Contrast-enhanced radiography for localization of ultrathin (1 F) PICCs in preterm infants: a retrospective observational study

Accurate catheter tip localization is crucial because catheter malposition may result in serious complications. We aimed to evaluate the visualization and tip localization of ultrathin (1 F) PICCs using contrast-enhanced radiography in preterm infants and to describe its utility in detecting catheter malposition and facilitating repositioning. This single-center retrospective observational study included 58 preterm infants and 63 catheterization episodes. Iohexol (300 or 350 mgI/mL) was used as the contrast agent. The target tip position was defined as between the second and fifth thoracic vertebral levels for upper extremity insertions and between the ninth and tenth thoracic vertebral levels for lower extremity insertions. Radiographs demonstrating superposition or absence of the “butterfly sign” were considered suboptimal and repeated. Serum creatinine levels were evaluated at baseline, 48–72 h, and 3–7 days after contrast administration. Clinical data and potential adverse events were also recorded. Fifty-eight preterm infants corresponding to 63 catheterization periods were analyzed. The median (IQR) gestational age and birth weight were 27 (26–29) weeks and 900 (740–1100) g, respectively. A total of 71 contrast administrations were performed, with a single dose being sufficient in 84% of catheterization periods. Only 20% of catheters were positioned at the predefined target level. Protocol-based contrast administration enabled clear visualization of the catheter trajectory, particularly when adequate catheter opacification (“butterfly sign”) was achieved. No allergic reactions, catheter occlusions, or clinically significant contrast-related thyroid dysfunction were observed. Stage 1 acute kidney injury occurred in 5 of 45 evaluable catheterization episodes (11.1%). Contrast-enhanced radiography enabled clear visualization and tip assessment of ultrathin (1 F) PICCs in low-birth-weight infants, facilitating the detection of malposition, with no evident short-term contrast-related safety signal observed in this cohort.