Scalp vein catheters are among the most common tools in neonatal and pediatric medicine. Because the veins of an infant’s scalp are superficial, visible, and relatively easy to puncture, nurses and doctors frequently use them to deliver fluids, antibiotics, and nutrition to babies whose limb veins are too small or too mobile to cannulate reliably. The catheters themselves are deliberately soft and thin, a design choice that protects delicate vessel walls but also makes the devices vulnerable. Infants move constantly, cry, flex their necks, and rub their heads, and all of that motion places repeated mechanical stress on a tube that may be only fractions of a millimeter thick.

Catheter breakage during removal is an extremely rare complication, but when it happens, the consequences can be serious. Once a fragment detaches, it becomes an intravascular foreign body. The vessel wall, recognizing the plastic as foreign material, begins to encapsulate it in fibrous tissue, and the fragment can soften, migrate with blood flow, and in the worst cases travel toward the central circulation and cause venous embolism. For parents, the discovery that a piece of a catheter has vanished into their child’s body is deeply distressing, and the medical team faces an equally difficult problem: how to find and extract something small, flexible, and mobile inside a body that is itself very small.

The three cases described by the team, led by surgeons at Beijing Children’s Hospital of Capital Medical University together with colleagues at Inner Mongolia Maternal and Child Health Care Hospital, illustrate exactly why. All three infants had already undergone failed removal attempts at other facilities before reaching the reporting hospital. In the first case, two separate operations within three days both failed to extract the catheter fragment. In the second and third cases, the fragments had been left in place far longer, remaining in the children’s bodies for nine months and five years respectively, and in both instances the plastic had migrated away from the original scalp puncture site down to the neck.

Those timelines matter. A fragment that sits in a vein for months or years becomes progressively more encapsulated, more embedded in surrounding tissue, and harder to distinguish from normal anatomy. Migration compounds the difficulty, because the surgeon who plans an incision based on where the catheter entered the body may find nothing there. The authors argue that this is precisely why blind exploration, cutting into the body and searching by feel or by plain X-ray alone, should be avoided. Each failed attempt adds scarring, extends anesthesia time, and increases the emotional and physical toll on an infant who cannot understand what is happening.

The alternative the team proposes is a multimodal localization strategy built around three-dimensional computed tomography. Modern CT scanners acquire thin-slice volumetric data, and reconstruction software can process that data in several complementary ways. Multi-planar reconstruction allows the radiologist and surgeon to scroll through the anatomy in axial, coronal, and sagittal planes, tracing the catheter fragment’s course vessel by vessel. Volume rendering goes further, generating a three-dimensional model in which bone, soft tissue, and the radiopaque fragment can be viewed together and rotated on screen, so that the fragment’s position can be understood in true spatial relation to landmarks such as the clavicle, the cervical vertebrae, and the great vessels of the neck.

Three-dimensional reconstruction alone, however, tells the surgeon where the fragment is inside the imaging dataset, not where to put the scalpel on the living patient. The second half of the strategy is body surface localization, in which the coordinates established on the CT model are translated onto the child’s skin before the operation begins. By projecting the fragment’s reconstructed position onto external reference points, the team marks an entry approach that minimizes the distance between incision and target. Complementary ultrasound verification adds real-time confirmation: ultrasound carries no radiation dose, can be repeated at the bedside, and lets the team confirm that the fragment has not shifted between the imaging study and the moment of surgery, which is particularly valuable in a population of patients who cannot hold still on command.

With the fragment localized in three dimensions and verified on the surface, the surgical removal itself becomes a targeted, minimally invasive procedure rather than an exploratory hunt. The reported cases support the approach: after the failures elsewhere, precise preoperative localization enabled successful extraction in these infants. The authors conclude that prompt surgical intervention is vital once a catheter fracture is recognized, and that the combination of 3D-CT reconstruction as the primary tool with ultrasound as a verification modality is the key to ensuring successful, minimally invasive treatment. The study was approved by the Ethics Committee of Beijing Children’s Hospital, and written informed consent for publication was obtained from the patients’ parents.

The broader lesson extends beyond this single rare complication. Peripheral intravenous catheters are placed millions of times a year in children worldwide, and the overwhelming majority of placements and removals proceed without incident. But the small subset of cases in which a fragment is retained demonstrates a principle that applies across pediatric surgery: in a small body, precision is not a luxury but a prerequisite. Imaging that would be helpful in an adult is often decisive in an infant, where a few millimeters of error can mean the difference between a short operation and a second failed one. The authors also situate their cases within the existing literature on intravascular foreign bodies, reinforcing that the management algorithm, recognize the fracture, image it in three dimensions, verify with ultrasound, mark the surface, and operate once, is generalizable.

For clinicians, the practical takeaways are concrete. When a catheter breaks during removal, the fragment should be assumed to be mobile and the child should be kept calm and still to reduce the chance of further migration. Prompt cross-sectional imaging should follow, with 3D reconstruction requested rather than plain radiographs alone, since a thin plastic tube can be difficult to see on a two-dimensional film and its depth cannot be judged from it at all. And when the first attempt fails, the answer is not another blind attempt but a step up in localization technology. For parents, the message is sobering but ultimately reassuring: although catheter fracture is frightening, it is rare, it is treatable, and with modern imaging the piece of plastic that once seemed lost can be found with millimeter accuracy and removed through a small, precisely planned incision, sparing a child the repeated operations that the three infants in this report had endured before reaching the team that finally got it right.

Subject of Research: Retained fractured scalp vein catheter fragments in infants and their precise preoperative localization and surgical removal using 3D-CT reconstruction and body surface localization

Article Title: Precise removal of fractured scalp vein catheters in infants using 3D-CT reconstruction and body surface localization: case reports and literature review

Article References: Sun, J., Zhang, J., Zhao, Y., Sun, D., Wang, X., & Huang, J. (2026). Precise removal of fractured scalp vein catheters in infants using 3D-CT reconstruction and body surface localization: case reports and literature review. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07637-1

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07637-1

Keywords: scalp vein catheter, catheter fracture, infants, 3D-CT reconstruction, body surface localization, ultrasound, intravascular foreign body, pediatric surgery, venous embolism, minimally invasive surgery, case report, BMC Pediatrics