Surgical technique and effectiveness of microendoscopic discectomy for large uncontained lumbar disc herniations: a prospective, randomized, controlled study with 8 years of follow-up.

BACKGROUND

There is a long-held concept among spine surgeons that endoscopic lumbar discectomy procedures are reserved for small-contained disc herniation; 8-year follow-up has not been reported. The purpose of this study is to assess microendoscopic discectomy (MED) in patients with large uncontained lumbar disc herniation (the antero-posterior diameter of the extruded fragment is 6-12 mm or more on axial cuts of MRI) and report long-term outcome.

METHODS

One hundred eighty-five patients with MED or standard open discectomy underwent follow-up for 8 years. Primary (clinical) outcomes data included Numerical Rating Scale (NRS) for back and leg symptoms and Oswestry Disability Index (ODI) to quantify pain and disability, respectively. Secondary (objective) outcomes data included operative time, blood loss, postoperative analgesics, length of hospital stay, time to return to work, reoperation and complication rate, patient satisfaction index (PSI), and modified (MacNab) criteria.

RESULTS

At the end of the follow-up, the leg pain relief was statistically significant for both groups. NRS back pain, ODI, PSI and MacNab criteria showed significant deterioration for control group. Secondary outcomes data of MED group were significantly better than the control group.

CONCLUSIONS

Large, uncontained, lumbar disc herniations can be sufficiently removed using MED which is an effective alternative to open discectomy procedures with remarkable long-term outcome. Although the neurological outcome of the two procedures is the same, the morbidity of MED is significantly less than open discectomy. Maximum benefit can be gained if we adhere to strict selection criteria. The optimum indication is single- or multi-level radiculopathy secondary to a single-level, large, uncontained, lumbar disc herniation.