1556. Effect of Diabetes on Postoperative Outcomes Following Anterior Lumbar Interbody Fusion

Authors: Annie Arrighi-Allisan; Sean Neifert, BS; Jeffrey Zimering, MD; Jonathan Gal; Brian Deutsch, BS; Daniel Snyder, BS; John Caridi, MD (New York, NY)

Introduction: The anterior lumbar interbody fusion (ALIF) technique, first described by Burns in 1933, is used to correct a variety of lumbar spine pathologies. Examination of the predictors for poor outcomes following ALIF is necessary for risk stratification prior to surgery. The present study analyzes diabetes mellitus (DM) as a risk factor for postoperative complications following ALIF. Methods: All patients undergoing ALIF at a single institution from 2008-2016 (n=494) were examined for demographic characteristics and perioperative information. Patients with and without a billable diagnosis of DM were compared on these qualities and outcomes with chi-square, Student’s t-test, and multivariable regression models. Results: Patients with diabetes were significantly older (mean age 60.38 vs. 53.24 years, P <0.0001) and sicker (75.00% of patients had ASA Class > 2 vs. 25.81%, P <0.0001) than were non-diabetic patients. They experienced higher rates of renal failure (4.69% vs. 0.93%, P =0.02), but lower rates of bleeding (12.50% vs. 25.35%, P =0.02) than those without diabetes. Unadjusted analysis showed that patients with diabetes experienced higher rates of 30-day readmissions (9.38% vs. 3.72%, P =0.04), 90-day readmissions (15.63% vs. 5.81%, P =0.004), 30-day ED visits (9.38% vs. 2.33%, P =0.003), and 90-day ED visits (9.38% vs. 3.26%, P =0.02), with lower rates of nonhome discharge (3.25% vs. 13.52%, P =0.02) than the non-diabetic patients. However, upon adjusted analysis, diabetes remained a risk factor for only 90-day readmissions (OR: 2.63; 95% CI: 1.09-6.35; P =0.03) and 30-day ED visits (OR: 3.64; 95% CI: 1.10-12.01; P =0.03). Initial cost modeling accounting for comorbidity burden demonstrated that diabetes was a negative predictor of cost (-$5,589; 95% CI: -$10,302 – -$877; P =0.02), but this association did not endure when accounting for resource utilization, operative time, and length of stay. Conclusion: In patients undergoing ALIF, diabetes is associated with 90-day readmissions and 30-day ED visits, but not with increased surgical costs.