gms | German Medical Science

Objectives: Endoscopic spine surgery is a globally expanding minimally invasive technique for the treatment of disc herniation as well as spinal stenosis. However, literature on the efficiency of interlaminar endoscopic decompression (IED) versus conventional microsurgical technique (CMT) in patients with lumbar spinal stenosis is scarce. The present study sought to conduct a case-matched comparison for treatment success with consideration of clinical and radiologic predictors.

Methods: We retrospectively reviewed 88 consecutive patients (IED: 36/88, 40.9%; CMT: 52/88, 59.1%) presenting with lumbar central spinal stenosis between 2018-2020. Surgery-related (operation time, complications, time to hospital release (THR), ASA score, C-reactive protein (CRP), white blood cell count, side (unilateral/bilateral), patient-reported outcome measures (PROMs) (ODI, NRS (leg-, back pain), eQ5D, COMI), and radiological (preoperative dural sack cross-sectional area (DSCA), Shizas score (SC), left and right lateral recess heights, left and right facet angle) parameters were extracted at different time points. Surgery-related and radiological parameters were correlated with patient-centered outcomes utilizing a multivariate regression model to determine predictors for propensity score matching.

Results and Conclusion: Complication (most often residual sensorimotor deficits and/or re-stenosis due to hematoma) rates were higher in the endoscopic (33.3%) than microsurgical (13.5%) treatment group (p<0.05). Despite this, THR was higher for the microsurgical group (11.2 ± 6.1 days versus 7.1 ± 8.1 days, p<0.0001). Age, THR, SC, CRP, and DSCA revealed significant associations with 3 weeks and 1 year postoperatively evaluated ODI, COMI, eQ5D, NRS leg, or NRS back values in our regression model. Consequently, they were used for the propensity score matching process (resulting in n=28 per group). We did not observe significant differences in the endoscopic versus microsurgical group for patient-centered outcomes. COMI scores evaluated 3 weeks postoperatively barely missed significance (2.76 ± 0.53 for endoscopic versus 2.04 ± 0.53 for the microsurgical group, p=0.087).

Age, THR, SC, CRP, and DSCA revealed significant associations with patient-centered outcomes and should be considered in future studies. Our first single-center study experience with endoscopic treatment of lumbar spinal stenosis was similarly successful as the conventional microsurgical approach regarding 3 weeks and 1 year follow-up PROMs. However, it was associated with higher complication rates, probably due to the learning curve of the surgeon, inexperienced with endoscopic surgery but trained in microsurgery. Interestingly, postoperative complication rates were not correlated with PROMs. A possible explanation could be shorter THR in the endoscopic group. Future prospective studies should validate these findings.