Risk Factors for Postoperative Complications in Single and Multi-level Anterior Lumbar Interbody Fusion

Introduction: Although there are studies that evaluate complications associated with anterior lumbar interbody fusion (ALIF), these studies are often limited to single-level ALIF cohorts. Additionally, prior studies often do not account for specific approaches (i.e retroperitoneal/transperitoneal) or additional surgeries done in conjunction with ALIF (i.e anterior/posterior instrumentation). This study aimed to identify risk factors for postoperative complications after hospital discharge from all causes in a large single and multi-level ALIF cohort.

Methods: Patients undergoing ALIF by neurosurgery spine faculty working with a specialized vascular surgeon were retrospectively reviewed. Demographics, intraoperative, and postoperative data up to three months were collected. Patients were split into complications and no complications groups. Outcome comparisons were conducted using chi-square exact and Mann-Whitney U test for categorical and continuous data, respectively. Backward stepwise logistic regression was used to investigate associations with postoperative complications. Univariate analysis was first conducted to identify candidate associations. Variables with p < 0.05 were then included in a multivariate analysis to identify predictors of postoperative complications.

Results: 299 ALIF procedures were identified, with 52.8% males (n=158) and 47.2% females (n=141). The mean age was 57.8 years, with 55.7% (n=166) having had prior lumbar surgery. The postoperative cohort complication rate was 19.1% (n=57). Postoperative complications were more likely to occur in older patients and patients reporting a history of hypertension and use of anticoagulants (all p < 0.05). Additionally, postoperative complication patients experienced more blood loss, higher number of levels fused, multi-level posterior instrumentation, intraoperative complications, immediate postoperative neurologic deficits, in-hospital postoperative complications, and longer hospital stays (all p < 0.05). Multivariate analysis revealed that multi-level posterior instrumentation, intraoperative complications, and length of hospital stay were significant predictors of postoperative complications (all p < 0.05).

Conclusion : Multi-level posterior instrumentation, intraoperative complications, and length of hospital stay were independent predictors of postoperative complications from all causes in ALIF patients following hospital discharge.