Preoperative screening for von Willebrand disease type 1: Low yield and limited ability to predict bleeding

Type 1 von Willebrand disease (vWd) is the most common hereditary bleeding disorder. The objective of this study was to measure the von Willebrand fac tor antigen (vWf:Ag) in a large cohort of patients who underwent surgery to assess the role of a new rapid immunoassay in a screening procedure for vW d in preoperative conditions. We studied 832 consecutive patients (540 chil dren, 292 adults) referred to the surgical departments. For each patient we determined the vWf:Ag level with two different assays, an enzyme-linked im munosorbent assay (ELISA)(Asserachrom vWf:Ag; Diagnostica Stage, France) an d a rapid immunoassay (Liatest vWf:Ag; Diagnostica Stage). Using the refere nce test, we found 30 of 832 patients with a vWf:Ag value below the lower l imits (21 U/dL to 46 U/dL). The coefficient of correlation between the two tests was 0.77 (P = .001). When receiver operating characteristic curves we re used, the cutoff value calculated to detect vWf:Ag defect with the rapid assay was 68.5 U/dL, leading to 0.36% false negatives and 9.7% false posit ives. Thus the rapid immunoassay appears to be a useful and easy method tha t is adaptable to urgent situations. Among the 30 patients with low values in ELISA, 8 had personal or familial bleeding history. Repeat blood samples confirmed the diagnosis of vWd in 5 cases, leading to a prevalence of vWd type 1 of 0.6%. However, in our series the absence of severe bleeding compl ications raises the question of the screening and the management of patient s bearing a type 1 Willebrand disease during surgery.