MECHANICAL VERSUS PHARMACOMECHANICAL THROMBOLYSIS FOR THE TREATMENT OF THROMBOSED DIALYSIS ACCESS GRAFTS

Pharmacomechanical thrombolysis offers the first practical approach for non-surgical therapy of thrombosed dialysis access grafts. This technique involves both lysis using a fibrinolytic enzyme and mechanical maceration of the clot. The technique can be accomplished in a short period of time, has a high degree of success and has a low level of complications. To evaluate the effectiveness of the mechanical aspects of this technique used alone without the lytic enzyme, a study was designed in which 103 cases of thrombosed PTFE grafts were randomly assigned to either a mechanical (M) group consisting of 55 cases or a pharmacomechanical (PM) group consisting of 48 cases. Both groups were treated in an identical manner using crossed pulse-spray catheters, except that in the M group heparinized saline was used as the pulsing agent while in the PM group concentrated urokinase was used. The two groups were completely comparable in all other respects. The combined procedure of thrombolysis and angioplasty was successful in restoring flow in 92.8% of the M group and 93.8% of the PM group. Life table analysis revealed 74%, 65%, 58% and 37% function in the M group at 15, 30, 60 and 90 days, respectively. The rates for the PM group at the same time intervals were 77%, 72%, 62% and 46%. In none of these parameters was there any significant difference between the two groups. The mean time required for the procedure in the M group was shorter because of the time delay between pulses of enzyme in the PM group built into the technique which was used. Only local complications were seen in either group and consisted of small hematomas at previous needle puncture sites. There was no significant difference between the two groups in this regard. It is concluded that mechanical thrombolysis using saline pulses generated by crossed pulse-spray catheters followed by balloon maceration and dilation is a safe technique and is as effective as pharmacomechanical thrombolysis for the treatment of thrombosed dialysis access grafts.