A hand held motor powered device for percutaneous thrombolysis and evacuation of a clot from a clotted arterio-venous fistula is disclosed. The percutaneous thrombectomy device is provided with a plurality of nested coaxial lubricious catheters. The multi-functional thrombectomy device can simultaneously and sequentially degrade and evacuate a blood clot from a blood vessel by multiple modalities that combines to degrade the clot by mechanical agitation, fragmentation and disruption, by peri-thrombus delivery of enzymatic fluids, by irrigation with biocompatible fluids, and by balloon displacement. The thrombectomy device further provides for balloon containment and isolation of clot debris from the general circulation, thereby minimizing the risks to a patient of embolic sequelae. There is also provided an optional steering mechanism for controlled deflection of the working end of the device.