Acquired bleeding disorders: shear-mediated von Willebrand proteolysis in circulatory support and aortic stenosis [descriptive label — exact article title VERIFICATION REQUIRED]

29, 36, 39

Explains why the quantity of von Willebrand factor can be normal or high while function is severely impaired: what is lost is a size distribution, not a concentration — and an antigen level cannot see a size distribution.

Congenital von Willebrand disease and other acquired bleeding disorders

Tiede A, Susen S, Lisman T. Haemophilia 2024;30(S3):29-38. DOI 10.1111/hae.14995

Review of mechanism, diagnosis and management

Narrative review; not ECMO-specific; no ECMO-specific thresholds or management data

Places extracorporeal support in the same mechanistic class as aortic stenosis and ventricular assist devices: increased proteolysis through shear stress followed by ADAMTS13, with frequent and recurrent mucosal bleeding. Under high shear the multimer unfolds and exposes the ADAMTS13 cleavage site, so the largest and most haemostatically potent multimers are removed first.

Patients with acquired von Willebrand syndrome from high-shear states — extracorporeal support, left ventricular assist devices, aortic stenosis