played a crucial role in managing a wide range of complex and refractory chronic pain, particularly back/leg pain as well as neuropathic pain. Currently, two primary types of leads, cylindrical and paddle leads, are prevalent in pain management. While both effectively alleviate pain, cylindrical leads, due to their small size, are susceptible to movement and migration as well as a smaller surface area for coverage, leading to device displacement and failure to provide pain relief. On the other hand, paddle leads offer a larger surface area and secure placement but require a relatively large incision for device insertion. To address the limitations of existing SCS devices, a novel SCS device has been developed with a low-profile, deployable, and retrievable design based on the human epidural anatomy.

Methods and results: A prototype SCS has been successfully designed, fabricated, and tested in vitro. This innovative design features a laser-trimmed nitinol mesh structure as the self-expanding deployable frame, an ultrathin ePTFE membrane isolating the conductive metallic frame, and platinum-iridium materials which can be seamlessly integrate with an external battery pack for the delivery of efficient electrical potential. The anatomical nitinol mesh frame allows the entire device to collapse into a size smaller than that of a 14-gauge needle (1.5-1.6 mm in diameter) and its corresponding delivery sheath. Additionally, mechanical and electrochemical tests were carried out to assess the performance of the developed device. The mechanical tests demonstrated the backbone's ability to expand within the epidural space. Similarly, electrochemical tests on the electrodes underscored that the selected materials were indeed appropriate.

Conclusion: This novel SCS design effectively prevents device dislocation and migration showing great wall apposition while providing a larger surface area for pain management. These results support its potential as a next-generation platform for effective chronic pain management.