Endoscopic anterior to psoas lumbarinterbody fusion: indications, techniques, and clinical outcomes.

Abstract

The retrospective study aimed to report the surgical technique and clinic-radiological outcomes of endoscopic anterior to psoas interbody lumbar fusionthrough the retroperitoneal approach with direct and indirect decompression. We retrospectively analyzed the results of clinical parameters of patients who underwent endoscopic anterior to psoas interbody lumbar fusion between June 2013 and June 2022. Clinical outcomes were evaluated by the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. The radiological outcomes were measured and statistically compared in disc height index (DHI), whole lumbar lordosis (WLL), pelvic Incidence (PI), pelvic tilt (PT), Segmental lordosis (SL), the sagittal vertical axis (SVA). A total of 35 patients were selected for the procedure ranging in age from 51 to 84years with 17.83 ± 8.85months follow-up. The mean operation time in lateral position for one level was 162.96 ± 35.76min (n = 24), and 207.73 ± 66.60min for two-level fusion. The mean endoscopic time was 32.83 ± 17.71min per level, with a total estimated blood loss of 230.57 ± 187.22cc. The mean postoperative VAS back, leg pain score and ODI improved significantly compared to the preoperative values; Radiological data showed significant change in WLL, SL, DHI, PI, PT, and SS; however, there is no significant difference in SVA postoperatively. Subgroup analysis for the radiographic data showed 50mm length cage has significantly improved for the DHI, SS and SVA compare to 40mm length cage. The subgroup analysis results showed that hypertensive patients had significantly higher proportion in the incomplete fusion group compare to complete fusion group at one-year follow-up. The endoscopic anterior to psoas interbody lumbar fusion achieves satisfactoryindirect and direct decompression. This convergent techniquepresents an effective choice for treating lumbar instability associated withdischerniations and foraminal stenosis, thus complementing the indications for oblique lumbar interbody fusion.