The patient came to the clinic 11-August-2021 complaining of right sciatica for one month. He was operated elsewhere 4 years ago  for extruded disc L5-S1 with right downward migration. MRI lumbar spine performed 03-July-2021 showing huge recurrence of L5-S1 with right foraminal occlusion.

On examination, the patient is not limping with no scoliotic stance . SLRS was 50 degrees right side with pain. There is weak dorsiflexion right foot 4/5.

The old wound was not used because it is too high, that it will cause difficulty in working, for what another separated incision below the first one was created. Neurolysis of the right S1 root. The extruded disc was removed lateral to the axilla and right sided intradiscal cleaning L5-S1 was achieved. The extrusion was severely adherent to the dura, that sharp dissection was needed to remove it. Using MultiGen, bipolar motor stimulation of the right S1 root was achieved even with 3.2 Volts, A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the right S1 root  was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right S1 root was achieved with 2.5 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. A piece of muscle tissue was used to cover the root territory to minimize the postoperative scar formation and prevent postoperative CSF leak. Routine closure of the wound. Smooth postoperative recovery. The power of the right foot dramatically improved. He was sent to the ward.

MultiGen

Too early now.

There is still an estimated postoperative disc re-recurrence around 7%, since the disc space is not completely shallow.

This is the 222d case using the BPRF mode with MultiGen. This procedure regained routine acceptance.  It became a usual part of the spine and peripheral nerves surgery. Click here for reference.

It still unclear to evaluate the differences of pre and post application motor responses. The only sure thing that it tells that the electrodes did not migrate during the procedure and the nerve is functioning properly. Here the threshold of motor stimulation of the affected nerves improved dramatically after BPRF.

With accumulation of data, it became clear that the irritated nerve with aberrant currents running in the C fibers up, not only causing no change or elevation of the required voltage to achieve motor response, but they could cause the preoperative weakness. Ablation of such currents results in facilitation of the motor response and improvement of function with disappearance of pain.

It is unclear why the roots have several motor response with different patients, despite the fact that the neurological status is the same and the anesthesia protocol also the same.

It could be that the nerve is recovering minute by minute after decompression and this can explain why the motor conductivity is improving after the BPRF application, which require 4 minute session in most cases.

After the 172d case, the elevation of motor stimulation above 5 V was abandoned to avoid delayed dural tear with subsequent CSF leak, which take place at the contact at the lower electrode shaft with the dura below the level of the axilla.