Intra-arterial fibrinolytic therapy of chronic arterial occlusions

Intra-arterial thrombolysis (reteplase) and ReoPro for subacute thrombosis of the distal aorta accomplished by radial arterial access: the radial-kissing-thrombolytic technique

A 33-year-old woman with subacute thrombosis of the distal aorta after aorto-bi-iliac stenting had local thrombolysis with reteplase in conjunction with systemic abciximab. The infusion was given as a bolus and then continuously for 14 hr by radial artery access with two selective kissing catheters. Patency of the stented segments was achieved with this technique in conjunction with resolution of her clinical symptoms.

Coagulation alterations due to local fibrinolytic therapy with recombinant tissue-type plasminogen activator (rt-PA) in patients with peripheral arterial occlusive disease

PURPOSE

To determine the systemic effects of local fibrinolytic therapy with low-dose recombinant tissue-type plasminogen activator (rt-PA).

METHODS

Ten patients received intrathrombal infusion of 20 mg rt-PA and heparin for local thrombolysis and had subsequent percutaneous transluminal angioplasty (PTA). Eight controls underwent PTA and received heparin alone. We measured t-PA, D-Dimer, and fibrinogen levels before, directly after, and 20, 40, and 60 min and 24 hr after therapy.

RESULTS

In the thrombolysis group the t-PA level peaked immediately after infusion and then declined within 1 hr. D-Dimer increased and remained elevated, whereas in the control group only t-PA levels increased, and only after 24 hr. Fibrinogen remained within the normal range in both groups. Eight of ten patients in the thrombolysis group and seven of eight with PTA had clinical improvement after the procedure.

CONCLUSIONS

The increase in D-Dimer in the rt-PA group indicates a good local fibrinolytic effect. The fact that fibrinogen levels remained unchanged indicates that there is a lack of systemic fibrinogenolysis.

A porcine model of chronic peripheral arterial occlusion

PURPOSE

To create a simple and reproducible model of chromic thrombosis for the evaluation of thrombolytic agents and devices.

MATERIALS AND METHODS

A stenosis was created in the superficial femoral artery of domestic swine, and autologous blood clot was deposited above the stenosis. Follow-up last for up to 3 months. Degree of clot organization was determined at histologic examination. Two thrombolytic agents, urokinase and collagenase, were used to test this model.

RESULTS

There was a 27% delayed recanalization rate with this model. At histologic examination, early thrombus organization was seen at the vessel periphery after 10 days. One-month-old thrombus was substantial but variable in amount. Three-month-old thrombus was completely organized. Neither urokinase nor collagenase proved effective against chronic clot in the doses and time course of this study.

CONCLUSION

This simple method yields a chronic porcine clot in a reliable number of domestic swine in 1 month.

Thrombolytic therapy compared with mechanical recanalization in non-acute peripheral arterial occlusions: a randomized trial

PURPOSE

To evaluate whether thrombolytic therapy followed by angioplasty has any added benefit compared with angioplasty alone for the treatment of chronic peripheral arterial occlusions.

PATIENTS AND METHODS

Twenty patients with claudication or limb-threatening ischemia of at least 3 weeks duration due to iliac or femoropopliteal artery occlusions were randomized either to thrombolytic therapy with recombinant tissue-type plasminogen activator for up to 4 hours (n = 11) followed by angioplasty or to angioplasty alone (n = 9). Clinical follow-up was obtained for 1 year.

RESULTS

Life-table analysis revealed a significant improvement in the cumulative primary patency rate for patients with claudication treated initially with thrombolysis followed by angioplasty (n = 7; 86% at 6 months; 51% at 1 year) compared with angioplasty alone (n = 9; 11% at 6 months and 1 year) (P < .02). All four patients with limb-threatening ischemia were randomized to thrombolytic therapy, and none exhibited continued patency at 1 year. The most common complication in the thrombolysis group was peripheral embolization; three of these four patients were among those who had limb-threatening ischemia as the indication for entry into this study. There was no increased incidence of bleeding with thrombolytic therapy.

CONCLUSIONS

A short course of thrombolytic therapy prior to angioplasty appears to improve the 1-year patency rate for claudication due to iliac or femoropopliteal occlusions. However, patients with limb-threatening ischemia have a high prevalence of peripheral embolization and dismal patency rates with this form of therapy. A larger scale study is necessary to confirm these findings.

Catheter-directed urokinase thrombolysis: an adjunct to PTA/surgery for management of lower extremity thromboembolic disease

Catheter-directed thrombolysis was used either alone or as an adjunct to percutaneous transluminal angioplasty (PTA) or surgery for peripheral vascular occlusion on 112 occasions in 102 patients. Symptom duration ranged from < one to > twenty-eight days. Thrombolytic therapy using urokinase plasminogen activator thrombolysis (uPAT), including intrathrombic injection when possible, was successful (> 50% lysis) in 99 procedures (88%). Technical failure (< 50% lysis) occurred in 13 procedures (12%). In 9 of the 13 failures, intrathrombic injection of urokinase was not possible, but the duration of occlusion was > twenty-eight days in all but 1. Two other failures were from embolic sources and 2 more occurred in patients with a hypercoagulable state. The uPAT was adjunctive to PTA/surgery in 56 cases (50%). PTA following uPAT was required and successfully performed in 24 of 27 cases (88.9%). Surgery followed lytic therapy in another 32 (including the 3 failed PTAs). In the remaining 56 cases (50%), no additional intervention was required. There were 20 complications (18%), minor in 16 of 20 (80%). Minor complications included small puncture site hematomas and distal embolization resolved by continued lytic therapy. Four major complications occurred. One was retroperitoneal hemorrhage directly contributing to the only death in the series. The other 3 were hematuria (2) and femoral neuropathy (1). The authors conclude that catheter-directed lytic therapy alone or as an adjunct to PTA/surgery is a valuable approach to peripheral vascular thromboembolic disease. It is less likely to succeed in chronic occlusion. The incidence of complications is moderate but acceptable.

Thrombolytic Therapy: A Comprehensive Review of Its Use in Clinical Medicine. Part II

The second part of this comprehensive review of thrombolytic therapy in clnical medicien focuses on its use in a wide renge of thrombotic disorders, including pulmonary embolism, deep venous thrombosis, arterial thrombocmbolism, catheter-related thrombosis, arterial thrombocmbolism, catheter-relted thrombosis, and prosthetic valve occlusion. New experimental applications in the management of unstable angina and cerebrovascular disease are also discussed.