Journal of Clinical Oncology, Vol 15, 2709-2714, Copyright © 1997 by American Society of Clinical Oncology
Low-dose urokinase infusions to treat fibrinous obstruction of venous access devices in cancer patients
MK Horne 3rd and DJ Mayo
Clinical Pathology Department, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA. mhorne@nih.gov
PURPOSE: This study was undertaken to determine the role of low-dose
urokinase infusions in treating fibrinous occlusions of venous access
devices (VADs) in cancer patients. PATIENTS AND METHODS: Forty-two patients
with VAD occlusions refractory to routine urokinase instillations were
documented by x-ray (cathetergram) to have fibrin sleeves at the catheter
tips. They were randomized to receive infusions of either urokinase (40,000
U/h) or urokinase with heparin (320 U/h) through their catheters. After 1,
3, 6, and 12 hours of treatment, the function of the VADs was reassessed.
Whenever the obstruction had been relieved, the infusion was stopped and a
repeat cathetergram was performed. The status of the unoccluded catheters
was followed to determine the longevity of the restored function. RESULTS:
Twenty-one catheters were treated with urokinase alone and 21 with the
combination of urokinase and heparin. In each group, 16 VADs opened within
12 hours of treatment and five did not. By actuarial analysis, the
probability was only 0.28 that a reopened catheter would reocclude within 6
months. CONCLUSION: Low-dose urokinase infusions can restore function to
the majority of catheters occluded by fibrin sleeves. Adding heparin to the
urokinase does not enhance the efficacy of the infusions. The restored
function often persists until the VADs are removed.
