Yes, Cathflo (alteplase) can and should be used to treat a clotted dialysis catheter.
Alteplase (Cathflo) is the recommended first-line fibrinolytic agent for restoring patency to thrombosed dialysis catheters, with success rates of 75-95% after one or two doses. 1, 2, 3
Evidence-Based Approach
Initial Assessment
Before using alteplase, exclude mechanical causes of occlusion (kinks, malposition, pinch-off syndrome). If mechanical obstruction is ruled out and the catheter cannot withdraw blood or infuse adequately, proceed with thrombolytic therapy.
Dosing Protocol for Dialysis Catheters
Standard dose: 2 mg in 2 mL per lumen 2, 3
- Instill volume sufficient to fill the catheter lumen
- Allow to dwell for 30-120 minutes 1, 4, 2
- Attempt to withdraw and assess function at 30 minutes; if unsuccessful, allow to dwell up to 120 minutes
- If first dose fails, administer a second dose 1, 3
The FDA-approved Cathflo label demonstrates 74% restoration of function after one dose versus 17% with placebo (p<0.0001), with cumulative success of 85-88% after up to two doses 3.
Administration Methods
Two approaches are equally effective 2, 5:
- Dwell protocol: Instill and leave in catheter for 30-120 minutes
- Push protocol: Administer over 30 minutes (more practical, equally effective)
Success Rates by Clinical Context
- Occlusions <14 days: 68% success after one dose, 88% after two doses 3
- Occlusions >14 days: 57% success after one dose, 72% after two doses 3
- Complete occlusions: 88% success with alteplase versus 43% with urokinase 6
Why Alteplase Over Other Agents
The 2018 ESPGHAN/ESPEN guidelines explicitly state alteplase (tPA) is the agent of choice over urokinase, citing 1:
- Higher fibrin specificity
- Lower immunogenicity
- FDA approval for catheter occlusion
- Previous FDA warning regarding urokinase safety
The 2019 KDOQI guidelines for vascular access support this, showing alteplase 2 mg achieved 95% success versus 82% with urokinase 2.
Safety Profile
Alteplase for catheter occlusion has an excellent safety record:
- No intracranial hemorrhage or major bleeding events in the 310-patient pediatric study 1
- Minimal systemic absorption when used intraluminally
- Local bleeding complications rare (9% in one series, mostly minor) 7
- Safe even in patients weighing <10 kg 8
Practical Algorithm
- First attempt: Forceful saline irrigation 4
- If unsuccessful: Alteplase 2 mg per lumen, dwell 30-120 minutes
- Assess at 30 minutes: Attempt withdrawal of 3 mL blood and infusion of 5 mL saline
- If unsuccessful at 30 minutes: Continue dwell to 120 minutes
- If still unsuccessful: Administer second dose of alteplase 2 mg
- If two doses fail: Consider mechanical interventions (guidewire, fibrin sheath stripping) or catheter replacement 4
Important Caveats
- Contraindications: Active bleeding, recent surgery, known mechanical obstruction 3
- Not for catheter-related thrombosis extending into vessels: This requires systemic anticoagulation with LMWH, not thrombolytics 9
- Cost consideration: Alteplase 1 mg may be as effective as 2 mg for hemodialysis catheters specifically, with one RCT showing 85% versus 86% success rates 10. However, the FDA-approved dose remains 2 mg 3
- Recurrence: 26% of successfully treated catheters experience re-occlusion within 30 days 3
Bottom Line
Alteplase is FDA-approved, guideline-recommended, and highly effective for dialysis catheter occlusions. Use 2 mg per lumen with 30-120 minute dwell time, repeating once if needed. This approach restores function in 85-88% of cases with minimal risk.