Observational Study of Dural Punctures
Epidural steroid injections are a routine treatment for low back pain despite the potential of dural puncture. The use of fluoroscopy remains controversial despite evidence that blind injections frequently are not placed correctly. Many studies report the technique and efficacy of steroid injections with no true consensus on either method.1,2 Despite the method used, complications can occur, including puncture of the dura, intravascular injection, nerve damage, hematoma, neurological compromise, and infection. Some of these complications are rare, but can be life threatening. Treatment studies published on epidural injections are not consistent in reporting complications during the epidural procedure.
Current opinion is mixed about the necessity of using fluoroscopy when performing epidural injections.3-5 Studies of fluoroscopic use during epidural injections have focused on correct needle placement in relationship to the site of pathology.5-9 These studies all support the use of fluoroscopy, citing needle placement accuracy rates of 98-99% when using fluoroscopy versus 48% to 62% without fluoroscopy. To our knowledge, no studies have addressed the number of dural punctures acquired when performing fluoroscopic-guided lumbar epidural injections. The intent of this study was to determine if the use of fluoroscopy reduces the number of dural punctures during epidural lumbar injections and thereby increases the safety of epidural injections.
This retrospective study compared the number of dural punctures observed in 500 fluoroscopically-guided lumbar epidural injections to the number reported in literature for non-fluoroscopically-guided lumbar procedures. Approval for this study was given by the Washington University Medical Center Humans Studies Committee. Medline and Embase was searched for the period of 1966 to 2006 using the following key words: lumbar, injections, steroids, epidural, sciatica, dural punctures, and complications. Citations within articles retrieved from these searches were also reviewed. Studies, used to compare dural puncture incidences were selected using the following criteria:
1) the study reported only lumbar epidural injections, 2) the study methodology clearly indicated that fluoroscopy had not been used to guide the needle placement, and 3) the study reported the number of dural punctures obtained in a specified number of injections.
|Study or Manuscript||Procedure to Locate Epidural Space||Patient Diagnosis||Number of Patients||# of Dural Punctures||Dural Punc.Rate (%)|
|Fredman (1999)7||Loss of Resistance using air||Failed Back Surgery Syndrome||50||4||6.0|
|Carette (1997)10||Barry and Kendall procedure (hanging drop with loss of resistance)||Sciatica||168||2||1.2|
|Rocco (1989)11||Two person technique using a saline extension tube as a manometer||Post Laminectomy||24||1||4.2|
|Ridley (1988)12||Barry and Kendall procedure||Sciatica||21||2||9.5|
|Klenerman (1984)13||Not specified||Sciatica||52||1||2.0|
|Dilke (1973)14||Barry and Kendall procedure||Sciatica–lumbar disc disease||51||6||11.8|
|Warr (1972)15||Not specified||Sciatica or lumbago lumbar disc derangement spondylosis, spondylolisthesis and persistent/recurred symptoms after laminectomy||500||7||1.4|
|Burn (1970)16||Not specified||Sciatica due to prolapse of intervertebral discs or spondylitis or spondylolisthesis||138||3||2.2|
|*All studies reviewed did not use fluoroscopic guidance of the needle. Fredman used fluoroscopy to check needle placement after insertion.|
|Radiographically Defined Diagnosis for Back Pain*:|
|Patients with Previous Back Surgery:|
|*Only 179 of the 202 patients had a radiographically confirmed diagnosis for back pain. Several of the subjects had more than one diagnosis. **Other diagnoses include: Listhesis, fusion, degenerative polyneuropathy, scoliosis, hypertrophy, Schmorl’s Node, arthritis, osteoarthritis, arachnoiditis, facet arthropathy, radiculopathy, sclerosis, lumbago, disc desiccation, diskectomy, compression fractures, ankylosis, facet disease, myelopathy, levoscoliosis, Tarlov cyst.|
Using these criteria, eight studies were reviewed and categorized according to: 1) the medical condition for which the injections were given, 2) the number of patients reported, and 3) the number of dural punctures reported.7,10-16
The charts of 202 patients receiving lumbar epidural steroid injections in the author’s community-based, academic-affiliated pain management center were examined. Procedure, nursing, and progress notes from five hundred epidural injection procedures were reviewed. The patient’s sex, age, number of injections, diagnosis, and complications noted — during the procedure and in the recovery area— were recorded.