The effect of normovolaemic haemodilution on the early patency rate of small calibre vascular prostheses studied in a new animal model

A new animal model has been developed to study early thrombosis in small calibre vascular prostheses. It consists of an eETFE graft 2 cm long and of 3mm internal diameter inserted into a rabbit abdominal aorta in which the distal run-off is reduced by narrowing both common iliac arteries using clips with a standard gap. Scanning electron microscopy and in vivo gamma imaging of the graft using labelled autologous platelets showed that, as in the human, platelets played a primary role in the model graft thrombosis. This model was used to study the effect of haemodulution on early graft patency. Moderate normovolaemic haemodilution dramatically improved the early patency rate.