Medical systems, devices and methods for creation of autologous tissue valves within a mammalian body are disclosed. One example of a device for creating a valve flap from a vessel wall includes an elongate tubular structure having a proximal portion and a distal portion and a longitudinal axis； a first lumen having a first exit port located on the distal portion of the elongate tubular structure； a second lumen having a second exit port located on the distal portion of the elongate tubular structure； a recessed distal surface on the distal portion of the elongate tubular structure, wherein the recessed distal surface is located distally to the first exit port； and an open trough on the recessed distal surface extending longitudinally from the first exit port.
