Occluded peripheral arteries and bypass grafts: lytic stagnation as an end point for pulse-spray pharmacomechanical...

Angiographic demonstration of luminal narrowing during pulse-spray pharmacomechanical thrombolysis (PSPMT) may reflect residual lysable clot, organized thrombus, platelet-rich clot, atherosclerosis, neointimal hyperplasia, or functional narrowing. The authors evaluated the efficacy and safety of lytic stagnation (initial rapid lysis followed by insubstantial further lysis with additional treatment) as an end point for PSPMT. Lytic stagnation was evaluated with serial angiography in 16 arterial and five bypass graft occlusions. Substantial lysis occurred after administration of mean doses of 512,000 units +/- 182,000 of urokinase or 5.3 mg +/- 2.0 of tissue-type plasminogen activator. Additional treatment with either of those agents produced minimal or no further change in the appearance of residual disease. Recanalization was successful in all patients after angioplasty. Distal emboli were noted in four cases, in three of which angioplasty of large intraluminal filling defects had been performed. The authors conclude that lytic stagnation is a reliable and safe end point for PSPMT in the absence of large intraluminal filling defects.