Evaluation of Contrast Flow Patterns with Fluoroscopic Guided Lumbar Transforaminal Epidural Injections

Kim, Dong Won; Shim, Jae Chol; Shin, Young Chul

Abstract

BACKGROUND
In most cases of lumbosacral radiculopathy secondary to stenosis, the site of impingement usually lies at the level of the supra-adjacent intervertebral disc, which is rostral to the conventional bevel position of the lumbar transforaminal epidural injection needle. However, one cannot always guarantee a rostral spread of injectate to bathe the epidural/preganglionic portion of the nerve root. The contrast flow patterns and intravascular needle placement of fluoroscopically guided lumbar transforaminal epidural injections were evaluated in patients with postlaminectomy syndrome and degenerative scoliotic stenosis. METHODS: A total of 22 patients, undergoing fluoroscopically guided transforaminal epidural steroid injections, were evaluated. Once the needle tip was felt to be in the anterior epidural space, 1 ml of contrast was injected. The contrast flow patterns, ventral or dorsal epidural filling, nerve root filling and intravascular needle placement were evaluated. RESULTS: Ventral contrast flow occurred in 68% (15 out of 22) of the procedures, in contrast to dorsal filling, which was noted in 22.7% (5 out of 22). Nerve root filling was seen in all procedures. Total intravenous placement of the needle was not noted, whereas negative flashback and aspiration were noted in 3 patients. The mean numbers of levels of flow with 1 ml of contrast were 0.37+/-0.36 and 0.39+/-0.41 segmental levels, respectively, both cephalad and caudad from the injection site. CONCLUSIONS: Lumbar transforaminal epidural injections provided comparable nerve root filling and ventral epidural filling patterns in patients with a postlaminectomy state and degenerative scoliotic stenosis. The observed contrast flow patterns should be studied clinically to determine whether they have any effect on the clinical outcome.