Fluoroscopy and Radiation Safety

Honorio T. Benzon, M.D.
Professor

Brian A. Chung, M.D.
Assistant Professor

Department of Anesthesiology
Northwestern University Feinberg School of Medicine
Chicago, IL

Needle Placement With and Without Fluoroscopy - TOP

Incorrect needle placements have been demonstrated when epidural steroid injections are performed without fluoroscopic guidance. These incorrect placements  occurred in 25% of caudal and 30% of interlaminar epidural steroid injections when performed by an experienced anesthesiologist and an orthopedic surgeon.1 Another study showed inaccurate needle placement in 17% of epidural injections performed by experienced anesthetists using the interlaminar technique, 85% of the injections were in the lumbar area.2   

For caudal injections, “experienced radiologists” incorrectly place the needle in 38% of their epidural injections.3 Success rates appear to be related to the experience of the radiologist however. Radiologists who performed less than 10 epidurals had a 48% failure rate. In a prospective observational study, senior PM&R physicians had a 74% success rate on their attempt, 88% when the landmarks were identified easily.4 They noted that the most common site of incorrect needle placement was along the subfascial plane posterior to the sacrum.  A study on the use of fluoroscopy in caudal injections implied higher success rates. Caudal epidural steroid injections done by radiologists under fluoroscopy resulted in a success rate of 97.3%.5  The authors recommended that epidurogram be performed to document position of the needle and to confirm that the medications are not injected intrathecally or intravenously. 

For cervical epidural steroid injections, a multicenter, retrospective study showed 47% success on first attempt; a second attempt was required in 63% of the patients.6 It was noted that there was unilateral contrast spread in 51% of the injections.

For post-laminectomy patients, anesthesiologists successfully placed the epidural in 92% of the attempts. The number of attempts to successfully enter the epidural space was 2 + 1.7 Even though the success rate was high, it was noted that the needle was placed 1 or 2 spaces above or below predetermined level in 53% of the attempts and that the contrast reached the level of pathology in only 26% of the cases

In a national survey of pain medicine physicians, it was noted that 73% of private practices use fluoroscopy compared to 39% of academic institutions.8

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