Background: The Hemopump was developed as a more powerful assist device for postcardiotomy support in patients in whom the intraaortic balloon pump is insufficient.
Methods: Over a 2-year period 21 (0.8%) of 2,585 patients undergoing cardiac operations needed a ventricular assist device because of postcardiotomy heart failure unresponsive to pharmacologic and intraaortic balloon support. Sixteen of these patients were assisted with the 24F transthoracic Hemopump left ventricular assist device. The aim of the mechanical support was myocardial recovery as the underlying conditions (age, arterial hypertension, diabetes, vascular and pulmonary disease) excluded heart transplantation.
Results: Hemodynamic improvement was apparent with a decrease in left atrial pressure (mean, 18.6 to 9.2 mm Hg), an increase in arterial blood pressure (mean, 54.1 to 70.1 mm Hg), and an increase in cardiac index. Five patients died within the first 24 hours because of low cardiac output. Although the heart was well unloaded (decrease in left atrial pressure of 8 +/- 4.69 mm Hg versus 9.3 +/- 5.51 mm Hg for the other patients), the increase in cardiac index was significantly lower (+0.516 versus +1.377 L.min-1.m-2; p = 0.027). Three of these 5 patients were known to have severe left ventricular hypertrophy. Of the remaining 11 patients, 2 were assisted for 1 week but failed to show recovery of the myocardium, 8 (50%) were weaned, and 4 (25%) were discharged. There were no device-related complications except the thrombosis of a cannula that was left for 10 days.
Conclusions: The transthoracic Hemopump is an easy-to-use and reliable assist device. Left ventricular hypertrophy is a relative contraindication for the use of the Hemopump.