Initial multi-centre clinical experience with prone transpsoas lateral interbody fusion: Feasibility, perioperative outcomes, and lessons learned

Lateral interbody fusion (LIF) is traditionally performed with the patient in lateral decubitus, requiring repositioning to prone for adjunctive posterior procedures, or modifying traditional posterior techniques to be done while positioned lateral. The benefits of lateral anterior column access may be achievable with the patient prone, allowing for concomitant posterior techniques in a more familiar single-position setting. Prone transpsoas (PTP) access was outlined and vetted by a group of LIF-experienced spine surgeons. Early clinical experience included prospectively capturing procedural details and perioperative outcomes across a multi-centre cohort of clinicians to assess feasibility and to identify efficiencies and/or challenges. Perioperative data was prospectively collected from 120 consecutive cases (176 levels) from 22 surgeons. Lateral exposure was achieved in an average 18 min/level, guided by triggered EMG; and retraction time averaged 25 min/level, with continued plexus monitoring via saphenous SSEP. Fixation was via percutaneous pedicle screws (65%), open pedicle screws (24%), other (11%). No re-positioning was required. Concomitant procedures facilitated by prone position included direct decompression (37%), treatment at L5-S1 (18%), posterior instrumentation revision (7%), and osteotomy/bony releases (9%). PTP procedure time, blood loss, and length of stay were consistent with established LIF experience. Challenges included patient movement with lateral instrument forces, retractor sag, stability of access relative to the patient, and surgeon ergonomics of the working channel. These challenges were overcome later in the experience through development of a specialized positioner and retractor system specific to this approach and a prescribed workflow developed by consensus of the surgeons. Initial multi-centre clinical experience suggests that PTP is not only feasible but creates efficiencies by allowing for single-position surgery maximizing both anterior and posterior column access and corrective techniques, with perioperative outcomes consistent with lateral decubitus experience. Learnings included the need for development of procedure-specific technologies and technique refinement.