SURGICAL PROCEDURE:
The aim of surgery was to prevent the tethering effect on the cord by
the fibro-neural stalk. A midline vertical skin incision encompassed the
flat lesion. Then, the incision was deepened, and the tract was
dissected off the fascial defect. There was the absence of L5-S1
posterior elements. L4 laminectomy was done. The dural tube, tract, and
skin lesion were delineated separately.
The simulation threshold for the filum / non-functioning tract was at
100 times the root/rootlets. The dura was opened, and tract stimulation
(10mA) was carried out to demonstrate the absence of neural elements.
Then, the tract was disconnected with the dura fully opened. The filum
was identified and, upon stimulation (10mA), showed no response
(Figure 4 A-E ). The quadriceps, anterior tibialis, Abductor
Hallucis and External Anal Sphincter, were assessed before the closure
by triggered EMGs at 1 mA current and the recordings are attached in the
figure. The operation was concluded by performing dural reconstruction
using 6-0 prolene. The lumbodorsal fascia was reconstructed. Lastly, the
subcutaneous tissue and skin were closed in layers, and a sterile
dressing was applied. The post-operative period was uneventful.