title: Acquired type 2A von Willebrand syndrome caused by aortic valve disease corrects during valve surgery.
abstract: BACKGROUND
  Aortic valve (AV) defects can destroy high molecular weight multimers (HMWM) of von Willebrand factor (VWF), leading to acquired von Willebrand syndrome (aVWS) type IIA. This syndrome is considered a cause for increased perioperative bleeding in AV surgery. If diagnosed before operation, administration of VWF/FVIII concentrates is recommended. However, there is currently no evidence that the VWF HMWM defect persists during surgery long enough to require haemostatic therapy. We hypothesized that the preoperative VWF HMWM defect corrects already during cardiopulmonary bypass (CPB) before any haemostatic therapy.
  
  
  METHODS
  This prospective observational study enrolled 17 patients undergoing AV surgery, either isolated or associated with mitral valve or aorta surgery, and also 10 patients undergoing coronary artery bypass surgery (CABG) for comparison. VWF HMWM, VWF antigen (VWF:Ag) concentration, and collagen-binding capacity (VWF:CB) were measured before operation, directly after weaning from CPB, and on the first postoperative day.
  
  
  RESULTS
  In 12 of the 17 subjects undergoing AV surgery (71%), VWF HMWM were abnormally absent before operation. At the end of CPB, VWF HMWM were normal in 15 of AV subjects (88%), and was normal in 16 subjects on the first postoperative day. VWF:Ag and VWF:CB were within or above the normal range at all three times. Two out of 10 subjects undergoing CABG (20%) had preoperative deficits of VWF HMWM that normalized after operation.
  
  
  CONCLUSIONS
  Preoperative VWF HMWM defects corrected at the end of CPB in the absence of haemostatic therapy in most patients undergoing AV surgery. Diffuse bleeding occurring after CPB is unlikely to be related to persisting type 2A von Willebrand syndrome; other causes of coagulopathy should be suspected. Administration of VWF/FVIII concentrates appears unnecessary in this setting.
authors.affiliation: Department of Anaesthesiology and Intensive Care, Salzburger Landeskliniken SALK, Salzburg, Austria. solomon.cristina@googlemail.com
authors.forename: C
authors.initials: C
authors.lastname: Solomon
authors.forename: U
authors.initials: U
authors.lastname: Budde
authors.forename: S
authors.initials: S
authors.lastname: Schneppenheim
authors.forename: E
authors.initials: E
authors.lastname: Czaja
authors.forename: C
authors.initials: C
authors.lastname: Hagl
authors.forename: H
authors.initials: H
authors.lastname: Schoechl
authors.forename: M
authors.initials: M
authors.lastname: von Depka
authors.forename: N
authors.initials: N
authors.lastname: Rahe-Meyer
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001780:Blood Coagulation Tests / Q000379:methods; D001803:Blood Transfusion; D001026:Coronary Artery Bypass; D005260:Female; D006349:Heart Valve Diseases / Q000097:blood / Q000150:complications* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011446:Prospective Studies; D056728:von Willebrand Disease, Type 2 / Q000097:blood / Q000209:etiology* / Q000628:therapy; D014841:von Willebrand Factor / Q000276:immunology / Q000378:metabolism
chemical_list: C029417:Von Willebrand antigen; D014841:von Willebrand Factor