Overcoming Anatomical Challenges: Epidural Blood Patch and Plica Mediana Dorsalis Case Report

The efficacy of epidural blood patch (EBP) is highly variable, and often, clinicians are unable to identify the underlying reasons for treatment failure. A 36-year-old parturient underwent a "blind" epidural blood patch (EBP) without image guidance but failed to obtain relief from a postural headache related to the labor epidural. During the second EBP, an intact plica mediana dorsalis (PMD) was visualized in the anterior-posterior fluoroscopic view after injection of contrast, and autologous blood was injected on both sides of the PMD, leading to the complete resolution of headache symptoms. This case study presents a unique finding, potentially the first identification of an intact PMD as the etiology behind the failure of an EBP to provide symptomatic relief. The first EBP was performed without image guidance, which would have allowed the identification of an intact PMD. Fluoroscopic guidance, utilizing anterior-posterior and lateral views in combination with an adequate volume of contrast to confirm bilateral spread, enables the identification of anatomic variants such as an intact PMD.