Catheter tip migration following power injection of contrast medium through a pressure-resistant central venous port: A case report

Abstract

Pressure-resistant central venous ports allow power injection of contrast medium for contrast-enhanced computed tomography scans. While such ports provide significant benefits for patients requiring long-term venous access, concerns remain regarding catheter-related complications, particularly catheter tip displacement. We present a case of catheter tip migration from the superior vena cava to the right brachiocephalic vein following the power injection of a contrast medium through a pressure-resistant central venous port during a contrast-enhanced computed tomography examination. We propose practical strategies for the safe use of pressure-resistant central venous ports for power injection of contrast medium based on our experience with the present case, highlighting the potential risks of catheter tip displacement and possible counter measures.

Introduction

Contrast-enhanced computed tomography (CT) scans are an essential diagnostic modality, providing high-resolution imaging for various clinical indications. Although contrast medium injection generally employs peripheral venous access, patients undergoing chemotherapy often have difficulty in securing safe peripheral access due to repeated venipunctures, vessel fragility, and venous sclerosis [1,2]. For such patients, central venous (CV) ports are commonly implanted to facilitate the administration of long-term chemotherapy, antibiotics, and parenteral nutrition [3]. This is particularly beneficial for cancer patients, as it reduces the need for repeated peripheral venous access, lowers the risk of extravasation, and enhances treatment adherence and patient comfort [[4], [5], [6], [7], [8]].

Traditionally, the power injection of a contrast medium has not been recommended for non-pressure-resistant CV ports due to the risk of catheter rupture, structural damage, or malfunction. However, advancements in medical device technology have led to the development of pressure-resistant CV ports, which allows power injection of contrast medium under specified conditions, thereby expanding their clinical applications [1,9].

Although contrast-enhanced CT scans using pressure-resistant CV ports are highly beneficial, their safety profile requires further investigation. Several reports have documented damage or displacement of catheters following power injection of a contrast medium, even under recommended conditions, in pressure-resistant peripherally inserted central catheters (PICC) [[10], [11], [12], [13]]. According to these reports, catheter displacement following contrast injection via a PICC has been observed in approximately 8%-15% of cases. While similar complications could potentially occur with pressure-resistant CV ports, to the best of our knowledge, no such cases have been reported.

At our institution, we actively perform contrast-enhanced CT scans using pressure-resistant CV ports. Between May and December 2024, we conducted 358 such examinations. Here, we report a case in which the catheter tip of a pressure-resistant CV port, initially placed in the superior vena cava (SVC), migrated into the right brachiocephalic vein following a contrast-enhanced CT scan.

Case presentation

An 81-year-old male outpatient was diagnosed with sigmoid colon cancer accompanied by liver metastasis and was scheduled to undergo preoperative chemotherapy in preparation for radical resection. To facilitate chemotherapy administration, a pressure-resistant CV port was implanted in the left upper arm. The CV port used was a P-U Celsite "baby size'' model (Toray Medical Co, Ltd, Tokyo, Japan), designed for power injection of contrast medium during CT scans. The catheter tip was positioned in the SVC under fluoroscopic guidance (Fig. 1).

Fig. 1.

X-ray image after implantation of a pressure-resistant central venous port catheter (A), and enlarged view of the catheter tip (arrow) (B). The catheter tip is positioned in the superior vena cava (SVC).

He received chemotherapy through the CV port using a 22-gauge Huber needle. To evaluate the response to the chemotherapy, a contrast-enhanced CT examination was scheduled. This was the first time the patient underwent a contrast-enhanced CT scan using the CV port. After obtaining the patient’s consent to perform a power injection of a contrast medium via the CV port, a 19-gauge Huber needle was inserted into the CV port, and blood return was confirmed without resistance, indicating catheter patency. Then, nonionic contrast medium iopamidol (300 mgI/mL) (Iopamiron, Bayer Yakuhin, Ltd, Tokyo, Japan) was administered using a dual-head power injector (DSGX-Ⅶ, Nemoto-Kyorindo Co, Ltd, Tokyo, Japan) at a flow rate of 2.9 mL/sec with a total volume of 99 mL. The contrast medium was injected with both arms elevated, as during the CT scan. Imaging was performed using an 80-row multislice CT scanner (Aquilion Prime SP, Canon Medical Systems, Tokyo, Japan), with a dynamic scan of the chest to the pelvis carried out based on the referring physician’s instructions.

During the initial non-contrast phase of the CT examination, the catheter tip was confirmed to be in the SVC, consistent with its original position at the time of placement (Fig. 2). However, after the power injection of the contrast medium, migration of the catheter tip into the right brachiocephalic vein was observed (Fig. 3). After the examination, the patency of the CV port was reconfirmed by manually injecting a saline solution, which was performed without resistance or complications. Also, no clinical symptoms, such as swelling, pain, or malfunction of the CV port, were observed. Given the absence of adverse effects, no further intervention was deemed necessary, and the patient was discharged without restrictions. One month later, a chest X-ray confirmed that the catheter tip had repositioned itself into the SVC (Fig. 4).

Fig. 2.

Curved planar reconstruction image of non-contrast computed tomography (CT) scan showing the central venous (CV) port catheter. The catheter tip (arrow) remained in the superior vena cava (SVC), retaining its position as initially placed.

Fig. 3.

Curved planar reconstruction image of contrast-enhanced computed tomography (CT) scan after power injection of a contrast medium via the central venous (CV) port catheter. The catheter tip migrated from its original position in the superior vena cava (SVC) to the right brachiocephalic vein.

Fig. 4.

Chest X-ray taken approximately one month after the contrast-enhanced computed tomography (CT) scan (A), and an enlarged view of the catheter tip (B). The catheter tip was spontaneously repositioned to be within the superior vena cava (SVC).

Discussion

In recent years, the importance of contrast-enhanced CT scans using CV access has been increasing. The availability of pressure-resistant devices compatible with power injectors has expanded, and their clinical utility has been reported. However, cases of catheter tip displacement following contrast-enhanced CT scans using pressure-resistant PICCs have also been documented. Catheter tip malposition can lead to complications such as thrombosis and catheter occlusion, making early detection of malposition crucial [[14], [15], [16]]. This phenomenon can occur with any type of CV access. To our knowledge, there have been no previous reports describing catheter tip migration associated with power injection in pressure-resistant CV ports.

The present case demonstrates that catheter tip migration can occur immediately following power injection of contrast medium through a pressure-resistant CV port. Importantly, the migration was asymptomatic and would likely have remained undetected without imaging. This suggests that catheter tip displacement in this setting may be under-recognized in routine clinical practice. Given that contrast-enhanced CT using CV ports is widely performed, even infrequent events may have meaningful clinical implications, particularly if they go unnoticed. At our institution, this phenomenon occurred in 1 of 358 examinations, suggesting that although rare, it is not negligible in routine clinical practice.

Several factors may contribute to the occurrence of catheter tip displacement. Power injection of a contrast medium may generate a retraction force on the catheter in accordance with Newton’s Third Law, potentially leading to tip displacement. Furthermore, catheter tip migration is thought to be influenced by factors such as the trajectory of the catheter and frictional interactions with the SVC wall [17]. In the present case, the catheter tip was in contact with the SVC wall, and that contact may have contributed to upward displacement during injection. Additionally, turbulence generated as the contrast medium impacted the vessel wall may have amplified the dislodging force, further promoting proximal migration of the catheter.

Variations in the access route of CV port catheters can contribute to catheter tip displacement. A study by Stonelake et al. [18] reported that only 14% of central venous catheters inserted from the left side were positioned below the tracheal bifurcation. This is likely due to the longer distance between the insertion site and the central veins compared to right-sided insertion. Additionally, in most patients, the left brachiocephalic vein forms a significant angle with the SVC, often causing a catheter inserted from the left side to contact the SVC wall during advancement [14,18,19]. Consequently, left-sided catheters tend to be placed more superficially than those inserted from the right side. Furthermore, studies have shown that PICCs placed in the upper SVC have a higher risk of displacement compared to those positioned in the lower SVC. Notably, the risk of displacement was significantly reduced when the catheter tip was positioned distal to the thoracic brachiocephalic angle [12]. These findings suggest that left-sided insertion and positioning in the upper SVC likely increased the risk of displacement in our case. Moreover, the anatomical structure of the central veins may have contributed to the outcome, as the proximal SVC has multiple tributary veins, increasing the likelihood of migration into other veins.

The flow rate of a contrast medium during power injection may influence catheter tip displacement. Morden et al. [12] emphasized that power injection of a contrast medium and saline through a PICC can lead to secondary catheter malposition. Furthermore, previous studies on PICCs have indicated that higher injection rates result in elevated peak injection pressures [20]. These findings suggest that similar effects could occur in CV port catheters as well. In this case, a flow rate of 2.9 mL/sec was used. Although this flow rate complies with the manufacturer’s guidelines for pressure-resistant the CV port, the relatively high injection rate may have increased intraluminal pressure, generating a stronger retraction force that pulled the catheter tip upward. Previous studies have recommended lowering the injection rate to 2 mL/sec for high-risk patients, including those with a PICC inserted from the left side, a catheter tip located in the upper SVC, or a history of catheter migration [11,13,17]. While reducing the injection rate may slightly compromise CT image quality, it could significantly decrease the risk of catheter tip displacement.

In the present case, the patient reported no adverse symptoms such as pain or swelling after the CT examination, and no evidence of CV port dysfunction was observed. Therefore, reinsertion of the CV port catheter was not considered, although catheter displacement generally poses a risk of complications, particularly venous thrombosis. As central venous thrombosis is one of the most serious complications related to implanted CV ports, vigilant monitoring and appropriate management are essential [[14], [15], [16]]. Lambeth et al. [13] reported that catheter tip displacement can resolve spontaneously due to blood flow and gravity. Similarly, Nakayama et al. [10] described a case in which a PICC catheter was displaced after a contrast-enhanced CT scan but spontaneously repositioned within 1 hour. Lozano et al. [11] demonstrated that in cases of PICC tip displacement, gentle manual injection of 20 mL of saline successfully facilitated catheter repositioning. They suggested that saline injection could serve as a simple and practical intervention that can be immediately performed on the CT examination table. In this case, manual saline injection was administered post-examination to confirm catheter patency and rule out CV port occlusion. During the 1-month period until catheter tip repositioning was confirmed, the patient remained asymptomatic, with no reports of pain or edema. These findings suggest that post-examination manual saline injection, in combination with venous blood flow and gravitational effects, may have contributed to the spontaneous repositioning of the CV port catheter.

In conclusion, to safely perform contrast-enhanced CT using a pressure-resistant CV port, we recommend:

• -Confirming catheter tip position before and after contrast injection using scout images or chest X-rays [1].
• -Verifying adequate blood return from the port prior to injection.
• -Maintaining the patient’s arm position throughout the injection and scan [21,22].
• -Performing a manual saline flush after the contrast-enhanced CT scan to assess catheter patency and potentially aid tip repositioning.
• -Monitoring for clinical symptoms (pain, swelling) suggestive of catheter-related complications.
• -Considering immediate reinsertion if catheter dysfunction or venous thrombosis is suspected.

This case highlights a potentially under-recognized complication of contrast-enhanced CT using pressure-resistant CV ports. Although rare, catheter tip migration can occur immediately following power injection and may be asymptomatic. Awareness of this phenomenon and appropriate precautionary measures may help ensure safe clinical practice.

Patient consent

The authors obtained written informed consent from the patient for the publication of this case report and any accompanying images.