Background The impact of anesthetic technique on spine surgery outcomes is controversial. Using a large national sample of patients, we compared outcomes after lumbar decompression under regional anesthesia (RA: spinal or epidural) or general anesthesia (GA).

Methods A retrospective population-based study of American College of Surgeons National Surgical Quality Improvement Program data (2009–2019). Patients were propensity score (PS) matched 3:1 (GA:RA) on demographic and surgical variables. The primary outcome was the association between anesthetic type and any complication (cardiac, pulmonary, renal, transfusion, stroke, infectious, deep vein thrombosis/pulmonary embolus). Secondary outcomes included the association between anesthetic type and individual complications, readmission and length of stay (LOS). Unadjusted comparisons (OR, 95% CI), logistic regression and adjusted generalized linear modeling (parameter estimate, PE, 95% CI) were performed before and after PS matching.

Results Of 1 51 010 cases, 149 996 (99.3%) were performed under GA, and 1014 (0.67%) under RA. After matching, 3042 patients with GA were compared with 1014 patients with RA. On unadjusted analyses, RA was associated with lower odds of complications (OR 0.43, 0.3 to 0.6, p<0.001), shorter LOS (RA: 1.1±3.8 days vs GA: 1.3±3.0 days; p<0.001) and fewer blood transfusions (RA: 3/1014, 0.3% vs GA: 40/3042, 1.3%; p=0.004). In adjusted analyses, RA was associated with fewer complications (PE −0.43, –0.81 to −0.06, p=0.02) and shorter LOS (PE −0.76, –0.90 to −0.63, p<0.001). There was no significant association between anesthetic type and readmission (PE −0.34, –0.74 to 0.05, p=0.09).

Conclusions Compared with GA, RA was associated with fewer complications, less blood transfusion and shorter LOS after spine surgery. Although statistically significant, the magnitude of effects was small and requires further prospective study.