Mounting the learning curve in unilateral biportal endoscopic lumbar decompression in an Asian population: experience of a single surgeon's first 105 consecutive cases with early functional outcomes.

Background: The benefits of minimally invasive spinal surgery have seen an increase in uptake by surgeons and an increase in acceptability by patients. This retrospective cohort study aims to evaluate the efficacy and safety of unilateral biportal endoscopic (UbE) lumbar decompressive surgery with a focus on outcomes, technique, and temporal relationship between surgeon experience and operative times. Methods: We performed a retrospective analysis of the first consecutive 105 patients undergoing UbE lumbar decompression (99 single-level and 6 double-level) for symptomatic herniated disc and/or spinal stenosis by a single surgeon at our institution. Data encompassed demographics, preoperative and postoperative assessments, operative details, complications, as well as patient-reported outcome measures (PROM). Results: The 105 Asian patients presented with diverse symptoms, predominantly leg pain/radiculopathy (93.3%) and lower back pain (75.2%). The commonest level operated on was L4/5 (56.2%), and the operative time averaged 117.58 minutes per level, with shorter times being associated with increased surgical experience (r=-0.254, P=0.009) and longer times associated with higher body mass index (BMI) (r=0.209, P=0.03). Left-sided and L5/S1 level decompression were associated with quicker operative time, but without reaching statistical significance. In the immediate postoperative period, all patients experienced an improvement of symptoms with 54.3% experiencing complete symptomatic relief. The average length of hospitalization was 1.88 days. Complications were minimal with 3 dural tears (2.86%), 1 postoperative wound bleeding (0.95%) and no infective sequelae. PROM at 1- and 3-month mark showed significant improvements in Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) and 36-item Short Form Survey (SF-36). Conclusions: UbE lumbar decompression in Asian patients at our institution demonstrated favorable outcomes, in terms of symptomatic relief, functional scores and length of stay with few complications. Surgical times improved with increased experience, suggesting feasibility with practice. We recommend having adequate surgical experience in traditional approaches before transitioning to endoscopic decompression, and to embark on learning UbE approach with careful patient selection. Given inherent limitations such as retrospective single-cohort design and a short follow-up, further longer-term comparative studies are warranted to establish its superiority definitively.