Evaluation of a modified Arrow-Trerotola percutaneous thrombolytic device for treatment of acute pulmonary embolus in a canine model

PURPOSE: Massive pulmonary embolus (PE) is often rapidly fatal. Surgical thrombectomy has a mortality rate as high as 74%. Multiple percutaneous methods have been tested with limited success. The purpose of this study was to evaluate the Arrow-Trerotola percutaneous thrombolytic device (PTD) for (i) the ability to clear pulmonary embolus and (ii) the effect on normal pulmonary vasculature. These were tested in a canine model. MATERIALS AND METHODS: Iatrogenic unilateral massive PEs were created in nine canines. These PEs were then treated with the PTD. The device was also activated in the normal pulmonary artery. Immediately after treatment, six animals were killed. Three animals were allowed to recover and underwent pulmonary arteriography 1 month later to evaluate pulmonary hypertension, stenosis, or occlusion; they were then killed. Autopsy specimens were evaluated for histologic evidence of acute or chronic vascular injury. RESULTS: Acutely, the PTD effectively thrombolysed the PE in all animals. Histologically, there was moderate intimal injury, but no evidence of pulmonary artery disruption. There was one device failure. One month after treatment, there was no radiographic evidence of pulmonary stenosis at device activation sites, no pulmonary hypertension, and only mild histologic evidence of scar formation. CONCLUSION: In preliminary animal testing, the PTD is safe and effective for treating large central pulmonary emboli. Human clinical trials are warranted.