title: Heparin-induced thrombocytopenia and thrombosis as an under-diagnosed cause of flap failure in heparin-naive patients: a case report and systematic review of the literature.
abstract: BACKGROUND
  Heparin-induced thrombocytopenia and thrombosis (HITT) is an immune complex mediated and potentially devastating cause of flap loss in microvascular surgery. HITT may be an under-reported cause of early-flap failure due to subclinical manifestations at the time of flap loss. A case report of a patient presenting with HITT-related flap failure and the results of a systematic literature review of the clinical presentation of HITT in microsurgery are presented here.
  
  
  METHODS
  A patient suffering from a chronic wound on the right medial malleolus was treated with an ALT flap, which was compromised by thrombosis. Multiple attempts to rescue the flap including thrombolysis, popliteal AV loop, and a second free flap were all unsuccessful. Six days following the initial procedure, a diagnosis of HITT was made following a positive HITT-antibody test as the cause of flap failure.
  
  
  METHODS
  PubMed, MEDLINE, and EMBASE searches yielded 113 results, of which 6 met our criteria for manuscripts describing HITT in microsurgical procedures.
  
  
  RESULTS
  Evaluation of the peer-reviewed literature describing HITT in microsurgery suggests that HITT-related flap failure occurs rapidly, more frequently in heparin-naïve patients, and in advance of systemic thrombosis and thrombocytopenia.
  
  
  CONCLUSIONS
  Due to the rapid and unpredictable onset of HITT during microsurgery, we recommend maintaining an index of suspicion for HITT in flaps with otherwise unexplained early thrombosis. We also encourage hematology consultation, discontinuing heparin use and initiating alternate thromboprophylaxis in order to inhibit the potential for subsequent life-threatening systemic complications as well as improving the potential for delayed reconstructive success.
authors.affiliation: Division of Plastic and Reconstructive Surgery, McGill University, Montreal, QC; Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, MA.
authors.forename: Oren
authors.initials: O
authors.lastname: Tessler
authors.forename: Joshua
authors.initials: J
authors.lastname: Vorstenbosch
authors.forename: Daniel
authors.initials: D
authors.lastname: Jones
authors.forename: Sebastien
authors.initials: S
authors.lastname: Lalonde
authors.forename: Teanoosh
authors.initials: T
authors.lastname: Zadeh
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects*; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000139:chemically induced*; D013524:Surgical Flaps; D013921:Thrombocytopenia / Q000139:chemically induced*; D013927:Thrombosis / Q000139:chemically induced*; D017211:Treatment Failure
chemical_list: D000925:Anticoagulants; D006493:Heparin