The Effect of Tip Placement on Fibrin Sheath Formation in Poorly Functioning Tunnelled Haemodialysis Lines

Background and Objectives: Fibrin sheath formation is a common cause of haemodialysis (HD) line dysfunction requiring frequent interventional line exchanges. This study assessed HD tip and line placement, line length, and demographics in poorly functioning HD lines due to fibrin sheath formation, to determine if there is a correlation between these factors and repeatedly poor function. Patients and Methods: Patient medical records were retrospectively reviewed to include those who have had poorly functioning HD lines with fluoroscopic evidence of a fibrin sheath from 2011–2019. Analysis of variance and t-tests were performed to determine the significance of various factors on the time until a line exchange was required. Results: Patients with an HD tip placed in the inferior vena cava underwent an exchange the soonest (130.23 days), while tips in the superior vena cava went the longest without required intervention (968.80 days; p=0.007). Lines in the left internal jugular vein had the most days without intervention, and lines in the femoral vein had the least (1,132.80 versus 142.50 days, respectively; p=0.007). Furthermore, 19 cm lines went 816.75 days without intervention, and 42 cm lines went 114.73 days without intervention (p=0.049). Intervention-free days decreased if the patient had undergone previous interventions (p<0.001). Patients with diabetes required intervention before those without diabetes (694.09 versus 917.08 days, respectively; p=0.033). Conclusion: Factors such as HD tip and line placement, line length, previous interventions, and diabetic status demonstrated a correlation with how frequently tunnelled HD lines required intervention due to fibrin sheath formation.