Is diabetes a contraindication to lower extremity flap reconstruction? An analysis of threatened lower extremities in the NSQIP database (2010-2020)

Background: The impact of diabetes on complication rates following free flap, pedicled flap, and amputation procedures on the lower extremity (LE) is examined. Methods: Patients who underwent LE pedicle flap (PF), free flap (FF), and amputation (AMP) procedures were identified from the 2010-2020 ACS-NSQIP® database using CPT and ICD-9/10 codes, excluding cases for non-LE pathologies. The cohort was divided into diabetics and non-diabetics. Univariate and adjusted multivariable logistic regression analyses were performed. Results: Among 38,998 patients undergoing LE procedures, 58% were diabetic. Among diabetics, 95% underwent amputation (AMP), 5% underwent pedicled flap (PF), and <1% underwent free flap (FF). Across all procedure types, non-insulin dependent (NIDDM) and insulin-dependent diabetes mellitus (IDDM) were associated with significantly greater all-cause complication rates compared to absence of diabetes, and IDDM was generally higher risk than NIDDM. Among diabetics, complication rates were not significantly different across procedure types (IDDM: p=0.5969; NIDDM: p=0.1902). On adjusted subgroup analysis by diabetic status, flap procedures were not associated with higher odds of complications compared to amputation for IDDM and NIDDM patients. Length of stay>30days (LOS>30) was statistically associated with IDDM, particularly those undergoing FF (AMP:5%, PF:7%, FF:14%, p=0.0004). Conclusion: Our study highlights the importance of preoperative diabetic optimization prior to LE procedures. For diabetic patients, there were few significant differences in complication rates across procedure type, suggesting that diabetic patients are not at higher risk of complications when attempting limb salvage instead of amputation. Key Words: Diabetes, Lower extremity, Flap reconstruction