title: The effect of postoperative anticoagulation on microvascular thrombosis.
abstract: BACKGROUND
  Numerous protocols exist to prevent thrombosis after free-tissue transfer. Many surgeons advocate using aspirin or other antiplatelet agents, but little objective evidence supports this practice. This study evaluates the rate of microvascular thrombosis in patients undergoing free-tissue transfer treated with or without antiplatelet agents.
  
  
  METHODS
  All consecutive free flaps from 2002-2005 at a single center were reviewed using a prospectively maintained database. Patients were in 2 groups based on postoperative anticoagulation administration. In group 1, 325 mg of aspirin was administered daily for 5 days postoperatively. In group 2, patients were treated with 5000 units of low-molecular-weight heparin (LMWH) per day until ambulating. Patient demographics, procedure type, diagnosis, adjuvant treatment, and procedure type were recorded. Outcome variables included microvascular thrombosis, partial or total flap loss, hematoma, bleeding, deep venous thrombosis (DVT), pulmonary embolism, and death.
  
  
  RESULTS
  Four hundred seventy patients underwent 505 microvascular free flaps to reconstruct oncologic defects. Two hundred sixty flaps (group A) received postoperative aspirin therapy; 245 flaps (group B) received LMWH therapy. Both groups were statistically similar in their composition. No statistically significant difference was noted between the 2 groups when comparing outcome variables including microvascular thrombosis, partial or total flap loss, hematoma, bleeding, DVT, pulmonary embolism, and death.
  
  
  CONCLUSIONS
  Postoperative anticoagulation choice has no statistically significant effect on the incidence of free flap complications, including bleeding, thromboembolism, and flap loss. We conclude that aspirin or LMWH therapy demonstrates equivalent outcomes when used as single-agent postoperative anticoagulation in oncologic free flap reconstruction.
authors.affiliation: Plastic and Reconstructive Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Ashjian
authors.forename: Constance M
authors.initials: CM
authors.lastname: Chen
authors.forename: Andrea
authors.initials: A
authors.lastname: Pusic
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Disa
authors.forename: Peter G
authors.initials: PG
authors.lastname: Cordeiro
authors.forename: Babak J
authors.initials: BJ
authors.lastname: Mehrara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods*; D013524:Surgical Flaps / Q000098:blood supply; D020246:Venous Thrombosis / Q000188:drug therapy*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D001241:Aspirin