A Cadaveric and in vitro Controlled Comparative Investigation of Percutaneous Spinal Cord Lead Anchoring

Spinal cord stimulator lead migration is a common problem. Anchor design may be a factor in its prevention. We have undertaken a cadaveric and in vitro comparative investigation of the force required to cause lead migration with a variety of anchor types. Thirty-eight spinal cord stimulator leads were anchored with short silastic (N = 8), long silastic (N = 16) and titanium (N = 10) devices in cadavers. Twenty-eight further spinal cord stimulator lead anchorings were undertaken on the bench with the titanium anchor and three different octrode leads. The median force to cause lead movement in cadavers was 0.55 Newtons (N) for short silastic anchors, 0.81 N and 0.63 N for two types of long silastic anchor, and 1.3 N for the titanium anchor. There was a significant difference between long and short silastic anchors (p < 0.01) and a significant difference between the titanium anchor and the silastic anchors (p < 0.003). There was an insignificant difference in the force required to cause lead movement repeated by the same operator (p = 0.36). There was no significant difference between inexperienced and experienced operators (p = 0.88). There was no significant difference between the different leads using the titanium anchor (p = 0.06). The titanium anchor prevents simulated lead movement at greater forces that the silastic anchors with a variety of leads. For silastic anchors, movement occurred at median force below that simulated with spinal movement; for the titanium anchor, movement occurred at a median force above that simulated with spinal movement. Further in vivo investigations are warranted to assess the potential of titanium anchoring to significantly reduce spinal cord stimulator lead migration.