Efficacy of thrombolytic therapy for occlusion of long-term catheters.

Nineteen ambulatory outpatients requiring a tunneled central venous access device with catheter occlusion were studied. Mean catheter life was 7.9 +/- 8.2 months (range, from 1-36 months) at the time of the occlusion. Urokinase (5000 units/ml) was injected in sufficient amount to fill the internal volume of the catheter and allowed to stay for 5 to 10 min before attempting to aspirate. Repeated aspiration attempts were performed every 5 to 10 min for a maximum of 30 to 60 min or patency. In the event catheter patency was not restored, the thrombolytic solution was aspirated from the catheter and a maximum of two additional trials were instituted. Results included clearance of four out of 15 withdrawal occlusions (27%) and two out of four resistance to infusion occlusions (50%). Overall, successful catheter clearance occurred in six out of 19 occlusions (32%). The efficacy rate of thrombolytic therapy for successfully clearing occluded catheters at our institution using conventional low-dose thrombolytic therapy is markedly lower than previously reported rates of 57 to 100%. The reasons for this discrepancy may reflect differences in dosage of thrombolytic agent, method of administration, frequency of monitoring of catheter patency, and catheter life.