Preoperative Iron Supplementation Mitigates the Risk of Postoperative Complications Associated With Iron Deficiency Anemia Following Lumbar Spinal Fusion.

STUDY

DESIGN

Retrospective cohort study.

OBJECTIVE

Evaluate postoperative outcomes in lumbar fusion patients with preoperative iron deficiency anemia (IDA) on iron supplementation.

BACKGROUND

IDA has been associated with impaired cognition, compromised immune response, and increased risk of morbidity and mortality after surgery. However, little is known about the relationship between IDA and postoperative complications among patients undergoing lumbar fusion, as well as about the impact of preoperative iron supplementation on these outcomes.

METHODS

A national all-payer claims database was queried for adult patients who underwent lumbar spinal fusion between 2010 and 2022. Patients were initially stratified by a preoperative diagnosis of IDA and matched 1:1 based on age, sex, and medical comorbidities. IDA patients were further stratified by preoperative iron supplementation use and similarly matched. Postoperative complications and hospital costs were compared using χ 2 , t test, and multivariate logistic regressions.

RESULTS

The matched cohorts consisted of 27,669 patients, with a mean age of 59 years and 89% female sex. IDA patients had higher rates of pulmonary embolism, acute kidney infection, deep venous thromboembolism, surgical site infection, urinary tract infection, blood transfusion, 90-day readmission rates, and hospital length of stay (all P <0.001). IDA patients on preoperative iron supplementation had lower rates of acute kidney injury, hematoma, pulmonary embolism, surgical site infection, urinary tract infection, stroke, 90-day readmission rates, and 90-day total hospital costs (all P <0.001). Non-IDA patients on preoperative iron supplementation similarly had lower rates of many of these complications as well.

CONCLUSION

IDA was associated with an increased risk of 90-day postoperative medical complications and hospital resource utilization. However, preoperative oral iron supplementation mitigated these risks. Further research is critical to understand how preoperative or perioperative iron supplementation can be used to optimize patients' hematologic status before lumbar fusion to maximize clinical outcomes.

LEVEL OF EVIDENCE: Level IV.