Type of interventional pain procedure, body weight, and presence of spinal pathology are determinants of the level of radiation exposure for fluoroscopically guided pain procedures.

In the recent years new technology has led to the development of a bewildering array of imaging procedures. Yet, conventional radiography remains one of the most used tools to diagnose and to aid procedural interventions. Fluoroscopy guidance facilitates targeted drug delivery or radiofrequency directly to the area of pathology, a benefit that has to be balanced against the risks of radiation exposure. In this prospective observational survey of routine practice, dose area product (DAP) and screening time (ST) were recorded in 127 consecutive patients undergoing fluoroscopically guided spinal procedures along with other probable measures of potentially greater radiation exposure such as weight, type of spinal pathology, the ease of recognition of the anatomical landmarks, and the radiographic quality of the image in terms of contrast and graininess. The mean ST was 34±27 seconds (range, 3 to 218 seconds), the mean DAP was 1.18±1.08 Gy cm(2) (range, 0.023 to 6.82 seconds). A correlation between weight and DAP was confirmed (r=0.230, P<0.05, Spearman's correlation coefficient). Patients with spinal pathology (n=33) had higher radiation exposure than those without (DAP median=0.85, U=978.00, P<0.005, r=-0.28, Mann-Whitney test). The DAP values obtained compare favourably with the recommended doses for radiographs and other procedures, although they generally exceed the values for a chest X-ray.

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.