Lower Dose and Duration of Tissue Plasminogen Activator for EKOS Used Successfully

Purpose: Thrombolytic therapy restores pulmonary perfusion more rapidly than systemic anticoagulation, but this comes with major risk of bleeding complications. Recently, catheter-directed and ultrasound-assisted catheter-directed thrombolysis techniques are being used for intermediate- and high-risk acute pulmonary embolism (PE). The potential advantage of catheter-directed thrombolytic is that lower doses of the thrombolytic agent can be administered, thereby reducing the risk of bleeding when compared with systemic therapy

Materials and Methods: Case details were gathered from electronic medical records. Detailed review of literature was performed using PubMed.

Results: A 75-year-old man presented with rectal bleeding and was found to have anorectal adenocarcinoma, which was removed surgically. One week after surgery, he developed high-grade bowel obstruction and underwent partial small bowel resection. Two days later, he developed acute dyspnea. He was tachycardic with a heart rate of 143 beats/min, hypotensive with a blood pressure of  98/54 mm Hg, tachypneic with a respiratory rate of 26 breaths/min, and hypoxic with spo₂ 83% on room air. Computed tomography chest angiogram showed massive bilateral PE with a right ventricular–to–left ventricular (RV/LV) ratio of 2:1. Echocardiogram confirmed elevated right heart pressure with akinetic mid free wall and hyperkinetic apex. In view of recent abdominal surgeries and high bleeding risk, it was decided to treat PE conservatively with systemic heparin. By the next day, the patient continued to be dyspneic and hypotensive with a systolic blood pressure of 80 mm Hg, which failed to respond to intravenous fluids. It was decided to proceed with an EKOS procedure using a lower dose of tissue plasminogen activator (t-PA), so 2 mg of t-PA was given as a bolus, and 0.5 mg/hr/catheter t-PA was infused for10 hours to bilateral pulmonary arteries. The total dose of t-PA given as infusion was 10 mg.

Conclusions: The SEATTLE II system is approved by the US Food and Drug Administration. describes using t-PA at a total dose of 24 mg over 24 and 12 hours for unilateral and bilateral acute PE, respectively. We used a lower dose and duration of t-PA with complete resolution of clinical symptoms and correction of RV/ LV ratio with no bleeding complication. Our case highlights the successful use of a lower dose of t-PA especially in patients with a higher risk of bleeding.