Background: The presence of intracoronary thrombus significantly increases the risk of conventional balloon angioplasty because of a high incidence of abrupt closure, distal embolization, and no-reflow phenomenon. The purpose of this study was to assess a new technique for treating intracoronary thrombus consisting of the local delivery of urokinase directly to the angioplasty site with a novel, catheter-based, drug delivery system.
Methods: The Dispatch catheter is a new local, drug-delivery device that allows for the prolonged infusion of therapeutic agents at an angioplasty site while still maintaining distal coronary perfusion. Six patients with angiographic or clinical evidence of intracoronary thrombus were treated with 150,000 units of urokinase over a 30-min period using this device prior to or following conventional balloon angioplasty and/or directional atherectomy.
Results: Successful delivery of urokinase directly to the angioplasty site was achieved in all 6 patients without hemodynamic or electrocardiographic compromise. In all six cases, local urokinase therapy resulted in complete dissolution of angiographic intracoronary thrombus and/or reduction of the coronary stenosis. Limited ischemia due to side-branch occlusion by the catheter's coils was noted in one patient. Distal embolization or no-reflow phenomenon were not observed in any case.
Conclusion: The local drug-delivery catheter used in this study was able to successfully and rapidly achieve intracoronary thrombolysis by delivering limited quantities of urokinase directly to the angioplasty site, while still maintaining distal coronary perfusion. This technique of local, thrombolytic drug delivery may be useful in the percutaneous treatment of intracoronary thrombus and thrombus-containing stenoses.