title: Severe bleeding after percutaneous transhepatic drainage of the biliary system: effect of antithrombotic agents--analysis of 34 606 cases from a Japanese nationwide administrative database.
abstract: OBJECTIVE
  To investigate the relationship between antithrombotic agents (antiplatelet agents and anticoagulants) and severe bleeding after percutaneous transhepatic biliary drainage (PTBD) for biliary obstruction, or cholecystostomy for acute cholecystitis.
  
  
  METHODS
  This retrospective study was institutional review board-approved, and patient consent was waived. Between July 2007 and March 2012, 34 606 patients who underwent PTBD (23 375 patients) or cholecystostomy (11 231 patients) were identified in the Diagnosis Procedure Combination database covering 1119 Japanese hospitals. The association between oral administration of antithrombotic agents prior to the procedure and severe bleeding was evaluated, with adjustment for other potential risk factors, such as age, chronic renal failure, liver cirrhosis, and procedure type. Users of antithrombotic agents were categorized as the continuation group, when they took these agents on the procedure day, or as the discontinuation group, when none were taken. Severe bleeding was defined as bleeding which required red blood cell transfusion or transcatheter arterial embolization within 3 days of the procedure. Univariate and multivariate logistic regression models fitted with generalized estimating equations were performed to evaluate the effect of antithrombotic agents on the bleeding complication.
  
  
  RESULTS
  Overall, 780 of 34 606 patients (2.3%) experienced severe bleeding. In the multivariate model, continuation of antiplatelet agents was significantly associated with severe bleeding versus nonuse (odds ratio [OR], 1.87; 95% confidence interval [CI]: 1.14, 3.05; P = .013), whereas discontinuation of antiplatelet agents showed no association (OR, 0.92; 95% CI: 0.70, 1.20; P = .517). The effect of neither continuation nor discontinuation of anticoagulants on severe bleeding was significant. Other significant risk factors for bleeding included older age, chronic renal failure, liver cirrhosis, academic hospital, and PTBD.
  
  
  CONCLUSIONS
  The continuation of antiplatelet agents can increase severe bleeding after percutaneous transhepatic drainage, whereas the effect of continuation of anticoagulants was inconclusive.
authors.affiliation: From the Department of Gastroenterology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan (T.H., Y.N., H.I., K.K.); Department of Clinical Epidemiology and Health Economics, School of Public Health, the University of Tokyo, Tokyo, Japan (H.Y.); Department of Clinical Data Management and Research, Clinical Research Center, National Hospital Organization Headquarters, Tokyo, Japan (H.H.); and Department of Health Care Informatics, Tokyo Medical and Dental University, Tokyo, Japan (K.F.).
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hamada
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Nakai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isayama
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Horiguchi
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fushimi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects*; D002779:Cholestasis / Q000628:therapy*; D016208:Databases, Factual; D004322:Drainage / Q000379:methods*; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced*; D006801:Humans; D007564:Japan; D008099:Liver; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors