Invisible Venous Ports from Medcomp

Abstract

To the Editor, Totally implantable venous ports play a vital role in many oncology patients’ chemotherapy regimens and occupy a serious amount of the daily workload for interventional radiology staff worldwided [1–3]. So many manufacturers are releasing different types of venous ports with different reservoirs or catheter materials in different sizes. Medcomp (Harleysville, PA) recently introduced the Pro-Fuse CT-compatible plastic port and then released the subgroup of ‘‘Dignity’’ ports, which are shaped port reservoirs constructed of magnetic resonance imaging–compatible, lightweight engineering plastic that allows for power injection of contrast media B5 cc/s @ 300psi for contrast-enhanced CT imaging (online product brochure from Medcomp). Using a unique printing technique, the letters ‘‘CT’’ can be visualized on X-ray to provide recognition of the power injectable Pro-Fuse CT device (Fig. 1). From our stand point, CT mark may also be great help in determining whether if the port is actually turn upside down. On the other hand, the most important downside of the Dignity ports is the plastic reservoir, which raises the question of the long-term durability of these ports compared with ports having titanium reservoirs. We have been using this port in our patients for the last year, and so far we have never had a problem with leakage as a result of reservoir puncture due to repetitive needle access. However, we recently noted a visibility problem with the Dignity port despite the clear CT mark at the base in a few patients. In most of our patients, the Dignity port reservoir and CT mark can easily be seen even on low frame–rate fluoroscopy images, whereas in some patients the reservoir itself cannot be seen on X-ray even with single-shot films (Figs. 2A, B, 3A, B). In these few cases, one can easily appreciate the CT mark of the port reservoir, but not the reservoir itself, as well as the indwelling port catheter (Figs. 3A, 3B). Because the port catheters, the connection material, and the syringe itself can be seen prominently under X-ray, lack of visualization of the reservoir seems to be caused mainly by the reservoir material and irrelevant with regard to X-ray values, port position, or tissue thickness over the port pocket. The question at this point is whether or not there is a manufacturing defect on some Dignity ports. The question was referred to the manufacturer and they emphasized the fact that the Dignity Port design complies with the international standard ASTM F640-07 titled ‘Standard Test Method for Determining Radiopacity for Medical Use’. Although, the CT mark, as the primary radiopaque feature desired is well seen, they stated that they will work on the exact cause of visibility issue of the rest of the reservoir. Although this issue does not seem to be a major concern at the moment, it made us question the quality of the relevant port material. Moreover, it is important to share this information with the