Complications of Umbilical Artery Catheterization in a Model of Extreme Prematurity

BACKGROUND: Umbilical artery catheter (UAC) use is common in the management of critically ill neonates; however, little information exists regarding the anatomic and vascular effects of UAC placement in premature newborns. METHODS AND RESULTS: Baboons were delivered at 125 d of gestation (term = 185 d), treated with surfactant, had UACs placed, and were ventilated for either 6 d or 14 d. Animals were assigned to short-term (6 d, n = 6) and long-term (14 d, n = 30) UAC placement. At necropsy, aortas were removed with UACs still in place. Histological examination of upper, middle, and lower aorta specimens stained with hematoxylin and eosin and immunolabelled to detect smooth muscle (α-actin) was done in a blinded manner. Controls were delivered at 125d, 140d, and 185d and the aortas acquired immediately after birth. None of the non-catheterized control animals (125 d, n = 4; 140 d, n = 5; 185 d, n = 5) had aortic vessel thrombi or vascular wall abnormalities. All 6 animals with short-term (6/6, 100%) and 18 animals with long-term (18/30, 60%) UAC placement displayed aortic thrombi and neointimal proliferation of the vascular wall. The majority (60%) of analyzed animals with UAC placement displaying neointimal hyperplasia were immunopositive for α-actin, indicating the presence of smooth muscle in these lesions. CONCLUSION: Our findings suggest that both short- and long-term UAC use is associated with aortic wall pathological abnormalities compared to control animals. This study emphasizes the judicious use and early removal of UACs if possible in order to potentially prevent significant hemostatic and aortic wall vascular complications.