A method and device for cutting venous valve located within the lumen of a vein. The device comprises an elongate shaft of rigid or flexible construction and a valvulotome blade positioned on the distal end of said elongate shaft. The valvulotome blade comprises an elongate shank portion which is disposed substantially parallel to the longitudinal axis of the shaft, and a head portion which extends laterally from the shank portion of the blade. The head portion of the blade comprises an outer venous wall abutment surface and a proximal cutting surface. The venous wall abutting surface is a spaced distance from the proximal cutting surface such that the venous wall abutment surface may be forced into abutment with the venous wall and the device may be drawn through a venous valve such that the proximal cutting surface will cut the venous valve, but will not come into contact with the adjacent vein wall. The device may incorporate a mechanism, such as a protruding loop of wire, which will abut against the blood vessel wall so as to force the venous wall abutment surface of the valvulotome blade against the opposite wall of the vein or during the venous valve cutting procedure. The method of the invention provides for operation of the device to effect cutting of venous valve, and may be performed concurrently with an in situ side branch occlusion procedure. The method is preferably performed under angioscopic guidance, and the angioscope used for guidance of the method may be integrated with a separate side branch occlusion device to facilitate concurrent performance of the side branch occlusion procedure and the venous valve cutting procedure.