June 2026 - Umbilical Venous Line and Hepatic Lesion

June 2026 — Umbilical Venous Line and Hepatic Lesion

By: Emilie Filion-Ouellet (Montreal Children's Hospital)

Case Summary

This case highlights the role of point-of-care ultrasound (POCUS) in confirming umbilical venous catheter (UVC) malposition and identifying associated hepatic complications in a preterm neonate. Although chest radiography suggested that the catheter tip was likely positioned within the intrahepatic inferior vena cava (IVC), bedside ultrasound demonstrated that the catheter had not reached the IVC–right atrial junction and was instead coursing within the intrahepatic portal venous system. An associated intrahepatic lesion concerning for parenchymal injury was identified. This case illustrates the limitations of radiography alone for UVC localization and emphasizes the value of POCUS for direct visualization of catheter position and early recognition of complications.

Clinical Situation

A 28 week preterm infant was admitted to the neonatal intensive care unit for prematurity and respiratory support. An umbilical venous catheter (UVC) was inserted shortly after birth for vascular access and parenteral nutrition administration. Following line insertion, anteroposterior and lateral chest and abdominal radiographs were performed. The radiographic interpretation stated: “UVC tip projecting over the upper third of the liver, likely within the intrahepatic IVC, for further advancement by 0.7 cm.”

On the following day, the clinical team questioned whether the catheter tip could still represent a potentially central position. Prior to withdrawing the catheter to a peripheral position, bedside point-of-care ultrasound (POCUS) was requested to better assess catheter tip location. Initial evaluation using a high-frequency linear “hockey stick” transducer failed to identify the catheter within the inferior vena cava or at the IVC–right atrial junction. Further assessment was therefore performed using a curvilinear probe to evaluate the intrahepatic vasculature. The catheter was visualized within an intrahepatic vessel supplying the posterior right hepatic segments, consistent with portal venous malposition. An associated intrahepatic lesion was identify. The UVC was pulled in peripheral position, and alternative central access was rapidly obtained with PICC insertion. A formal abdominal ultrasound performed by radiology subsequently confirmed the presence of an intrahepatic parenchymal hematoma. Serial follow-up ultrasounds demonstrated progressive resolution of the hematoma without further sequelae.

Chest X-Ray Findings

Initial anteroposterior and lateral radiographs demonstrated the UVC tip projecting over the upper third of the liver and were interpreted as likely terminating within the intrahepatic IVC. However, radiography alone could not reliably confirm that the catheter had successfully traversed the ductus venosus and reached the IVC–right atrial junction. The lateral radiograph did not clearly confirm a central trajectory toward the right atrium, illustrating the limitations of x-ray imaging for precise catheter localization.

POCUS Findings

Point-of-care ultrasound was performed at bedside using a GE Venue Go ultrasound system equipped with both a high-frequency linear “hockey stick” transducer and a curvilinear (8C) probe. Initial assessment was performed using a sagittal subxiphoid approach with the probe positioned in the midline just below the xiphoid process in a sagittal orientation. Slight probe translation toward the infant’s right side and subtle clockwise rotation adjustments were used to optimize visualization of the inferior vena cava (IVC)–right atrial junction and expected central catheter trajectory. The optimal UVC tip position is at the inferior vena cava–right atrial junction, outside the hepatic vasculature. Despite optimization of this view, the catheter tip could not be identified within the IVC or at the IVC–right atrial junction. Failure to visualize the catheter at the expected location may occasionally result from ultrasound beam angulation rather than true absence of the catheter. When the ultrasound beam is not perpendicular to a smooth structure such as a catheter wall, echoes may be reflected away from the probe instead of back toward the transducer, limiting catheter visualization. In these situations, only posterior acoustic shadowing or subtle reverberation artifacts may remain visible. Small adjustments in probe position may improve visualization. From the same midline subxiphoid position, imaging of the portal sinus (PS) and ductus venosus (DV) may be optimized by rotating the transducer slightly counterclockwise and tilting the probe tail slightly toward the infant’s left side. After entering through the umbilicus, the umbilical vein courses superiorly toward the liver and joins the portal sinus (PS), a vascular confluence from which multiple portal venous branches arise. Under ideal conditions, the catheter should then pass through the ductus venosus (DV) before entering the inferior vena cava near the right atrium. However, because of the multiple branching pathways arising from the portal sinus, the catheter may instead deviate into intrahepatic portal venous branches, including the right portal vein or left portal venous branches.

Discussion

In this case, ultrasound findings were most consistent with malposition within the right intrahepatic portal venous system supplying the posterior hepatic segments. Further evaluation using the curvilinear probe allowed identification of the catheter within an intrahepatic vessel consistent with a branch of the right portal venous system supplying hepatic segments VII and VIII. An adjacent heterogeneous intrahepatic lesion was visualized near the catheter tip.

Differential diagnosis included:

TPN extravasation injury (“TPN-oma”)
Intraparenchymal hepatic hematoma

TPNoma results from extravasation of hypertonic parenteral nutrition through a malpositioned UVC, leading to endothelial injury, hepatic parenchymal necrosis, and formation of a complex intrahepatic fluid collection. Sonographically, TPNomas are typically heterogeneous lesions that may appear hyperechoic in the acute phase and progressively evolve into more complex masses with irregular contours, hyperechoic rims, hypoechoic or cystic centers, internal septations, and occasional calcifications during healing. They are usually located adjacent to the catheter tip and generally demonstrate no internal Doppler flow (Kim et al., 2023).

In contrast, intraparenchymal hepatic hematomas represent localized blood collections within the liver parenchyma. Their sonographic appearance varies according to the age of the hemorrhage, ranging from relatively homogeneous echogenic lesions in the acute phase to progressively more heterogeneous or hypoechoic collections as clot organization and liquefaction occur. Compared with TPNomas, hematomas are often less septated and less cystic in appearance, although overlap between both entities may occur, particularly in evolving lesions. Overall, the ultrasound findings were highly suggestive of portal venous UVC malposition with associated hepatic parenchymal injury.

Teaching Points

Point-of-care ultrasound (POCUS) is an essential bedside tool for confirming umbilical venous catheter (UVC) position in neonates and offers significant advantages over conventional radiography. Although chest radiography may suggest appropriate central UVC placement, several studies have demonstrated discordance rates of approximately 20–40% compared with ultrasound evaluation. This limitation stems from the fact that radiography relies on indirect anatomical landmarks, whereas ultrasound allows direct visualization of vascular anatomy and real-time localization of the catheter tip. Accurate confirmation of central positioning therefore requires direct visualization of the catheter tip at the inferior vena cava (IVC)–right atrial junction.

When the catheter is not visualized within the IVC, careful sonographic evaluation should be performed to identify potential malposition within the portal venous branches, hepatic veins, or other intrahepatic vascular structures. This is clinically important because portal venous malposition may lead to serious complications, including TPN extravasation injury, hepatic necrosis, intraparenchymal hematoma, and portal venous thrombosis.

Catheter tip migration after insertion is also common in neonates, with displacement reported in up to 94% of cases by day 2 and 98% by day 4 post-insertion (Xie et al., 2023). To address this, standardized POCUS-based surveillance protocols for neonatal central lines, including PICCs and umbilical catheters, have been proposed to improve catheter monitoring and facilitate early detection of complications (Amer et al., 2023). POCUS further supports neonatal vascular access management by enabling direct visualization of catheter trajectory, dynamic bedside reassessment, and early identification of complications without radiation exposure.

Conclusion

This case demonstrates the important role of POCUS in neonatal vascular access assessment, highlighting how bedside ultrasound can identify malpositioned umbilical venous catheters and associated hepatic injury despite apparently reassuring radiographic findings. Direct visualization of the catheter tip at the IVC–right atrial junction should be considered the reference standard for confirming central UVC position in neonates.

References

Amer R, Rozovsky K, Elsayed Y, Bunge M, Chiu A. The utility of point-of-care ultrasound protocol to confirm central venous catheter placement in the preterm infant. European journal of pediatrics. 2023;182(11):5079-5085. doi:10.1007/s00431-023-05172-0
Kim MJ, Yoo SY, Jeon TY, Kim JH, Kim YJ. Imaging of Umbilical Venous Catheter-Related Hepatic Complications in Neonates. J Korean Soc Radiol. 2023 May;84(3):586-595. doi: 10.3348/jksr.2022.0056. Epub 2023 Mar 23. PMID: 37324991; PMCID: PMC10265250.
Singh Y, Tissot C, Fraga MV, Conlon T, eds. Point-of-Care Ultrasound for the Neonatal and Pediatric Intensivist : A Practical Guide on the Use of POCUS. Springer; 2023. doi:10.1007/978-3-031-26538-9
Xie, H., Xie, C., Liao, J., Xu, F., Du, B., Zhong, B., … & Li, N. (2023). Point-of-care ultrasound for monitoring catheter tip location during umbilical vein catheterization in neonates: a prospective study. Frontiers in Pediatrics, 11. https://doi.org/10.3389/fped.2023.1225087
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