Fig. 2.

(a, b) Schematic drawing of the operative findings. (a) Dural opening at the S3 and S4 vertebral levels reveals a fatty filum terminated slightly to the left of the midline of the dural cul-de-sac. (b) The filum is severed at the rostral part of the operative field, and the severed end of the filum is elevated rostrally. The caudal part of the filum is also severed at the dural cul-de-sac and resected as a column. (c) Four months after the second surgery, serial sagittal views of 3D heavily T2WI (slice thickness, 1 mm) show a successful untethering surgery. The severed end is located at the upper part of S3 vertebral level (yellow arrows). (d, e) On the axial section of the resected filum, histopathologically, glial fibrillary acidic protein (GFAP)-positive neuroglial tissue is observed in the center of the fibroadipose tissue. The location of the section is indicated as a red line in (b). The area of the enlarged view is indicated as a dotted square in (d). Hematoxylin and eosin (H&E).