Epidural Contrast Volume on Post-Myelogram Lumbar CT Predicts the Rate of Subsequent Blood Patch Treatment.

BACKGROUND AND PURPOSE Headaches due to cerebrospinal fluid (CSF) leakage are a well-known complication of dural puncture. The purpose of this study was to determine whether the presence and volume of epidural contrast on postmyelogram CTs of the lumbar spine were associated with post-dural puncture headaches (PDPHs) requiring epidural blood patch (EBP) treatment. METHODS A retrospective case control study of all fluoroscopically guided lumbar myelograms performed over a 5-year period by a single radiology practitioner assistant was performed. Ten patients who underwent EBP treatment after their myelograms were identified. Forty-six patients with similar demographics who did not receive blood patches were then selected. CT-lumbar myelogram images of patients and controls were reviewed. The volume of epidural contrast was then quantified as "severe" or "mild." Severe epidural contrast was defined as contrast detected in the ventral epidural space, the extra-foraminal space, or extending greater than or equal to the length of two vertebral bodies from the level of dural puncture. RESULTS Some amount of epidural contrast was seen in all patients. However, a severe volume of epidural contrast was associated with increased risk for PDPH requiring an EBP (odds ratio = 37.00; 95% CI = 4.1-330.8, p = 0.0012). CONCLUSION Severe epidural contrast on postmyelogram CTs of the lumbar spine was associated with an increased risk of PDPH requiring EBP treatment. When present, this finding can alert the proceduralist that the patient may require closer observation and follow up with earlier intervention.