Comparison of Blood Removal Catheters for Extracorporeal Circulation in Low Body Weight Animals

Perfusion rate under extracorporeal circulation may be low-flow rate in low body weight animals, which can sometimes cause a serious problem. Our aim of the present study was to investigate the shapes of blood removal catheters for extracorporeal circulation. In a pilot study, flow rates of several blood removal and sending catheters were recorded in water tank. Flow rate was consistent with the width of the blood removal catheter and significantly increased. In contrast, it opposed to the length of the catheter and significantly decreased. Flow rate in blood removal catheters with side-hole was significantly higher than in blood removal catheters without side-hole. In vivo study, to compare the flow rate of blood removal catheters between side-hole and end-hole, Japanese white rabbits (n=5) were used under extracorporeal circulation. Compared to the end-hole catheters, side-hole catheters significantly elevated flow rate, systemic arterial pressure, PaO2, and plasma HCO3- concentration. Our results suggested that blood removal catheters with side-hole may provide the safety under extracorporeal circulation in low body weight animals.