title: Prevention of catheter lumen occlusion with rT-PA versus heparin (Pre-CLOT): study protocol of a randomized trial [ISRCTN35253449].
abstract: BACKGROUND
  Many patients with end-stage renal disease use a central venous catheter for hemodialysis access. A large majority of these catheters malfunction within one year of insertion, with up to two-thirds due to thrombosis. The optimal solution for locking the catheter between hemodialysis sessions, to decrease the risk of thrombosis and catheter malfunction, is unknown. The Prevention of Catheter Lumen Occlusion with rt-PA versus Heparin (PreCLOT) study will determine if use of weekly rt-PA, compared to regular heparin, as a catheter locking solution, will decrease the risk of catheter malfunction.
  
  
  METHODS
  The study population will consist of patients requiring chronic hemodialysis thrice weekly who are dialyzed with a newly inserted permanent dual-lumen central venous catheter. Patients randomized to the treatment arm will receive rt-PA 1 mg per lumen once per week, with heparin 5,000 units per ml as a catheter locking solution for the remaining two sessions. Patients randomized to the control arm will receive heparin 5,000 units per ml as a catheter locking solution after each dialysis session. The study treatment period will be six months, with 340 patients to be recruited from 14 sites across Canada. The primary outcome will be catheter malfunction, based on mean blood flow parameters while on hemodialysis, with a secondary outcome of catheter-related bacteremia. A cost-effectiveness analysis will be undertaken to assess the cost of maintaining a catheter using rt-PA as a locking solution, compared to the use of heparin.
  
  
  CONCLUSIONS
  Results from this study will determine if use of weekly rt-PA, compared to heparin, will decrease catheter malfunction, as well as assess the cost-effectiveness of these locking solutions.
authors.affiliation: Division of Nephrology, Department of Medicine, University of Calgary, Calgary, Alberta, Canada. brenda.hemmelgarn@calgaryhealthregion.ca
authors.forename: Brenda R
authors.initials: BR
authors.lastname: Hemmelgarn
authors.forename: Louise
authors.initials: L
authors.lastname: Moist
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Pilkey
authors.forename: Charmaine
authors.initials: C
authors.lastname: Lok
authors.forename: Marc
authors.initials: M
authors.lastname: Dorval
authors.forename: Paul Y W
authors.initials: PY
authors.lastname: Tam
authors.forename: Murray J
authors.initials: MJ
authors.lastname: Berall
authors.forename: Martine
authors.initials: M
authors.lastname: LeBlanc
authors.forename: Edwin B
authors.initials: EB
authors.lastname: Toffelmire
authors.forename: Braden J
authors.initials: BJ
authors.lastname: Manns
authors.forename: Nairne
authors.initials: N
authors.lastname: Scott-Douglas
mesh_terms: D016470:Bacteremia / Q000453:epidemiology / Q000209:etiology; D001777:Blood Coagulation / Q000187:drug effects*; D002404:Catheterization / Q000009:adverse effects; D003362:Cost-Benefit Analysis; D003625:Data Collection; D018572:Disease-Free Survival; D004311:Double-Blind Method; D016527:Drug Costs; D004868:Equipment Failure; D006493:Heparin / Q000191:economics / Q000494:pharmacology*; D006801:Humans; D015993:Life Tables; D018579:Patient Selection; D011994:Recombinant Proteins / Q000191:economics / Q000494:pharmacology; D006435:Renal Dialysis / Q000295:instrumentation*; D012107:Research Design; D018401:Sample Size; D012996:Solutions; D016019:Survival Analysis; D013927:Thrombosis / Q000517:prevention & control*; D010959:Tissue Plasminogen Activator / Q000191:economics / Q000494:pharmacology*; D016896:Treatment Outcome
chemical_list: D011994:Recombinant Proteins; D012996:Solutions; D006493:Heparin; D010959:Tissue Plasminogen Activator