Peripheral arterial occlusions: Local low-dose thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA)

Abstract

OBJECTIVE: To study the efficacy and risks of local thrombolytic therapy of peripheral arterial occlusions using rt-PA. DESIGN: This open study was performed in one clinic in Munich, Germany. METHODS: 288 patients suffering from occlusions of the lower limb arteries were subjected to 336 treatments performed with a permanently controlled technique. In a short pilot study 10mg rt-PA/h were administered for 5 h but in the majority of the cases only 2.5mg/h were administered for a maximum of 5 h. The average total dose of rt-PA was 2.97mg and the average time for lysis was 78 min. RESULTS: 43 (84.3%) out of 51 embolic occlusions and 168 (71.5%) out of 235 thrombotic occlusions were recanalised with a cumulative patency of 95% and 79.7% respectively after 2 years. One systemic bleeding occurred in the pilot study with 10mg rt-PA/h whereas with the 2.5mg/h dosage no systemic bleeding or embolism occurred in the 315 treatments. There were no deaths during hospitalisation. Six major and two forefoot amputations were necessary. Thirteen patients required a bypass operation and one an embolectomy. The advantages of our controlled technique are: short duration of treatment, small doses of activating agent, an accurately directed pathway with the possibility of dilating stenoses during the same session, no danger of systemic bleeding or embolism and, therefore, good prospects of success with minimal risk. CONCLUSION: The use of rt-PA for local lysis substitutes the inadequate tissue activator available for effective spontaneous lysis and is, therefore, almost physiological. The effect of a very low dose of rt-PA was as good as that of higher doses.