Intra-aortic ballon pump for relief of aortic regurgitation. Experimental study.

Backflow from the aorta to the left ventricle during diastole in aortic regurgitation can be reduced by expanding, during diastole, a small air balloon positioned in the ascending aorta downstream to the regurgitant valve. A spherical catheter-mounted balloon, acting as a prosthetic aortic valve for the correction of acute aortic regurgitation, was tested in 12 dogs. This "valve" was actively inflated and deflated by means of a common intra-aortic balloon pumping system (Datascope). A significant increase of end-diastolic pressure in the descending aorta, from 51.72 +/- 1.72 to 70.35 +/- 1.92 mm Hg (mean +/- standard error, p less than 0.001), was obtained, without a significant pressure gradient across the "valve". The "valve" prevented the backward flow of the descending aorta by up to 100%, so that there was a mean increase in t-e effective forward flow of 12.61 +/- 5.27% (mean +/- standard error, p less than 0.05). Coronary arterial flow changes varied during the application of the "valve." They depended directly on the changes of the diastolic component of the flow velocity wave, and this relationship was significant (x2 = 33.04, p less than 0.0001). Contractility indices were not significantly affected during the function of the "valve." It is suggested that the spherical "valve" mounted on a catheter may easily be inserted without thoracotomy for a temporary satisfactory correction of the aortic regurgitation.