Anemia is not a predictor of free flap failure: a review of NSQIP data.

Abstract

Thrombosis is a common cause of flap failure in microvascular tissue transfer, which questions the effects of anemia on this outcome. This article seeks to contribute a large, multi-institutional data analysis to this debate. Free tissue transfer patients were identified in the National Surgical Quality Improvement database through a specified Current Procedural Terminology algorithm. Bivariate analysis compared anemic and nonanemic groups with respect to flap failure and other outcomes. Multivariable logistic regression was used to determine risk factors for flap failure. Of the 864 patients who met inclusion criteria, 244 were anemic and 620 were not. Bivariate analysis showed no significant difference between groups with respect to flap failure (3.28% vs. 4.03%, P = 0.0603). Multivariate regression analysis supported this (OR 95% CI = 0.371-1.912). These findings, based on the largest sample in the literature, show anemia is neither a predictor of free tissue transfer failure nor is it protective.