Total endoscopic approach to the cauda in a patient with a tight filum.

In this report we describe a patient with a tight filum associated with a small concentric lipoma that was treated by cutting the filum terminale through a totally endoscopic approach. Our approach required the creation of a midline surgical corridor provided by the placement of a telescopic self-retaining retractor over the ligamentum flavum at L5-S1, under endoscopic control. The ligamentum was partially removed, the dura and the arachnoid opened and the filum terminale and the roots of the cauda exposed. After neurophysiological confirmation of the absence of neural structures the filum was coagulated and cut, the dura was closed by a continuous suture and sealed with fibrin glue. The entire surgery was performed under the illumination and magnification provided by a rigid endoscope working in an aerial environment. This case shows that the cauda can be explored and the filum terminale cut with a minimally invasive endoscopic approach that does not significantly compromise the structural integrity of the spine, requires only a short dural incision, therefore reducing the risk of postoperative cerebrospinal fluid leakage, and allows the use of multiple surgical instruments in an aerial environment.