Intracoronary urokinase infusion during prolonged perfusion balloon inflation for massive thrombus in acute myocardial infarction: case series.

Primary percutaneous coronary intervention remains the cornerstone of management in ST-segment elevation myocardial infarction (STEMI). However, thrombus-rich lesions frequently impede optimal reperfusion, increasing the risk of procedural complications and limiting the achievement of Thrombolysis in Myocardial Infarction grade 3 flow. Various adjunctive techniques-including thrombus aspiration, prolonged balloon inflation, excimer laser coronary angioplasty, and intracoronary thrombolysis-have been employed in such scenarios. This case series describes two STEMI patients treated with a novel approach: intracoronary infusion of low-dose urokinase (60,000 units) during prolonged (10-min) inflation with a perfusion balloon (Ryusei, Kaneka, Osaka, Japan), which maintains distal perfusion during dilation. This strategy effectively achieved reperfusion and thrombus resolution while minimizing myocardial ischemia and reducing stent length. In contrast to conventional high-dose thrombolysis, this method enables localized low-dose delivery (60,000 units), potentially enhancing drug retention and tissue penetration. These cases suggest that intracoronary infusion of low-dose urokinase during perfusion balloon inflation may represent a safe and effective adjunctive strategy for managing thrombus-rich lesions in STEMI. Learning objective: To present an innovative technique involving intracoronary infusion of urokinase during prolonged perfusion balloon inflation. This strategy enables simultaneous compression of the culprit plaque and thrombolysis, potentially leading to improved outcomes in STEMI with a high thrombus burden. Additionally, lesion-selective infusion of urokinase through perfusion balloon microholes allows effective thrombolysis with a lower urokinase dose compared to standard administration.