[Experimental study on the effect of simple percutaneous left heart bypass (LHB) in cases of brain death--hemodynamic and histological evaluation].
Preservation of the donor heart is an important and controversial subject in heart transplantation. The donor's heart function must be maintained at the most viable state possible. This study examined the effectiveness of LHB in cases of brain death and clarified the possibility of this application for donors as a bridge to heart transplantation. Changes in hemodynamic parameters and histological findings in brain-dead dogs were studied. Two groups of brain-dead dogs were involved in this study: group L (n = 10) as a LHB support and group C (n = 10) as a control. Brain death was induced by an ethanol injection into the subdural space of the dogs. This condition was maintained with volume replacement and dobutamine administration (5 micrograms/kg/ min). In group L, LHB that was achieved with a transaortic valve left ventricular drainage cannula inserted from a carotid artery and return via a femoral artery cannula was performed after brain death. A Bio-pump was utilized for the kind of assist device. Left ventricular output assist ratio averaged 60%. The parameters of left ventricular function (Max. dp/dt, Emax) at the time of brain death deteriorated by about 70%. In group L, they could keep this level over the 6-hr study period. On the other hand, the Emax value at 3 hours and the Max. dp/dt value at 4 hours decreased significantly when compared to the time of brain death (0-hr) for group C. At the 6-hr study period, histological findings showed only minimal change in the myocardium with slightly interstitial edema in group L. On the other hand, severe ischemic change in the myocardium with many contraction bands was found in group C. This data suggests that LHB is effective to preserve heart function in cases of brain death. This application may make it possible to maintain the viability of other organs by maintaining circulatory blood flow and pressure.
Kokaji
K
K
Department of Surgery, School of Medicine, Keio University, Tokyo, Japan.
D000818:Animals; D001794:Blood Pressure; D001926:Brain Death / Q000503:physiopathology*; D002302:Cardiac Output; D004285:Dogs; D018611:Heart Bypass, Left; D006339:Heart Rate; D006439:Hemodynamics / Q000502:physiology*; D009206:Myocardium / Q000473:pathology*