An assembly for joining two vessel segments of a patient comprises a coupler formed of adjoining coupler halves, and a cuff having a large diameter portion and a small diameter portion. Each of the coupler halves includes an aperture for receiving an end of one of the vessel segments. One of the coupler halves comprises a connector element sized and shaped for connection to the other coupler half. The vessel segments are alignable in the respective coupler halves such that a path for fluid flow is formed therebetween upon connection of the coupler halves. The large diameter portion of the cuff is positioned over at least a portion of the coupler, and the small diameter portion of the cuff is positioned over one of the vessel segments. The cuff further includes a probe positioned at the small diameter portion. The probe is positioned within the cuff in a manner such that a signal is receivable therein corresponding to fluid flow through the vessel segment.