We are writing to you about a case that raises a number of points we feel would be of interest to your readership.
A 36-year-old female patient on chronic haemodialysis treatment was referred to the interventional radiology department for assessment of a non-functional twin tunnelled Bio-flex catheter (Medcomp, Harleysville, PA). The lines had been placed without the aid of fluoroscopy 11 months previously. Post-procedural radiography had demonstrated the tips of the lines to lie in the right ventricle and right atrium, respectively. Due to significant patient co-morbidity, the lines were not exchanged and functioned well for 11 months.
Fluoroscopy revealed that one line tip remained against the wall of the right ventricle and that the end of the second line had fractured 2.5 cm from its tip, with the fractured portion lodged in the right atrium wall. The precise time of catheter fracture could not be determined as the last radiograph prior to malfunction was 5 months previously. This had demonstrated the tip of the proximal line curled against the right atrial wall and we postulate that repetitive stress with atrial systole led to the catheter fracture at the apex of the curl. As the fragment could be embedded in the right atrial wall, trans-oesophageal echo was performed prior to attempted fragment retrieval. This showed a small volume of thrombus in the superior aspect of the right atrium near the superior vena cava which was separate from the line fragment lying at the junction of the lateral atrial wall and tricuspid valve.
Accordingly the patient was heparinized and scheduled for percutaneous removal of the catheter fragment in the interventional radiology department. This has now become the primary method of removal in most scenarios [1,2]. In recent years, single loop snares such as the nitinol gooseneck snare (Microvena, White Bear Lake, MN) have been used with great success. In this case, following failure to grasp the fragment with gooseneck snares, we used a new type of snare, the En Snare (Medtech, FL), which immediately grasped the catheter fragment. This snare system has three interlaced loops rather than the traditional single loop, and the speed with which the catheter fragment was captured would suggest that this design offered a particular advantage in this case (Figure 1).
|
Conflict of interest statement. None declared.
Royal Liverpool University and Broadgreen Hospitals NHS Trust Radiology Liverpool UK Email: andrewhealey{at}yahoo.co.uk
References