EPIDUROGRAPHY: CHARACTERISTICS OF EPIDURALGRAMS PERFORMED DURING LESI

David C. Miller MD, DABPM Woodland Pain Center, Michigan City, IN Fluoroscopically guided, contrast enhanced lumbar epidural steroid injections are commonly performed for persistent or sever lumbar radicular pain. An epiduralgram is a real‐time fluoroscopic image of contrast injected into the epidural space prior to the injection of local anesthetic and steroid. This report details the results of one hundred consecutive epiduralgrams. The epidural needle was placed under continuous multiplainer fluoroscopic guidance using ISIS protocol. Three ml. of Omnipaque 300 were injected after initial insertion to obtain the epiduralgram. This was followed by injection of 3 ml. of Celestone diluted with 4 ml. of preservative‐free 1% lidocaine to obtain the epiduralgram. The epidural needle was placed at the predetermined spinal level and appropriate side 100% of the time. Needles were successfully placed into the epidural space on the first attempt in 95%. One needle was subarachnoid, one was intra vascular, three were in tissue plains superficial to the epidural space and were apparent only with contrast injection. Three ml. of contrast flowed unilaterally in 74% of lumbar epidural injections. The contrast flowed cephalad only in 20%, caudad only in 28%, and bidirectional in 52%. Contrast spread less than three spinal levels 64% of the time. The desired nerve root was visualized in 62%. Contrast was seen in the ventral epidural space on lateral views 88% of the time. Ventral spread was always fewer levels than the dorsal spread. Epidurography provides essential information for the accurate performance of lumbar epidural steroid injections. One out of every twenty presumed epidural injections were inaccurately placed even by an experienced operator. One out of every fifty was dangerously positioned and identified only by performance of an epiduralgram.