A comparative analysis of unilateral biportal endoscopic and open laminectomy in multilevel lumbar stenosis

Abstract

Background: Approximately 103 million people across the globe suffer from symptomatic lumbar spinal stenosis, impacting their health and quality of life. The unilateral biportal endoscopic technique is effective for treating single-segment degenerative lumbar spinal stenosis and is seen as a viable alternative to traditional open lumbar laminectomy. However, research on the application of this technique for multilevel lumbar spinal stenosis remains lacking.

Objective: To compare the clinical effects of unilateral biportal endoscopy (UBE) and open lumbar decompression (OLD) in the treatment of multilevel lumbar spinal stenosis (MLSS).

Methods: This retrospective study was conducted from February 2019 to December 2023 and compared the outcomes of Multilevel UBE surgery to OLD. The included patients were divided into two groups, namely the UBE group (n = 42, 86 surgical segments) and the OLD group (n = 40, 82 surgical segments). At the 1-year follow-up, the imaging findings, visual analogue scale (VAS), Oswestry disability index (ODI), and Zurich Claudication Questionnaire (ZCQ) were assessed. MRI measurements of the dural sac (CSA) and paravertebral cross-sectional area (PMA) were taken before surgery and at the final follow-up.

Results: The surgical segments of the two groups primarily consisted of adjacent segments (UBE 78.6% vs. OLD 78.8%), with a higher proportion of bilateral decompression in the OLD group (UBE 24.4% vs. OLD 28.0%). Preoperative imaging evaluation indicated a higher prevalence of grade C (severe stenosis) compared to grade D (severe stenosis) in both groups (UBE 74.4% vs. OLD 72%). The OLD group exhibited significantly greater blood loss compared to the UBE group (147.63 ± 26.55 vs. 46.19 ± 25.25 mL, p < 0.001). In addition, the duration of hospitalization in the OLD group was notably longer compared to the UBE group (7.58 ± 1.39 vs. 4.38 ± 1.56 days, p < 0.05). Paravertebral muscle atrophy (PMA) in the UBE group was significantly lower than in the OLD group (3.49 ± 3.03 vs. 5.58 ± 3.00, p < 0.05). Significantly elevated serum creatine kinase (CK) levels were observed in both groups, peaking at 1-day post-surgery, with the UBE group showing significantly lower levels than the OLD group (108.1 ± 12.2 vs. 364.13 ± 20.24 U/L, p < 0.05). On postoperative day 7, a significant decrease in liver enzyme levels was found in UBE group compared to the preoperative levels (61.81 ± 7.14 vs. 66.10 ± 8.26 U/L, p < 0.05). The Oswestry Disability Index (ODI) and Zurich Claudication Questionnaire (ZCQ) scores at 1 week, 6 months, and 1 year post-operation showed significant improvement compared to the preoperative scores in both groups (p < 0.05). The study found statistically significant differences in both the Visual Analog Scale (VAS) score (2.28 ± 0.59 vs. 2.85 ± 0.74, p < 0.05) and the Oswestry Disability Index (ODI) score (36.28 ± 2.03 vs. 37.57 ± 1.98, p < 0.05) at 1 week post-surgery between the two groups. However, no significant variations in scores were noted between preoperative and postoperative time points at other follow-up intervals.

Conclusion: The unilateral biportal endoscopic technique was applied to treat multilevel lumbar spinal stenosis, demonstrating decreased intraoperative bleeding and lower postoperative muscle-related complications compared to open lumbar decompression. Furthermore, UBE was found to promote early mobilization.

Keywords: multilevel lumbar spinal stenosis; open lumbar decompression; spinal endoscopy; unilateral approach bilateral decompression; unilateral biportal endoscopy.

Figure 1

A 70-year-old female patient with disc herniation at the L4-5 and L5-S1 levels presented with pain and numbness in the lateral and posterior regions of the left lower leg, along with pain in the lateral aspect of the right calf. Preoperative axial and sagittal MR images revealed significant spinal canal stenosis at the L4-5 and L5-S1 levels (A–D). Subsequent postoperative three-dimensional CT scans displayed an increase in the width of the spinal canal following the surgical intervention (E,F).

Figure 2

Based on the patient’s condition, L4-5 ULBD (unilateral laminotomy for bilateral decompression) and L5-S1 UBE (unilateral biportal endoscopy) surgeries were performed. (A) The radiofrequency electrode was used to create a pathway through the interlaminar muscles. (B) Laminar rongeurs and high-speed burrs were utilized to remove the laminar tissue on the left side. (C) The ligamentum flavum was preserved to facilitate further operations. (D–E) Removal of the base of the spinous process, crossing the V-point, was performed for over-the-top decompression, effectively decompressing the contralateral recess. Contralateral disc material was excised. (F–H) Decompression on the same side and excision of ipsilateral disc material were performed. (I) Disc material was removed on the left side at L5-S1. (H) Exploration and loosening of the nerve root were conducted.

Figure 3

A 49-year-old male patient presented with L4-5 disc herniation and L5-S1 epidural lipomatosis, exhibiting clinical symptoms of pain and numbness in both lower limbs, with more severe manifestations on the right side (A,B). Preoperative axial and sagittal magnetic resonance imaging revealed L4-5 disc herniation and increased L5-S1 epidural fat, leading to spinal stenosis(C,D). Subsequent axial CT findings post-unilateral laminectomy demonstrated postoperative spinal canal widening on three-dimensional CT scan (E,F).