Biportal Endoscopic Transforaminal Lumbar Interbody Fusion for Two-Level Fusion: Hemodynamic Profiles and Early Clinical Outcomes Compared with Tubular MIS and Open Approaches - Tae Hoon Kang; Byungjun Kang; Geumho Lee; Jeongwoon Han; Seokin Jang; Minjoon Cho; Jung-Man Lee; Jae Hyup Lee (Journal of Clinical Medicine, 2026)