Changes in pulmonary water content and histopathological findings of the lung by various types of assisted circulation

Abstract

Various types of assisted circulation have been classified into the following 3 groups according to indication for their applications, through the serial experimental and clinical studies by Akune and co-workers : assisted circulation (1) for right -sided heart failure, (2) for left-sided heart failure ; selective left ventricular bypass (SLVB) and synchronized arterial counterpulsation (SAC-P), and (3) for both left- and right-sided heart failure. The purpose of this paper is to report the investigation of the effects of SLVB and SAC-P, each being a method of assisted circulation for left-sided heart failure, upon the lungs in the view of changes in pulmonary water content and the histological findings. The experimental dogs were divided according to the method of assisted circulation into 3 groups : (1) SLVB group of 8 dogs, (2) SAC-P HB group of 12 dogs in which SAC-P was performed with an arterial cannula inserted via the innominate artery, and (3) SAC-P HAL group of 11 dogs in which SAC-P was performed using an arterial cannula inserted through the abdominal aorta. Moreover, in SLVB group, the experimental dogs were divided into 2 groups : group I of 3 dogs in which a vent to the left ventricle was used and group II of 5 dogs in which no vent was used. Each SAC-P group was further divided according to the results of hemodynamic performance : group I of SAC-P carried out under proper phasing and group II of SAC-P carried out under improper phasing. The author discussed the problems concerning the determination of changes in pulmonary water content and the method to excise a lung specimen for a histological examination. The change in pulmonary water content was determined by the method reported by Wood and Moe. A lung specimen was excised from the segment of the lingular or left lower lobe. Regarding to the histological study hyperemia, congestion, exsudate in alveoli and edema around pulmonary arteriole were specially examined by the staining of hematoxylin-eosine.