A retrospective study on safety and clinical outcomes of unilateral biportal endoscopic technique for spinal degenerative diseases.

Background and Objective: Unilateral biportal endoscopy (UBE) has been developing rapidly in coincidence with the popularization of minimally invasive spine surgery (MISS). However, the clinical outcome and invasiveness of UBE-assisted spinal surgery (UBESS) are undefined. The aim of the present study was to summarize the clinical outcome and surgical invasiveness of UBE for the treatment of various spinal degenerative diseases in a single center to validate the safety and application value of UBESS. Methods: Included in this study were 105 patients who received UBESS from November 2021 to June 2022 in our center. All patients were followed up postoperatively for at least 12 months. All basic information was recorded to depict the demographic and surgical variables. Clinical outcomes were assessed in terms of the operation time, complications, days of hospital stay, total blood loss, intraoperative blood loss, postoperative drainage volume, hidden blood loss, biochemical changes associated with surgical injury, comparison of the visual analogue scale (VAS) for back and leg pain, Japanese Orthopedic Association (JOA) scores for cervical diseases at preoperative and postoperative stage, as well as Oswetry Disability Index (ODI), and modified MacNab scores one year after treatment. Results: Of the 105 included patients, 68 patients were with single-level lumbar degenerative diseases, 22 with two-level diseases, two with three-level diseases, 10 with single-level isthmic spondylolisthesis, and three with single-level cervical spondylotic radiculopathy. UBE was performed by using five surgical approaches. The operation time, days of hospital stay, blood loss, postoperative immobilization time and prognosis were all estimated in consideration of the surgical approaches and the number of operated segments. The mean operation time ranged from 80 min to 214 min for single-level spinal diseases, and 112 min to 330 min for two-level ones. Total blood loss was higher in multilevel spinal surgery and single-level UBE-assisted lumbar interbody fusion+discectomy (ULIFD). The postoperative immobilization duration was between 0.5 and 2 days for single level spinal diseases, 1 and 3 days for 2-level diseases, fewer than 2 days for three-level diseases, and 1.5-12 days for isthmic spondylolisthesis (IS). The VAS and ODI for lumbar diseases decreased significantly and the JOA scores for cervical diseases improved after operation. The satisfaction rate was 89.70%, 85.71%, 90.00%, 66.67%, and 90.00% for the five surgical approaches respectively. Conclusions: UBESS has proved to be a safe, reliable and minimally invasive option for spinal degenerative diseases, with significant benefits of pain control, rapid functional recovery, short hospitalization, and early rehabilitation. However, postoperative hidden blood loss should be put under the careful management when performing UBESS.