Reduced thrombus formation with silicone elastomere (silastic) umbilical artery catheters

This report describes clinical experience with a radiopaque silicone elastomere (Silastic) umbilical artery catheter. Twenty infants, ten with polyvinyl chloride (PVC) umbilical artery catheters and ten with Silastic umbilical artery catheters, all positioned at the aortic bifurcation, had aortograms performed at the time of catheter removal. Catheter-associated thrombus formation was observed in nine of the ten infants (90%) with PVC umbilical artery catheters and in one of the ten infants(10%) with Silastic catheters. The incidence of lower extremity vasospasm associated with the two catheters was not significantly different. Aortic pressure tracing recorded through Silastic catheters were accurate, but slightly damped. Autopsies were performed on five additional infants who died with indwelling Silastic umbilical artery catheters. None of the catheters, nor their surrounding tissues, showed evidence of thrombus formation on either gross or microscopic examination. It is our experience that radiopaque silicone elastomere tubing can be used as an umbilical artery catheter and appears to have the advantage of being less thrombogenic than the standard PVC tubing currently in general use.