title: Preoperative anemia predicts thrombosis and free flap failure in microvascular reconstruction.
abstract: Patients undergoing microvascular reconstruction are often anemic from a combination of iatrogenic hemodilution and acute blood losses. No major clinical study describes the impact of preoperative anemia on free flap morbidity. The plastic surgery service at a high-volume academic center performed 156 free flaps among 147 patients from December 2005 to December 2010. One hundred thirty-two had a preoperative hemoglobin (Hb) or hematocrit (Hct), with mean values of 11.8±2.4 g/dL and 35.2%±7.0%, respectively. The overall failure rate was 9% (12/132), primarily from vascular thrombosis (6/12). Through logistic regression analysis, Hb and Hct were significant predictors of flap failure (P<0.005) and vascular thrombosis (P<0.05). Fisher exact test revealed a significant increase in failure risk at Hct level less than 30% (Hb<10 g/dL) (relative risk, 4.76, P=0.006), and probit analysis demonstrated an exposure-response relationship to decreased Hct level (P<0.005). These findings support that preoperative anemia could significantly impact free flap morbidity.
authors.affiliation: Vanderbilt University Medical Center, Nashville, TN 37232-2345, USA.
authors.forename: J Bradford
authors.initials: JB
authors.lastname: Hill
authors.forename: Ashit
authors.initials: A
authors.lastname: Patel
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Del Corral
authors.forename: Kevin Wayne
authors.initials: KW
authors.lastname: Sexton
authors.forename: Jesse M
authors.initials: JM
authors.lastname: Ehrenfeld
authors.forename: Oscar Dean
authors.initials: OD
authors.lastname: Guillamondegui
authors.forename: R Bruce
authors.initials: RB
authors.lastname: Shack
mesh_terms: D000740:Anemia / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D005260:Female; D058752:Free Tissue Flaps / Q000098:blood supply / Q000473:pathology* / Q000637:transplantation; D006085:Graft Survival; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D016015:Logistic Models; D008297:Male; D055806:Microvessels / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009336:Necrosis / Q000209:etiology; D011183:Postoperative Complications / Q000209:etiology*; D057234:Preoperative Period; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D013927:Thrombosis / Q000209:etiology*
chemical_list: D015415:Biomarkers; D006454:Hemoglobins