Two cases of spinal epidural abscess with granulation tissue associated with epidural catheterization.

Two cases of spinal epidural abscess are reported whose abscesses became granulated after epidural catheterization. Although emergency surgical intervention was performed almost within 24 h after the diagnosis of epidural abscess in case 1, the patient revealed a poor outcome. After laminoplasty, case 2 received lumbar epidural catheterization, and he had a complete recovery. The abscesses were recognized to spread around the catheter insertion site of the operative procedure in both cases, and MRI in case 2 showed the connection between the epidural abscess and the interspinous space where the catheter had been inserted. Methicillin-sensitive Staphylococcus aureus (MSSA) was identified at the operative field in both cases. Also, MSSA was identified at the subcutaneous abscess around the catheter in case 1 and at the catheter tip in case 2. Those findings suggest the midpoint of the abscess is the puncture site and that MSSA is found in or around the catheter. Infection at epidural catheterization seems to be caused by catheter insertion or skin contamination after catheterization. As those catheterizations were completed in the outpatient theater, we conclude that epidural catheterization should be performed in the operating room or with a restricted aseptic technique.