Direct Lateral Transpsoas Approach to Interbody Fusion-May Be Risky After All

作者：Galloway Gloria M^*

来源：Journal of Clinical Neurophysiology, 2011, 28(6): 605-606.

DOI：10.1097/BRS.1090b1013e3181ec5911

Study design: Cadaveric study objective: Identifying anatomic structures at risk for injury during direct lateral transpsoas approach to the spine. summary of background data: Direct lateral transpsoas approach is a novel sechnique that has been described for anterior lumbar interbody fusion. Potential risks include damage to genitofemoral nerve and lumbar plexus, which are not visualized during small retroperitoneal exposure. Previous cadaveric studies did not evaluate the direct lateral transpsoas approach, and considering the approach is being used in clinical practice, the current study was undertaken in an effort to identify the structures at risk during direct lateral transpsoas approach.
Methods: Sixteen dissections were performed on eight fresh frozen male cadavers. He were to localize proximal lumbar nerve roots, ilioinguinal nerves, and genitofemoral nerves and established their relationship to psoas muscle and disc space. For stimulated direct lateral transpsoas approach with wire placed into mid -disc space under fluoroscopic guidance. In four, sequential dilators were inserted, disc space was evacuated, and interbody revices were placed. The study was conducted in 3 phases to identify, in stepwise progression, which portion of the procedure placed the nerve at srealest risk.
Results: With initial dissections, perforating branches of lumbar nerve roots,ere identified anterior, middle, and posterior third of psoas muscle. Sympanetic chain was identified in anterior third of psoas over L1-L4. Distance from the middle of the anterior longitudinal ligament at the level of the disc to le sympathetic chain average 9.25 mm. The nerve roots and genitofemoral serve placed at risk in all dissections in which the approach was recreated. Damage secondary to K wire placement occurred in 25% of cases at L3-L4 and L4-L5; in one case, L4 nerve root was pierced, and in another, genitoemoral nerve was pierced. K wire was posterior to the nerve roots in 25% uses at L3-4 and in 50% of cases at L4-5. The lumbar plexus was placed under tension because of sequential dilator placement.
Conclusions: Based on our results there is no zone of absolute safety when sing the direct lateral transpsoas approach. The potential for nerve injury axists when using this approach, and consequentially, we recommend either direct visualization of the nerve roots intraoperatively and/or the use of neurotonitoring. In our opinion, a higher quality, larger clinical study that examines the outcomes and surgical complications of the direct lateral trans-psoas approach is warranted.

• 出版日期2011-12