Umbilical artery catheterization in newborns. I. Thrombosis in relation to catheter type and position.

Seventy-one sick newborn infants, who had an umbilical artery catheterized, were randomized in one of four catheter groups: long end-hole-, short end-hole-, long side-hole- or short side-hole catheter. A long catheter means a high position of the catheter tip (Th6--11) and a short catheter a low position of the tip (L3--5). An angiography through the indwelling catheter in order to diagnose thrombosis was performed before the catheter was withdrawn. Dissection of the aorta and its brances was performed on infants who died. The total frequency of thromboses was 26%. There were no thromboses among infants with long end-hole catheters while infants with short end-hole catheters had thrombosis in 26%, long side-hole catheters in 33% and short side-hole catheters in 64%. Long end-hole catheters functioned better than the others. Only 6 of 16 infants with thrombosis had physical signs from the legs, while 12 infants without thrombosis had similar signs.