This invention relates to devices and methods for sutureless-sealing of vessels. A device for coupling vessels is described which comprises: a main trunk first and second stent-anchors associated with the main trunk a graft extension extending from the main trunk a bypass vessel and an internal anchor and an external anchor. The internal anchor and the external anchor cooperate to seal the graft extension and the bypass vessel.An alternative device for coupling vessels is also described which comprises: a main vessel having an end a bypass vessel having an end a coupling graft disposed within the main vessel end and the bypass vessel end a main vessel internal stent-anchor configured to seal the main vessel with the coupling graft and a bypass vessel internal stent-anchor configured to seal the bypass vessel with the coupling graft. The main vessel and the bypass vessel are held in fluid communication via the coupling graft.