title: Incidence and risk factors of deep vein thrombosis after liver transplantation.
abstract: BACKGROUND
  Deep venous thrombosis (DVT) occurs in 0.1% of persons per year, affecting 15%-40% of general surgical procedures without prophylaxis. Thromboembolic prophylaxis is not commonly used after orthotopic liver transplantation (LT) owing to the risks of bleeding and coagulopathy. Cirrhosis and the association with the coagulation cascade, before and after transplantation, are not well understood. The purpose of this study was to determine the incidence of DVT and its risk factors after LT.
  
  
  METHODS
  We retrospectively reviewed LTs performed at our center from 2005 to 2012. We identified patients with Doppler examinations showing DVT after LT, platelet count, and international normalized ratio (INR) at time of DVT, associated symptoms, DVT prophylaxis, and perioperative risk factors. We determined the incidence of DVT, the odds ratio of each preoperative risk factor, the difference in platelet count and INR between those with and without a DVT, and the weighted risk of each factor in the development of DVT with the use of logistic regression modeling.
  
  
  RESULTS
  Of 314 patients, the incidence of DVT was 8.6% (27/314). Between those with and without DVT there was no significant difference in age, sex, platelet count, INR, infection, hepatocellular cancer, use of venous bypass, and prior surgery. There was a significant difference in mobility, 67% vs 20% (P < .0001), and the use of factor VII, 11% vs 2% (P < .05). The estimated risk for of developing DVT for patients with neither of these factors was 4%; with factor VII the risk rose to 17%; with mobility difficulty the risk rose to 23%; and with both the risk was 62%. In our entire population, there were no cases of pulmonary embolism.
  
  
  CONCLUSIONS
  The risk of developing a DVT after LT is ≥9% even with mechanical DVT prophylaxis. Consideration should be given to using both mechanical and chemical prophylaxis after LT.
authors.affiliation: Cedars Sinai Medical Center, Los Angeles, California. Electronic address: alagappan.annamalai@cshs.org.
authors.forename: A
authors.initials: A
authors.lastname: Annamalai
authors.affiliation: Cedars Sinai Medical Center, Los Angeles, California.
authors.forename: I
authors.initials: I
authors.lastname: Kim
authors.affiliation: Cedars Sinai Medical Center, Los Angeles, California.
authors.forename: V
authors.initials: V
authors.lastname: Sundaram
authors.affiliation: Cedars Sinai Medical Center, Los Angeles, California.
authors.forename: A
authors.initials: A
authors.lastname: Klein
mesh_terms: D002140:California / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D016031:Liver Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D018608:Ultrasonography, Doppler; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology