Histological Changes in the Heart-Lung Preparation by the Autoperfusion

Han, Sung Sae

Abstract

The experimental study for extracorporeal preservation of the autoperfused working heart-lung preparation was performed in 5 dogs. Their weights were between 14??6kg, average of 14.8kg. The preparations were observed from 6 to 8 hours under autoperfusion, average of 5.2 hours. Hemodynamic and hematologic variables were measured during preharvest and autoperfusion. The experimental results during the autoperfusion were as follow : The arterial blood pH revealed severe respiratory alkalosis due to very low PaCO2. PaO2, 130~150mmHg remained constant; Heart rates remained constant at 110/min and the mean aortic pressures were maintained at 75mmHg; Serum Na and Ca showed mild decrease and serum K, moderate increase; Hemoglobulin and white cell count decreased progressively. The lung showed grossly focal congestion and atelectasis following 3~4 hours of autoperfusion and both findings worsened progressively, and little abnormality appeared in the heart. According to the light microscopic findings in the lung, congestion increased 3~4hours following autoperfusion and worsened between the 6th and 8th hours of autoperfusion. Atelectasis, inflammatory infiltration, edema, and hemorrhage worsened after the 4th hour. Emphysematous changes were initially severe to decreasel later on. Hyaline membrane developed after 6 to 8 hours. Hyaline thrombi appeared after 2 hours. The heart was examined by and electron microscope. Vacuolization increased mildly at the 6th to 7th hour. Mitochondrial swelling and cellular swelling showed focally near the end of the perfusion. Glycogen amount was rich throughout the perfusion. It was concluded that the heart preservation was good but the preparation of the lung seemed to be inadequate after 3~4 hours by this autoperfusion technique.