Lumbar Endoscopic Microdiscectomy: Where Are We Now? An Updated Literature Review Focused on Clinical Outcome, Complications, and Rate of Recurrence

Abstract

Endoscopic disc surgery (EDS) for lumbar spine disc herniation is a well-known but developing field, which is increasingly spreading in the last few years. Rate of recurrence/residual, complications, and outcomes, in comparison with standard microdiscectomy (MD), is still debated and need further data. We performed an extensive review based on the last 6 years of surgical series, systematic reviews, and meta-analyses reported in international, English-written literature. Articles regarding patients treated through endoscopic transforaminal or interlaminar approaches for microdiscectomy (MD) were included in the present review. Papers focused on endoscopic surgery for other spinal diseases were not included. From July 2009 to July 2015, we identified 51 surgical series, 5 systematic reviews, and one meta-analysis reported. In lumbar EDS, rate of complications, length of hospital staying, return to daily activities, and overall patients' satisfaction seem comparable to standard MD. Rate of recurrence/residual seems higher in EDS, although data are nonhomogeneous among different series. Surgical indication and experience of the performing surgeon are crucial factors affecting the outcome. There is growing but still weak evidence that lumbar EDS is a valid and safe alternative to standard open microdiscectomy. Statistically reliable data obtained from randomized controlled trials (better if multicentric) are desirable to further confirm these results.

Figure 1

(a-b) Sagittal and axial T2-weighted MRI images of an L4-L5 right disc bulging causing foraminal stenosis. Approach is performed through an entry point located ~7 cm from the midline. (c-d) Intraoperative fluoroscopy and lateral and anteroposterior (AP) projections showing the position of the instrumentation. (e) Fragment of the disc removed from the endoscopic cannula.

Figure 2

(a-b) Preoperative T2-weighted sagittal and axial MRI showing an L5-S1 disc herniation impinging the left S1 nerve root. (c-d) Intraoperative fluoroscopy showing different phases of the transforaminal approach. AP view: pointer showing the L5-S1 interlaminar window and lateral view showing the radiofrequency bipolar endoscopic probe inside the L5-S1 intervertebral disc. (e) Removal of the herniated disc material has been completed. At the end of the procedure, the dural sac (ds), the S1 nerve root (s1) with its axilla (a), and shoulder (s) can be clearly visualized. Taken from the senior author's personal series.

Figure 3

(a) Instrumentation: light source at the center of the surgical table, endoscopic cannula, and different pituitary forceps adapted for endoscopic use on the top of the picture. (b) Positioning of the endoscope during an interlaminar approach. (c) Positioning of the endoscope during a transforaminal approach, extreme lateral variation.