Cm. Clase et al., Thrombolysis for restoration of patency to haemodialysis central venous catheters: A systematic review, J THROMB TH, 11(2), 2001, pp. 127-136
Urokinase, previously used to restore patency to thrombosed haemodialysis c
atheters, is now unavailable in North America.
We performed systematic reviews of four questions related to the safety and
efficacy of alternative agents for catheter thrombolysis, searching Medlin
e and the Cochrane Controlled Clinical Trials Register.
In dialysis patients, large case series have documented that urokinase is s
afe and effective (> 70 % efficacy for catheter instillation, and > 80 % fo
r systemic lysis). Experience with streptokinase is limited and allergic co
mplications develop with repeated use. Studies of catheter instillation wit
h 1-2 mg of tPA per lumen reported short-term success in 83-98 % of uses. O
ne non-peer-reviewed study described 44-59 % success using systemic tissue
plasminogen activator (tPA), 2.5 mg through each of 2 lumens, over 1 h. Met
a-analysis of randomized comparisons of urokinase and tPA as full-dose thro
mbolytic agents suggested that 1 mg tPA was likely equivalent in thrombolyt
ic potency to 36,000 units urokinase. In nondialysis populations, four case
series suggested that catheter instillation with 0.5-2 ]mg tPA was effecti
ve and safe in reestablishing patency, and a randomized controlled trial fo
und 2-4 mg tPA more effective than 5,000-10,000 units urokinase. No complic
ations have been reported in any patient treated with systemic or local tPA
for catheter thrombolysis. In studies of fistula thrombolysis with 5-50 mg
tPA major complications occurred in one episode in 130 patients treated.
This review suggests that 1-2 mg/lumen tPA is a suitable dose for catheter
instillation and likely to be more effective than 5000 units/lumen urokinas
e. Systemic lysis with 5-10 mg tPA is likely to be safe and effective in su
itably selected patients. Further studies are needed.