Intraoperative urokinase as an alternative to heparin for patients with suspected heparin-induced thrombocytopenia requiring arterial reconstruction: report of a case and review of the literature.

Patients with heparin-induced thrombocytopenia (HIT) require an alternative antithrombotic treatment to heparin during arterial reconstruction. Ancrod and Iloprost have been employed but are not readily available and carry the risks of systemic side effects (depletion of fibrinogen, hypotension). A patient with HIT in whom intraoperative intraarterial urokinase (UK) was successfully utilized to enable safe arterial reconstruction is described. An 80 year old white female with diffuse arteriosclerotic cardiovascular disease and multiple vascular reconstructions had thrombotic complications following use for heparin during two of her prior operations associated with documented thrombocytopenia and anti-platelet antibodies. She presented with limb-threatening ischemia which was evaluated with angiography revealing severe stenosis of the proximal left superficial femoral artery, occlusion of both anterior tibial and peroneal arteries and several digital vessels, with intact posterior tibial runoff. A common femoral to mid-superficial femoral artery bypass was performed, utilizing contralateral reversed greater saphenous vein, while being treated with aspirin and a continuous intravenous infusion of low molecular weight dextran. During the procedure the clamped arteries were locally perfused with a high volume of dilute UK solution to prevent blood stasis, and enable local delivery of a thrombolytic agent. Although clot formation was observed in the operative field, none occurred within the clamped arteries. A total of 191,200 units of UK were employed with no bleeding complications. Following surgery the patient had a palpable pedal pulse and markedly improved perfusion of her toes. She was discharged on aspirin and coumadin on postoperative day five. It is concluded that for patients with HIT, systemic aspirin and dextran combined with local intraarterial UK are a simple and effective substitute for systemic anticoagulation with heparin during arterial reconstruction.