Unilateral biportal endoscopic decompression for two-level adjacent lumbar spinal stenosis through a single sliding approach: technical report and early follow-up

Abstract

Background: Traditional unilateral biportal endoscopic (UBE) decompression for two-level adjacent lumbar spinal stenosis (LSS) often requires a third incision, potentially leading to increased blood loss, longer operative time, and greater reliance on fluoroscopy. To address these limitations, we propose a novel sliding approach UBE (S-UBE) for treating two-level adjacent LSS. This study presents the technique and its preliminary clinical outcomes. Methods: In this retrospective study, 41 patients with two-level adjacent LSS were treated with S-UBE between April 2021 and October 2023. Treatment outcomes were evaluated based on operative time, blood loss, surgical complications, hospital stay duration, visual analog scale (VAS) scores, Oswestry Disability Index (ODI), and modified MacNab criteria. Radiological evaluations were performed at regular intervals during follow-up. Results: All patients successfully underwent surgery with the S-UBE technique. The mean operative time was 118.27 ± 11.79 min, average blood loss was 92.46 ± 11.75 ml, and the mean hospital stay was 5.20 ± 1.45 days. No major surgical complications occurred, though two patients experienced transient numbness and pain in their lower limbs, which recovered from conservative treatment. Postoperative VAS scores were significantly lower (P < 0.05), while ODI scores improved significantly compared to preoperative values (P < 0.05). The excellent-to-good outcome rate based on the modified MacNab criteria was 95.12%. Facet joint preservation rates were 84.76% at the L3-L4-L5 segment and 88.38% at the L4-L5-S1 segment. No cases of lumbar instability were observed during follow-up. Conclusion: The S-UBE technique is an effective alternative for treating two-level adjacent LSS, offering a minimally invasive solution with only two skin incisions. This approach demonstrates promising clinical outcomes, including reduced operative time, minimal blood loss, and high facet joint preservation rates.