A catheter system for removal of a thrombus from a vessel, comprising: a multi-lumen inner catheter having a proximal end, an infusion segment, and a distal end, the inner catheter comprising: at least three lumina extending from the proximal end to the distal end of the inner catheter; at least one infusion fenestration along the infusion segment; and a distal encapsulation balloon at the distal end; and a multi-lumen outer sheath having a proximal end and a distal end, the outer sheath comprising: an inflation lumen, a catheter lumen and a suction lumen, wherein the catheter lumen is configured to receive the multi-lumen inner catheter such that at least a portion of the inner catheter is surrounded by the outer sheath; a proximal encapsulation balloon at the distal end, an agitator operable to agitate or fragment the thrombus, wherein the agitator is rail mounted on the outside of the catheter lumen and operable to advance and retract over the catheter lumen of the outer sheath such that the agitator is within the suction lumen when retracted, wherein the distal encapsulation balloon and the proximal encapsulation balloon are separated by an adjustable distance along the infusion segment, the adjustable distance forming a thrombolytic treatment area, and wherein the inner catheter and outer sheath are operable to provide isovolumetric suction and restoration of fluid within the thrombolytic treatment area. a multi-lumen inner catheter having a proximal end, an infusion segment, and a distal end, the inner catheter comprising: at least three lumina extending from the proximal end to the distal end of the inner catheter; at least one infusion fenestration along the infusion segment; and a distal encapsulation balloon at the distal end; and at least three lumina extending from the proximal end to the distal end of the inner catheter; at least one infusion fenestration along the infusion segment; and a distal encapsulation balloon at the distal end; and a multi-lumen outer sheath having a proximal end and a distal end, the outer sheath comprising: an inflation lumen, a catheter lumen and a suction lumen, wherein the catheter lumen is configured to receive the multi-lumen inner catheter such that at least a portion of the inner catheter is surrounded by the outer sheath; a proximal encapsulation balloon at the distal end, an inflation lumen, a catheter lumen and a suction lumen, wherein the catheter lumen is configured to receive the multi-lumen inner catheter such that at least a portion of the inner catheter is surrounded by the outer sheath; a proximal encapsulation balloon at the distal end, an agitator operable to agitate or fragment the thrombus, wherein the agitator is rail mounted on the outside of the catheter lumen and operable to advance and retract over the catheter lumen of the outer sheath such that the agitator is within the suction lumen when retracted, wherein the distal encapsulation balloon and the proximal encapsulation balloon are separated by an adjustable distance along the infusion segment, the adjustable distance forming a thrombolytic treatment area, and wherein the inner catheter and outer sheath are operable to provide isovolumetric suction and restoration of fluid within the thrombolytic treatment area.