Veins and other blood vessels may be reshaped by introducing an implant through the vessel walls with anchors positioned on opposite sides of the wall. The anchors typically include an elongate body having coils or other anchors formed therein. The implants may be delivered percutaneously using a cannula which can hold the anchor externally or internally. The methods and devices are useful in treating a dorsal vein to reduce blood flow in patients suffering from erectile dysfunction.