Thrombus formation after umbilical arterial catheterisation. An angiographic study.

included in the study. There were 47 infants - 36 male and 11 female. The clinical presentation and, hence, the indication for arterial catheterisation in order to obtain repeated samples for pH and blood gases, is listed in Table 1. SUMMARY Forty-seven newborn infants who had umbilical arterial catheterisation were studied prospectively to determine the incidence of arterial thrombus formation. Pull-out angiography was performed on 30 patients at the time of removal of the catheter. Arterial thrombus formation was demonstrated in 9 of the 30, Le. 30%. No clinical signs referable to thrombus formation were present. There was no statistically significant difference in birthweight or duration of catheterisation between infants who showed thrombus formation and those who did not. At autopsy, arterial thrombus was found in 5 infants out of 8. The major aortic tributaries were localised by angio­ graphy, and the need for the correct placement of the catheter is emphasised.