종사지방종(filum terminale lipoma)

made by Haneul Lee

#S1

The filum terminale is a cord-like structure formed by the pia mater extending below the spinal cord.Normally, it does not contain adipose tissue; however, if fatty tissue becomes incorporated during fetal development, dense fibrous tissue may also be included. As the child grows, this structure can tether the spinal cord.

#S2

When the spinal cord remains tethered during growth, the lower portion of the cord becomes damaged, leading to problems such as lower extremity weakness or neurogenic bladder.

#S3

On physical examination, the palpable bony structures of the lower back are the spinous processes.

#S4

After identifying the anatomical landmarks, a horizontal skin incision of approximately 2–2.5 cm is made over the interspinous space, usually between L3–L4 or L4–L5.The paraspinal muscles are carefully separated laterally to minimize damage.

#S5

Using Bovie and bipolar cautery, the interspinous ligament is dissected to approach the dura.For sufficient exposure, a rongeur or punch may be used to remove small portions of the superior and inferior laminae.

#S6

Once the ligament is opened, an epidural fat layer covering the dura is encountered.After gently removing a small portion of this fat and coagulating the epidural vessels to prevent bleeding, the dura is exposed and incised for about 1 cm in the cranio-caudal direction.Through this opening, the filum terminale lipoma appears as a glistening fatty structure between the nerve roots.With the aid of a stimulator to ensure no functional nerve roots are involved, only the fibrous and fatty filum terminale is transected to release the tethering.

#S7

After untethering, the dural incision is closed with watertight sutures, and an anti-adhesion material is applied for protection.

#S8

Possible complications include cerebrospinal fluid leakage, retethering, or meningitis due to intraoperative infection.However, in most cases, tethering is successfully resolved without significant issues.