Flow analysis in vascular shunts that bypass the carotid artery.

When blood flow through a carotid artery is impaired and vascular surgery is necessary to restore adequate circulation a vascular shunt can be applied to maintain cerebral blood flow. Several vascular shunts are commercially available, but there is only limited test data on their flow capacity. The purpose of this study is to determine the flow capacity of three vascular shunt systems. A theoretical model has been developed for this purpose. To validate the model, in vitro flow measurements were taken. Application of the model showed that all shunts cause a decrease in blood flow. The amount of flow decrease varied widely from 13% (Javid shunt) to 55% (Pruitt-Inahara). In vitro measurements confirmed the validity of the model. In conclusion, it is important for the vascular surgeon to realise that vascular shunts show large differences in flow capacity. Of the three investigated shunts, the Javid has the highest flow capacity.