PMC8769481_01
Preoperative and post-1st operative MRI of lumbar spine. (A-C) Preoperative T2-weighted MRI demonstrating the L2/3 canal stenosis with L3 collapse. (D-F) Postoperative T2-weighted MRI demonstrating the ventral SSEH 8 days after surgery (black asterisk). There were no appearance of herniated cauda equina fibers. MRI: magnetic resonance imaging, SSEH: spinal subdural extra-arachnoid hygroma.
nmccrj-8-261-g001.jpg
PMC8769481_01_nmccrj-8-261-g001.jpg
F1
In imaging, there was crushing in L3 and advanced spinal stenosis in L2/3 (Figs. 1A-1C). A routine lumbar magnetic resonance imaging (MRI) performed 8 days after the surgery confirmed fluid collection on the ventral side of the cauda equina in the extended dural sac (Figs. 1D-1F).
1st and 2nd intraoperative photographs. (A) Final operative view of the index surgery. L2-L3 decompression was achieved with no dural injury. (B) Operative view of the 2nd operation. Transdural herniation of cauda equina fibers through a dural defect. (C) The black asterisk indicates ventral arachnoid membrane containing fluid collection. (D) For the dural repair, myofascial patch was used, and no leakage of CSF was noted. CSF: cerebrospinal fluid.
nmccrj-8-261-g002.jpg
PMC8769481_01_nmccrj-8-261-g002.jpg
F2
There was no intraoperative damage to the dura, and there was no waste spinal fluid even during the Valsalva maneuver (Fig. 2A). Spinal fluid collected around the dural sac, and a part of the cauda equina incarcerated from the fistula on the dura (Fig. 2B; yellow arrow). When the arachnoid membrane on the ventral side of the cauda equina (Fig. 2C; black asterisk) was incised, a large volume of waste spinal fluid was discovered. Incised dura was sutured tightly using a myofascial flap (Fig. 2D).
Preoperative and post-2nd operative MRI of lumbar spine. (A, B) Herniated cauda equina fibers at L2-3 level (yellow arrows). (D) SSEH extending from lumber spine to the cranium (yellow arrows). (C, E) Lumbar MRI after the post-2nd operation demonstrating disappeared SSEH. The displaced spinal cord returned to its original position. MRI: magnetic resonance imaging, SSEH: spinal subdural extra-arachnoid hygroma.
nmccrj-8-261-g003.jpg
PMC8769481_01_nmccrj-8-261-g003.jpg
F3
Lumbar MRI revealed that fluid collection in the dural sac had notably increased, extending to the cranium (Figs. 3A, 3B, and 3D). Spinal cord was severely compressed to the dorsal side from the upper cervical cord by the collected fluid (Fig. 3D). In addition, at the fenestrated L2/3, the cauda equina was found to have perforated through the dura (Fig. 3A; yellow arrow). Lumbar MRI demonstrated the disappearance of SSEH after the reoperation (Figs. 3C and 3E).