• Claudia Heilmann, Ulrich Geisen, Friedhelm Beyersdorf, Lea Nakamura, Georg Trummer, Michael Berchtold-Herz, Christian Schlensak, and Barbara Zieger.
• Department of Cardiovascular Surgery, University Heart Center Freiburg - Bad Krozingen, Hugstetter Str 55, 79194 Freiburg, Germany. claudia.heilmann@uniklinik-freiburg.de
• Eur J Cardiothorac Surg. 2011 Dec 1;40(6):1328-33; discussion 1233.

ObjectiveAcquired Von Willebrand syndrome (AVWS) can contribute to bleeding complications in patients with ventricular assist devices (VADs). AVWS results from shear stress, which causes unfolding of the high-molecular-weight (HMW) multimers of Von Willebrand factor (VWF) with subsequent cleavage. Loss of the HMW multimers of VWF is the leading finding in AVWS. In consequence, binding of VWF to collagen and to platelets is impaired. The onset of AVWS after VAD implantation is not yet determined. We examined VAD patients for presence of an AVWS in the early, intermediate, and late phase after VAD implantation.MethodsPatients with a biventricular Thoratec-PVAD(®) (BVAD, n = 6) or a left-ventricular HeartMateII(®) (HMII, n = 11) were analyzed prior to VAD implantation and after 1, 3, 14, 30, and 60 days. Diagnosis of AVWS based on VWF:ristocetin cofactor activity/VWF:VWF antigen (VWF:RCo/VWF:Ag), collagen-binding capacity:VWF antigen (VWF:CB/VWF:Ag), and multimeric analysis. In addition, we analyzed the number of bleeding episodes, which required surgical intervention.ResultsNo patient had an AVWS prior to VAD implantation. An AVWS was identified already in the very early postoperative period, that is, in almost all patients on the first day and in all patients on the third day. The AVWS was also detected in the majority of patients in the further course. Nine of all 17 patients suffered bleeding complications and required a total of 25 interventions due to hemorrhages. Forty percent of re-interventions were carried out within the first 10 days after implantation; five of these were necessary within the first 24h.ConclusionThe AVWS is present already in the early postoperative phase after VAD implantation. Therefore, reduced shear stress has to be an important feature of newly developed assist devices in the future.Copyright © 2011 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

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