Multiple Endoscopic Access Lumbar Interbody Fusion (MALIF): A New Technique for Unilateral Biportal Endoscopic Lumbar Interbody Fusion Using Monoportal Endoscopic Spine Surgery Techniques

This study aims to present a new endoscopic lumbar interbody fusion technique, multiple endoscopic access lumbar interbody fusion (MALIF), which applies the assisted full-endoscopic spine surgery (AFESS) technique to unilateral biportal endoscopic lumbar interbody fusion (UBE-LIF). AFESS represents an advancement over UBE by utilizing a monoportal scope in the camera portal during biportal endoscopic spine surgery, which enables greater stability, controlled irrigation for muscle preservation, and improved protection of neural structures. We performed MALIF on 15 consecutive patients with symptomatic lumbar spondylolisthesis resistant to conservative treatment and showing radiographic evidence of instability. The technique was performed through a unilateral percutaneous pedicle screw (PPS) incision, minimally exposing the lateral facet joint, followed by superior articular process (SAP) resection and interbody cage placement for indirect decompression and fusion. The mean operative time was 97.4 ± 17.5 minutes (range: 70-129 minutes), with minimal blood loss (mean: 24.3 ± 13.8 ml) and short hospital stay (mean: 15.0 ± 3.5 days). All patients showed symptomatic improvement without major complications, except for one case of transient dysesthesia that resolved within two weeks. MALIF offers three key advantages: (1) multi-angle endoscopic access to the surgical site, (2) precise endoscopic discectomy, and (3) enhanced safety through monoportal sleeve protection of the exiting nerve root. These initial results suggest that MALIF is a promising minimally invasive surgical option for lumbar interbody fusion.