Title: Observational study of the use of an epidurogram in interlaminar lumbar epidural steroid injection
Abstract: The first report of epidural steroid injection was in 19521Robecchi A Capra R L' idrocortisone (composoto F): prime esperienze cliniche in campo reumatologico.Minerva Med. 1952; 98: 1259-1263Google Scholar and lumbar epidural steroid injection (LESI) subsequently became popular in Europe. Accurate placement of the needle in the epidural space is important to avoid a series of injections rather than a single injection that often has been effective in our experience. There is controversy over the simple cost-effective blind technique vs fluoroscopic technique and epidurogram. Some reports suggest that the chance of false loss of resistance (LOR) using the blind technique could be more than 30%.2Liu SS Melmed AP Klos JW et al.Prospective experience with a 20-gauge Tuohy needle for lumbar epidural steroid injections: is confirmation with fluoroscopy necessary?.Reg Anesth Pain Med. 2001; 26: 143-146PubMed Google Scholar We compared the accuracy of interlaminar LESI using fluoroscopy, with and without the epidurogram in 371 consecutive patients. We included patients with radicular pain but no significant neurological deficit, surgical candidates who were undecided on surgery, had declined surgery, or were medically unfit for surgery. We excluded patients with cauda equina syndrome requiring immediate surgical intervention, patients with uncontrolled heart failure or uncontrolled diabetes, and patients with systemic or local conditions that precluded an epidural. An 18 G Tuohy needle was inserted in the appropriate epidural space (side and level of radiculopathy) using LOR and fluoroscopy. The level of pathology was determined by neurological examination and imaging. The accuracy was checked by careful review of anterior–posterior and lateral views of intraoperative fluoroscopy. Non-ionic contrast (0.5 ml) was then injected and the fluoroscopy views were repeated. The containment of the contrast in the epidural space and the absence of the contrast in the intrathecal sac or in the extradural soft tissue was evidence of optimal epidurogram. We enrolled 371 patients between March 2004 and November 2005. The age range was 18–89 yr (mean age of 52.7 yr), and there were 134 males (36%) and 237 females (64%). The number of false-positive images detected by fluoroscopy was 39 (12.3%). In a report of the use of fluoroscopy and epidurogram in 5179 cases undergoing LESI, correct placement of the Tuohy needle in the epidural space was achieved in all patients except two.3Johnson BA Schellhaus KP Pollei SR Epidurography and therapeutic epidural injections: technical considerations and experience with 5334 cases.Am J Neuroradiol. 1999; 20: 697-705PubMed Google Scholar The authors recommended epidurography with fluoroscopy unless there was a history of allergy to iodine (155 patients, 2.8%). A prospective double-blind study of 100 patients reported a 92% success rate using a 20 G Tuohy needle with the blind technique.2Liu SS Melmed AP Klos JW et al.Prospective experience with a 20-gauge Tuohy needle for lumbar epidural steroid injections: is confirmation with fluoroscopy necessary?.Reg Anesth Pain Med. 2001; 26: 143-146PubMed Google Scholar The success rate was improved to 99% using fluoroscopy and epidurogram. In 304 consecutive patients who had LESI in blind technique, needle placement was incorrect in 30% of cases,4White AH Debry R Wynne G Epidural injections for the diagnosis and treatment of low-back pain.Spine. 1980; 5: 78-86doi:10.1097/00007632-198001000-00014Crossref PubMed Scopus (293) Google Scholar and in 100 patients using LOR for LESI, there were 17 false positives.5Mehta M Salmon N Extradural block: confirmation of the injection site by X-ray monitoring.Anaesthesia. 1985; 40: 1009-1012doi:10.1111/j.1365-2044.1985.tb10558.xCrossref PubMed Scopus (129) Google Scholar On the basis of our observation of interlaminar LESI, using the LOR and fluoroscopy without epidurogram, the rate of suboptimal injection was 12.3%. We therefore support the use of an epidurogram in these patients. None declared.