Pharmacomechanical thrombolysis of natural vein fistulas: reduced dose of TPA and long-term follow-up.

Twenty-five episodes of pharmacomechanical thrombolysis of 20 clotted arteriovenous fistulas (AVFs) are reported. The technique presented utilizes the local instillation of tissue plasminogen activator (TPA) in small doses together with manual maceration to dissolve clot and balloon angioplasty to correct the underlying stenoses. Since the minimum dose of TPA necessary to successfully perform thrombolysis of a natural vein fistula had never been determined, an attempt to use as minimal a dose of TPA as possible was made. Five procedures were performed in fistulas which had previously undergone a thrombolysis procedure with TPA. The procedures were successful in 92% of cases with an average dose of TPA required of 2.3 +/- 0.32 mg/procedure. In addition to the 20 accesses in this article, we offer follow-up life table data on 15 fistulas that were previously reported for a total of 35 accesses salvaged with pharmacomechanical thrombolysis. Primary patency was 11.2 months and secondary patency was 25 months. Fifty-five percent of fistulas required repeat angioplasty procedures at an average of 3.6-month intervals. In addition, more than half of the fistulas that presented with clotting required repeat interventions for continued patency. This report demonstrates the effectiveness of small doses of TPA in successful pharmacomechanical thrombolysis of clotted fistulas.