Percutaneous interlaminar endoscopic lumbar discectomy for sciatica

A retrospective study of 60 patients comparing interlaminar endoscopic lumbar discectomy (n=30) against transforaminal endoscopic lumbar discectomy (n=30) reported a significant improvement in mean visual analogue scale (VAS) scores (ranging from 0 to 10 from best to worst), in both groups, for leg and back pain from before the procedure to a mean follow-up of 2.2 years. In the interlaminar group, back pain scores changed from 5.5 to 2.4 and leg pain scores changed from 7.6 to 1.7 (level of significance not reported). In the transforaminal group, back pain scores changed from 5.2 to 2.4 and leg pain scores changed from 7.4 to 1.6 (level of significance not reported). There was no significant difference between the interlaminar and transforaminal groups.

A case series of 400 patients treated by interlaminar endoscopic lumbar discectomy reported an improvement in mean VAS scores for back and leg pain from 7.9 before the procedure to 1.5 at 3 months after the procedure; it also reported that the VAS scores improved significantly in 90% of patients when compared against scores before the procedure.

The retrospective comparative study of 60 patients reported significant improvements in mean Oswestry Disability Index (ODI) scores (ranging from 0 to 100, from no disability to maximum disability) from before the procedure to a mean follow-up of 2.2 years; from 51% to 15% in the interlaminar group, and from 52% to 12% in the transforaminal group (no significant difference between groups). A case series of 372 patients treated by percutaneous interlaminar endoscopic discectomy reported improvement in mean ODI score from 79% before the procedure to 21% at 2 years after the procedure (level of significance not stated). The same study reported mean North American Spine Society neurology scores (ranging from 1 to 6, from best to worst) of 3 before the procedure and 2 at 2 years (level of significance not stated).

A prospective comparative study of 200 patients with disc herniation treated by full-endoscopic discectomy (interlaminar approach, n=59; transforaminal approach, n=41) or microsurgical discectomy (n=100) reported recurrence rates at 2‑year follow-up of 6% (3 of 53) in the interlaminar group, 8% (3 of 38) in the transforaminal group and 6% (5 of 87) in the microsurgical group (no significant difference between groups). All patients with recurrence were treated a second time by the same technique; in the transforaminal group, 2 patients had another recurrence.

A prospective comparative study of 100 patients with recurrent lumbar disc herniation treated by full-endoscopic discectomy (interlaminar approach, n=29; transforaminal approach, n=21) or microsurgical discectomy (n=50) reported re-recurrence rates at 2‑year follow-up of 4% (1 of 24) in the interlaminar group, 10% (2 of 21) in the transforaminal group and 5% (2 of 42) in the microsurgical group (no significant difference between groups). All patients with re‑recurrence were treated a second time by the same technique.

The retrospective comparative study of 60 patients reported recurrence in 7% (2 of 30) of patients treated by the interlaminar approach and in 3% (1 of 30) of patients treated by the transforaminal approach within a minimum of 2 years after the procedure (no significant difference between groups). The case series of 400 patients reported recurrence in 2 patients; they were treated again by surgery at 3 and 6 months after the first procedure.

The case series of 400 patients reported conversion to open surgery in 1 patient who had root protrusion after sustaining a dural tear during the procedure; the authors stated that this happened during the period when the surgeons were gaining experience in how to do the procedure. A case series of 163 patients (175 procedures) with lumbar disc herniations treated by interlaminar (n=104) or transforaminal (n=71) endoscopic lumbar discectomy reported no conversion to open surgery for either approach.

The retrospective comparative study of 60 patients reported complete removal of the disc fragment in 93% (28 of 30) of patients treated by the interlaminar approach and in 97% (29 of 30) of patients treated by the transforaminal approach (no significant difference between groups).

The retrospective study of 60 patients reported that the mean time to return to work was 4.4 weeks for patients treated by the interlaminar approach and 4.9 weeks for patients treated by the transforaminal approach (no significant difference between groups). The case series of 372 patients reported that 98% (247 of 251) of patients who were not unemployed or retired returned to their occupation or sport activities; 2% (4 of 251) were not able to return to their occupation because of persistent paresis. Sick leave following hospitalisation ranged from 5 to 33 days (mean of 16 days).

The case series of 400 patients reported good-to-excellent results according to MacNab criteria in 91% (364 of 400) of patients; poor results were reported in 2% (8 of 400) of patients (no further details reported). The case series of 372 patients reported that 91% (301 of 331) of patients reported subjective satisfaction up to 2 years after the procedure and would have the procedure again; 9% (29 of 331) had a poor result (defined as no reduction in leg pain or having to be retreated by open surgery).

Specialists advisers listed key efficacy outcomes as resolution of leg pain, improvement in disability score, recurrence rate (reoccurrence of leg pain following an initial resolution of the leg pain), improvement in a generic quality of life measure (such as EQ‑5D), return to activity, reduced operating time and hospital length of stay.