Restoration of flow following haemodialysis catheter thrombus. Analysis of rt-PA infusion in tunnelled dialysis catheters.

PROBLEM: Urokinase and streptokinase are commonly used thrombolytic agents for obstructed central venous catheters. Although proven to be efficacious, these agents have the potential to induce fibrin breakdown and streptokinase cannot be used repeatedly because of its allergenic nature. Published evidence suggests that Urokinase is safe and effective (>70% efficacy for catheter installation) and that Tissue-type plasminogen activator (rt-PA) can achieve as much as 98% success.

OBJECTIVE: To describe our experience with and our protocol for the use of rt-PA as an alternative agent for catheter thrombolysis.

DESIGN: Investigation of a cohort of haemodialysis patients with tunnelled central venous catheter (SPCVC) placed between December 2001 to August 2003 and who developed catheter thrombus (female, n = 8: male, n = 12). Each patient was given an infusion of between 1 and 2 mg rt-PA/h for 4 h. The dose was dependent on partial or total line obstruction. The technical success of rt-PA is defined as returning catheter blood flow to >250 mL/min for a 4-h period.

FINDINGS: Twenty patients required 57 infusions in 38 lumens between 01/01/02 to 01/09/03. For completely blocked lines rt-PA was infused at 2 mg/h for 4 h achieving 85% success rate. For inadequate flow (<250 mL/min) rt-PA was infused at 1 mg/h for 4 h achieving an 88% success rate.

CONCLUSION: Rt-PA administered at 2 mg/h for blocked lines effectively restores haemodialysis catheter patency, and at 1 mg/h for sluggish lines is also effective in restoring blood flow through catheters.