Application of the far-lateral approach in uni-portal non-coaxial spinal endoscopic surgery: an evidence-based and Delphi consensus approach among Chinese expert opinions

Introduction: Degenerative lumbar spine diseases significantly affect patients' quality of life. The far-lateral approach (FLA) in uni-portal non-coaxial spinal endoscopic surgery (UNSES) offers a minimally invasive solution for complex lesions; however, a lack of expert consensus exists regarding its use. Research question: This study aimed to establish a consensus definition for the clinical application of FLA in UNSES by aggregating expert opinions through a modified Delphi method, thereby guiding clinical decision-making. Methods: A cross-sectional modified Delphi consensus survey was conducted. Seventy-eight spine endoscopy experts were invited to complete two rounds of anonymous questionnaires. The questionnaire covered six FLA-related categories: indications, advantages, preoperative evaluation, surgical details, complications, and postoperative rehabilitation. The consensus threshold was set at ≥ 70%. Results: The effective response rates for the two survey rounds were 94.87% and 97.44%, respectively. The expert authority coefficients were high (0.88-0.92), and Kendall's coefficients were 0.47 and 0.52, respectively. Grade A and grade B consensus were achieved for 89.5% (17/19) and 10.5% (2/19) of all items, respectively. Discussion and conclusions: This study demonstrates a high degree of agreement among experts on the key aspects of using FLA in UNSES. It provides a framework for standardizing surgery, optimizing patient outcomes, guiding future research, and promoting safe and effective UNSES implementation.