Peripheral thrombolysis with tissue plasminogen activator. Results of two treatment regimens

The purpose of this study was to document the response to tissue plasminogen activator given as either a low-dose intra-arterial infusion or a bolus infusion in patients with peripheral arterial or bypass graft occlusion.

Fifty thrombolytic procedures were carried out in 45 patients with a recent occlusion of a peripheral artery (41) or bypass graft (nine). A continuous infusion of 1.0 mg/h of tissue plasminogen activator was used in 27 patients (group A), while 23 patients were given a 20-mg bolus followed by an infusion of 1.0 mg/h (group B). Patients in the two groups were followed up for 12.1 +/- 9.3 months and 11.1 +/- 9.1 months, respectively.

In group A, the angiographic lysis rate was 74% and clinical success rate was 67%. In group B, the comparable rates were 70% and 48%. Lysis was quicker when a bolus infusion was used, the mean lysis time being 14.4 +/- 7.9 hours compared with 26.7 +/- 9.4 hours following infusion alone (P = .0005). There was one instance of major hemorrhage in group A and eight in group B (P = .0022), including two patients with cerebral hemorrhage, one of whom died.

Low-dose tissue plasminogen activator infusion is safe and reasonably effective, although a long treatment time is required. A bolus infusion regimen speeds lysis but is attended by a high incidence of serious hemorrhage.