Advantages of New Endoscopic Unilateral Laminectomy for Bilateral Decompression (ULBD) over Conventional Microscopic ULBD

BACKGROUD: Biportal endoscopic unilateral laminectomy for bilateral decompression (ULBD) is an emerging minimally invasive procedure for spinal stenosis. However, reports of the results associated with this surgical method are still lacking. METHODS: We conducted a retrospective study of 60 patients who underwent bilateral decompression for lumbar central canal stenosis. The patients were divided into 2 groups according to the surgical method (endoscopic ULBD vs. microscopic ULBD). We compared the outcomes between the 2 groups in terms of postoperative segmental spinal instability, dura expansion, operation time, estimated blood loss, serum creatine kinase (CK), serum C-reactive protein (CRP), visual analog scale (VAS) score, Oswestry Disability Index (ODI), modified MacNab score, and the incidence of complications. RESULTS: The mean VAS, ODI, and modified MacNab score improved significantly from the preoperative period to the last follow-up in both groups and were better in the endoscopic ULBD group until the first day after treatment. The degree of horizontal displacement was lower in the endoscopic ULBD group than in the microscopic ULBD group at postoperative 12 months. Dura expansion, operation time, and estimated blood loss did not differ significantly between the 2 groups. Serum CK and CRP on the first day after treatment were lower in the endoscopic ULBD group than in the microscopic ULBD group. CONCLUSIONS: This study shows that both endoscopic ULBD and microscopic ULBD can provide favorable outcomes for lumbar central canal stenosis. However, compared to microscopic ULBD, endoscopic ULBD has advantages in terms of postoperative segmental spinal instability, pain control, and serum CK and CRP.