An implantable device intended to be used to permanently join vascular structures (blood vessels) that includes an attached ultrasound (Doppler) probe for measuring blood flow through the anastomosis; it is typically used during microvascular surgery. It consists of two ring-shaped components over which the ends of the vessels are everted and held in place by pins; the rings are approximated using a dedicated device to create the anastomosis. The probe is connected to an external monitor and used to confirm vessel patency during and after the procedure for up to 14 days before it is removed.