The malfunctioning infusion port: can the chest radiograph predict need for revision?

Purpose Malfunction of chest infusion ports leads to unnecessary peripheral IV placement and delays in infusion. When this occurs in our institution, the patient is sent for a contrast injection study. The port is injected looking for evidence of a fibrin sheath. Since tip location is the most important factor contributing to fibrin sheath formation, this expensive and potentially harmful study could be avoided if there was a way to predict the likelihood of intervention based on the tip location on chest radiograph. Materials and Methods A retrospective single-center review was performed after approval by our IRB. The chest radiographs of 60 consecutive patients who underwent 62 individual port studies within a two year period (2010-2012) were reviewed and the tip location of the port catheter was recorded. Tip locations were divided anatomically into ten zones, with appropriate position residing in zones 4 and 5 (lower 1/3 superior vena cava (SVC) and right atrium (RA)). If a tip was in a location other than 4 and 5 it was deemed “inappropriate.” The medical records of the patients were then reviewed and the findings of the port study and the outcome of the port was recorded. Results Sixty patients, (21 male and 39 female, age range 18-82) underwent 62 individual port studies preceded by frontal chest radiography. Of 62 port studies, 42 (68%) were found to be within appropriate tip zone (lower SVC or RA), and 20 (32%) were found to be malpositioned. Twelve (29%) of the appropriately positioned ports required intervention, whereas nine (45%) of the malpositioned ports were intervened upon. (p = 0.00056). Conclusion A significantly greater proportion of catheters who have a tip location outside the lower SVC and RA need to be revised or removed as opposed to ports with their catheter tip in this location. We suggest that the clinical workup of a patient with a malfunctioning infusion port start with a standard chest radiograph. If the port tip is outside of the lower SVC or RA, then a port study is unnecessary and the patient should be referred for removal or revision. The application of this screening method for infusion port studies can help reduce cost and radiation exposure to the patient.