Efficacy and Safety of Unilateral Interlaminar Endoscopic Decompression for Lumbar Spinal Stenosis: A Retrospective Study of 176 Cases With a 3-6 Year Follow-Up.

Abstract

Objective: Spinal endoscopic surgery is widely acknowledged as an effective and minimally invasive approach for treating lumbar disc herniation. Comprehensive descriptions of the endoscopic decompression technique for lumbar spinal stenosis (LSS) are limited in existing literature. With a focus on long-term follow-up outcomes, this study investigates the safety and efficacy of endoscopic decompression using a unilateral interlaminar approach.

Methods: Between August 1, 2018, and December 1, 2020, a total of 316 consecutive cases underwent endoscopic decompression for LSS following conservative treatment. Based on specific selection criteria, 176 of these cases were retrospectively included in this study. The minimally invasive decompression was performed using a percutaneous uniportal and lateral interlaminar endoscopic approach under local anesthesia. This endoscopic procedure involved comprehensive decompression of the central canal and unilateral recess, addressing the lamina, hypertrophic ligamentum flavum (LF), and medial osteophytes of the facet joint. Clinical outcomes were assessed using the single continuous walking distance (SCWD) without pain, the modified MacNab criteria, the Oswestry Disability Index (ODI), and the visual analogue scale (VAS). Radiographic changes, both preoperative and postoperative, were documented and analyzed. This analysis included evaluating the stability of the lumbar spine through lumbar hyper-flexion and hyper-extension X-rays, as well as determining the lumbar canal cross-sectional area (CCA) using CT scans.

Results: The mean follow-up period was 47.4 ± 7.1 months. The average operative duration was 65.3 ± 12.6 min, and the mean estimated blood loss was 10.4 ± 8.5 mL. The average length of postoperative hospital stay was 2.2 ± 1.3 days. There was a significant improvement in SCWD without pain (p < 0.05). Postoperatively, the ODI and VAS scores for both back and leg pain showed significant reductions (p < 0.05). Based on the modified MacNab criteria, the overall rate of good-to-excellent outcomes was 95.45%. The CCA increased significantly from 52.0 ± 11.0 to 122.5 ± 12.1 mm² (p < 0.05). The stability of the spine did not exhibit significant changes compared to the preoperative state.

Conclusions: The unilateral interlaminar approach for bilateral endoscopic decompression in the treatment of LSS demonstrated both safety and efficacy, as evidenced by clinical and radiographic outcomes.