Biportal endoscopic versus microscopic discectomy for lumbar herniated disc: a randomized controlled trial

Abstract

Background context: Biportal endoscopic discectomy has been frequently performed in recent years and has shown acceptable clinical outcomes. However, evidence regarding its efficacy and safety remains limited.

Purpose: This study aimed to compare the clinical efficacy and safety of biportal endoscopic with that of open microscopic discectomy in patients with single-level herniated lumbar discs.

Study design: Prospective, randomized, multicenter, open-label, assessor-blind, non-inferiority controlled trial.

Patient sample: Sixty-four participants suffering from low back and leg pain with a single-level herniated lumbar disc and required discectomy.

Outcome measures: Outcomes were assessed with the use of patient-reported outcome measures (PROMs), visual analog scale (VAS) pain score for surgical site, low back and lower extremity, Oswestry Disability Index (ODI) for lumbar disabilities, European Quality of Life-5 Dimensions value for quality of life, and painDETECT for neuropathic pain. Surgery-related outcomes such as hospital stay, operation time, and opioid usage were collected. Adverse events occurring during the follow-up period were also noted.

Methods: All participants were randomly assigned in a 1:1 ratio to undergo biportal endoscopic (biportal group) or microscopic discectomy (microscopy group). The primary outcome was the difference in ODI scores at 12-months post surgically based on a modified intention-to-treat strategy, with a non-inferiority margin of 12.8 points. The secondary outcomes included PROMs, surgery-related outcomes, and adverse events.

Results: The ODI score at the 12-month follow-up was 11.97 in the microscopy group and 13.89 in the biportal group (mean difference, 1.92; 95% confidence interval [CI], -3.50 to 7.34), showing the non-inferiority of biportal group. The results for the secondary outcomes were similar to those for the primary outcome. Creatinine phosphokinase ratios were low in the biportal group. Early surgical site pain was slightly lower in the biportal group (mean difference of VAS pain score at 48-hr, -0.98; 95% CI, -1.77 to -0.19). Adverse events including reoperation showed no significant difference between the groups.

Conclusion: Biportal endoscopic discectomy was non-inferior to microscopic discectomy over a 12 month period. Biportal endoscopic discectomy is suggested to be a relatively safe and effective surgical technique with the slight advantage of reduced muscle damage. However, the clinical implications of surgical site pain should be carefully considered.

Keywords: Biportal endoscopic spinal surgery; Degenerative spine; Discectomy; Lumbar herniated disc; Microscopy; Oswestry disability index.