Insufficient Labor Epidural Analgesia Due to Asymptomatic Sacral Perineural Cyst: A Case Report.

Lumbar epidural anesthesia is widely used for labor epidural analgesia (LEA), but it often results in insufficient analgesia in the sacral region. We report a case where we performed LEA using lumbar epidural anesthesia, and an asymptomatic sacral perineural cyst was considered the potential cause of inadequate analgesia in the sacral region. A 33-year-old primigravida was admitted with premature rupture of membranes. Lumbar epidural anesthesia was performed after spontaneous labor occurred. Labor epidural analgesia alleviated the pain, but it worsened again during the second stage of labor. No nerve blockade in the sacral region was confirmed. Despite catheter adjustment and additional medication, pain relief was not achieved. A review of past imaging studies revealed an asymptomatic sacral perineural cyst. A sacral perineural cyst can be considered one of the causes of insufficient analgesia in the sacral region during LEA. We propose strategies for managing similar cases and emphasize the importance of pre-anesthetic imaging review when available.