ORGAN PERFUSION WITH HEMOPUMP DEVICE ASSISTANCE WITH AND WITHOUT INTRAAORTIC BALLOON PUMPING

Objective: Our objective was to analyze the potential advantage of com bining an intraaortic balloon pump with a transthoracic Hemopump devic e (Medtronic, Inc., Minneapolis, Minn.) (Nimbus Medical, Inc., Rancho Cordova, Calif.). Methods: Twelve sheep underwent implantation of a tr ansthoracic Hemopump device and an intraaortic balloon pump. In the fi rst series (n = 6), we analyzed the influence of the counterpulsation on the performance of the Hemopump device. In the second group (n = 6) , hemodynamic changes, myocardial wall thickening, organ perfusion, an d myocardial perfusion (determined with colored microspheres) were ana lyzed under the following conditions: (1) control situation, (2) durin g application of coronary stenosis, (3) during support with the Hemopu mp device, and (4) during support with the Hemopump device combined wi th intraaortic balloon pump support. Results: In the first series, we found that addition of counterpulsation reduced output with the Hemopu mp device by 11.1% +/- 6%. In the second series, it was shown that cor onary stenosis significantly reduced contractility (rate of pressure c hange and wall thickening) but did not cause hemodynamic collapse. Myo cardial blood Bow was significantly reduced in the poststenotic subend ocardial regions (mean subendocardial blood flow dropped from 78 +/- 3 3 to 24 +/- 17 ml/min/100 gm; p = 0.0486). Support with the Hemopump d evice alone improved the ratio of subendocardial to subepicardial bloo d flow, but endocardial underperfusion remained (analysis of variance, p < 0.001). The Hemopump device with an intraaortic balloon pump comp letely restored perfusion in poststenotic regions. Peripheral organ pe rfusion did not change during ischemia or mechanical support. Conclusi ons: The association of balloon counterpulsation with the Hemopump dev ice reduces the Hemopump output by 11% and increases myocardial blood flow to ischemic regions. Perfusion to peripheral organs remains unalt ered. The transthoracic Hemopump device combined with an intraaortic b alloon pump is an ideal support system for the ischemic, failing heart .