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Updated: Oct 2, 2026

An In vitro System to Gauge the Thrombolytic Efficacy of Histotripsy and a Lytic Drug
Published on: June 4, 2021
Mechanical and enzymatic thrombolysis for massive pulmonary embolism
Miguel Angel De Gregorio1, M J Gimeno, A Mainar
1Department of Interventional Radiology, Hospital Clínico Universitario, Avda Gomez Laguna s/n., Zaragoza, Spain. mgregori@separ.es
Purpose:
To assess the efficacy and safety of mechanical fragmentation combined with intrapulmonary thrombolysis in massive pulmonary thromboembolism (PTE) with hemodynamic impairment.
Materials And Methods:
Fifty-nine patients diagnosed with massive PTE with hemodynamic impact were treated. The initial clinical symptoms were shock in 23 patients (38.9%), syncope in eight (13.5%), and dyspnea at rest in 28 (47.4%). Mean O2 saturation was 67.8%. Mean pulmonary artery pressure (PAP) was 42.1 mm Hg. During fragmentation, thrombolysis was administered in the form of a urokinase bolus of 200,000-500,000 U in 57 patients and 20 mg of recombinant tissue plasminogen activator (rt-PA) in two patients. The mean urokinase dose used was 2,500,000 IU, whereas the total dose of rt-PA was 100 mg. Heparin sodium infusion was performed to reach activated partial thromboplastin time ratios of 2. The follow-up consisted of clinical assessment, pulmonary scintigraphy, and echocardiography. The patients received treatment with dicoumarin for 6 months after the procedure.
Results:
Clinical improvement was seen in 56 patients (94%). Three patients died. The mean PAP after the treatment was 21.8 mm Hg. The mean posttreatment Miller index was 0.35. Technical success was achieved in all cases and clinical symptoms improved in all cases except those in which the patients died. Pulmonary scintigraphy showed improved perfusion in all cases. Echocardiography was performed after 3-6 months, showing a mean pressure of 22.8 mm Hg (corrected values). There were no signs of recurrent PTE or arterial hypertension in the follow-up.
Conclusion:
The data provided confirm the efficacy and safety of mechanical fragmentation and pharmacologic thrombolysis in the treatment of massive PTE with hemodynamic impairment, showing improvement of symptoms and a decrease in PAP.
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