Hemolytic Effect of the Amplatz Thrombectomy Device

The hemolytic effect of the Amplatz thrombectomy device (ATD) was evaluated in nine dogs and in nine patients. The device was activated for 1–2 minutes in the abdominal aorta, inferior vena cava, or femoral artery of nine dogs. The device was activated for 1–4 minutes in the nine patients in occluded lower extremity bypass grafts ( n = 5), native superficial femoral artery ( n = 1), a pulmonary artery embolus ( n = 1), a portocaval shunt ( n = 1), and an iliac vein stent ( n = 1). Patients were examined for laboratory evidence of hemolysis following mechanical thrombectomy. In all dogs haptoglobin level decreased, free hemoglobin level in the plasma increased, and hemoglobinuria was present. There was no change in renal function. The level of haptoglobin decreased and the level of plasma free hemoglobin increased in eight patients, with hemoglobinuria detected in one. More hemolysis was observed in the animals than in the patients. The ATD has a definite transient hemolytic effect. Until further studied, it should not be used in children and should be used with caution in patients who are anemic, hypoxemic, or have potentially reversible renal insufficiency. Activation time should be monitored closely because hemolysis probably increases with increasing activation time.