Catheter dysfunction and thrombosis of double-lumen hemodialysis catheters placed in the femoral vein.

Objective: Intraluminal thrombosis of the catheter was thought to be a major cause of catheter dysfunction. We evaluated if thrombi appear in the luminal side or outside of the catheters placed in the femoral vein in 21 hemodialysis patients.

Methods: 23 double-lumen catheter (25 cm long and 4 mm diameter polyurethane) strippings were consecutively performed. Mean catheter dwell time was 17.9 +/- 11.2 days (2-45 days). The femoral vein was observed with ultrasound echography, and thrombo-venous ratio (thrombus diameter/vein diameter) was calculated. X-rays were also taken to clearly visualize the thrombi followed by contrast medium injection through the catheter.

Results: Tube-shaped thrombi were echographically detected in 22 of 23 catheters (95.7%) when the catheter was stripped. Ten catheters (43.5%) were stripped due to the reduced blood flow, and tube-shaped thrombi were observed in the femoral vein, whereas no thrombus was found in the intraluminal side of the catheter. In 7 of 23 patients (30.4%) with leg edema on the same side of the catheter, the thrombovenous ratio was 78.9 +/- 7.4%, which was higher than that in the patients without leg edema (52.1 +/- 11.1%).

Conclusion: The tube-shaped thrombi, formed around the double-lumen catheter, may cause catheter dysfunction and reduced venous return of the lower legs. The catheter should be removed as soon as thrombosis is diagnosed, especially when accompanied by leg edema.