Pulmonary embolism from pulse-spray pharmacomechanical thrombolysis of clotted hemodialysis grafts: Urokinase versus heparinized saline

PURPOSE: To compare the frequency and extent of pulmonary embolism (PE) occ urring during pulse-spray pharmacomechanical thrombolysis (PSPMT) of clotte d hemodialysis grafts with use of either urokinase (UK) or heparinized sali ne (HS), Postintervention primary patency and complication rates were compa red for each method of thrombolysis. METHODS AND MATERIALS: Twenty-seven patients were enrolled in this prospect ive, randomized, double-blind study evaluating PE with two PSPMT agents. Th e doses of heparin were similar between groups. The only variable was that one group of patients received UK and the other received HS, In two cases, the venous anastomosis could not be crossed. Eleven patients were treated w ith UK and 14 with HS, Nuclear medicine perfusion lung scans were performed before treatment and after graft declotting procedures. Lung perfusion was quantified to 10% of a pulmonary segment (0 = normal perfusion, 1 = segmen tal perfusion defect), with nine segments counted for each lung. RESULTS: Baseline nuclear medicine perfusion lung scan results were abnorma l (greater than or equal to 20% segmental perfusion defect) in 19 patients (70.4%). New PE (one or more pulmonary segments) occurred in two patients t reated with UK (18.2%) and nine patients treated with HS (64.3%; P =.04). A ll cases of PE were asymptomatic. Quantitative global pulmonary perfusion a nalyses revealed that treatment with UK improved flow to 0.2 +/- 2.0 pulmon ary segments, whereas treatment with HS decreased perfusion to 1.0 +/- 1.7 segments (P =.16, NS), Although postintervention primary patency rates were similar according to life-table analysis (P =.76, NS), complication rates were higher with use of HS (n = 4, 28.6%) than with use of UK (n = 2, 18.2% ) (P =.6, NS). CONCLUSIONS: All PE were asymptomatic during PSPMT, but treatment with UK r educed the rate of PE and tended to result in smaller defects in lung scan results. Most patients undergoing hemodialysis have abnormal baseline perfu sion scan results, but PSPMT with UK improved many of them. The postinterve ntion primary patency rates were similar between groups, but complications were more frequent after treatment with HS.