Complications Associated With Minimally Invasive Anterior to the Psoas (ATP) Fusion of the Lumbosacral Spine

Study Design. Retrospective cohort study. Objectives. To analyze complications associated with minimally invasive anterolateral retroperitoneal antepsoas lumbosacral fusion (MIS-ATP). Summary of Background Data. MIS-ATP provides anterolateral access to the lumbar spine allowing for safe anterior lumbar interbody fusions between T12-S1. Anecdotally, many surgeons believe that ATP approach is not feasible at L5-S1 level, predisposing to catastrophic vascular injuries. This approach may help overcome limitations associated with conventional straight anterior lumbar interbody fusions, MIS lateral lumbar interbody fusion, and oblique lateral interbody fusion. Methods. A detailed retrospective chart review of patients who had underwent MIS-ATP approach for lumbar fusion between T12-S1 was performed. Available electronic data from surgeries performed between January 2008 and March 2017 was carefully screened for surgical patients treated for spondylolisthesis, spondylosis, stenosis, sagittal, and/or coronal deformity. Detailed review of electronic medical records including operative notes, progress notes, discharge summaries, laboratory results, imaging reports, and clinic visit notes performed by a single independent reviewer not involved in patient care for documented complications. A complication is defined as any adverse event related to the index spine procedure for which patient required specific intervention or treatment. Results. Nine hundred forty patients with a total of 2429 interbody fusion levels performed via MIS-ATP were identified during the study period. Sixty-seven patients (7.2%) sustained one or more complications during the perioperative period, of which 25.5% were surgical and 74.5% were medical. Overall, 78 (8.2%) surgical complications pertaining to the index procedure were noted during a postoperative period of 1 year from the date of surgery. No major vascular or direct visceral injuries were encountered. Conclusions. MIS-ATP approach provides a safe access to anterolateral interbody fusions between T12-S1. The ATP approach is performed by the spine surgeon, does not require neuromonitoring, and warrants minimal to no psoas muscle retraction resulting in significantly reduced postoperative thigh pain and rare neurologic injuries. Additionally, the direct and clear visualization of the retroperitoneal vasculature provided by the ATP approach minimizes the risk of inadvertent vascular injury.