A single operator exchange fluid jet thrombectomy device having an outer catheter assembly and separable and exchangeable components in the form of an inner catheter assembly allowing functioning as a rheolytic thrombectomy catheter or as a crossflow thrombectomy catheter. Embodiments include an outer catheter assembly common to any mode of usage having a guide catheter having a lumen through which a guidewire and the greater portion of a hypo-tube carrying a flow director are passed and advanced. For use as a rheolytic thrombectomy catheter, thrombus is dislodged, entrained, and broken into pieces by jets and evacuated through the lumen of the guide catheter. For use as a crossflow thrombectomy catheter, a flow director having outflow and inflow orifices is provided.